bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypoxia/reoxygenation: A dynamic regulator of lysyl oxidase‐facilitated breast cancer migration
Authors: Postovit Lynne‐Marie , Abbott Daniel E. , Payne Stacey L. , Wheaton William W. , Margaryan Naira V. , Sullivan Richard , Jansen Matthias K. , Csiszar Katalin , Hendrix Mary J.C. , Kirschmann Dawn A.
Published: August 2007

Fluctuating oxygen levels characterize the microenvironment of many cancers and tumor hypoxia is associated with increased invasion and metastatic potential concomitant with a poor prognosis. Similarly, the expression of lysyl oxidase (LOX) in breast cancer facilitates tumor cell migration and is associated with estrogen receptor negative status and reduced patient survival. Here we demonstrate that hypoxia/reoxygenation drives poorly invasive breast cancer cells toward a more aggressive phenotype by up‐regulating LOX expression and catalytic activity. Specifically, hypoxia markedly increased LOX protein expression; however, catalytic activity (β‐aminopropionitrile inhibitable hydrogen peroxide production) was significantly reduced under hypoxic conditions. Moreover, poorly invasive breast cancer cells displayed a marked increase in LOX‐dependent FAK/Src activation and cell migration following hypoxia/reoxygenation, but not in response to hypoxia alone. Furthermore, LOX expression is only partially dependent on hypoxia inducible factor‐1 (HIF‐1α) in poorly invasive breast cancer cells, as hypoxia mimetics and overexpression of HIF‐1α could not up‐regulate LOX expression to the levels observed under hypoxia. Clinically, LOX expression positively correlates with tumor progression and co‐localization with hypoxic regions (defined by HIF‐1α expression) in ductal carcinoma in situ and invasive ductal carcinoma primary tumors. However, positive correlation is lost in metastatic tumors, suggesting that LOX expression is independent of a hypoxic environment at later stages of tumor progression. This work demonstrates that both hypoxia and reoxygenation are necessary for LOX catalytic activity which facilitates breast cancer cell migration through a hydrogen peroxide‐mediated mechanism; thereby illuminating a potentially novel mechanism by which poorly invasive cancer cells can obtain metastatic competency. J. Cell. Biochem. 103: 1369–1378, 2008. © 2007 Wiley‐Liss, Inc.
Optimization of pullulan production using Ca‐alginate‐immobilized Aureobasidium pullulans by response surface methodology
Authors: Ürküt Zümrüt , Daǧbaǧlı Seval , Göksungur Yekta
Published: August 2007

BACKGROUND: The production of pullulan from synthetic medium by Aureobasidium pullulans P56 immobilized in Ca‐alginate beads was investigated using batch and repeated batch fermentation systems.

RESULTS: The highest pullulan concentration (19.52 ± 0.37 g dm−3) was obtained with 2.0‐2.4 mm beads prepared from 2% sodium alginate solution. Pullulan production was mainly accomplished by immobilized fungal cells since leaked cells in the fermentation medium comprised 17.4% of the total fungal population at the end of fermentation. The pullulan proportion was 84.5% of the total polysaccharide in the fermentation medium. Response surface methodology was used to investigate the effects of three fermentation parameters (initial pH, agitation speed and incubation time) on the concentration of pullulan. Results of the statistical analysis showed that the fit of the model was good in all cases. The maximum pullulan concentration of 21.07 ± 0.48 g dm−3 was obtained at the optimum concentrations of process variables (pH 7.31, agitation speed 191.5 rpm, incubation time 101.2 h). The gel beads produced pullulan under the optimized conditions for six consecutive batch fermentations without marked activity loss and deformation.

CONCLUSION: The results of this study suggest that the immobilization of A. pullulans cells in Ca‐alginate gel beads is suitable for batch and repeated batch production of pullulan. Copyright © 2007 Society of Chemical Industry
Sonographic detection of subcutaneous fly larvae in human myiasis
Authors: Richter Joachim , Schmitt Marcus , Müller‐Stöver Irmela , Göbels Klaus , Häussinger Dieter
Published: August 2007

Sonographers increasingly face imported diseases such as subcutaneous myiasis. In myiasis, some fly species such as the American Dermatobia hominis and the African Cordylobia anthropophaga use humans as intermediate hosts for the maturation of their larvae. High‐resolution gray‐scale and color Doppler sonography enabled us to identify D hominis larvae in 2 travelers to Central America by visualizing their typical shape, segmentations, and the continuous fluid transport inside the larval body cavity and spiracles. The small C anthropophaga larva in an individual returning from Namibia was initially not detected. Only when using color Doppler sonography was the larva discerned by its intralarval fluid transport. Sonography enables clinicians to locate viable subcutaneous larvae in suspected cases of myiasis. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Neuro MR: Principles
Authors: Roberts Timothy P.L. , Mikulis David
Published: August 2007

The principles of contrast mechanisms and fast pulse sequences underlying neurological and neuroradiological application of MRI are introduced in this part of a two‐part review. In particular, the relaxation time constants T1, T2, and T are introduced, along with pulse sequences harnessing their contrast, spin‐echo, fast spin echo (FSE), inversion recovery (IR), gradient recalled echo (GRE), and echo planar imaging (EPI). The use of gadolinium (Gd)‐based contrast is discussed in both T1‐ and T‐weighted sequences. Tradeoffs between speed and image quality are discussed, particularly in the context of long echo train sequences (FSE imaging and EPI). The influence of parallel imaging strategies is also discussed. T sensitivity is discussed as both a source of artifact as well as a contrast mechanism (perfusion imaging with contrast agents, susceptibility weighted imaging [SWI], and blood oxygenation level dependent [BOLD] imaging). Finally, the contrast mechanism of diffusion is introduced, as well as the concept of anisotropy. From these principles, the other part of this two‐part review draws upon the pulse sequences and contrast mechanisms to design disease and indication‐specific protocols for state‐of‐the‐art clinical use. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Microstructural changes in ischemic cortical gray matter predicted by a model of diffusion‐weighted MRI
Authors: Vestergaard‐Poulsen Peter , Hansen Brian , Østergaard Leif , Jakobsen Rikke
Published: August 2007

Purpose

To understand the diffusion attenuated MR signal from normal and ischemic brain tissue in order to extract structural and physiological information using mathematical modeling, taking into account the transverse relaxation rates in gray matter.

