bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineering cartilage with human nasal chondrocytes and a silanized hydroxypropyl methylcellulose hydrogel
Authors: Vinatier C. , Magne D. , Moreau A. , Gauthier O. , Malard O. , Vignes‐Colombeix C. , Daculsi G. , Weiss P. , Guicheux J.
Published: September 2006

Tissue engineering strategies, based on developing three‐dimensional scaffolds capable of transferring autologous chondrogenic cells, holds promise for the restoration of damaged cartilage. In this study, the authors aimed at determining whether a recently developed silanized hydroxypropyl methylcellulose (Si‐HPMC) hydrogel can be a suitable scaffold for human nasal chondrocytes (HNC)‐based cartilage engineering. Methyltetrazolium salt assay and cell counting experiments first revealed that Si‐HPMC enabled the proliferation of HNC. Cell tracker green staining further demonstrated that HNC were able to form nodular structures in this three‐dimensional scaffold. HNC phenotype was then assessed by RT‐PCR analysis of type II collagen and aggrecan expression as well as alcian blue staining of extracellular matrix. Our data indicated that Si‐HPMC allowed the maintenance and the recovery of a chondrocytic phenotype. The ability of constructs HNC/Si‐HPMC to form a cartilaginous tissue in vivo was finally investigated after 3 weeks of implantation in subcutaneous pockets of nude mice. Histological examination of the engineered constructs revealed the formation of a cartilage‐like tissue with an extracellular matrix containing glycosaminoglycans and type II collagen. The whole of these results demonstrate that Si‐HPMC hydrogel associated to HNC is a convenient approach for cartilage tissue engineering. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Poly(hexyl‐substituted lactides): Novel injectable hydrophobic drug delivery systems
Authors: Trimaille Thomas , Gurny Robert , Möller Michael
Published: September 2006

Poly(hexyl‐substituted lactides) (PHLA) as new hydrophobic polyesters with controlled molecular weights and narrow distributions were synthesized by ring‐opening polymerization (ROP) using tin(II) 2‐ethylhexanoate (Sn(Oct)2) and benzyl alcohol as catalyst and initiator. Glass transition temperatures (Tg) and zero shear viscosities (η0) at 25°C could be modulated from Tg= −42°C to −10°C and 40 to 4850 Pa s, respectively, by varying the polymer molecular weight and the number of hexyl groups along the polymer chain. Degradation studies were performed in terms of both mass and molecular weight loss in the course of time. The degradation mechanism is shown to be of the “bulk erosion” type, and comparable to standard poly(D,L‐lactide) (PLA). Despite the increased steric hindrance in the poly(monohexyl‐substituted lactide) (PmHLA) due to the hexyl side groups, its degradation rate at pH 7.4 and 37°C was found to be slightly higher than observed for the analogue standard PLA. This could be attributed to the flexible rubbery state of the hexyl‐substituted polymer (Tg∼−15°C) at the physiological temperature, which is favoring the degradation in comparison to the rigid and glassy standard PLA (Tg∼40°C). In contrast, degradation studies performed at 60°C, where both polymers are above their glass transition temperature, confirmed that the degradation rate is lower for the sterically more hindered PmHLA. The degradation products were analyzed by ESI‐MS. Hydrolysis lead first to the corresponding oligo‐ester fragments and finally to the nontoxic 2‐hydroxyoctanoic acid and lactic acid. Tetracycline was tested as a model drug for release studies. This drug was found to be released faster and in higher amounts in its active form from the PHLA matrix than from standard PLA. The results presented in this work demonstrate the potential of these hydrophobic polylactide‐based semisolid materials as an alternative to conventional PLA/PLGA for injectable drug delivery systems. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Enumerating Motzkin–Rabin geometries
Authors: van Wamelen Paul
Published: September 2006

The main result of this paper is an enumeration of all Motzkin‐Rabin geometries on up to 18 points. A Motzkin‐Rabin geometry is a two‐colored linear space with no monochromatic line. We also study the embeddings of Motzkin‐Robin geometries into projective spaces over fields and division rings. We find no Motzkin‐Rabin geometries on up to 18 points embeddable in ℂ2 or 𝔽2(t)2. We find many examples of Motzkin‐Rabin geometries with no proper linear subspaces. We give an example of a proper linear space embeddable in ℙ(ℚ($\sqrt -7$)2). © 2006 Wiley Periodicals, Inc. J Combin Designs 15: 179–194, 2007
The analysis of solvation in ionic liquids and organic solvents using the Abraham linear free energy relationship
Authors: Acree William E , Abraham Michael H
Published: September 2006

The original article to which this Erratum refers was published in Journal of Chemical Technology and Biotechnology (81: 1441–1446).
Are ionic liquids kosmotropic or chaotropic? An evaluation of available thermodynamic parameters for quantifying the ion kosmotropicity of ionic liquids
Authors: Zhao Hua
Published: September 2006

The original article to which this Erratum refers was published in Journal of Chemical Technology and Biotechnology (81: 877–891).
Enhanced therapeutic efficacy of oncolytic herpes vector G207 against human non‐small cell lung cancer—expression of an RNA‐binding protein, Musashi1, as a marker for the tailored gene therapy
Authors: Kanai Ryuichi , Eguchi Keisuke , Takahashi Miwa , Goldman Steven , Okano Hideyuki , Kawase Takeshi , Yazaki Takahito
Published: September 2006

Background

Oncolytic herpes vectors like G207 have shown considerable promise in the treatment of solid tumors, but their potency must be enhanced for the full achievement of therapeutic efficacy. Deletion of the innate γ34.5 gene made these vectors extremely safe, but their efficacy was also severely attenuated. Use of tumor‐specific promoters is one method to direct toxicity and enhance efficacy against tumors. Recently, Musashi1 has been shown expressed in some tumor tissues.

