bluuebunny/crossref_metadata_2025 huggingface dataset:
Doxazosin treatment alters stromal cell behavior and increases elastic system fibers deposition in rat prostate
Authors: Delella Flávia Karina , Felisbino Sérgio Luis
Published: July 2010

Doxazosin (DOX), an α‐adrenoceptor antagonist, induces the relaxation of smooth muscle cell tonus and reduces the clinical symptoms of benign prostatic hyperplasia (BPH). However, the effects of DOX in the prostate stromal microenvironment are not fully known. In a previous study, we showed that DOX treatment for 30 days increased deposition of collagen fibers in the three rat prostatic lobes. Herein, we investigated the effects of DOX on stromal cell ultrastructure and elastic fiber deposition. Adult Wistar rats were treated with DOX (25 mg/kg/day); and the ventral, dorsal, and anterior prostates were excised at 30 days of treatment. The prostatic lobes were submitted to histochemical and stereological‐morphometric analyze and transmission electron microscopy (TEM). Histochemical staining plus stereological analysis of the elastic fiber system showed that DOX‐treated prostatic lobes presented more elaunin and elastic fibers than controls, mainly in the ventral lobe. Ultrastructural analysis showed that fibroblasts and smooth muscle cells from DOX‐treated prostates presented active synthetic phenotypes, evidenced by enlarged rough endoplasmic reticulum and Golgi apparatus cisterns, and confirmed the observation of thickened elaunin fibers. Our findings suggest that, under α‐adrenergic blockade by DOX, the fibroblasts become more active and smooth muscle cells shift from a predominantly contractile to a more synthetic phenotype. The deposition of collagen and elastic system fibers in the prostatic stroma may counterbalance the absence of smooth muscle tone during α‐blockers treatment. Microsc. Res. Tech. 73:1036–1044, 2010. © 2010 Wiley‐Liss, Inc.
Subgraph‐avoiding coloring of graphs
Authors: Shen Jia
Published: July 2010

Given a “forbidden graph” F and an integer k, an F‐avoiding k‐coloring of a graph G is a k‐coloring of the vertices of G such that no maximal F‐free subgraph of G is monochromatic. The F‐avoiding chromatic number acF(G) is the smallest integer k such that G is F‐avoiding k‐colorable. In this paper, we will give a complete answer to the following question: for which graph F, does there exist a constant C, depending only on F, such that acF(G) ⩽ C for any graph G? For those graphs F with unbounded avoiding chromatic number, upper bounds for acF(G) in terms of various invariants of G are also given. Particularly, we prove that \documentclass{article}\footskip=0pc\pagestyle{empty}\begin{document}${{ac}}_{{{F}}}({{G}})\le {{2}}\lceil\sqrt{{{n}}}\rceil+{{1}}$\end{document}, where n is the order of G and F is not Kk or \documentclass{article}\footskip=0pc\pagestyle{empty}\begin{document}$\overline{{{K}}_{{{k}}}}$\end{document}. © 2009 Wiley Periodicals, Inc. J Graph Theory 63: 300–310, 2010
Walter Miles, Pop Warner, B. C. Graves, and the psychology of football
Authors: Baugh Frank G. , Benjamin Jr. Ludy T.
Published: July 2010

In 1926–1927, a graduate student, B. C. Graves, working with Stanford University psychologist Walter Miles and legendary football coach Pop Warner, conducted an investigation of variations in signal calling as they affected the charging times of football players. The study was one of two that involved Miles and the ingenious multiple chronograph that he had invented to time the reactions of seven players simultaneously. These studies represented a brief digression in the career of Miles, who certainly was no sport psychologist. They tell of an interesting collaboration between scientist and coaches that produced one of the richest studies in sport psychology in the first half of the twentieth century. © 2006 Wiley Periodicals, Inc.
A survey of state medicaid policies on nursing home legal risk management programs
Authors: Kapp Marshall
Published: July 2010

This survey studied Medicaid policies on reimbursing long‐term care facilities for costs associated with legal risk management programs. Of the 45 responding jurisdictions, 26 allow risk management reimbursement (within allowable limits) as a general administrative expense, while 19 states do not reimburse for risk management costs. To the extent that (a) risk management can be demonstrated as cost/beneficial, and (b) that Medicaid policy influences institutional behavior, states should liberalize Medicaid reimbursement for risk management in long‐term care.
Chemical, radiochemical and biological studies of Sm and Ho complexes of H4dota analogues containing one methylphosphonic/phosphinic acid pendant arm
Authors: Lacerda Sara , Marques Fernanda , Campello Paula , Gano Lurdes , Kubíček Vojtěch , Hermann Petr , Santos Isabel
Published: July 2010

This work intends to investigate samarium and holmium complexes with a set of H4dota‐analogues bearing methylphosphonate/methylphosphinic acid pendant arms (H5do3ap, H5do3apPrA and H4do3apABn) as new bifunctional ligands for radiolanthanide targeted therapy. Radiolanthanide complexes of these ligands were prepared and evaluated and thermodynamic solution studies were also performed to get a better insight on the radiochemical results. The radiocomplexes were quantitatively prepared, are hydrophilic and negatively charged. They present a high in vitro and in vivo stability, a low plasma protein binding and a rapid clearance from the main organs with a high rate of whole body radioactivity excretion. Stability constants with Sm(III) and Ho(III) were determined by potentiometry and the values found are very high for all the ligands. Actually, they are similar to those of H4dota for the phosphinate analogues and even higher for the phosphonate ligand, being the constants similar to those with other lanthanide(III) ions. The effect of methylphosphorus acid pendant arms functionalization and the use of these ligands as bifunctional chelate agents are discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of superparamagnetic iron oxide on tumor‐to‐liver contrast at T2*‐weighted gradient‐echo MRI: Comparison between 3.0T and 1.5T MR systems
Authors: Kim Tonsok , Murakami Takamichi , Hori Masatoshi , Onishi Hiromitsu , Tomoda Kaname , Nakamura Hironobu
Published: July 2010

Purpose

To compare 3.0T and 1.5T MR systems in terms of the effect of superparamagnetic iron oxide (SPIO) on tumor‐to‐liver contrast in T2*‐weighted gradient‐echo MRI.

