bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclic tensile stretch load and oxidized low density lipoprotein synergistically induce lectin‐like oxidized ldl receptor‐1 in cultured bovine chondrocytes, resulting in decreased cell viability and proteoglycan synthesis
Authors: Akagi Masao , Nishimura Shunji , Yoshida Kohji , Kakinuma Takumi , Sawamura Tatsuya , Munakata Hiroshi , Hamanishi Chiaki
Published: June 2006

Mechanical stimulation is known to be an essential factor in the regulation of cartilage metabolism. We tested the hypothesis that expression of lectin‐like oxidized low‐density lipoprotein receptor‐1 (LOX‐1) can be modulated by cyclic tensile stretch load in chondrocytes. Cyclic loading of repeated stretch stress at 10 cycles per minute with 10 kPa of stress for 6 h induced expression of LOX‐1 to 2.6 times control in cultured bovine articular chondrocytes, equivalent to the addition of 10 µg/mL oxidized low density lipoprotein (ox‐LDL) (2.4 times control). Application of the cyclic load to the chondrocytes along with 10 µg/mL ox‐LDL resulted in synergistically increased LOX‐1 expression to 6.3 times control. Individual application of cyclic loading and 10 µg/mL ox‐LDL significantly suppressed chondrocytes viability (84.6% ± 3.4% and 80.9% ± 3.2% of control at 24 h, respectively; n = 3; p < 0.05) and proteoglycan synthesis [81.0% ± 7.1% and 85.7% ± 5.2% of control at 24 h, respectively; p < 0.05 when compared with 94.6% ± 4.6% for native‐LDL (n = 3)]. Cyclic loading and 10 µg/mL ox‐LDL synergistically affected cell viability and proteoglycan synthesis, which were significantly suppressed to 45.6% ± 4.9% and 48.7% ± 6.7% of control at 24 h, respectively (n = 3; p < 0.01 when compared with individual application of cyclic loading or 10 µg/mL ox‐LDL). In this study, we demonstrated synergistic effects of cyclic tensile stretch load and ox‐LDL on cell viability and proteoglycan synthesis in chondrocytes, which may be mediated through enhanced expression of LOX‐1 and which has important implications in the progression of cartilage degeneration in osteoarthritis. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1782–1790, 2006
Mechanical and radiological assessment of the influence of rhTGFβ‐3 on bone regeneration in a segmental defect in the ovine tibia: Pilot study
Authors: Maissen Otto , Eckhardt Christina , Gogolewski Sylwester , Glatt Markus , Arvinte Tudor , Steiner Adrian , Rahn Berton , Schlegel Urs
Published: June 2006

Limitations in the use of autologous bone graft, which is the gold standard therapy in bone defect healing, drive the search for alternative treatments. In this study the influence of rhTGFβ‐3 on mechanical and radiological parameters of a healing bone defect in the sheep tibia was assessed. In the sheep, an 18‐mm long osteoperiosteal defect in the tibia was treated by rhTGFβ‐3 seeded on a poly(L/DL‐lactide) carrier (n = 4). In a second group (n = 4), the defect was treated by the carrier only, in a third group (n = 4) by autologous cancellous bone graft, and in a fourth group (n = 2) the defect remained blank. The healing process of the defect was assessed by weekly in vivo stiffness measurements and radiology as well as by quantitative computed tomographic assessment of bone mineral density (BMD) every 4 weeks. The duration of the experiment was 12 weeks under loading conditions. In the bone graft group, a marginally significant higher increase in stiffness was observed than in the PLA/rhTGFβ‐3 group (p = 0.06) and a significantly higher increase than in the PLA‐only group (p = 0.03). The radiographic as well as the computed tomographic evaluation yielded significant differences between the groups (p = 0.03), indicating the bone graft treatment (bone/per area, 83%; BMD, 0.57 g/cm3) performing better than the PLA/rhTGFβ‐3 (38%; 0.23 g/cm3) and the PLA‐only treatment (2.5%; 0.09 g/cm3), respectively. Regarding the mechanical and radiological parameters assessed in this study, we conclude that rhTGFβ‐3 has a promoting effect on bone regeneration. However, under the conditions of this study, this effect does not reach the potential of autologous cancellous bone graft transplantation. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1670–1678, 2006
One‐pot synthesis of polysaccharide 3,5‐dimethylphenylcarbamates having a random vinyl group for immobilization on silica gel as chiral stationary phases
Authors: Chen Xiao‐Ming , Yamamoto Chiyo , Okamoto Yoshio
Published: June 2006