Methods

Eleven human cancer cell lines including five non‐small cell lung cancers (NSCLCs) were investigated. Musashi1 mRNA expression was examined by RT‐PCR analysis. Western blotting was also performed. Transcriptional activity of P/musashi1 in NSCLCs was assayed by GFP reporter plasmids. Then we constructed a defective amplicon vector containing musashi1 promoter/ICP34.5 with G207 as helper virus (dvM345). In vitro cytotoxicity against NSCLCs and growth characteristics of helper virus were examined. A Lu‐99 subcutaneous tumor model was used in an animal study. The tumor volume treated with G207 alone or dvM345 was measured.

Results

Musashi1 mRNA was detected in four cell lines. Two in five NSCLCs were positive, and P/musashi1 was proved functional within them. Against these cell lines, dvM345 showed enhanced cytotoxicity, and helper viral growth was augmented. A subcutaneous tumor study confirmed the enhanced therapeutic efficacy of G207 by dvM345 without compromising safety.

Conclusions

These results suggest that Musashi1 might be involved in the development of several carcinomas including NSCLC. In the context of oncolytic herpes vector strategy, the P/musashi1‐ICP34.5 method could be used for the treatment of cancers expressing Musashi1. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis of deuterium and 15N‐labelled 2,5‐Bis[5‐amidino‐2‐pyridyl]furan and 2,5‐Bis[5‐(methoxyamidino)‐2‐pyridyl]furan
Authors: Ismail Mohamed A. , Boykin David W.
Published: September 2006

The acetate salt of 2,5‐bis[5‐amidino‐2‐pyridyl]furan‐d2/15N2 (4) was synthesized from 2,5‐bis[5‐cyano‐2‐pyridyl]furan‐d2 (2), through the bis‐O‐acetoxyamidoxime followed by hydrogenation. Compound 2 was obtained via a Stille coupling reaction of 6‐chloronicotinonitrile with 2,5‐bis[tri‐n‐butyltin]‐furan‐d2 (1). 2,5‐bis[5‐amidino‐2‐pyridyl)furan‐d6 (10) was synthesized from 2,5‐bis[5‐cyano‐2‐pyridyl)furan‐d6 (9) via a direct reaction with lithium bis(trimethylsilyl)amide, followed by deprotection with ethanolic HCl. 15N and/or deuterium‐labelled methoxy‐amidines 5a‐d2/15N2, 5b‐d8, 12, 14‐d6 were prepared in good yield via direct methylation of their respective diamidoximes with either dimethylsulfate‐d0 or dimethylsulfate‐d6 in DMF solution and using LiOH as a base. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis of deuterated isoflavone disulfates
Authors: Soidinsalo Otto , Wähälä Kristiina
Published: September 2006

Efficient synthesis of polydeuterated di‐O‐sulfates of three isoflavones, daidzein (1), genistein (2), glycitein (3), is described. The isoflavones were first deuterated with CF3COOD under microwave irradiation to yield daidzein‐d6 (4), genistein‐d4 (5) and glycitein‐d6 (6) in 90% yield and in a high isotopic purity. The deuterated isoflavones were then sulfated with chlorosulfonic acid and pyridine to give the title compounds, again in high yield and isotopic purity (>90%). The compounds are useful as internal standards in LC‐MS quantitation of isoflavones. Copyright © 2006 John Wiley & Sons, Ltd.
Dynamics of lateral ventricle and cerebrospinal fluid in normal and hydrocephalic brains
Authors: Zhu David C. , Xenos Michalis , Linninger Andreas A. , Penn Richard D.
Published: September 2006

Purpose

To develop quantitative MRI techniques to measure, model, and visualize cerebrospinal fluid (CSF) hydrodynamics in normal subjects and hydrocephalic patients.

Materials and Methods

Velocity information was obtained using time‐resolved (CINE) phase‐contrast imaging of different brain regions. A technique was developed to measure the change of lateral ventricle (LV) size. The temporal relationships between the LV size change, CSF movement, and blood flow could then be established. The data were incorporated into a first‐principle CSF hydrodynamic model. The model was then used to generate specific predictions about CSF pressure relationships. To better‐visualize the CSF flow, a color‐coding technique based on linear transformations was developed that represents the magnitude and direction of the velocity in a single cinematic view.

Results

The LV volume change of the eight normal subjects was 0.901 ± 0.406%. Counterintuitively, the LV decreases as the choroid plexus expands, so that they act together to produce the CSF oscillatory flow. The amount of oscillatory flow volume is 21.7 ± 10.6% of the volume change of the LV from its maximum to its minimum.

Conclusion

The quantification and visualization techniques, together with the mathematical model, provide a unique approach to understanding CSF flow dynamics. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Idiopathic normal pressure hydrocephalus may be a “Two Hit” disease: Benign external hydrocephalus in infancy followed by deep white matter ischemia in late adulthood
Authors: Bradley William G. , Bahl Gautam , Alksne John F.
Published: September 2006

Purpose

To determine if normal pressure hydrocephalus (NPH) could result from decreased resorption of cerebrospinal fluid (CSF) by the arachnoidal villi, leading to benign external hydrocephalus [BEH] in infancy, followed by deep white matter ischemia (DWMI) in late adulthood (the more hydrophilic environment increasing resistance to CSF flow through the extracellular space (ECS) of the brain).