Materials and Methods

We fit our diffusion model to the diffusion‐weighted MR signal obtained from cortical gray matter in healthy subjects. Our model includes variable volume fractions, intracellular restriction effects, and exchange between compartments in addition to individual diffusion coefficients and transverse relaxation rates for each compartment. A global optimum was found from a wide range of parameter permutations using cluster computing. We also present simulations of cell swelling and changes of exchange rate and intracellular diffusion as possible cellular mechanisms in ischemia.

Results

Our model estimates an extracellular volume fraction of 0.19 in accordance with the accepted value from histology. The absolute apparent diffusion coefficient obtained from the model was similar to that of experiments. The model and the experimental results indicate significant differences in diffusion and transverse relaxation between the tissue compartments and slow water exchange. Our model reproduces the signal changes observed in ischemia via physiologically credible mechanisms.

Conclusion

Our modeling suggests that transverse relaxation has a profound influence on the diffusion attenuated MR signal. Our simulations indicate cell swelling as the primary cause of the diffusion changes seen in the acute phase of brain ischemia. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Evaluation of ganglion cysts using vastly undersampled isotropic projection reconstruction (VIPR)
Authors: Amrami Kimberly K. , Desy Nicholas M. , Stanley David W. , Skinner John A. , Felmlee Joel P. , Barger Andrew V. , Block Walter F. , Spinner Robert J.
Published: August 2007

For some atypical para‐articular ganglia, the presence of a joint connection is highly controversial. The proper preoperative diagnosis and identification of this joint connection for ganglion cysts is important for patient treatment and outcome. MRI is the imaging modality of choice when evaluating such lesions, but the detection of subtle joint connections remains difficult with conventional MR protocols. We investigated the utility of a steady‐state free‐precession acquisition with isotropic high resolution using the vastly undersampled isotropic projection reconstruction (VIPR) pulse sequence to determine if joint connections for ganglion cysts could be seen more effectively, using the knee region as a model. We evaluated four patients: two with peroneal intraneural ganglion cysts, one with adventitial cystic disease of the popliteal artery, and one patient with a more typical extraneural (intramuscular) cyst. Both conventional MR and VIPR techniques were used. In our clinical experience, we found VIPR to be superior to conventional MR techniques in detecting and depicting joint connections in typical and atypical ganglion cysts around the knee. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Quantitative regional oxygen transfer imaging of the human lung
Authors: Arnold Johannes F.T. , Kotas Markus , Fidler Florian , Pracht Eberhard D. , Flentje Michael , Jakob Peter M.
Published: August 2007

Purpose

To demonstrate that the use of nonquantitative methods in oxygen‐enhanced (OE) lung imaging can be problematic and to present a new approach for quantitative OE lung imaging, which fulfills the requirements for easy application in clinical practice.

Materials and Methods

A total of 10 healthy volunteers and three non‐small‐cell lung cancer (NSCLC) patients were examined using a 1.5T scanner. OE imaging was performed using a snapshot fast low‐angle shot (FLASH) T1‐mapping technique (TE = 1.4 msec, TR = 3.5 msec) as well as a series of T1‐weighted inversion recovery (IR) half‐ Fourier acquisition single‐shot turbo spin‐echo (HASTE) (TEeffective = 43 msec, TEinter = 4.2 msec, and inversion time [TI] = 1200 msec) images. Semiquantitative relative signal enhancement ratios (RER) of T1‐weighted images before and after inhalation of oxygen‐enriched gas were compared to the quantitative change in T1. A hybrid method is proposed that combines the advantages of T1‐weighted imaging with the quantification provided by T1‐mapping. To this end, the IR‐HASTE images were transformed into quantitative parameter maps. To prevent mismatching and incorrect parameter maps, retrospective image selection was performed using a postprocessing navigator technique.

Results

The RER was dependent on the intrinsic values of T1 in the lung. Quantitative parameters, such as the decrease of T1 after switching the breathing gas, were more suited to oxygen transfer quantification than to relative signal enhancement. The mean T1 value during inhalation of room air (T1,room) for the volunteers was 1260 msec. This value decreased by about 10% after switching the breathing gas to carbogen. For the patients, the mean T1,room value was 1182 msec, which decreased by about 7% when breathing carbogen. The parameter maps generated using the proposed hybrid method deviated, on average, only about 1% from the T1‐maps.