Materials and Methods

SPIO‐enhanced gradient‐echo MR images of the liver with four different TEs (3, 5.3, 6.5, and 8.5 msec) were obtained by means of 1.5T and 3.0T systems. Quantitative analyses of relative signal intensities (SIs) and relative tumor contrast and qualitative analyses of image quality and lesion conspicuity of the liver were performed in 22 patients, 16 of whom had malignant liver tumors.

Results

With both 1.5T and 3.0T, at TE = 8.4 msec, the relative SI of liver and relative tumor contrast were significantly (P < 0.01) lower and higher, respectively, than that for any of the other TEs. There were no significant differences in the relative SI of the liver, relative tumor contrast, image quality, and tumor conspicuity for the same TE between the 1.5T and 3.0T systems.

Conclusion

Our results showed that the effect of SPIO on tumor‐to‐liver contrast at T2*‐weighted gradient‐echo imaging was similar for the 1.5T and 3.0T systems, and that the 8.4‐msec TE was optimal of the four TEs used in this study at 3.0T. J. Magn. Reson. Imaging 2009;29:595–600. © 2009 Wiley‐Liss, Inc.
Biliary anatomy on 3D MRCP: Comparison of volume‐rendering and maximum‐intensity‐projection algorithms
Authors: Morita Satoru , Saito Naoko , Suzuki Kazufumi , Mitsuhashi Norio
Published: July 2010

Purpose

To compare volume‐rendering (VR) and maximum‐intensity‐projection (MIP) of three‐dimensional T2‐weighted turbo spin‐echo magnetic resonance cholangiopancreatography using a free‐breathing navigator‐triggered prospective acquisition correction (3D‐TSE‐PACE‐MRCP) to define biliary anatomies.

Materials and Methods

VR and MIP images of 3D‐TSE‐PACE‐MRCP for 102 patients were retrospectively evaluated. Interpretation of cystic duct variation and biliary branching patterns of each image were recorded independently by two radiologists in a blinded fashion. Interpretation confidence on a five‐point scale was compared using the Wilcoxon signed‐rank test. The McNemar test was used to compare the accuracies of each reformation with the reference standard obtained by consensus interpretation of both the images and source images.

Results

The reference standard identified all biliary bifurcations and 95 of 102 cystic duct confluences (93.1%). VR findings agreed with the reference standard findings more often than MIP with regard to cystic duct variation (94 [92.2%] vs. 76 [74.5%], P < 0.01) while there was no significant difference for biliary branching patterns (99 [97.1%] vs. 92 [90.2%], P = 0.092). The mean confidence score was significantly higher with VR than MIP with regard to both cystic duct variation and biliary branching patterns (3.7 vs. 2.4; P < 0.01; 4.1 vs. 3.3; P < 0.01).

Conclusion

VR reformation of 3D‐TSE‐PACE‐MRCP defines biliary anatomies more accurately than MIP. J. Magn. Reson. Imaging 2009;29:601–606. © 2009 Wiley‐Liss, Inc.
In vivo high‐resolution imaging of the injured rat spinal cord using a 3.0T clinical MR scanner
Authors: Sandner Beatrice , Pillai Deepu R. , Heidemann Robin M. , Schuierer Gerhard , Mueller Matthias F. , Bogdahn Ulrich , Schlachetzki Felix , Weidner Norbert
Published: July 2010

Purpose

To investigate the feasibility of obtaining high‐resolution MR images for the detection of pathological changes occurring in the injured rat spinal cord with a routine clinical 3.0T imaging system.

Materials and Methods

Adult female Fischer 344 rats received thoracic spine contusion injuries. In vivo MR imaging was performed on days 1 and 43 postinjury with a clinical head 3.0T imaging system equipped with a dedicated small animal 4‐channel phased array spine surface coil using T2‐weighted turbo spin‐echo and T1‐weighted spin‐echo sequences.

Results

The acquired images provide good spatial resolution allowing reliable gray/white matter differentiation in the intact spinal cord as well as detection of hemorrhage, edema, and cystic degenerative changes in the injured rat spinal cord as confirmed by correlation with structural alterations in histological sections.

Conclusion

Results from the present study demonstrate that a routine clinical MR imaging system can be employed for noninvasive analysis of pathological changes occurring in the injured rat spinal cord and thus might represent a more broadly available, powerful tool to monitor the effects of experimental therapeutic interventions in vivo. J. Magn. Reson. Imaging 2009;29:725–730. © 2009 Wiley‐Liss, Inc.
Unilateral luteoma of pregnancy mimicking a malignant ovarian mass on magnetic resonance and ultrasound
Authors: Tannus Joao Fernando Kazan , Hertzberg Barbara S. , Haystead Clare M. , Paulson Erik K.
Published: July 2010

Luteoma of pregnancy is a rare, tumorlike ovarian mass that develops during pregnancy and regresses after delivery. Generally, these masses are discovered incidentally during cesarean delivery or tubal ligation. Some of these patients will develop hirsutism or virilization during late pregnancy with or without fetal masculinization due to circulating androgens. The imaging features of this entity have been only rarely reported. An incidentally discovered luteoma of pregnancy in a 23‐year‐old patient during routine obstetric ultrasound is described and the image features in ultrasound and magnetic resonance (MR) imaging are discussed and compared with other studies. The patient underwent surgery to extract this mass considering the imaging findings were suspicious for neoplasia and the size and location could have potentially caused dystocia. This type of mass can mimic ovarian neoplasia and a correlation with imaging and laboratory findings can avoid an unnecessary surgical procedure during pregnancy. J. Magn. Reson. Imaging 2009;29:713–717. © 2009 Wiley‐Liss, Inc.
Diffusion tensor imaging of the median nerve in healthy and carpal tunnel syndrome subjects
Authors: Stein Dan , Neufeld Arnon , Pasternak Ofer , Graif Moshe , Patish Hagar , Schwimmer Etti , Ziv Efrat , Assaf Yaniv
Published: July 2010

Purpose

To determine if diffusion tensor imaging (DTI) of the median nerve could allow identification of patients with carpal tunnel syndrome (CTS).