Materials and Methods

CSF outflow via the fourth ventricle and the ECS of the brain was mathematically modeled using a parallel electrical circuit analog. The apparent diffusion coefficient (ADC) was measured as a surrogate of the amount of water in the ECS in normals, patients with symptomatic NPH, and patients with dilated ventricles without symptoms of NPH (“pre‐NPH”).

Results

The electrical circuit model demonstrates increasing ventricular volume with increasing resistance to flow through the ECS of the brain. ADC measurements performed in the centrum semiovale are significantly higher in patients with NPH and “pre‐NPH” than in age‐matched controls (P < 0.05), controlling for the same degree of DWMI indicating increased fluid in the ECS of the brain.

Conclusion

The electrical circuit analog and finding of increased periventricular ADC support the theory that NPH is a “two hit” disease. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Imaging artifacts at 3.0T
Authors: Bernstein Matt A. , Huston John , Ward Heidi A.
Published: September 2006

Clinical MRI at a field strength of 3.0T is finding increasing use. However, along with the advantages of 3.0T, such as increased SNR, there can be drawbacks, including increased levels of imaging artifacts. Although every imaging artifact observed at 3.0T can also be present at 1.5T, the intensity level is often higher at 3.0T and thus the artifact is more objectionable. This review describes some of the imaging artifacts that are commonly observed with 3.0T imaging, and their root causes. When possible, countermeasures that reduce the artifact level are described. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Brain MRI: Tumor evaluation
Authors: Young Robert J. , Knopp Edmond A.
Published: September 2006

The designation “brain tumors” is commonly applied to a wide variety of intracranial mass lesions that are distinct in their location, biology, treatment, and prognosis. Since many of these lesions do not arise from brain parenchyma, the more appropriate term would be “intracranial tumors.” The term “tumor” is used to include both neoplastic and non‐neoplastic mass lesions, and should be considered in its broadest sense to simply indicate a space‐occupying mass. This review describes an imaging‐based approach for evaluating intracranial tumors. Conventional MRI is discussed in the setting of a regional classification system. This system provides a framework for analysis, and imaging clues can then be applied to narrow the differential possibilities. Emphasis is placed on advanced MRI techniques and their utility for deciphering common diagnostic problems. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Evaluation of different cerebral mass lesions by perfusion‐weighted MR imaging
Authors: Hakyemez Bahattin , Erdogan Cuneyt , Bolca Naile , Yildirim Nalan , Gokalp Gokhan , Parlak Mufit
Published: September 2006

Purpose

To investigate the contribution of perfusion‐weighted MR imaging (PWI) by using the relative cerebral blood volume (rCBV) ratio in the differential diagnosis of various intracranial space‐occupying lesions.

Materials and Methods

This study involved 105 patients with lesions (high‐grade glioma (N = 26), low‐grade glioma (N= 11), meningioma (N = 23), metastasis (N = 25), hemangioblastoma (N = 6), pyogenic abscess (N = 4), schwannoma (N = 5), and lymphoma (N = 5)). The patients were examined with a T2*‐weighted (T2*W) gradient‐echo single‐shot EPI sequence. The rCBV ratios of the lesions were obtained by dividing the values obtained from the normal white matter. Statistical analysis was performed with the Mann‐Whitney U‐test. A P‐value less than 0.05 was considered statistically significant.

Results

The rCBV ratio was 5.76 ± 3.35 in high‐grade gliomas, 1.69 ± 0.51 in low‐grade gliomas, 8.02 ± 3.89 in meningiomas, 5.27 ± 3.22 in metastases, 11.36 ± 4.41 in hemangioblastomas, 0.76 ± 0.12 in abscesses, 1.10 ± 0.32 in lymphomas, and 3.23 ± 0.81 in schwannomas. The rCBV ratios were used to discriminate between 1) high‐ and low‐grade gliomas (P < 0.001), 2) hemangioblastomas and metastases (P< 0.05), 3) abscesses from high‐grade gliomas and metastases (P < 0.001), 4) schwannomas and meningiomas (P < 0.001), 5) lymphomas from high‐grade gliomas and metastases (P < 0.001), and 6) typical meningiomas and atypical meningiomas (P < 0.01).

Conclusion

rCBV ratios can help discriminate intracranial space‐occupying lesions by demonstrating lesion vascularity. It is possible to discriminate between 1) high‐ and low‐grade gliomas, 2) hemangioblastomas and other intracranial posterior fossa masses, 3) abscesses from high‐grade gliomas and metastases, 4) schwannomas and meningiomas, 5) lymphomas and high‐grade gliomas and metastases, and 6) typical and atypical meningiomas. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Magnetic resonance angiography of the human middle meningeal artery: Implications for migraine
Authors: Schoonman Guus G. , Bakker Dick , Schmitz Nicole , van der Geest Rob J. , van der Grond Jeroen , Ferrari Michael D. , van Buchem Mark A.
Published: September 2006

Purpose

To describe a novel noninvasive method for studying middle meningeal artery (MMA) diameter changes in vivo in humans. Dilatation of the MMA has been implicated in the pathophysiology of migraine headache, but no direct evidence has been obtained in humans.

Materials and Methods

The diameter of the MMA (the extracranial part) was measured in 19 healthy volunteers before and after administration of a vasodilator (nitroglycerin (NTG), 1.2 mg sublingually) known to provoke headache. We used magnetic resonance angiography (MRA) in combination with a 47‐mm microscopy coil and a semiautomatic contour detection program.