Conclusion

For the purpose of intersubject comparison, OE lung imaging should be performed quantitatively. The proposed hybrid technique produced reliable quantitative results in a short amount of time and, therefore, is suited for clinical use. J. Magn Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Comparison of three accelerated pulse sequences for semiquantitative myocardial perfusion imaging using sensitivity encoding incorporating temporal filtering (TSENSE)
Authors: Weber Stefan , Kronfeld Andrea , Kunz R. Peter , Fiebich Martin , Horstick Georg , Kreitner Karl‐Friedrich , Schreiber Wolfgang G.
Published: August 2007

Purpose

To investigate the parallel acquisition technique sensitivity encoding incorporating temporal filtering (TSENSE) with three saturation‐recovery (SR) prepared pulse sequences (SR turbo fast low‐angle shot [SR‐TurboFLASH], SR true fast imaging with steady precession [SR‐TrueFISP], and SR‐prepared segmented echo‐planar‐imaging [SR‐segEPI]) for semiquantitative first‐pass myocardial perfusion imaging.

Materials and Methods

In blood‐ and tissue‐equivalent phantoms the relationship between signal intensity (SI) and contrast‐medium concentration was evaluated for the three pulse sequences. In volunteers, signal‐to‐noise ratio (SNR), contrast‐to‐noise ratio (CNR), and normalized upslopes (NUS) were calculated from signal–time curves (STC). Moreover, artifacts, image noise, and overall image quality were qualitatively evaluated.

Results

Phantom data showed a 40% increased linear range of the relation between SI and contrast‐medium concentration with TSENSE. In volunteers, TSENSE introduced significantly residual artifacts and loss in SNR and CNR. No differences were found for NUS values with TSENSE. SR‐TrueFISP yielded highest SNR, CNR, and quality scores. However, in SR‐True‐FISP images, dark‐banding artifacts were most pronounced. NUS values obtained with SR‐TrueFISP were significantly higher and with SR‐segEPI significantly lower than with SR‐TurboFLASH.

Conclusion

Semiquantitative myocardial perfusion imaging can significantly benefit from TSENSE due to shorter acquisition times and increased linearity of the pulse sequences. Among the three pulse sequences tested, SR‐TrueFISP yielded best image quality. SR‐segEPI proved to be an interesting alternative due to shorter acquisition times, higher linearity and fewer dark‐banding artifacts. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Improvement of the diffusion‐weighted images acquired with radial trajectories using projection data regeneration
Authors: Han Yeji , Hwang JinYoung , Chung Jun‐Young , Yun Sungdae , Park HyunWook
Published: August 2007

Purpose

To reduce the artifacts due to pulsatile motion artifacts in diffusion‐weighted imaging (DWI) with radial trajectories and to improve the image quality using projection data regeneration.

Materials and Methods

The projection data is obtained by a radial spin‐echo DWI (rSE‐DWI) sequence, from which a temporary image is generated using the inverse Radon transform (IRT). The projection data include some degraded data due to cardiac pulsatile motion. The degraded data are then replaced with data that are regenerated using the Radon transform (RT) of the temporary image. The proposed method for image quality improvement is demonstrated through a computer simulation and in vivo images obtained by rSE‐DWI.

Results

In general, electrocardiograph (ECG) triggering is used to reduce the degradation of projection data in the DWI with radial trajectories, where the amount of degradation depends on the cardiac phase. Cardiac gating reduces the artifacts resulting from the cardiac pulsatile motion to a certain extent only. The proposed projection data regeneration method successfully improves image quality.

Conclusion

The regeneration method based on back‐projection reconstruction effectively uses the features of the degraded projections having lower signal intensity than the normal projections, resulting in image quality improvement without acquisition of additional data. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Effect of deficit irrigation on apricot fruit quality at harvest and during storage
Authors: Pérez‐Pastor Alejandro , Ruiz‐Sánchez Maria Carmen , Martínez Juan A , Nortes Pedro A , Artés Francisco , Domingo Rafael
Published: August 2007

The effect of different irrigation strategies on the fruit quality at harvest and during storage at 1 °C of 'Búlida' apricots (Prunus armeniaca L.) was studied. Irrigation treatments consisted of a control irrigated at 100% of crop evapotranspiration (ETc) throughout the season, and two deficit irrigation treatments consisting of continuous irrigation at 50% of control, and regulated deficit irrigation (RDI) at 100% of ETc during the critical periods (second rapid fruit growth and early post‐harvest) and at 25% during the rest of the season. Fruits at harvest from both deficit irrigation treatments showed higher values of total soluble solids (TSS), titratable acidity and hue angle (h°) than control fruits, whereas their diameter, fresh weight, firmness and maturity index values were similar to those in the control. During the first 10 days of the 30‐day chilling storage period, higher TSS and h° values were found in deficit irrigated fruits, whilst the other parameters were similar for all treatments. Weight loss and fungal attacks (mainly Rhizopus sp. and Monilinia sp.) during a subsequent retail sale period of 4 days at 13 °C were the lowest in RDI. Deficit irrigation was demonstrated to be commercially advantageous for keeping fruit quality, saving considerable amounts of water. Copyright © 2007 Society of Chemical Industry
Reconstruction with pasteurized autograft‐total hip prosthesis composite for periacetabular tumors
Authors: Jeon Dae‐Geun , Kim Min Suk , Cho Wan Hyeong , Song Won Seok , Lee Soo‐Yong
Published: August 2007

Background

With the development of preoperative adjuvant treatment, imaging techniques, and improvement of surgical technique, limb salvage is now possible even in patients with pelvic tumors. However, reconstruction after periacetabular resection is complicated and challenging.

Methods

We retrospectively evaluated the usefulness of pasteurized autograft‐total hip composite in pelvic reconstruction with regard to graft survival, union, graft‐related complications, and functional outcome in 14 patients with periacetabular tumor.

Results

The 5‐year and 10‐year survival rates of the pasteurized bones were 64.3% and 32.1%, respectively. Major complications that necessitated graft removal included infection in three, fracture in two, and loosening in three patients. The average functional score of seven long‐term successful patients was 25.6 (85.2%).