Materials and Methods

A total of 13 healthy subjects and 9 CTS patients were scanned on a 3T magnetic resonance imaging (MRI) scanner. The MRI protocol included a DTI sequence from which the fractional anisotropy (FA), apparent diffusion coefficient (ADC), and the parallel and radial diffusivities could be extracted. Those parameters were quantified at different locations along the median nerve (proximal to the carpal tunnel, within the carpal tunnel, and distal to the carpal tunnel).

Results

At the carpal tunnel, the FA, radial diffusivity, and ADC differed significantly between healthy subjects and CTS patients (P < 0.0002). This highly significant difference between the two groups was due to an opposite trend of changes in the DTI indices between the proximal to the carpal tunnel and within the carpal tunnel locations. In healthy subjects the FA increased (+20%, P < 0.001) and the radial diffusivity and ADC decreased (by −15% and −8%, respectively, P < 0.05) between the proximal to the carpal tunnel and within the carpal tunnel locations. In CTS subjects the FA decreased (by −21%, P < 0.05) and the radial diffusivity increased (by +23%, P < 0.01) between the proximal to the carpal tunnel and within the carpal tunnel locations.

Conclusion

DTI enables visualization and characterization of the median nerve in healthy subjects and CTS patients. DTI indices show clear‐cut discrimination between the two groups and in fact enables the of use DTI in the diagnosis of CTS. J. Magn. Reson. Imaging 2009;29:657–662. © 2009 Wiley‐Liss, Inc.
Magnetization transfer (MT) asymmetry around the water resonance in human cervical spinal cord
Authors: Ng Man‐Cheuk , Hua Jun , Hu Yong , Luk Keith D. , Lam Edmund Y.
Published: July 2010

Purpose

To demonstrate the presence of magnetization transfer (MT) asymmetry in human cervical spinal cord due to the interaction between bulk water and semisolid macromolecules (conventional MT), and the chemical exchange dependent saturation transfer (CEST) effect.

Materials and Methods

MT asymmetry in the cervical spinal cord (C3/C4–C5) was investigated in 14 healthy male subjects with a 3T magnetic resonance (MR) system. Both spin‐echo (SE) and gradient‐echo (GE) echo‐planar imaging (EPI) sequences, with low‐power off‐resonance radiofrequency irradiation at different frequency offsets, were used.

Results

Our results show that the z‐spectrum in gray/white matter (GM/WM) is asymmetrical about the water resonance frequency in both SE‐EPI and GE‐EPI, with a more significant saturation effect at the lower frequencies (negative frequency offset) far away from water and at the higher frequencies (positive offset) close to water. These are attributed mainly to the conventional MT and CEST effects respectively. Furthermore, the amplitude of MT asymmetry is larger in the SE‐EPI sequence than in the GE‐EPI sequence in the frequency range of amide protons.

Conclusion

Our results demonstrate the presence of MT asymmetry in human cervical spinal cord, which is consistent with the ones reported in the brain. J. Magn. Reson. Imaging 2009;29:523–528. © 2009 Wiley‐Liss, Inc.
Proton, diffusion‐weighted imaging, and sodium (23Na) MRI of uterine leiomyomata after MR‐guided high‐intensity focused ultrasound: A preliminary study
Authors: Jacobs Michael A. , Ouwerkerk Ronald , Kamel Ihab , Bottomley Paul A. , Bluemke David A. , Kim Hyun S.
Published: July 2010

Purpose

To determine the feasibility of using combined proton (1H), diffusion‐weighted imaging (DWI), and sodium (23Na) magnetic resonance imaging (MRI) to monitor the treatment of uterine leiomyomata (fibroids).

Materials and Methods

Eight patients with uterine leiomyomata were enrolled and treated using MRI‐guided high‐intensity frequency ultrasound surgery (MRg‐HIFUS). MRI scans collected at baseline and posttreatment consisted of T2‐, T1‐, and 1H DWI, as well as posttreatment 23Na MRI. The 23Na and 1H MRi were coregistered using a replacement phantom method. Regions of interest in treated and untreated uterine leiomyoma tissue were drawn on 1H MRI and DWI, wherein the tissue apparent diffusion coefficient of water (ADC) and absolute sodium concentrations were measured.

Results

Regions of treated uterine tissue were clearly identified on both DWI and 23Na images. The sodium concentrations in normal myometrium tissue were 35.8 ± 2.1 mmol (mM), in the fundus; 43.4 ± 3.8 mM, and in the bladder; 65.3 ± 0.8 mM with ADC in normal myometrium of 2.2 ± 0.3 × 10−3mm2/sec. Sodium concentration in untreated leiomyomata were 28 ± 5 mM, and were significantly elevated (41.6 ± 7.6 mM, P < 0.05) after treatment. Apparent diffusion coefficient values in the treated leiomyomata (1.30 ± 0.38 × 10−3 mm2/sec) were decreased compared to areas of untreated leiomyomata (1.75 ± ‐4048μ‐4050μ36 × 10−3 mm2/sec; P = 0.04).