Different kinds of vinyl groups were randomly introduced onto the glucose units of cellulose 3,5‐dimethylphenylcarbamates by a one‐pot method using the bifunctional reagents dec‐1‐ene‐10‐isocyanate, 2‐isocyanatoethyl methacrylate, and methacryloyl chloride. The chiral recognition properties of the prepared derivatives were then evaluated by coating and immobilizing them on silica gel as HPLC packing material. Immobilization was carried out by radical copolymerization with a vinyl comonomer, 1,5‐hexadiene, in toluene at 80°C. The effects of the structures and content of the vinyl groups on the immobilization and on enantioseparations were investigated. This one‐pot method was also extended to the synthesis of amylose 3,5‐dimethylphenylcarbamates having a random vinyl group. Comparisons of the chiral resolution powers of our laboratory‐made packing materials and the newly commercialized Chiralpak IA with immobilized amylose 3,5‐dimethylphenylcarbamate and Chiralpak IB with immobilized cellulose 3,5‐dimethylphenylcarbamate are discussed.
Gas chromatographic determination of the interconversion energy barrier for dimethyl‐2,3‐pentadienedioate enantiomers
Authors: Mydlová Janka , Krupcík Jan , Májek Pavel , Skacáni Ivan , Jakubík Tibor , Armstrong Daniel W.
Published: June 2006

The enantiomers of dimethyl‐2,3‐pentadienedioate undergo interconversion during gas chromatographic separation on 2,6‐di‐O‐methyl‐3‐O‐pentyl‐β‐, 2,6‐di‐O‐methyl‐3‐O‐pentyl‐γ‐, and 2,3‐di‐O‐methyl‐6‐O‐tert butyldimethylsilyl‐β‐CD chiral stationary phases. The combination of a deconvolution method with an internal standard was used to determine individual enantiomer peak areas and retention times needed for the calculation of the interconversion rate constants and the energy barrier for dimethyl‐2,3‐pentadienedioate enantiomers. The kinetic and thermodynamic data obtained for the interconversion data (rate constants, energy barriers, enthalpies, and entropies) were in good agreement with the published data (Trapp, O., Schurig, V., Chirality 2002, 14, 465–470) using permethylated‐β‐CD (Chirasil‐β‐Dex).
Novel SPG6 mutation p.A100T in a Japanese family with autosomal dominant form of hereditary spastic paraplegia
Authors: Kaneko Satoshi , Kawarai Toshitaka , Yip Edwin , Salehi‐Rad Shabnam , Sato Christine , Orlacchio Antonio , Bernardi Giorgio , Liang Yan , Hasegawa Hiroshi , Rogaeva Ekaterina , St George‐Hyslop Peter
Published: June 2006

We describe a Japanese family in which inheritance of a novel mutation p.A100T in SPG6 resulted in an autosomal dominant form of hereditary spastic paraplegia (ADHSP). Clinical investigation showed a pure form of HSP. Our study demonstrates further allelic heterogeneity of SPG6. © 2006 Movement Disorder Society
1H, 13C and 15N NMR spectral characterization of twenty‐seven 1,2‐diaryl‐(4E)‐arylidene‐2‐imidazolin‐5‐ones
Authors: Laihia Katri , Kolehmainen Erkki , Nikiforov Vladimir , Miltsov Sergei
Published: June 2006