Results

The diameter of the MMA was 1.5 ± 0.26 mm (mean ± SD) before and 1.79 ± 0.30 mm after NTG administration. This increase was 20.1% (95% CI = 12.9–27.3; P < 0.001). The mean increase in subjects who developed headache (N = 11) was 0.34 ± 0.19 mm as compared to 0.22 mm ± 0.20 mm in the eight subjects who did not (95% CI for difference = −0.07 to 0.31; P = 0.188).

Conclusion

MRA in combination with a 47‐mm microscopy coil is a novel, noninvasive method to measure changes in the diameter of human meningeal vessels, with potential applications for migraine and other fields of neurovascular research. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
1H NMR spectroscopic imaging of the mouse brain at 9.4 T
Authors: Miyasaka Naoyuki , Takahashi Kan , Hetherington Hoby P.
Published: September 2006

Purpose

To assess the feasibility of 1H spectroscopic imaging (SI) in the mouse brain at 9.4 T, and investigate regional variations in brain metabolites.

Materials and Methods

A total of 21 SI studies were performed in CD‐1 mice to evaluate the basal ganglia (N = 5), hippocampus and thalamus (N = 11), and cerebellum (N = 5). We adjusted the B0 homogeneity for each slice using a fully automated shim calculation method based on the B0 map, which we measured using a multislice gradient‐echo sequence with multiple phase evolution delays. The SI employed a modified localization by adiabatic selective refocusing (LASER) sequence with TE/TR of 50/2000 msec, 24 × 24 encodes over a field of view (FOV) of 24 mm × 24 mm, 1 μL voxel resolution, and two averages, for a total acquisition time of 38 minutes.

Results

Sufficient shimming was achieved and high‐quality spectra were consistently obtained in each slice. N‐acetyl aspartate (NAA)/creatine (Cr) ratios in the basal ganglia and thalamus (0.86 ± 0.07, and 0.87 ± 0.07, respectively) were significantly higher than those in the hippocampus and cerebellum (0.76 ± 0.03 and 0.67 ± 0.07), which were also significantly different from each other.

Conclusion

1H SI of the mouse brain is highly reproducible and allows differences in regional metabolite ratios to be easily visualized. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Contrast enhancement of manganese‐hydroxypropyl‐tetraacetic acid, an MR contrast agent with potential for detecting differences in myocardial blood flow
Authors: Eriksson Rolf , Johansson Lars , Bjerner Tomas , Karlsson Jan Olof G. , Ahlström Håkan
Published: September 2006

Purpose

To determine whether the contrast agent MnHPTA has potential for detecting differences in myocardial blood flow.

Materials and Methods

R1 in the myocardium was calculated from MR signal intensity measurements in 18 pigs after intravenous injection of 5, 15, or 25 μmol MnHPTA/kg body weight. Measurements were made in each animal after administration at rest and during dobutamine‐induced stress.

Results

A difference of approximately 0.1 sec−1 in the R1 increase between rest and stress still remained 31 minutes after administration of 25 μmol MnHPTA/kg body weight. When two consecutive MnHPTA injections were performed, the second injection induced a lower R1 increase than the corresponding first injection.

Conclusion

MnHPTA at a dose of 25 μmol/kg body weight (b.w.) has the potential to detect perfusion differences in myocardium. When two consecutive injections of MnHPTA were administered, the R1 change after the second injection was affected by the earlier administration. Therefore, a protocol including more than one administration is not ideal for this contrast agent. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Ethyl pyruvate attenuates kainic acid‐induced neuronal cell death in the mouse hippocampus
Authors: Cho Ik‐Hyun , Kim Seung‐Woo , Kim Jung‐Bin , Kim Tae‐Kyung , Lee Kang‐Woo , Han Pyung‐Lim , Lee Ja‐Kyeong
Published: September 2006

Recent studies have shown that ethyl pyruvate (EP) acts as an anti‐inflammatory molecule in several cell lines including RAW264.7 macrophages. However, the potential therapeutic value of EP for the treatment of the pathologic brain has not been investigated fully. In the present study, we examined whether EP has a beneficial effect on KA‐induced neuronal cell death. Intracerebroventricular (i.c.v.) injection of 0.94 nmol (0.2 μg) of KA produced typical neuronal cell death in the CA1 and CA3 pyramidal layers of the hippocampus, and the systemic administration of EP significantly attenuated KA‐induced neuronal cell death in these regions. Ethyl pyruvate was found to exert a protective effect when it was injected as late as 12 hr after KA‐injection. Moreover, this EP‐induced neuroprotection was accompanied by reduced levels of reactive gliosis and COX‐2, IL‐1β, and TNF‐α in the hippocampus. In addition, in passive avoidance tests, KA‐induced memory impairment was improved markedly by EP. These results suggest that EP has a therapeutic potential for suppressing KA‐induced pathogenesis in the brain. © 2006 Wiley‐Liss, Inc.
Relative proportion of inorganic and total nitrogen in broiler litter as determined by various methods
Authors: Kpomblekou‐A Kokoasse
Published: September 2006