Conclusion

Multiparametric imaging permits identification of uterine leiomyomata, revealing altered 23Na MRI and DWI levels following noninvasive treatment that provides a mechanism to explore the molecular and metabolic pathways after treatment. J. Magn. Reson. Imaging 2009;29:649–656. © 2009 Wiley‐Liss, Inc.
Confirmation of an interglacial age for the Condat tufa (Dordogne, France) from biostratigraphic and isotopic data
Authors: Preece R. C. , Thorpe P. M. , Robinson J. E.
Published: July 2010

The Condat tufa is a localised deposit, reaching 8.2m in thickness, composed of freshwater carbonates deposited in a complex series of environments which include marsh, spring and stream facies. Five radiocarbon determinations had previously been obtained from different stratigraphic levels within the tufa and had given a consistent series, ranging from 12320 ± 175 BP to 31050 ± 1500BP. Although the youngest two dates, from near the surface of the tufa, had been rejected as being anomalously young, the older dates were regarded as indicating tufa formation during the last cold stage. Biostratigraphic analyses of the molluscan and ostracod faunas, presented here, demonstrate that the tufa formed under fully temperate conditions throughout. The occurrence of certain snails that are either locally extinct (e.g.Belgrandia marginata) or unknown living in western France (e.g.Daudebardia brevipes), together with the geomorphological setting, suggest that the tufa is of interglacial age. New radiocarbon determinations of the Condat tufa all proved to be >33 Ka BP and support this conclusion.
Raman spectroscopic study of the phosphate mineral churchite‐(Y) YPO4·2H2O
Authors: Frost Ray L. , Sejkora Jiří , Keeffe Eloise C. , Plášil Jakub , Čejka Jiří , Bahfenne Silmarilly
Published: July 2010

Raman spectroscopy has been used to study the rare‐earth mineral churchite‐(Y) of formula (Y,REE)(PO4) ·2H2O, where rare‐earth element (REE) is a rare‐earth element. The mineral contains yttrium and, depending on the locality, a range of rare‐earth metals. The Raman spectra of two churchite‐(Y) mineral samples from Jáchymov and Medvědín in the Czech Republic were compared with the Raman spectra of churchite‐(Y) downloaded from the RRUFF data base. The Raman spectra of churchite‐(Y) are characterized by an intense sharp band at 975 cm−1 assigned to the ν1 (PO43−) symmetric stretching mode. A lower intensity band observed at around 1065 cm−1 is attributed to the ν3 (PO43−) antisymmetric stretching mode. The (PO43−) bending modes are observed at 497 cm−1 (ν2) and 563 cm−1 (ν4). Some small differences in the band positions between the four churchite‐(Y) samples from four different localities were found. These differences may be ascribed to the different compositions of the churchite‐(Y) minerals. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of growth hormones and maturity of the fruits on the callus culture of guava (Psidium guajava) fruits using response surface methodology
Authors: Madhavi D L , Chand Nagin , Rajalakshmi D , Patwardhan M V
Published: July 2010

Guava, a tropical fruit, is valued for its aroma and is used in many fruit products. Earlier work from this laboratory has shown that the expression of the flavour as a secondary metabolite through tissue culture in vitro is possible. In the present study an attempt has been made to maximise the callus culture growth through optimisation of the hormonal combinations of indole acetic acid (IAA), 2,4‐dichlorophenoxy acetic acid (2,4D) and kinetin (Kn). The effect of using fruits of different maturity was also assessed. The study of the complex interactions of the growth hormones and the identifications of the optimal hormonal levels have been carried out using appropriate design of experiments which are specially framed for such purposes. Simplex optimisation techniques were used to obtain the optimum levels of these hormones for highest relative growth in the experimental region. The results indicate that callus culturing with fruits before reaching climacteric with MS medium supplemented with 0.01 mg litre−1 of IAA and 2,4D and 2.87 mg litre−1 of Kn results in a high relative growth of 8.97 for the callus.
Determination of melamine in milk powder, milk and fish feed by capillary electrophoresis: a good alternative to HPLC
Authors: Wen Yingying , Liu Huitao , Han Ping , Gao Yuan , Luan Feng , Li Xiuyong
Published: July 2010

BACKGROUND: Since September 2008, an increased incidence of kidney stones and renal failure in infants, associated with the ingestion of infant formula contaminated with melamine has been reported in China. Furthermore, melamine was not only found in many protein‐based food commodities, but also in the feeds for cattle and poultry. So it is necessary to develop a suitable method to determine melamine.

RESULTS: A capillary zone electrophoresis (CZE) method for analysis of melamine was developed by use of running electrolyte containing 35 mmol L−1 sodium dihydrogen phosphate at pH 3.5, with UV detection at 210 nm. Regression equation revealed linear relationships (r = 0.9999) between the peak‐area and the content of melamine from 0.8 to 80 µg mL−1. The detection limit was 0.08 µg mL−1. The method was successfully applied to the determination of melamine in milk powder, milk and fish feed, with the recoveries from 94.5% to 103.7%.

CONCLUSION: The performance of the CZE method evaluated in terms of precision, limits of detection, accuracy and quantification were comparable and in good agreement with those obtained by the HPLC method, with the advantage of shorter analysis time and lower cost. Copyright © 2010 Society of Chemical Industry
Some factors influencing patulin production by Penicillium expansum in pome fruits
Authors: Menniti Anna M , Neri Fiorella , Gregori Roberto , Maccaferri Massimo
Published: July 2010

BACKGROUND: The objective of our study was to examine the effects of Penicillium expansum on patulin production in relation to isolates, species and cultivar type, incidence and severity of decay. In addition, patulin production at different incubation times and its diffusion were also investigated. These factors were evaluated in pome fruits inoculated with P. expansum and kept at 20 °C for short periods of time.