1H, 13C and 15N NMR chemical shifts and couplings nJ(H,C) in DMSO‐d6 at 30 °C have been determined for 1,2‐diaryl‐(4E)‐arylidene‐2‐imidazolin‐5‐one derivatives 1–27. Their chemical shift assignments are based on PFG DQF 1H,1H COSY, PFG 1H,13C HMQC as well as PFG 1H,13C and 1H,15N HMBC experiments. For compounds 1–10 including aryl fluorine substituent(s) also the couplings nJ(F,C) (n = 1 − 4) are reported. Copyright © 2006 John Wiley & Sons, Ltd.
Solid‐state NMR spectra of paramagnetic silica‐based materials: observation of 29Si and 27Al nuclei in the first coordination spheres of manganese ions
Authors: Bakhmutov Vladimir I. , Shpeizer Boris G. , Clearfield Abraham
Published: June 2006

Some silica‐based solids, prepared by the sol/gel method in the presence of high Mn2+ concentrations, have been characterized by the 29Si, 27Al MAS NMR spectra and 29Si T1 measurements. The single‐pulse 29Si and 27Al MAS NMR spectra have shown broad spinning sideband patterns that are interpreted in terms of anisotropic bulky magnetic susceptibility (BMS) and dipole‐field effects. In the absence of paramagnetic isotropic shifts, the 29Si and 27Al nuclei observed in the single‐pulse NMR spectra have been assigned to nuclei remote from paramagnetic centers. It has been demonstrated that the 29Si and 27Al nuclei, which are in the vicinity of the manganese ions, can be detected by the Hahn‐echo MAS NMR experiments at different carrier frequencies. Copyright © 2006 John Wiley & Sons, Ltd.
MR assessment of changes of tumor in response to hyperbaric oxygen treatment
Authors: Matsumoto Ken‐ichiro , Bernardo Marcelino , Subramanian Sankaran , Choyke Peter , Mitchell James B. , Krishna Murali C. , Lizak Martin J.
Published: June 2006

Enhancement of image intensity, using the T1‐weighted spoiled gradient‐echo (SPGR) sequence, was measured in SCC tumor implanted in the flank of C3H mice while they were subjected to several types of oxygenation challenges inside a hyperbaric chamber designed and constructed to fit in an MRI resonator. The central portions of the tumor gave a positive enhancement, while the periphery showed signal reduction during both normobaric (NBO) and hyperbaric (HBO) oxygen challenges. In the contralateral normal leg, nearly 70% of the region showed a decrease in intensity, and the rest showed a positive enhancement. The positive signal enhancement was markedly greater under HBO compared to NBO. Calculated R1, R2, and M0 maps from multivariate fitting of images acquired by a multislice multiecho (MSME) sequence with variable TR before, during, and after HBO treatment confirm that the source of SPGR signal enhancement in the tumor is associated with shortening of T1. Magn Reson Med, 2006. Published 2006 Wiley‐Liss, Inc.
Discrimination of errors from neuronal activity in functional MRI of the human spinal cord by means of general linear model analysis
Authors: Stroman P.W.
Published: June 2006

Functional MRI (fMRI) of the spinal cord has been demonstrated to provide reliable and sensitive maps of neuronal activity, particularly when combined across several experiments. Individual experiments reveal neuronal activity as well as errors. The dominant source of errors is hypothesized to be physiological motion, including cardiac and respiratory motion, flow of blood and cerebrospinal fluid (CSF), and motion of the spinal cord within the spinal canal. All of the hypothesized sources of error are therefore related to cardiac and respiratory motion, which can be recorded during an fMRI experiment. Analyses were carried out with a general linear model (GLM) with peripheral pulse and respiration recordings used as models of errors. The results demonstrate that the sensitivity of spinal fMRI is improved and errors are reduced when peripheral pulse traces are used in the GLM, but no improvement was detected with the inclusion of respiratory traces. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Targeted‐HASTE imaging with automated device tracking for MR‐guided needle interventions in closed‐bore MR systems
Authors: Zimmermann H. , Müller S. , Gutmann B. , Bardenheuer H. , Melzer A. , Umathum R. , Nitz W. , Semmler W. , Bock M.
Published: June 2006