We report relative proportion of inorganic N in broiler litter and compare the regular Kjeldahl method with three of its modifications (the salicylic acid–thiosulfate modification, the Devarda's alloy modification, and the potassium permanganate–reduced iron modification), and with a Leco‐combustion (CHN‐600) method for the degree to which they include NO3−‐N and NO2−‐N in broiler litter analysis. Inorganic N in the litter (<500 µm) was determined after extraction with 2 mol L−1KCl. NH4+‐N and (NO3−+ NO2−)‐N in the filtrate were analysed by steam distillation while NO2−‐N was determined by a modified Griess–Ilosvay colorimetric method. For the determination of total N, 25 mg broiler litter (<1000 µm) was digested according to four semi‐micro‐Kjeldahl methods in a 100‐mL Pyrex Kjeldahl flask using an electrically heated six‐flask micro‐Kjeldahl digestion rack. Ammonium‐N in the digest was determined by steam distillation. The results showed that inorganic N represents a small portion of total N in the samples. Ammonium is the most dominant inorganic N (1.61–5.39 g kg−1) in the samples; it represents between 42 and 94% of the inorganic N. The (NO3−+ NO2−)‐N contents varied between 0.19 and 5.56 g kg−1while NO2−‐N contents in the samples were negligible (<0.6 g kg−1). The regular Kjeldahl method and its modifications recovered all the NH4+‐N added but recovery of added NO2−‐N and NO3−‐N varied considerably with the methods. The Devarda's alloy and the potassium permanganate methods showed the highest N measurements while the Leco‐combustion showed the lowest N measurements. Copyright © 2006 Society of Chemical Industry
Modelling the effect of superatmospheric oxygen concentrations on in vitro mushroom PPO activity
Authors: Gómez Perla A , Geysen Sabine , Verlinden Bert E , Artés Francisco , Nicolaï Bart M
Published: September 2006

The kinetics of polyphenol oxidase (PPO, EC 1.14.18.1) with respect to oxygen concentrations from 5 to 100% using chlorogenic acid (CGA) as substrate was examined. In vitro mushroom PPO activity was determined by measuring the consumption of oxygen during the oxidation reaction. A differential Michaelis–Menten model was fitted to the obtained total depletion curves. The product concentration as well as the concentration of oxygen had a clear inhibitory effect on the reaction rate. However, the inhibitory effect of oxygen was more evident at low product concentration. A linear mixed inhibition model that considered both the product (oxidised CGA) and oxygen as inhibitors was developed. A model with the product as a competitive inhibitor and oxygen as an uncompetitive inhibitor was the most appropriate to explain the reaction kinetics. The values of the inhibition constants calculated from the model were 0.0032 mmol L−1 for Km (Michaelis–Menten constant related to oxygen), 0.023 mmol L−1 for Kmc (constant for competitive inhibition due to the product), 1.630 mmol L−1 for Kmu (constant for uncompetitive inhibition due to oxygen) and 1.77 × 10−4 mmol L−1 s−1 for Vmax (maximum reaction rate). The results indicate that superatmospheric oxygen concentrations could be effective in preventing enzymatic browning by PPO. Copyright © 2006 Society of Chemical Industry
Distribution of 127 edible plant species for antioxidant activities by two assays
Authors: Yang Ray‐Yu , Tsou Samson CS , Lee Tung‐Ching , Wu Wan‐Jan , Hanson Peter M , Kuo George , Engle Liwayway M , Lai Po‐Yung
Published: September 2006

Epidemiological studies have demonstrated the protective effects of fruit and vegetable consumption on human health. A total of 150 edible plants representing 127 species were evaluated for Trolox equivalent antioxidant capacity (TEAC) and superoxide scavenging (SOS) activity. Distributions of vegetables for TEAC and SOS were not continuous but highly skewed. TEAC values on a dry weight basis ranged from 0 to 2105 µmol TE g−1 and SOS values ranged from 0 to 6206 µmol ascorbate equivalent (AE) g−1. The majority of vegetables clustered within 200 µmol TE g−1 and 400 µmol AE g−1. Vegetable species were grouped into six classes after natural logarithm transformation of TEAC and SOS values. Most highly consumed vegetables fell in the very low to medium classes. Species in the very high class for both TEAC and SOS included leaves of Cedrela sinensis (Chinese cedar), Oroxylum indicum (Damocles tree), Cassia siamea (cassod tree) and Cassia tora (sickle senna). Edible plants high in antioxidant activity (AOA) were mostly perennial and underutilised crops, while commonly consumed vegetables were generally low in AOA. There is great potential to increase dietary antioxidants and improve human health through consumption of diverse vegetable species, especially those high in AOA. Copyright © 2006 Society of Chemical Industry
Determination of amphetamines in human urine by liquid chromatography with fluorimetric detection using a solid‐phase extraction procedure
Authors: Bugamelli Francesca , Mandrioli Roberto , Cavallini Annalisa , Baccini Cesare , Conti Matteo , Raggi Maria Augusta
Published: September 2006

A precise and feasible HPLC method has been developed for the analysis of amphetamine (AMPH), methamphetamine (MAMPH) and methylenedioxymethamphetamine (MDMA, ecstasy) in human urine. A chromatographic run on a C8 Genesis (150 mm×4.6 mm, 5 μm) column maintained at 30°C lasts about 17 min, using a mobile phase composed of ACN (12%) and a pH 2.5 phosphate buffer (88%) containing 0.3% triethylamine. Mirtazapine was used as the internal standard. Good linearity was found in the 100–2000 ng/mL concentration range for AMPH and MAMPH and in the 12–2000 ng/mL concentration range for MDMA. The pretreatment of urine samples was carried out by means of a careful SPE procedure on C2 cartridges. The extraction yields were very satisfactory for all analytes, with average values greater than 97%. The leading conditions allowed the determination of AMPH, MAMPH and MDMA with satisfactory precision and accuracy. The method has been successfully applied to the determination of the analytes in urine of AMPH users.
Continuous dopaminergic stimulation: Is it the answer to the motor complications of Levodopa?
Authors: Nutt John G.
Published: September 2006