RESULTS: The ability of five P. expansum isolates to grow and produce patulin in inoculated Golden Delicious apples varied among the strains from below the limit of quantification to 662 µg kg−1. Variety and species of pome fruits influenced patulin production. P. expansum isolate PE97.IT produced a higher patulin content in apples than in pears. The highest patulin production was 386 µg kg−1 in Golden Delicious. No blue mould symptom appeared in pears inoculated with P. expansum and no patulin was detected after 3 days at 20 °C. However, patulin increased with incubation time after 6 and 8 days. No patulin was detected in healthy pear tissue but it was high in the decayed area.

CONCLUSION: Since patulin production is associated primarily with infected rotten tissue, patulin control is possible by using healthy fruits, sorting damaged and rotten fruits before processing. Copyright © 2010 Society of Chemical Industry
A study of N2O decomposition rate constant at high temperature: Application to the reduction of nitrous oxide by hydrogen
Authors: Javoy S. , Mevel R. , Paillard C. E.
Published: July 2010

Atomic resonance absorption spectroscopy has been used to investigate the thermal decomposition of N2O by monitoring the formation of O atoms behind reflected shock waves in the temperature range 1490–2490 K and at total pressures from 58 to 347 kPa, by using the mixtures of N2O highly diluted in Ar. For the chosen experimental conditions, the rate coefficient k1,0 for the reaction N2O + Ar → N2 + O + Ar had the greatest effect on the O atom concentration increase, so this reaction rate constant could be deduced by comparison between experiment and computed simulation. In the actual temperature range, we found k1,0 (cm3 mol−1s−1) = 7.2 × 1014 exp(−28878/T(K)), with an overall uncertainty evaluated to be less than 20%, by considering all the parameters, which contributed to uncertainties in the rate constant determination. The possible absorption at the O triplet emission line of N2O has been investigated. The absorption cross section of N2O at the O line has been estimated and taken into account for the determination of k1,0 at high concentrations of N2O and at temperatures lower than 1850 K. The effect of the presence of impurities like H2O on rate constant determination has been examined and was found to be negligible. The choice of the rate coefficient for the consumption of O atoms by reaction with N2O and that of the high‐pressure limiting rate coefficients k1,∞ were also discussed. The rate constant reported in the present study was compared with the literature values and was found to be overall higher than those determined experimentally by other teams in the last decade. Finally, the effect of the modified constant value on reaction rate of diluted Ar–N2O mixtures and H2–N2O–Ar systems was investigated. In the temperature range 1500–2500 K, the use of the rate constant deduced from this study has led to a better prediction of N2O decomposition and N2O reduction by H2 than with lower rate constants proposed in the literature. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 357–375, 2009
Rate constants for the OH reactions with oxygenated organic compounds in aqueous solution
Authors: Gligorovski S. , Rousse D. , George C. H. , Herrmann H.
Published: July 2010

The kinetics of the oxidation of functionalized organic compounds of atmospheric relevance by the hydroxyl radical (OH) was measured in the aqueous phase. Competition kinetics, using the thiocyanate anion (SCN−) as competitor, was applied using both a laser flash photolysis long path absorption (LP‐LPA) setup and a Teflon AF waveguide photolysis (WP) system. Both experiments were intercompared and validated by measuring the rate coefficients for the reaction between OH and acetone where values of k1 = (1.8 ± 0.4) × 108 M−1 s−1 were obtained with the WP system, which agrees very well with the rate constant of k1 = (2.1 ± 0.6) × 108 M−1 s−1 determined before by LP‐LPLA [1]. The following temperature dependencies of the rate constants (M−1 s−1) for the reactions of OH with ketones, dicarboxylic acids, and unsaturated compounds were obtained in Arrhenius' form: Reaction of OH with: methylisobutyl ketone (MIBK): k2 = (1.0 ± 0.1) × 1012

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, N‐methyl pyrrolidone (NMP): k3 = (1.8 ± 0.2) × 1011 exp

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, malic acid (pH = 1): k4 = (7.9 ± 0.8) × 1010

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, maleate monoanion (pH = 4.3): k5 = (2.9 ± 0.4) × 1011

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, maleate dianion (pH = 9): k6 = (1.2 ± 0.2) × 1011

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, mesoxalic acid (pH = 1): k7 = (3.8 ± 0.8) × 1010

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, triethyleneglycol divinyl ether (DVE‐3): k9 = (2.3 ± 0.1) × 1013

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methacrolein: k10 = (3.0 ± 0.1) × 1013

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. The Ea/A values are given with full precision to avoid rounding errors. Equations were derived from the regression line of the Evans‐‐Polanyi plot in the form activation energy (Ea) versus bond dissociation energy (BDE) and from the regression line for the region 380 ⩽ BDE ⩽ 412 kJ mol−1 of the Evans–Polanyi plot in the form log kH versus BDE. Both equations can be used as a tool for predicting unknown rate coefficients and activation energy for the reactions of OH with different organics in the aqueous phase. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 309–326, 2009
Iron carburization in CO‐H2‐He gases, Part I: Experiment
Authors: Wang Zhe , Yetter Richard A.
Published: July 2010