Percutaneous MR‐guided interventions with needles require fast pulse sequences to image the needle trajectory with minimal susceptibility artifacts. Spin‐echo pulse sequences are well suited for reducing artifact size; however, even with single‐shot turbo spin‐echo techniques, such as rapid acquisition with relaxation enhancement (RARE) or half‐Fourier acquisition single‐shot turbo spin‐echo (HASTE), fast imaging remains challenging. In this work we present a HASTE pulse sequence that is combined with inner‐volume excitation to reduce the scan time and limit the imaging field of view (FOV) to a small strip close to the needle trajectory (targeted‐HASTE). To compensate for signal saturation from fast repeated acquisitions, a magnetization restore pulse (driven equilibrium Fourier transform (DEFT)) is used. The sequence is combined with dedicated active marker coils to measure the position and orientation of the needle so that the targeted‐HASTE image slice is automatically repositioned. In an animal experiment the coils were attached to an MR‐compatible robotic assistance system for MR‐guided interventions. Needle insertion and infusion via the needle could be visualized with a temporal resolution of 1 s, and the needle tip could be localized even in the presence of a stainless steel mandrel. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Spectrum and presentation of pediatric malignancies in the HIV era: Experience from Blantyre, Malawi, 1998–2003
Authors: Sinfield R.L. , Molyneux E.M. , Banda K. , Borgstein E. , Broadhead R. , Hesseling P. , Newton R. , Casabonne D. , Mkandawire N. , Nkume H. , Hodgson T. , Liomba G.
Published: June 2006

Background

Data on childhood cancers in Africa are sparse, particularly since the spread of HIV. We aimed to document the frequency of pediatric cancers presenting to a large central hospital in Malawi, detailing the presenting features, initial investigations, and HIV status of these children.

Procedure

A retrospective audit of the spectrum and clinical presentation of cancers among children (<16 years) seen at Queen Elizabeth's Central Hospital (QECH), between 1998 and 2003.

Results

Seven hundred seven children with cancer were seen, the number of cases per year increased over the time period; 50% (351) had Burkitt lymphoma, 13% (89) had retinoblastoma, and 9% (61) had Kaposi sarcoma, with a variety of other tumors comprising the remainder. Kaposi sarcoma markedly increased in frequency over time. Histological verification of diagnosis was available for 49% (348). The proportion of children with cancer who were tested for HIV increased over time, but varied by cancer type. Amongst those tested, the seroprevalence was 93% (52/56) for children with Kaposi sarcoma, 4% (11/289) for those with Burkitt lymphoma, 31% (8/26) for those with other non‐Hodgkin lymphomas, 7% (1/15) for those with Hodgkin disease, and 5% (5/103) for those with other cancers.

Conclusions

The number of cases seen per year has increased over the study period for almost all cancers, but in particular for Kaposi sarcoma. Burkitt lymphoma remains the commonest pediatric tumor in Malawi. In the case of Burkitt lymphoma, non‐Hodgkin lymphoma, and Kaposi sarcoma there is a significant difference in the presentation of HIV‐seropositive and ‐seronegative children. Pediatr Blood Cancer 2007;48:515–520. © 2006 Wiley‐Liss, Inc.
Renin‐induced hypertension in Wilms tumor patients
Authors: Maas M.H. , Cransberg K. , van Grotel M. , Pieters R. , van den Heuvel‐Eibrink M.M.
Published: June 2006

Background

Since the report that hypertension associated with Wilms tumor (WT) may be renin‐induced, no larger series than 13 patients have been published. Nevertheless, angiotensin converting enzyme (ACE) inhibitors have become treatment of choice for hypertension in WT patients. The purpose of this study was to investigate the correlation between plasma renin levels and blood pressure in a larger cohort of WT patients.

Procedure

In this retrospective, single‐center study, data on blood pressure and plasma renin were analyzed in 86 WT patients treated according to the consecutive SIOP protocols 6, 9, 93‐01, and 2001.