Continuous dopaminergic stimulation (CDS) is a treatment strategy hypothesized to avoid or reduce the motor complications of long‐term levodopa therapy, motor fluctuations, and dyskinesia, by preventing or reversing sensitization induced by pulsatile dopaminergic stimulation. The CDS hypothesis is itself based on several hypotheses. First, tonic dopaminergic stimulation is physiological. Second, sensitization is undesirable and should be reversed. Third, reduction of off time and dyskinesia can be induced simultaneously. Finally, clinical studies substantiate the CDS hypothesis. The evidence for these hypotheses is reviewed, and the need for randomized clinical trials that rigorously test the CDS hypothesis is emphasized. © 2006 Movement Disorder Society
Metric attributes of the unified Parkinson's disease rating scale 3.0 battery: Part II, construct and content validity
Authors: Forjaz Maria João , Martinez‐Martin Pablo
Published: September 2006

This article is the second of a two‐part series concerning the metric properties of the following three Parkinson's disease (PD) scales: modified Hoehn and Yahr staging (H&Y), Schwab and England (S&E), and Unified Parkinson's Disease Rating Scale (UPDRS) 3.0. Part II focuses on construct and content validity. To assess construct validity, a sample of 1,136 PD patients completed the above‐mentioned PD scales. Correlation coefficients between measures of disability and dysfunction [S&E, UPDRS Activities of Daily Living (ADL), and UPDRS Motor Examination] were |r| = 0.69–0.77, indicating good convergent validity. Results showed that the S&E (F(5,945) = 193.47; P < 0.0001) and UPDRS subscales discriminated between modified H&Y stages (F(20,2784) = 25.28; P < 0.001). A panel of 12 to 13 international experts rated the relevance of the scales and items. This enabled the scales' content validity index to be calculated, which ranged from 41.7% (UPDRS Mentation) to 83.3% (UPDRS Motor Examination). In conclusion, while the modified H&Y, S&E, and UPDRS displayed satisfactory construct validity, the content validity of all scales except UPDRS Motor Examination failed to attain adequate standards. © 2006 Movement Disorder Society
Developments in neuroacanthocytosis: Expanding the spectrum of choreatic syndromes
Authors: Walker Ruth H. , Danek Adrian , Dobson‐Stone Carol , Guerrini Renzo , Jung Hans H. , Lafontaine Anne‐Louise , Rampoldi Luca , Tison François , Andermann Eva
Published: September 2006

As with other neurodegenerative disorders, research into the group of diseases known under the umbrella term of “neuroacanthocytosis” has greatly benefited from the identification of causative genes. The distinct and unifying aspect of these disorders is the presence of thorny deformations of circulating erythrocytes. This may be due to abnormal properties of red cell membranes, which could lead to insights into mech‐ anisms of neurodegeneration. Research approaches in this field, in addition to examining functions and protein interactions of the affected proteins with particular respect to neurons, have also drawn upon the expertise of hematologists and red cell membrane biologists. In this article, recent developments in the field are presented. © 2006 Movement Disorder Society
Exploring the limits of RF shimming for high‐field MRI of the human head
Authors: Mao Weihua , Smith Michael B. , Collins Christopher M.
Published: September 2006

Several methods have been proposed for overcoming the effects of radiofrequency (RF) magnetic field inhomogeneity in high‐field MRI. Some of these methods rely at least in part on the ability to independently control magnitude and phase of different drives in either one multielement RF coil or in different RF coils in a transmit array. The adjustment of these drive magnitudes and phases alone to create uniform RF magnetic (B1) fields has been called RF shimming, and has certain limits at every frequency as dictated by possible solutions to Maxwell's equations. Here we use numerical calculations to explore the limits of RF shimming in the human head. We found that a 16‐element array can effectively shim a single slice at frequencies up to 600 MHz and the whole brain at up to 300 MHz, while an 80‐element array can shim the whole brain at up to 600 MHz. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Quantification of intravoxel velocity standard deviation and turbulence intensity by generalizing phase‐contrast MRI
Authors: Dyverfeldt Petter , Sigfridsson Andreas , Kvitting John‐Peder Escobar , Ebbers Tino
Published: September 2006

Turbulent flow, characterized by velocity fluctuations, is a contributing factor to the pathogenesis of several cardiovascular diseases. A clinical noninvasive tool for assessing turbulence is lacking, however. It is well known that the occurrence of multiple spin velocities within a voxel during the influence of a magnetic gradient moment causes signal loss in phase‐contrast magnetic resonance imaging (PC‐MRI). In this paper a mathematical derivation of an expression for computing the standard deviation (SD) of the blood flow velocity distribution within a voxel is presented. The SD is obtained from the magnitude of PC‐MRI signals acquired with different first gradient moments. By exploiting the relation between the SD and turbulence intensity (TI), this method allows for quantitative studies of turbulence. For validation, the TI in an in vitro flow phantom was quantified, and the results compared favorably with previously published laser Doppler anemometry (LDA) results. This method has the potential to become an important tool for the noninvasive assessment of turbulence in the arterial tree. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Diffusional kurtosis imaging in the lung using hyperpolarized 3He
Authors: Trampel Robert , Jensen Jens H. , Lee Ray F. , Kamenetskiy Igor , McGuinness Georgeann , Johnson Glyn
Published: September 2006