Conclusions

In spite of the high complication rate, pasteurized autograft can be considered as an option for periacetabular reconstruction in the selected patients who meet the following criteria. First, iliopectineal and ilioischial lines are radiologically intact; second, the tumor volume is small (preferably less than 100 ml). J. Surg. Oncol. 2007;96:493–502. © 2007 Wiley‐Liss, Inc.
Structure–retention relationship study of diastereomeric (Z)‐ and (E)‐2‐alkylidene‐4‐oxothiazolidines
Authors: Natić Maja , Marković Rade , Milojković‐Opsenica Dušanka , Tešić Živoslav
Published: August 2007

Quantitative structure–retention relationship (QSRR) was developed for a series of the (Z)‐ and (E)‐2‐alkylidene‐4‐oxothiazolidine derivatives by the multiple linear regression (MLR) analysis. Full geometry optimization based on Austin Model 1 (AM1) semiempirical molecular orbital method was carried out and a set of physicochemical molecular descriptors was calculated from the optimized structures. In order to obtain useful experimental parameters, the lipophilic character of analytes was measured by RP‐TLC, and lipophilicity parameters were correlated with physicochemical structural descriptors. Statistically significant and physically meaningful structure–retention relationships were obtained.
16.4 W laser output at 1.34 μm with twin Nd:YVO4 crystals and double-end-pumping structure
Authors: Lu C , Gong M , Liu Q , Huang L , He F
Published: August 2007

High-power high-beam-quality 1.34 μm continuous-wave laser with twin Nd:YVO4 crystals pumped by four fiber-coupled laser diodes, which constructed a double-end-pumping structure, is reported. With total 60 W pumping power incident, the highest 16.4 W output laser power was generated, the slope efficiency and optical efficiency were measured as better than 30.0% and 27.3%, respectively. With 12 W laser output, the beam quality was measured to be better than two times diffraction-limit and the instability of laser output was determined to be better than 1% over an hour time.
High-power, continuous-wave, Nd:LuVO4 microchip lasers
Authors: Wang Z , Zhang H , Xu F , Hu D , Xu X , Wang J , Shao Z
Published: August 2007

Nd:LuVO4 crystal was used for the most compact and the simplest laser, i.e. the microchip construction. LD (laser diode)-pumped, continuous-wave output property was detected on several Nd:LuVO4 microchips with different Nd3+ doping level, crystal length, and transmittance of output surface. With a 0.5 at.%, 1.5 mm, T = 1% crystal, 9.7 W maximum output was achieved, corresponding an optical-optical conversion efficiency of 32.0%. With a 1 at.%, 1.5 mm, T = 1% crystal, 9.1 W maximum output was achieved at a pump power of 20.5 W, which had the highest optical-optical conversion efficiency of 44.4%.
CAESURA Studies of Helical Jump Motions in Semi‐Crystalline Polymers
Authors: Shao Limin , Titman Jeremy J.
Published: August 2007

Applications of the CAESURA experiment to studies of helical jump motions in semi‐crystalline polymers are described. CAESURA is a recently proposed magic angle spinning exchange NMR experiment which provides detailed information about the timescale and geometry of molecular motions. The potential utility of CAESURA in studies of helical jump motions in a range semi‐crystalline polymers is illustrated using simulated data. In addition, a full experimental investigation of isotactic poly(propylene) is described which confirms the geometry of the helical jump motion and provides a measurement of the jump rate.

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On the number of positive solutions of elliptic systems
Authors: O'Regan Donal , Wang Haiyan
Published: August 2007

The paper deals with the existence, multiplicity and nonexistence of positive radial solutions for the elliptic system div(|∇|p –2∇) + λki (|x |) fi (u1, …,un) = 0, p > 1, R1 < |x | < R2, ui (x) = 0, on |x | = R1 and R2, i = 1, …, n, x ∈ ℝN , where ki and fi, i = 1, …, n, are continuous and nonnegative functions. Let u = (u1, …, un), φ (t) = |t |p –2t, fi0 = lim‖u‖→0((fi (u))/(φ (‖u‖))), fi∞= lim‖u‖→∞((fi (u))/(φ (‖u‖))), i = 1, …, n, f = (f1, …, fn), f0 = ∑n i =1 fi 0 and f∞ = ∑n i =1 fi ∞. We prove that either f0 = 0 and f∞ = ∞ (superlinear), or f0 = ∞and f∞ = 0 (sublinear), guarantee existence for all λ > 0. In addition, if fi (u) > 0 for ‖u‖ > 0, i = 1, …, n, then either f0 = f∞ = 0, or f0 = f∞ = ∞, guarantee multiplicity for sufficiently large, or small λ, respectively. On the other hand, either f0 and f∞ > 0, or f0 and f∞ < ∞ imply nonexistence for sufficiently large, or small λ, respectively. Furthermore, all the results are valid for Dirichlet/Neumann boundary conditions. We shall use fixed point theorems in a cone. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On Clarkson's inequality in the real case
Authors: Maligranda Lech , Sabourova Natalia
Published: August 2007

The best constant in a generalized complex Clarkson inequality is Cp,q (ℂ) = max {21–1/p , 21/q , 21/q –1/p +1/2} which differs moderately from the best constant in the real case Cp,q (ℝ) = max {21–1/p , 21/q ,Bp,q }, where . For 1 < q < 2 < p < ∞ the constant Cp,q (ℝ) is equal to Bp,q and these numbers are difficult to calculate in general. As applications of the generalized Clarkson inequalities the (p, q)‐Clarkson inequalities in Lebesgue spaces, in mixed norm spaces and in normed spaces are presented. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Intermediate Hamiltonian via Glazman's splitting and analytic perturbation for meromorphic matrix‐functions
Authors: Mikhailova Anna B. , Pavlov Boris S. , Prokhorov Lev V.
Published: August 2007