Carburization of iron was studied at atmospheric pressure over the temperature range 850°C to 1150°C in gaseous mixtures of CO, H2, and He. The resistance relaxation method was applied to measure the carburization rates. Experimental results show that for carburization in CO‐He mixtures, the carburization rate increased proportionally with CO partial pressure with a reaction order of unity. The overall rate also increased with temperature up to approximately 960°C and subsequently decreased with further increases in temperature. For carburization in CO‐H2‐He mixtures, the carburization rate increased with both the CO and H2 partial pressures under most conditions and was considerably faster than the rate in mixtures without hydrogen. Up to approximately 960°C, the rate was nearly independent of temperature with H2 present, but decreased with a further increase in temperature. The decrease in reaction rate for mixtures with and without H2 at 960°C coincides closely with the change in phase of iron from α to γ. Experiments at 925°C with constant P and PCO indicate that CO dissociation on the iron surface is faster than oxygen removal from the surface except at high ratios of P/PCO, and therefore oxygen removal was generally the rate‐limiting step. The rate of oxygen removal from the surface by H2 was found to be of the same order as that by CO. At high hydrogen levels, the rate of oxygen removal exceeds dissociative absorption of CO and the latter becomes rate controlling. The present results are used to establish a numerical model for the carburization of iron, which is described in a companion paper. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 327–336, 2009
Kinetics and modeling of (R,S)‐1‐phenylethanol acylation over lipase
Authors: Kirilin Alexey , Sahin Serap , Mäki‐Arvela Päivi , Wärnå Johan , Salmi Tapio , Murzin Dmitry Yu.
Published: July 2010

The kinetics of the acylation of (R,S)‐1‐phenylethanol was investigated using lipase as a catalyst. The main parameters were temperature, reaction atmosphere, different acyl donors, and different amounts of acyl donor as well as the presence of some additives in the reaction mixture. The initial reaction rate increased with increasing temperature and with a decreasing amount of an acyl donor. The activated esters, such as isopropenyl‐ and vinyl acetate, exhibited very high acylation rates for R‐1‐phenylethanol, whereas low rates were obtained with ethyl acetate and 2‐methoxyethyl acetate. The addition of water and acetophenone decreased the acylation rate. A kinetic model was developed based on a sequential step mechanism, in which enzyme was reacting in the first step with an acyl donor followed by the reaction of a modified enzyme complex with the reactant, R‐1‐phenylethanol. Comparison with experimental data obtained at different temperatures allowed simplification of this model, leading to a kinetic equation with just one apparent parameter. The influence of the amount of acyl donor, ethyl acetate, could be quantitatively described by taking into account the competitive inhibition of the ethanol produced. The rate constants and apparent activation energy for experiments performed under different temperatures and the amounts of acylation agent were determined. The apparent activation energy was 24.5 kJ/mol. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 629–639, 2010
Prognostic factors affecting survival after recurrence in adult living donor liver transplantation for hepatocellular carcinoma
Authors: Shin Woo Young , Suh Kyung-Suk , Lee Hae Won , Kim Joohyun , Kim Taehoon , Yi Nam-Joon , Lee Kuhn Uk
Published: July 2010

Liver transplantation is regarded as an effective treatment for early hepatocellular carcinoma (HCC). However, some patients experience recurrence and subsequently rapid progression of the disease. We investigated prognostic factors affecting survival after recurrence in patients who underwent adult living donor liver transplantation (LDLT) for HCC. From October 1992 to December 2005, 138 adult patients underwent LDLT for HCC. Among these, 28 patients (20.3%) who suffered recurrence were retrospectively reviewed. Univariate and multivariate analyses were performed to analyze factors affecting survival after recurrence. The median time to recurrence was 7.9 months. The median survival time after recurrence was 11.7 months, and the 1- and 3-year survival rates after recurrence were 52.8% and 15.8%, respectively. Initially, 7 patients (25%) showed multiorgan involvement; however, in the follow-up, 21 patients (75%) had multiorgan involvement. On univariate analysis, a pretransplant alpha-fetoprotein level >1000 ng/mL, major vascular invasion, a poorly differentiated tumor, a time to recurrence ≤6 months, unresectable disease, and bony metastases were related to shorter survival after recurrence. The independent prognostic factors by multivariate analysis were major vascular invasion [hazard ratio (HR) = 7.6], a poorly differentiated tumor (HR = 4.3), unresectable disease (HR = 10.4), and bony metastases (HR = 3.2). Two patients survived more than 36 months. One of them underwent retransplantation and survived for 45 months without additional recurrences. In conclusion, after transplantation, recurrent HCC has a tendency to involve multiple organs, and the prognosis is very poor. However, some patients have a good prognosis, and the appropriate treatment can prolong their survival. If the recurrent lesion is locally controllable, surgical resection should be considered. Liver Transpl 16:678-684, 2010. © 2010 AASLD.
The decreasing incidence of diaphragmatic dysfunction in liver transplantation: A probable advantage of the piggy-back liver transplant technique
Authors: Ishitani Michael B.
Published: July 2010

Abstract

Background

Pediatric orthotopic liver transplantation (OLT) has a low mortality. Some children, however, have an adverse outcome defined as a prolonged ventilatory support requirement and protracted pediatric intensive care unit (PICU) stay. The aim of this study was to determine if that adverse outcome related to the child’s condition pre-OLT and/or the development of a pleural effusion or diaphragmatic dysfunction.