Diseases of the small airspaces represent an increasingly important health problem. Asthma is primarily a disease of airway dysfunction, while chronic obstructive pulmonary disease (COPD) is associated with abnormalities in both the small airways and the alveoli. Conventional diffusion magnetic resonance imaging (MRI) of hyperpolarized noble gases, because of the short T2* of the gas, is only capable of monitoring diffusion over short times and hence only short distances. Diffusion imaging is therefore only sensitive to changes in small structures of the lung (primarily the alveoli), and will not adequately interrogate diffusion along the longitudinal axes of bronchi and bronchioles. In this communication we present a new method, termed diffusional kurtosis imaging (DKI), that is particularly sensitive to diffusion over longer distances. DKI may therefore be more sensitive to abnormalities in the bronchioles and bronchi than conventional diffusion imaging. Preliminary DKI measurements on healthy human subjects and one patient with symptoms suggestive of small airway disease are presented. Although the apparent diffusion coefficient (ADC) in the patient was similar to that in the normal controls, diffusional kurtosis was markedly reduced. This suggests that DKI measurements may be useful for assessing diseases of the small airways. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Stabilized updated Lagrangian corrected SPH for explicit dynamic problems
Authors: Vidal Y. , Bonet J. , Huerta A.
Published: September 2006

Smooth particle hydrodynamics with a total Lagrangian formulation are, in general, more robust than finite elements for large distortion problems. Nevertheless, updating the reference configuration may still be necessary in some problems involving extremely large distortions. However, as discussed here, a standard updated formulation suffers the presence of zero‐energy modes that are activated and may completely spoil the solution. It is important to note that, unlike an Eulerian formulation, the updated Lagrangian does not present tension instability but only zero‐energy modes. Here a stabilization technique is incorporated to the updated formulation to obtain an improved method without any mechanisms and which is capable to solve problems with extremely large distortions. Copyright © 2006 John Wiley & Sons, Ltd.
Layerwise mixed element with sublaminates approximation and 3D zig‐zag field, for analysis of local effects in laminated and sandwich composites
Authors: Icardi U.
Published: September 2006

The analysis of damaged sandwich composites and thick laminates remains a still challenging task, owing to their intricate distributions of displacements and stresses across the thickness. The arduous task is capturing these distributions with an affordable computational effort. The use of sublaminate zig‐zag models appears promising since they allow to group several physical layers into a sublaminate without violating the continuity of interlaminar stresses. To contribute to research in this field, a mixed, sublaminate element is developed in which displacements and stresses are approximated by two independent zig‐zag models. Like for any zig‐zag model, the interfacial contact conditions are fulfilled a priori suitably choosing the continuity functions and constants. In addition to the contact conditions on interlaminar shears, here those on the transverse normal stress and stress gradient are also fulfilled, as required by the elasticity theory. This uncustomary feature implies the presence of unwise terms which need C2 continuous shape functions. To overcome this drawback, C1 and C2 terms are eliminated from the displacement field, as allowed by the mixed approach, then the interlaminar stresses obtained by the C0‐made displacement model are cast into a separate zig‐zag representation which restores their continuity at the interfaces. As nodal d.o.f. the three displacements and the three interlaminar stresses at the upper and lower faces are assumed, in order to fulfil the contact conditions assembling the sublaminates. Standard, C0, serendipity interpolation polynomials are used to represent both internal displacements and stress fields. As a consequence of this choice, the intra‐element stress equilibria are fulfilled in an approximate integral form. This makes easier the development of the element, but does not compromise its accuracy and convergence rate, as shown by former applications. A postprocessing procedure is developed which improves the estimation of interlaminar stresses and helps to reduce the number of sublaminates. The result is that the analysis can be carried out using a single computational layer across the thickness and a reasonably fine in‐plane discretization, even with distinctly different material properties of layers and in presence of damage. The overall computational time is reduced to an half of that required by a conventional sublaminate model, like present one deprived of zig‐zag terms and postprocessing procedure. The numerical applications concern thermally loaded and piezoelectrically actuated thick laminates and damaged sandwich panels. Copyright © 2006 John Wiley & Sons, Ltd.
Modeling and investigation of the reinforcing effect of maize hull in PE matrix composites
Authors: Dogossy Gábor , Czigány Tibor
Published: September 2006

The applicability of maize hull as the reinforcement of composites was examined using the Kelly–Tyson relation modified by the authors. The data obtained from the tensile tests of maize hull were used in the model, and it was concluded that maize hull may function as a reinforcing material provided there is sufficient interfacial adhesion. Hence, polyethylene (PE) composites with 10, 20, 30 wt% filling material content were produced. Two series were manufactured; in the first one no interfacial modifiers have been used, while in the second series 5 wt% maleic‐anhydride‐grafted PE (PEgMA) was applied. Tensile tests revealed that the tensile properties (strength and modulus) of composites decreased if no modifier was used, while the strength of modified composites almost reached that of the matrix, furthermore the modulus improved. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of stirring on film formation from a Eudragit RS aqueous dispersion
Authors: Bajdik János , Regdon Géza , Lebák Gábor , Berkesi Ottó , Pintye‐Hódi Klára
Published: September 2006

The permeable polymer film‐formation behavior of a Eudragit RS dispersion was investigated in response to stirring at various rates and for various times in an Ultra Turrax instrument. No additives were used. The minimum film‐forming temperature of the liquid, the thermal behavior of the film and the compositions of the dispersion and the foam arising were investigated. It was found that, at a given mixing time, shape‐retaining foam formation could be detected at over 17,500 rpm. The polymer was enriched in the foam, while its quantity was decreased in the liquid. The minimum film‐forming temperature of the liquid phase did not vary significantly, with the exception of the rate of 24,000 rpm, when a uniform film was not formed because of the bubbles. The glass‐transition temperatures of the films formed did not exhibit any differences. Film formation was not influenced by the stirring time at a given rate. It was found that the efficiency of homogenization should not be increased by using a high stirring rate, as a uniform, smooth film did not develop, such a film being indispensable to ensure appropriate drug release. Copyright © 2006 John Wiley & Sons, Ltd.
Charge‐transporting polymers and molecular glasses for optoelectronic applications
Authors: Grazulevicius J. V.
Published: September 2006

Organic charge transport materials used in optoelectronic devices such as electrophotographic photoreceptors, light emitting diodes, solar cells, photorefractive materials can be devided into polymers, molecularly doped polymers and molecular glasses.