Results

At diagnosis, 47 WT patients suffered from hypertension (55%). In 31 of these patients plasma renin levels were analyzed; increased plasma renin levels were found in 25/31 patients (81%). In contrast, normal plasma renin levels were measured in 8/13 of the patients with a normal blood pressure (P = 0.012). Twenty‐eight children received antihypertensive treatment before surgery, in 25 of them blood pressure normalized before surgery. Blood pressure was normal directly after surgery in all patients but 4, in whom blood pressure recovered to normal within a few weeks.

Conclusions

This retrospective study shows that hypertension in WT patients is associated with elevated plasma renin levels, indicating that ACE inhibitors may be a good therapeutic option in at least a subset of WT patients with hypertension before nephrectomy. Pediatr Blood Cancer 2007;48:500–503. © 2006 Wiley‐Liss, Inc.
Vaccines, antibiotics, and atopy
Authors: Mullooly John P. , Schuler Roberleigh , Barrett Michael , Maher Julie E.
Published: June 2006

Purpose

Early exposure to vaccines and antibiotics may increase the risk of developing atopy by protecting against infectious agents and reducing duration and severity of infections (the hygiene hypothesis). It may also shift the developing immune system towards a more allergic response. We assess possible associations in young allergy clinic patients.

Methods

We conducted a case‐control study of 6‐ to 16‐year‐old new allergy clinic patients who were skin tested for inhalant allergens during 1987–2001 and enrolled in KPNW since birth (n = 1074). Atopic cases had positive tests for at least one inhalant allergen. Non‐atopic controls had negative tests for all inhalant allergens. Using logistic regression analysis, we estimated atopy odds ratios for vaccine and antibiotic exposure variables and associations between vaccine and antibiotic exposures during the first 2 years of life and subsequent new allergy diagnoses.

Results

Atopy was not significantly associated with numbers of vaccine and antigen doses, or number of different antigens during the first 2 years of life. Number of antibiotic prescriptions was negatively associated with atopy risk. Neither exposure was significantly associated with risk of new allergy diagnoses in atopic children.

Conclusions

Atopy development appears to be unrelated to early vaccine exposure. Frequency of antibiotic prescriptions during early life, a proxy for infection frequency, appears to protect against allergic sensitization. Neither vaccines nor antibiotics appear to induce subsequent allergic reactions in atopic children. Copyright © 2006 John Wiley & Sons Ltd.
Radiation‐induced dispersion polymerization of methyl methacrylate using waterborne polyurethane as stabilizer
Authors: Zhang Guixi , Zou Mingxuan , Wang Shijie , Zhang Zhicheng
Published: June 2006

Waterborne polyurethane (WPU) without vinyl groups was synthesized and used as a stabilizer to prepare poly(methyl methacrylate) (PMMA) particles via dispersion polymerization with γ‐rays. The WPU molecular structure was characterized by Fourier transform infrared spectroscopy and 1H NMR. PMMA particles were observed using scanning electron microscopy. The grafting reaction between PMMA and WPU was ascertained using 1H NMR. Copyright © 2006 Society of Chemical Industry
Effect of coupling agents on the thermal and mechanical properties of polypropylene–jute fabric composites
Authors: Acha Betiana A , Reboredo María M , Marcovich Norma E
Published: June 2006

Composites with different jute fabric contents and polypropylene (PP) were prepared by compression molding. The composite tensile modulus increased as the fiber content increased, although the strain at break decreased due to the restriction imposed on the deformation of the matrix by the rigid fibers. Moreover, and despite the chemical incompatibility between the polar fiber and the PP matrix, the tensile strength increased with jute content because of the use of long woven fibers. The interfacial adhesion between jute and PP was improved by the addition of different commercial maleated polypropylenes to the neat PP matrix. The effect of these coupling agents on the interface properties was inferred from the resulting composite mechanical properties. Out‐of‐plane instrumented falling weight impact tests showed that compatibilized composites had lower propagation energy than uncompatibilized ones, which was a clear indication that the adhesion between matrix and fibers was better in the former case since fewer mechanisms of energy propagation were activated. These results are in agreement with those found in tensile tests, inasmuch as the compatibilized composites exhibit the highest tensile strength. Scanning electron microscopy also revealed that the compatibilized composites exhibited less fiber pullout and smoother fiber surface than uncompatibilized ones. The thermal behavior of PP–compatibilizer blends was also analyzed using differential scanning calorimetry, to confirm that the improvements in the mechanical properties were the result of the improved adhesion between both faces and not due to changes in the crystallinity of the matrix. Copyright © 2006 Society of Chemical Industry
Preparation of nano‐sized poly(ethylene oxide) star microgels via reversible addition‐fragmentation transfer polymerization in selective solvents
Authors: Zheng Quan , Zheng Gen‐hua , Pan Cai‐yuan
Published: June 2006