Methods

The study included 210 children with a median age at transplantation of 45.5 months (range 0.2-252 months). Fourteen had undergone retransplantation. The duration of ventilatory support (intermittent positive pressure ventilation [IPPV]) and PICU admission and development of a pleural effusion and/or diaphragmatic dysfunction were documented for each child. The patients were divided into three groups according to whether they had acute liver failure (ALF), chronic liver disease at home (CHOM), or chronic liver failure sufficiently ill to be in the hospital awaiting transplantation (CHOSP)

Results

The 36 children with ALF were of similar age to the 138 CHOM and 36 CHOSP children but required longer IPPV (P < 0.0001) and PICU stay (P < 0.0001). Overall, 17 children developed diaphragmatic dysfunction and 138 pleural effusions; affected children required longer IPPV and PICU stay (P <0.01). Regression analysis demonstrated that diaphragmatic dysfunction, but not pleural effusion development, was associated with prolonged ventilation (P <0.01) and protracted PICU stay (P <0.05). Other risk factors were ALF (P <0.01), retransplantation (P <0.01), and young age (P <0.05)

Conclusion

Diaphragmatic dysfunction adversely influences PICU morbidity after OLT. Early assessment of diaphragmatic function, and if necessary aggressive management, might improve outcome.
Die Struktur Kollagenähnlicher Homo‐ und Heteropolytripeptide, 2. Unterschung des Tripelhelix‐Knäuel‐Übergangs an (L‐Pro‐L‐Ala‐Gly‐L‐Pro‐L‐Ala‐Gly)‐Oligomeren
Authors: Heymer Gerd , Heidemann Eckhart R.
Published: July 2010

Die Oligomeren von L‐Pro‐L‐Ala‐Gly‐L‐Pro‐L‐Ala‐Gly (9) mit n=4, 5, 6, 7, 8, 12–13 und ≈︁ 31 wurden aus Polykondensationsgemischen mittels Gelchromatographie isoliert, nachdem der schrittweise Aufbau durch Tripeptidkondensation mit der Festphasenmethode am Bromacylharz trotz 20fachem Überschuß der Monomeren zu geringe Ausbeuten und damit zu große Uneinheitlichkeit ergeben hat. Durch Messung des Circulardichroismus konnte nach langer Einstellzeit bis zum Gleichgewicht der Helixzustand und nach ganz kurzer Einstellzeit, ausgehend von hoher Temperatur, der Knäuelzustand erfaßt werden. Hierzu dienten die Messungen beim Absorptionsmaximum bei 198 nm bzw. in einigen Fällen die Messung bei dem viel kleineren Maximum bei 225 nm. Die Helixbildung beginnt in Wasser bei n=6, in 1,1,1,3,3,3‐Hexafluor‐2‐propanol/Äthylenglykol (1:2V/V) bei n=6 und in 1,3‐Propandiol bei n=5. Es wurde die mittlere innere Restelliptizität im Knäuelzustand errechnet und der Helixanteil im Gleichgewichtszustand bei verschiedenen Temperaturen, Lösungsmitteln und Kettenlängen bestimmt. Nach Anpassung der Umwandlungskurven nach Rosenbrock bestimmten wir für das Oligomere mit n=8 in 1,3‐Propandiol nach van't Hoff ΔH0 zu −0,8 kcal/mol (−3,35 kJ/mol) und ΔS0 zu −1,7 cal mol−1 K−1 (−7.12J mol−1 K−1).
A kinetic study of the photoinitiated polymerization of isobutylene in the presence of vanadium tetrachloride
Authors: Toman L. , Marek M.
Published: July 2010

A kinetic study of the polymerization of isobutylene with VCl4 induced with monochromatic light, wave length 436 nm, has revealed that the light‐induced polymerization is spontaneously quenched after the light source has been switched off; this process depends on the duration of preceding irradiation. The polymerization rate increases with increasing concentration of catalyst and monomer and with the intensity of light. The polymerization rate with respect to the catalyst and monomer concentration at constant light intensity can be expressed by an experimentally found relationship:

The polymerization rate increase with decreasing temperature (in polychromatic visible light) and its activation energy for temperatures ranging from −20 to −78°C is E = −19,2±0,8 KJ/mol.

The molecular weight of the polymer increases with increasing monomer concentration and with decreasing polymerization temperature. The “activation energy” of the degree of polymerization is EDP = −20,9±0,8 kJ/mol. The molecular weight of the polymer is independent of the catalyst concentration and of light intensity. It slightly decreases from the very beginning depending on conversion. The induction period decreases with increasing catalyst and monomer concentration at constant light intensity.

The kinetic study has shown that the propagation in the polymerization of isobutylene proceeding via cation‐radical intermediates is cationic.
Polynomial stabiization of the wave equation with Ventcel's boundary conditions
Authors: Nicaise Serge , Laoubi Karima
Published: July 2010

We consider the wave equation on the unit square of the plane with Ventcel boundary conditions on a part of the boundary. It was shown by A. Heminna [8] that this problem is not exponentially stable. Here using a Fourier analysis and a careful analysis of the 1‐d problem with respect to the Fourier parameter l, we show a polynomial stability of this system (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the Modular Figure and Ford‐Spheres
Authors: Rieger G. J.
Published: July 2010

In §1 we study Figure 1 for variable h. In §2 and §3 this is combined with Ford‐circles (Figure 2) and the choice h = 0 (Figure 3). In §4 a limit is evaluated. In §5 we treat Figure 5 (“Ford‐circles inside the unit‐circle”) and a technical application. In §6 contains various modular figures (Figures 7, 8, 9). §7 treats synchronous rotation of Figure 1 and Eoing from R2 to R3; the rotating upper half‐plane of C corresponds then to the unit‐sphere. In §8 a sphere‐packing on C is introduced. Finally in §9 a sphere‐packing inside the unit‐sphere arises.
Murine p53 intron sequences 5–8 and their use in polymerase chain reaction/direct sequencing analysis of p53 mutations in CD‐1 mouse liver and lung tumors
Authors: Goodrow Tamra L. , Storer Richard D. , Leander Karen R. , Prahalada Srinivasa R. , van Zwieten Matthew J. , Bradley Matthews O.
Published: July 2010