We consider the spectral problem for the Schrödinger operator ℒ︁ on a quantum network, represented as a union of a finite number of quantum wells and finite or semi‐infinite straight quantum wires connecting them to each other and to infinity. The absolutely continuous spectrum of the Schrödinger operator, with real piecewisecontinuous potential on the wells and constant potential on the wires, has a band structure defined by the geometry and the potentials on the semi‐infinite wires. We split the Schrödinger operator, depending on the Fermi level Ë, into an orthogonal sum of two operators ℒ︁ → lΛ ⊕ LΛ, which have the complementary branches of the absolutely continuous spectra coincident, counting multiplicity, respectively with the unions

Σ = ∪σopen , Σ = ∪σclosed

of absolutely continuous branches σ = [λσ , ∞) of open and closed channels in the semi‐infinite wires, with thresholds λσ < Λ, λσ > Λ, respectively. This enables us to reduce the problem of evaluation of the scattering matrix on the network to the solution of a finite linear system, involving the Dirichlet‐to‐Neumann map of the intermediate Hamiltonian LΛ. We calculate the intermediate Dirichlet‐to‐Neumann map approximately, for thin networks, based on the classical DN‐map of the relevant Schrödinger operator on the compact part of the network. To this end we develop a modified analytic perturbation procedure for meromorphic operatorfunctions with small one‐dimensional residues. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Silole‐Containing Polymers: Chemistry and Optoelectronic Properties
Authors: Chen Junwu , Cao Yong
Published: August 2007

In this review, the synthesis and optoelectronic properties of various π‐conjugated‐, σ‐conjugated‐, pendanted‐, and hyperbranched or dendritic silole‐containing polymers (SCPs) are described. So far, substituted silole, dibenzosilole, dithienosilole, and bis‐silicon‐bridged stilbene have been incorporated into SCPs. The tunable bandgaps from 4.0–1.55 eV, variable fluorescent colors from UV to blue, green, and red (RGB) light, fluorescent chemo‐sensors for 2,4,6‐trinitrotoluene (TNT)‐type explosives, aggregation‐induced emission, efficient electroluminescence emissions for RGB lights, phosphorescent hosts with high triplet energy level, efficient solar cells, stable field‐effect transistors with high hole mobility in air, and attenuation of strong laser power, are the important features of SCPs.

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Beitrag niedriger Lastamplituden zur Ermüdungsschädigung von 0,15 %C Stahl
Authors: Mayer H. , Stojanovic S. , Ede C. , Zettl B.
Published: August 2007

Die Wöhlerkurve von 0,15 %C Stahl zeigt eine Dauerfestigkeit. Zweistufen Blockprogrammversuche dienen dazu, den Einfluss einer Vielzahl von Lasten unterhalb der Dauerfestigkeit auf die Ermüdungsschädigung zu untersuchen. Liegt die hohe Stufe im Zweistufenkollektiv mehr als ca. 15 % über der Dauerfestigkeit, dann tragen Schwingspiele unterhalb der Dauerfestigkeit wesentlich zur Ermüdungsschädigung bei. Untersuchungen des Risswachstums mit Zweistufenkollektiven zeigen, dass die Ursache dafür die Beschleunigung des Ermüdungsrisswachstums durch eine Vielzahl an niedrigen Lasten ist. Liegen die hohen Stufen im Zweistufen Ermüdungsversuch weniger als ca. 15 % oberhalb der Dauerfestigkeit, dann zeigt sich ein positiver Einfluss einer Vielzahl an niedrigen Lasten. Unter diesen Bedingungen können im Zweistufen Blockprogramm eine weitaus größere Zahl an Lastamplituden ohne Bruch ertragen werden, als mit einer Miner‐Rechnung vorhergesagt. Rissausbreitungsuntersuchungen zeigen, dass unter diesen Bedingungen für die hohe Last zahlreiche niedrige Amplituden zu einem Stoppen des Ermüdungsrisswachstums führen.
Distal lesion of the lateral femoral cutaneous nerve
Authors: Kushnir Mark , Klein Colin , Kimiagar Yitzhak , Pollak Lea , Rabey Jose M.
Published: August 2007

We report three patients with a typical clinical picture of unilateral meralgia paresthetica in whom routine nerve conduction studies were normal. However, cortical somatosensory evoked potentials were absent after lateral femoral cutaneous nerve (LFCN) stimulation on the affected side. After stimulation of the LFCN in the anterosuperior iliac spine (ASIS) region and recording the responses distal to conventional sites (20 cm from the ASIS), sensory nerve action potentials (SNAPs) were absent in the symptomatic leg, but present in the normal leg. We suggest that thigh paresthesias may be caused by a distal LFCN lesion. Eliciting this requires recording SNAPs distal to conventional sites. Muscle Nerve, 2007
Capacity allocation to sales agents in a decentralized logistics network
Authors: Demirag Ozgun Caliskan , Swann Julie L.
Published: August 2007