Poly(ethylene oxide) (PEO) star microgels with a cross‐linked polystyrene core were successfully prepared by reversible addition‐fragmentation transfer polymerization of styrene (St) and divinylbenzene (DVB) with dithiobenzoate‐terminated PEO monomethyl ether (DTB‐MPEO) as macro chain transfer agent in mixtures of ethanol and tetrahydrofuran (THF). The formation of star polymers was affected by polymerization time, solvents and St:DVB:DTB‐MPEO molar ratios. Narrow polydispersed star microgels with high molecular weight were obtained under appropriate polymerization conditions. Transmission electron micrographs suggest that PEO star polymers could form nano‐size spherical micelles in mixtures of water and THF, which further demonstrates the amphiphilic nature of the star polymers. Copyright © 2006 Society of Chemical Industry
Role of ionic interactions in the compatibility of polyester ionomers with poly(ethylene terephthalate) and nylon 6
Authors: Iyer Subramanian , Schiraldi David A.
Published: June 2006

Water absorption and other properties of polyamides can potentially be modified by blending with polyesters. The compatibility of a polyester ionomer melt‐blended with nylon‐6 is studied in this article, examining the effect of blending upon crystallization behaviors, morphology, thermal/mechanical properties, and water absorption. Comparisons of the crystallization behaviors of the ionomer/nylon‐6 blends with poly(ethylene terephthalate)/nylon‐6 blends suggest increased compatibility due to greater interactions between the two phases. The results indicate that the presence of a significant amount of the ionomeric groups is required to improve polyester compatibility with polyamides. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2091–2103, 2006
Solution properties of NR/PU block copolymers by size‐exclusion chromatography and viscometry
Authors: Gopakumar S. , Gopinathan Nair M. R.
Published: June 2006

Soluble block copolymers based on natural rubber and polyurethane oligomers derived from 1,3 butane diol and toluene diisocyanate were synthesized for the first time. The dilute solution properties of these block copolymers dissolved in tetrahydrofuran (THF) were studied by viscometry and gel permeation chromatography (GPC). The Mark–Houwink constants K and a of the block copolymer system were determined by the molecular weight data from GPC combined with the viscosity data. Both the values were found to be in the range usually given by flexible elastomers. The intrinsic viscosity values were found to decrease successively with a decrease in the NCO/OH ratio from 1.12 to 1.05. The unperturbed chain parameters, Kθ and B were determined from the viscosity data. The Kθ calculated was used to get the unperturbed end‐to‐end distance and radius of gyration of the block copolymer systems in THF. The viscosity data were also used to study the chain conformation in dilute solutions. It was found that the molecules adopt a compressed core and shell conformation in which the higher molecular weight component, NR, forms the shell, which compresses the PU core. All the block copolymers assume a compressed segregated core and shell model which changes to a partially segregated core and shell conformation, or partially Gaussian conformation, at the transition temperature located at 70 °C. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2104–2111, 2006
Application of Two‐Dimensional Detectors in X‐ray Diffraction Materials Structure Analysis
Authors: Fiala Jaroslav , Kolega Michal
Published: June 2006