Among charge‐transporting polymers hole‐transporting polymers are the most widely used and studied. An aromatic amino group is a common feature of many known charge‐transporting polymers. Almost all practical systems used in electrophotography belong to this category.

Organic low‐molar‐mass compounds with stable solid amorphous phase above room temperature are called molecular glasses, amorphous molecular materials or low‐molar‐mass glasses. A real explosion of interest in organic electronically active low‐molar‐mass glass‐forming materials occurred after the discovery of high performance multilayer electroluminescent devices prepared from vacuum‐sublimed organic dye amorphous films.

In this presentation the recent results of the work on the synthesis and properties of charge‐transporting polymers and molecular glasses performed in the author's laboratories are reviewed. The main attention is paid to the synthesis and studies of hole‐transporting polymers and molecular glasses. In the design and synthesis of these materials aromatic amino groups such as carbazolyl, tripehenylamino, phenothiazinyl and hydrazone moieties, have been used as the main building blocks. The properties of the charge‐transporting compounds synthesized are reported. Ionization potentials established by the electron photoemission in air technique range from 5.00 to 5.60 eV. Hole drift mobilities in the amorphous films of some hydrazones and aromatic amines approach 10−2 cm2/V sec at high electric fields as revealed by the time‐of‐flight technique. Copyright © 2006 John Wiley & Sons, Ltd.
Peak quantification in surface‐enhanced laser desorption/ionization by using mixture models
Authors: Dijkstra Martijn , Roelofsen Han , Vonk Roel J. , Jansen Ritsert C.
Published: September 2006

Surface‐enhanced laser desorption/ionization (SELDI) time of flight (TOF) is a mass spectrometry technology for measuring the composition of a sampled protein mixture. A mass spectrum contains peaks corresponding to proteins in the sample. The peak areas are proportional to the measured concentrations of the corresponding proteins. Quantifying peak areas is difficult for existing methods because peak shapes are not constant across a spectrum and because peaks often overlap. We present a new method for quantifying peak areas. Our method decomposes a spectrum into peaks and a baseline using so‐called statistical finite mixture models. We illustrate our method in detail on 8 samples from culture media of adipose tissue and globally on 64 samples from serum to compare our method to the standard Ciphergen method. Both methods give similar estimates for singleton peaks, but not for overlapping peaks. The Ciphergen method overestimates the heights of such peaks while our method still gives appropriate estimates. Peak quantification is an important step in pre‐processing SELDI‐TOF data and improvements therein will pay off in the later biomarker discovery phase.
Thiophenol derivatives as a reducing agent for in situ generation of Cu(I) species via electron transfer reaction in copper‐catalyzed living/controlled radical polymerization of styrene
Authors: Mert Humeyra , Tunca Umit , Hizal Gurkan
Published: September 2006

The copper‐catalyzed living radical polymerization (LRP) of styrene (St) was carried out in the presence of thiophenol derivative such as sodium thiophenolate (PhSNa) or p‐methoxythiophenol as a reducing agent for Cu(II) by using either 1‐chloro‐1‐phenyl ethane or ethyl‐2‐bromoisobutyrate as an initiator and N,N,N′,N″,N″‐pentamethyldiethylenetriamine as ligand at 110 °C. Kinetic experiments were carried out to reveal the effect of PhSNa concentration on copper‐catalyzed LRP of St. This technique was successfully applied for the preparation of both chain‐extended polymer and block copolymer polystyrene‐b‐poly(methyl methacrylate). The obtained polymers were characterized using GPC, 1H‐NMR, and MALDI‐TOF measurements. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5923–5932, 2006
Synthesis and antibacterial activities of water‐soluble methacrylate polymers containing quaternary ammonium compounds
Authors: Dizman Bekir , Elasri Mohamed O. , Mathias Lon J.
Published: September 2006

New water‐soluble methacrylate polymers with pendant quaternary ammonium (QA) groups were synthesized and used as antibacterial materials. The polymers with pendant QA groups were obtained by the reaction of the alkyl halide groups of a previously synthesized functional methacrylate homopolymer with various tertiary alkyl amines containing 12‐, 14‐, or 16‐carbon alkyl chains. The structures of the functional polymer and the polymers with QA groups were confirmed with Fourier transform infrared and 1H and 13C NMR. The degree of conversion of alkyl halides to QA sites in each polymer was determined by 1H NMR to be over 90% in all cases. The number‐average molecular weight and polydispersity of the functional polymer were determined by size exclusion chromatography to be 32,500 g/mol and 2.25, respectively. All polymers were thermally stable up to 180 °C according to thermogravimetric analysis. The antibacterial activities of the polymers with pendant QA groups against Staphylococcus aureus and Escherichia coli were determined with broth‐dilution and spread‐plate methods. All the polymers showed excellent antibacterial activities in the range of 32–256 μg/mL. The antibacterial activity against S. aureus increased with an increase in the alkyl chain length for the ammonium groups, whereas the antibacterial activity against E. coli decreased with increasing alkyl chain length. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5965–5973, 2006