Many logistics systems operate in a decentralized way, while most optimization models assume a centralized planner. One example of a decentralized system is in some sea cargo companies: sales agents, who share ship capacity on a network, independently accept cargo from their location and contribute to the revenue of the system. The central headquarters does not directly control the agents' decisions but can influence them through system design and incentives. In this paper, we model the firm's problem to determine the best capacity allocation to the agents such that system revenue is maximized. In the special case of a single‐route, we formulate the problem as a mixed integer program incorporating the optimal agent behavior. For the NP‐hard multiple‐route case, we propose several heuristics for the problem. Computational experiments show that the decentralized system generally performs worse when network capacity is tight and that the heuristics perform reasonably well. We show that the decentralized system may perform arbitrarily worse than the centralized system when the number of locations goes to infinity, although the choice of sales incentive impacts the performance. We develop an upper bound for the decentralized system, where the bound gives insight on the performance of the heuristics in large systems. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
Thermal and mechanical properties of electrospun PMMA, PVC, Nylon 6, and Nylon 6,6
Authors: Carrizales Clarisa , Pelfrey Sean , Rincon Roman , Eubanks Thomas M. , Kuang Anxiu , McClure Michael J. , Bowlin Gary L. , Macossay Javier
Published: August 2007

Poly(methyl methacrylate) (PMMA), poly(vinyl chloride) (PVC), Nylon 6, and Nylon 6,6 have been electrospun successfully. The nanofibers have been characterized by scanning electron microscopy (SEM), confirming the presence of bead free and fiber‐bead free morphologies. Thermogravimetric analysis (TGA) indicated differences between the thermal stability of PMMA nanofibers and PMMA powder. However, no significant differences were observed between the starting physical form (powder or pellet) of PVC, Nylon 6 and Nylon 6,6, and their corresponding electrospun nanofibers. Differential scanning calorimetry (DSC) demonstrated a lower glass transition temperature (Tg) and water absorption for PMMA electrospun nanofibers. Furthermore, electrospun Nylon 6 and Nylon 6,6 had a slight decrease in crystallinity. Tensile testing was performed on the electrospun nanofibers to obtain the Young modulus, peak stress, strain at break, and energy to break, revealing that the non‐woven mats obtained had modest mechanical properties that need to be enhanced. Copyright © 2007 John Wiley & Sons, Ltd.
The g‐factor of international cognitive ability comparisons: the homogeneity of results in PISA, TIMSS, PIRLS and IQ‐tests across nations
Authors: Rindermann Heiner
Published: August 2007

International cognitive ability and achievement comparisons stem from different research traditions. But analyses at the interindividual data level show that they share a common positive manifold. Correlations of national ability means are even higher to very high (within student assessment studies, r = .60–.98; between different student assessment studies [PISA‐sum with TIMSS‐sum] r = .82–.83; student assessment sum with intelligence tests, r = .85–.86). Results of factor analyses indicate a strong g‐factor of differences between nations (variance explained by the first unrotated factor: 94–95%). Causes of the high correlations are seen in the similarities of tests within studies, in the similarities of the cognitive demands for tasks from different tests, and in the common developmental factors at the individual and national levels including known environmental and unknown genetic influences. Copyright © 2007 John Wiley & Sons, Ltd.
The big g‐factor of national cognitive ability
Authors: Rindermann Heiner
Published: August 2007

The response deals with several controversial issues: theoretical concepts of cognitive abilities, their cultural relativity in definition or level, the meaning and validity of national cognitive ability, methodological questions like the ecological fallacy, the variance of intelligence at different levels of observation, multi‐level analysis, the correctness and importance of levels of analysis in cognitive‐ability research, the aggregation and adjustment process, and the similarities of different cognitive assessment approaches. Central to this research are questions of causality (the causes and consequences of national cognitive‐ability homogeneity and level), of malleability of these levels, and of ethical and political consequences of intelligence research. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis, crystallinity and degradation properties of biodegradable poly[(sebacic anhydride)‐co‐caprolactone] triblock copolymers
Authors: Miao Hui , Hao Jianyuan , Liu Yan , Liu Yu , Deng Xianmo
Published: August 2007

BACKGROUND: A series of novel biodegradable poly[(sebacic anhydride)‐co‐caprolactone] (PSA‐co‐PCL) triblock copolymers were prepared by melt condensation of acylated PSA and monofunctional hydroxyl‐terminated PCL prepolymers. These copolymers could be used as novel drug delivery carriers with expected good drug permeability due to the PCL component. The degradation rate and mode can be modulated by varying the ratio of monomers in the copolymer.

RESULTS: The homopolymers and copolymers were characterized using 1H NMR, gel permeation chromatography and differential scanning calorimetry (DSC). 1H NMR confirmed the formation of triblock copolymers that comprise a middle PSA block and two side PCL blocks. DSC revealed that the melting temperature and degree of crystallinity for both sebacic anhydride (SA) and caprolactone (CL) components are strongly composition dependent, implying the hindrance effect of the two components on the crystallinity. In vitro degradation experiments showed that the mass loss is significantly accelerated for samples in base buffer solution and more rapid for the copolymers with a higher SA content. Scanning electron microscopy revealed that for SA‐rich copolymer, PSA(80 wt%)‐co‐PCL, surface erosion dominated the degradation mode of the sample. In contrast, for CL‐rich copolymer, PSA(20 wt%)‐co‐PCL, a micropore structure developed at a degradation time of 155 h along the edges of the sample, owing to the hydrolysis of SA.