The examination of the azimuthal (lateral) diffraction line profile, i.e., the size, number and shape of individual diffraction spots of which discontinuous diffraction line consist, often reveals useful information on the material's structure which cannot be obtained by the application of other analytical techniques. The information obtained can be advantageously used in the development and optimization of technological processes as well as for monitoring of processes which degrade the material's structure during their use.
In‐situ Investigation during Tempering of a High Speed Steel with X‐ray Diffraction
Authors: Wießner Manfred , Kleber Siegfried , Kulmburg Alfred
Published: June 2006

The combined use of a X‐ray diffractometer and a high temperature chamber allows in‐situ determination of microstructure during heat treatment. X‐ray diffractograms are recorded during tempering of high speed steels. The Rietveld method is used in connection with size‐strain analysis. Lattice parameters of austenite and martensite are utilized for estimating the change of carbon content that has massive influence on the secondary hardening. Nevertheless, it was shown that the heat treatment of deep‐frozen high speed steel cannot be deduced a priori from the applied tempering process under conventional quenching conditions. The differently conditioned microstructures are based on different phase amounts and microstrain‐situations.
Real‐time XRD Investigations During the Formation of Cu(IngGa)Se2 Thin Films
Authors: Hergert Frank , Jost Stefan , Hock Rainer , Purwins Michael
Published: June 2006

Knowledge of the solid‐state reactions providing the synthesis of the absorber material Cu(IngGa)Se2 well below its melting point is an essential prerequisite for the further optimization of the technologically relevant production processes. Therefore, powder XRD has been applied as nondestructive tool to follow chemical solide‐state reactions in‐situ. Subsequent Rietveld refinement provides the quantitative phase evolution time.
Temperature Resolved X‐ray Diffraction for the Investigation of the Phase Transitions of FOX‐7
Authors: Kempa P. B. , Herrmann M.
Published: June 2006

The phase behavior of 1,1‐Diamino‐2,2‐dinitroethylene (FOX‐7) was investigated by means of temperature resolved X‐ray powder diffraction. Three phases were observed, and α‐ and β‐FOX‐7 were identified by X‐ray diffraction. The following transition scheme was found:

Heating: α → β → γ at 113 °C (α→β) and 173 °C (β→γ)

Cooling: α (+γ) ← γ between 50 and 75 °C

The α/β‐transition is completely reversible, and the γ/α‐transition on cooling revealed to be incomplete. A fourth phase which is described in literature was not found.
Observation and Characterization of Structural Phase Transitions by X‐Ray Powder Diffraction
Authors: Depmeier Wulf
Published: June 2006

Some of the basic properties of powder diffraction are summarized after a short introduction into the theory. Then it is described phenomenologically how various kinds of structural transformations affect the powder diffraction pattern. This is achieved on emphasizing that diffraction studies on powders are statistically more sound than those on single crystals, thus allowing the reliable determination of the generic properties of a given crystal structure.
Toxicity of indoxacarb and spinosad to the multicolored Asian lady beetle, Harmonia axyridis (Coleoptera: Coccinellidae), via three routes of exposure
Authors: Galvan Tederson L , Koch Robert L , Hutchison William D
Published: June 2006

The use of selective insecticides may improve conservation of natural enemies and therefore contribute to the success of integrated pest management (IPM) programs. In this study, the toxicity of two commonly used selective insecticides, indoxacarb and spinosad, to the multicolored Asian lady beetle, Harmonia axyridis (Pallas), was evaluated. Third instars and adults of H. axyridis were exposed to indoxacarb at 50 and 100% of the field rate (FR), to spinosad at 100% FR and to water (untreated check) under laboratory conditions via three routes of exposure. Treatments were applied directly on insects (i.e., topical application), on Petri dishes (i.e., residues), or on soybean aphids, Aphis glycines Matsumara (i.e., treated prey). Mortality of exposed individuals in each life stage was recorded 2 and 7 days after treatment. Logistic regression indicated that indoxacarb at 100% FR, followed by indoxacarb at 50% FR, was more insecticidal than spinosad to third instars. Mortality was higher when H. axyridis were exposed to both insecticides via residues followed by treated prey. Indoxacarb at 100 or 50% FR was insecticidal to adults. Adults were tolerant to spinosad via all routes of exposure. The present results suggest that indoxacarb may decrease H. axyridis field populations by causing mortality to larvae and adults via all routes of exposure. Implications of the toxicity of indoxacarb to H. axyridis within an IPM context and possible reasons for the differences in susceptibility of H. axyridis for each route of exposure are discussed. Copyright © 2006 Society of Chemical Industry
Antifeedant and toxicity effects of thiophenes from four Echinops species against the Formosan subterranean termite, Coptotermes formosanus
Authors: Fokialakis Nikolas , Osbrink Weste LA , Mamonov Leonid K , Gemejieva Nadejda G , Mims Amelia B , Skaltsounis Alexios L , Lax Alan R , Cantrell Charles L
Published: June 2006