Inactivating point mutations and small deletions in the p53 tumor suppressor gene have been found in human liver and lung tumor—derived cell lines and tumors. However, little evidence has been reported concerning inactivation or mutation of the p53 gene in mouse primary tumors. To examine CD‐1 mouse liver and lung tumors for mutations in the p53 gene, we first sequenced p53 introns 5–8 so that polymerase chain reaction amplification and sequencing primers located within the introns could be prepared. Use of these primers prevented amplification of the mouse p53 pseudogene and allowed sequencing of exons 5–8 in their entirety as well as their intron‐exon junctions. DNA isolated from CD‐1 mouse tumors was amplified and directly sequenced using nested primers. Nine spontaneous hepatocellular carcinomas (HCCs) and 34 chemically induced HCCs (induced by single intraperitoneal injections of N‐nitrosodiethylamine [DEN] [8 HCCs], 7,12‐dimethylbenz[a]anthracene [DMBA] [8 HCCs], 4‐aminoazobenzene [8 HCCs], and N‐OH‐2‐acetylaminofluorene [10 HCCs]) were examined for mutations in exons 5–8 of the p53 gene. In addition, 12 spontaneous, 10 DMBA‐induced, and 13 DEN‐induced lung adenocarcinomas or adenomas were analyzed for mutations. No mutations were found in any of the tumors examined. However, a mutation was demonstrated at codon 135 in the positive‐control plasmid LTRp53cG(val). The results of this study suggest that inactivation of p53 is unlikely to play a major role in murine lung or liver carcinogenesis. However, inactivation of p53 may occur at a very low frequency, or it may occur as a late event and therefore be present in only a very small number of the tumor cells, rendering it undetectable by this method. Lastly, although few p53‐inactivating mutations are found outside of exons 5–8 in human tumors, it is possible that these murine tumors contained mutations outside of this region and were therefore missed by our approach.
The same γ‐glutamyl transpeptidase RNA species is expressed in fetal liver, hepatic carcinomas, and rasT24‐transformed rat liver epithelial cells
Authors: Habib Geetha M. , Rajagopalan Sridharan , Godwin Andrew K. , Lebovitz Russell M. , Lieberman Michael W.
Published: July 2010

In rats, ‐γ‐glutamyl transpeptidase (γGT) exists as a single‐copy gene, and three distinct species of RNA (types I, II, and III) that differ in their 5′ untranslated regions have been identified. To compare steady‐state levels of these ‐γGT RNAs in rat tissues, hepatic carcinomas, and cultured cells, we used RNA dot‐blot hybridization and a reverse transcriptase‐polymerase chain reaction (RT‐PCR) technique with oligonucleotides specifically designed for each type of RNA. Fetal liver, hepatic carcinomas, rasT24‐transformed rat liver epithelial (RLE) cells and pancreas make only type III RNA. Liver and untransformed RLE cells do not make detectable levels of γGT RNA. We found that both fetal and adult kidneys synthesize all three types of RNA, indicating that increases in γGT RNA known to occur after birth do not result from recruitment of additional RNA species. When we increased the sensitivity of the assay approximately 1000 fold by sequencing the RT‐PCR product directly after an additional round of amplification, we found that very low levels of types I and II RNA were present in fetal liver, rasT24‐transformed RLE cells, and pancreas, and that adult liver and untransformed RLE cells synthesized very low levels of all three RNA species. Rat‐1 fibroblasts did not make levels of γGT RNA detectable by this method. These results demonstrate that different γGT RNA species are regulated differently during development and neoplastic transformation and that there is a commitment in some cell types to very‐low‐level expression of γGT RNAs.
Premotor Parkinson's disease: Clinical features and detection strategies
Authors: Stephenson Randolph , Siderowf Andrew , Stern Matthew B.
Published: July 2010

In many areas of medicine, the focus has shifted from treating existing disease to screening and prevention. The technology to screen for Parkinson's disease (PD) already exists. The current challenge is to define the appropriate use of predictive testing for PD. Imaging technologies currently offer the highest degree of accuracy for identifying premotor PD, but they are expensive as screening tools. Efficiency is greatly enhanced by combining imaging with a prescreening test, such as olfactory testing. This two‐step process has the potential to greatly reduce costs while retaining diagnostic accuracy. Ultimately, the role of preclinical detection of PD will be determined by the ability of emerging therapies to influence clinical outcomes. As such, implementation of large‐scale screening strategies awaits the arrival of clearly safe and effective therapies that address the underlying pathogenesis of PD. Current research to evaluate efficient screening methods and to understand the clinical and physiological features of “premotor” PD will lay the foundation for the screening and prevention strategies of the future. © 2008 Movement Disorder Society
123I‐metaiodobenzylguanidine scintigraphy in Parkinson's disease and related disorders
Authors: Rascol Olivier , Schelosky Ludwig
Published: July 2010

Autonomic dysfunction is common in Lewy body disorders (Parkinson's disease, Dementia with Lewy Bodies, Pure Autonomic Failure, and REM sleep disorder). The loss of post‐ganglionic myocardial sympathetic nerve fibers is a prominent feature of autonomic dysfunction in such disorders. 123I‐metaiodobenzylguanidine (MIBG) scintigraphy that visualizes catecholaminergic terminals in vivo is a biomarker used to detect cardiac sympathetic degeneration. Abnormal MIBG uptake has been consistently reported in Lewy body disorders. Some studies agree in the notion that increasing bradykinesia is related with an incremental cardiac sympathetic denervation, whereas tremor is not closely linked to cardiac denervation. “Atypical” parkinsonian syndromes, including Multiple System Atrophy, Progressive Supranuclear Palsy, and others, show modest reductions of cardial MIBG uptake. MIBG scintigraphy is moderately sensitive and specific in differentiating Parkinson's disease from such syndromes. Conversely, its sensitivity and specificity might be better in cognitively impaired patients, helping differential diagnosis between Dementia with Lewy Bodies, and Alzheimer disease. Confounding factors (comorbidities, comedications) should be carefully controlled before analyzing MIBG scintigraphy. © 2009 Movement Disorder Society