CONCLUSION: It is concluded that the rate and mode of degradation of these copolymers can be tuned by varying the composition of the copolymers. Copyright © 2007 Society of Chemical Industry
Composite TiOx/Hydrocarbon Plasma Polymer Films Prepared by Magnetron Sputtering of TiO2 and Poly(propylene)
Authors: Drabik Martin , Hanus Jan , Kousal Jaroslav , Choukourov Andrei , Biederman Hynek , Slavinska Danka , Mackova Anna , Pesicka Josef
Published: August 2007

This study describes the preparation and the properties of TiOx/hydrocarbon plasma polymer composite films. Films are prepared by simultaneous sputtering in argon from two balanced magnetrons equipped with TiO2 and PP targets. The resulting films exhibit a wide range of properties in dependence on the preparation conditions – primarily on the ratio of the deposition rates r(TiOx)/r(PP) and thus the power delivered to the magnetrons. The deposition process is monitored by optical emission spectroscopy. The composition and morphology of the composite films have been analyzed by means of RBS/ERDA, FTIR, AFM, and TEM. Optical properties of the films are studied in the UV and visible range of the spectrum. Finally, an attempt has been made to express the amount of inorganic phase present in the organic matrix in terms of a filling factor.

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Tumour preventive effect of Aloe vera leaf pulp lectin (Aloctin I) on Ehrlich ascites tumours in mice
Authors: Akev Nuriye , Turkay Gulhan , Can Ayse , Gurel Aydin , Yildiz Funda , Yardibi Hasret , Ekiz Elif Ergul , Uzun Hafize
Published: August 2007

In this study, the prophylactic effect of the main lectin present in Aloe vera leaf pulp extract (Aloctin I) was assayed against Ehrlich ascites tumours in mice. The lectin administered prophylactically before tumour implantation regressed tumour size, however, this activity was less potent than that of the A. vera leaf pulp extract previously shown in our laboratory. Accordingly, serum sialic acid and tumour necrosis factor alpha (TNFα) levels, chosen as tumour markers, were decreased significantly by the prophylactic administration of the lectin. The increase in spleen and thymus weights in the group given only Aloctin I, could be explained by the immunomodulatory and mitogenic effects of lectins. These findings, along with lymphoid hyperplasia observed in spleen and thymus, suggest that the tumour preventive effect of Aloctin I could be due to its immunomodulatory activity. Copyright © 2007 John Wiley & Sons, Ltd.
New tertiary amine‐based surface active polymers
Authors: Schmolka Irving R. , Seizinger Reinhold K.
Published: August 2007

Surface active polymers with molecular weight ranging from 5600 up to 30,000 were synthesized by the oxyethylation of polyoxpropylene glycol adducts of ethylene diamine, which range in molecular weight from 4750 up to 6750. The toxicological properties of some of these new nonionics indicated that they would be nontoxic when used in contact with the skin and scalp. Their typical physical properties such as wetting, emulsifying, foaming and thickening are reported. A variety of cosmetic formulations has been prepared utilizing these new nonionic surface active polymers. This illustrates their versatility when used in products as diverse as a floating bath oil, an antiperspirant gel, a cold cream and a sun screen lotion.
Influence of various surfactants on the antimicrobial activity of bromsalans and other ring‐halogenated substances
Authors: Molnar Nicholas M.
Published: August 2007

Test methods used in the assessment of activity are discussed, utilizing the gradient plate dilution technique of Curry (1) for screening work. The various classes of surfactants studied included anionics, nonionics, amphoterics, and cationics.

A study was made in vitro of the influence of these surface‐active agents on five antimicrobial agents. Based upon these tests it appears that, in general, Temasepts I, II, and IV show greater activity and a broader spectrum than G‐11 and TCC. This is particularly evident in the presence of conventional soap and the newer non‐soap bars.

An interesting pattern of results was observed when nonionic BC720 was used in the system. All of the antimicrobial agents were equal in activity againstStaphylococcus aureus, Escherichia coli, andCandida albicans, but Temasept I showed the highest activity againstPityrosporum ovale andAspergillus niger, with TCC occupying an intermediate position.

The cationic vehicles alone, in addition to any possible enhancement of the ring‐halogenated aromatics, contribute significantly in the system to inhibit all of the test strains.

With the amphoteric vehicles, the antimicrobial agents for the most part were equally effective, with G‐11 being slightly less effective. In striking contrast, the three Temasepts showed far greater activity againstP. ovale, C. albicans, andA. niger, especially in Miranol CS.

The data presented may be utilized for the formulation of fabric softeners, and the tests employed aid in the selection of the proper surfactant for textile and skin applications. The work demonstrates that in any technical appraisal of the antimicrobial potency of a compound, the influence of the surfactant vehicle is of paramount importance.
Alcohol ether sulfates in shampoos
Authors: Watanabe Henry , Groves W. L.
Published: August 2007

Mono‐, di‐ and triethanolamine sulfates of several different molecular weight alcohol ether sulfates were formulated into shampoos. The ethylene oxide content of the alcohol ethoxylates varied from about 20 to 60%, although 40% was usual. The shampoo formulation was 20% active ether sulfate and 5% foam stabilizer. Lauric diethanolamide and amine oxides were used as foam stabilizers.

The shampoos were tested for quality and quantity of foam, viscosity and cloud point. Although no “hair effects” tests were run, a limited home use test was made.

Alcohol ether sulfate shampoos are equal or superior to several popular commercial products on the basis of a laboratory foam test. They are comparable in foam to alcohol sulfates in similar formulations. Cloud points of these shampoos were generally good. Amine oxide foam stabilizers reduced the cloud point more than the amide. Viscosities of the shampoos were readily controllable. Although the choice of alkanolamine, alcohol molecular weight and degree of ethoxylation had some effect on these properties, none were highly critical; this allows considerable leeway in their selection. The home use tests assured us that these shampoos were not obviously deficient in the desired “hair effect” properties. The literature records that alcohol ether sulfates are preferred to alcohol sulfates for low skin and eye irritation.

By varying the free oil (unsulfated ethoxylate) content and making the proper choice of ether sulfate and foam stabilizer, bright and clear liquid shampoos with viscosities from about 10 centipoise to over 50,000 centipoise were made. The latter are essentially gels. Paste shampoos were also made from these ether sulfates.
Isomeric phenylstearic acids and related compounds: Composition and partial separation
Authors: Smith F. D. , Stirton A. J. , Dooley C. J.
Published: August 2007

Reaction of benzene with oleic acid, methyl oleate, oleyl alcohol and oleonitrile, catalyzed by AlCl3, yielded the expected phenylstearic acid or the related ester, alcohol or nitrile as a viscous oil which failed to crystallize.

Gas liquid chromatography of the ketone fraction obtained by CrO3 oxidation showed 12 position isomers, with the phenyl group at C atoms 6–17, for phenylstearic acid, methyl phenylstearate and phenylstearonitrile. Oxidation of phenyloctadecanol revealed one more isomer, (5‐phenyloctadecanol). Distribution of isomers was quite similar for the acid, ester, alcohol and nitrile. Repeated low temperature crystallization from acetone and other solvents separated the 17‐, 16‐ and 15‐phenyl isomers in a pure state. Initial crystallization gave the 17‐phenyl isomer, except for phenylstearic acid. In this case, contrary to our previous report, the product from initial crystallization was 16‐phenylstearic acid.
Variability of degree of high order compositeness in fats from the same biological species: Fats from geographic varieties ofpongamia glabra, Nerium thevetifolium andMoringa pterygosperma
Authors: Kartha A. R. S. , Upadhyay G. S.
Published: August 2007

Seed fats from four geographic varieties ofP. glabra (Sm 20.2, 27.1, 25.2 and 24.7), three ofN. thevetifolium (Sm 33.5, 36.3 and 33.1) and two ofM. pterygosperma (Sm 23.2 and 20.6) showed high order compositeness (HOC) indices of GS3nil, GS2U +5.2, −3.1, +5.2 and +9.0, GS3nil, GS2U +0.9, +7.0 and +2.0 and GS3nil, GS2U +2.0 and +7.3 respectively. Since geographic varieties are morphologically indistinguishable no fixed relationship can any longer be expected between the proportions of acids and glycerides in different specimens of fat from the same biological variety. Prediction of glyceride structures of different specimens of fat from the same variety can hence be made only to the extent of HOC ranges just as in the case of fats from different varieties or species.

Fats from geographic varieties belonging to different biological species show different kinds of relationships between the component saturated and unsaturated acids. No quantitative or even qualitative correlation exists between the HOC indices and the proportions of saturated acids in fats from geographical varieties belonging to the same biological source.
Neutron activation analysis and its application to the analysis of food products
Authors: Guinn Vincent P.
Published: August 2007

High‐flux thermal‐neutron activation analysis (NAA) is an extremely sensitive means of quantitatively determining most of the elements of the periodic system. The usual limits of detection, for 75 of the elements, in the absence of appreciable interferences, range from picograms (for some elements) to as high as micrograms (for less sensitive elements). A typical element can be determined down to as low as a nanogram. This high sensitivity enables one to analyze food products, for example, for numerous trace‐level elements that may be present: whether natural or added beneficial essential trace elements, or deleterious elements introduced from pesticide residues (such as Br, As and Hg), or from processing (such as Cr, Sn, Sb and Cu). Studies to be reported include the nondestructive determination of Hg in foodstuffs down to levels as low as 0.01 ppm, and of Br in foodstuffs down to about 0.1 ppm. With radiochemical separations, these detection limits can both be extended to 0.001 ppm, if needed. By combination with paper chromatographic or solvent extraction techniques, phosphorus‐ and halogen‐containing pesticides can be sensitively determined. The NAA method can also be used to advantage at element levels much higher than trace levels, and in such cases the very high neutron flux of a nuclear reactor may not be necessary. For example, even with a small 14 Mev neutron generator, the nitrogen content of foodstuffs can be determined nondestructively, rapidly and accurately, down to levels of about 100 ppm. These determinations can also be made on‐line, in food processing plants.
Computer aided spectroscopy
Authors: Crisler Robert O.
Published: August 2007

Techniques are being developed which have as their objective improvement in the accuracy of infrared absorbance measurements and more exact recording of the true band shapes. From these improved spectra, accurate quantitative parameters are being obtained which can supplement or even supplant the present chart recordings as the fundamental spectral representations. These techniques include methods for processing spectra to eliminate most of the instrumentally introduced artifacts and to resolve the corrected spectra into algebraic representations in the form of sums of distribution functions. The consequences of the increasing use of these techniques will be to improve significantly our ability to do both qualitative and quantitative analysis.
Glycolipids isolated from ginkgo nuts(Ginkgo biloba) and their fatty acid compositions
Authors: Kameyama Haru , Urakaml Chieko
Published: August 2007

The total amount of glycolipids isolated fromGinkgo biloba nut was 3.12% of crude lipids, and the largest fraction of the glycolipids was digalactosyldiglyceride 64.1%, followed by mono‐galactosyldiglyceride 31.2% and cerebroside 4.7%. Chief fatty acids present in the former two were oleic and linoleic acids, while the main compo‐nent amounting to 85% of total fatty acids in the last fraction was α‐hydroxypalmitic acid. The sugar component in cerebroside was glucose, and its long chain base was found to be similar in structure with octadecasphingadiene that had been isolated from oyster glycolipids. The major compound in the cerebroside fraction, therefore, is considered to be N‐α‐hydroxypalmitoyl‐glucosyloctadecasphingadiene.