Over 220 crude extracts from repositories generated from plants native to Greece and Kazakhstan were evaluated for termiticidal activity against the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). Emerging from this screening effort were bioactive extracts from two Greek species (Echinops ritro L. and Echinops spinosissimus Turra subsp. spinosissimus) and extracts from two Kazakhstan species (Echinops albicaulis Kar. & Kir. and Echinops transiliensis Golosh.). Fractionation and isolation of constituents from the most active extracts from each of the four species has been completed, resulting in the isolation of eight thiophenes possessing varying degrees of termiticidal activity. 2,2′:5′,2”‐Terthiophene and 5′‐(3‐buten‐1‐ynyl)‐2,2′‐bithiophene demonstrated 100% mortality against C. formosanus within 9 days at 1 and 2 wt% concentrations respectively. In addition, all but two of the eight compounds tested were significantly different from the solvent controls in the filter paper consumption bioassay. Copyright © 2006 Society of Chemical Industry
Resistance of avocado thrips (Thysanoptera: Thripidae) to sabadilla, a botanically derived bait
Authors: Humeres Eduardo C , Morse Joseph G
Published: June 2006

Bioassays were conducted on four avocado thrips (Scirtothrips perseae Nakahara) populations in southern California that had had limited past exposure to the botanical pesticide sabadilla, with the objective of establishing baseline susceptibility levels for the purpose of resistance monitoring. Reports of avocado thrips resistance in a grove that had received six sabadilla sprays over 2 years were confirmed when a bioassay indicated resistance ratios of 7.6 and 18.8 at the LC50 and LC90, respectively. Owing to the availability of other unrelated pesticides, sabadilla sprays were discontinued at this site, and, after 5.5 years, resistance ratios had dropped to near baseline levels. Avocado thrips baseline susceptibility to cyfluthrin was also obtained from one grove for future resistance monitoring studies. Resistance management principles are discussed in relation to the limited future options available for avocado thrips control. Copyright © 2006 Society of Chemical Industry
Molecular dynamics simulations of a set of isoniazid derivatives bound to InhA, the enoyl‐acp reductase from M. tuberculosis
Authors: Pasqualoto Kerly F. M. , Ferreira Márcia M. C. , Santos‐Filho Osvaldo A. , Hopfinger Anton J.
Published: June 2006

Ligand‐receptor molecular dynamics simulations (MDS) were carried out for a set of hydrazides bound to the enoyl‐acp reductase from M. tuberculosis, InhA (PDB entry code 1zid). The hypothesized active conformations resulting from a previous receptor‐independent (RI) 4D‐QSAR analysis and related optimum model/alignment were used in this study. The molecular dynamics simulations (MDS) protocol employed 500000 steps for each ligand‐receptor complex, the step size was 0.001 ps (1 fs), and the simulation temperature was 310 K, the same temperature used in the biological assay. An output trajectory file was saved every 20 simulation steps, resulting in 25,000 conformations. The hydration shell model was used to calculate the solvation energy of the lowest‐energy conformation obtained from each MDS. Structural parameters as well as binding energy contributions were considered in this analysis. The thermodynamic descriptors ELE1,4, ELtors, ELvdW, ELel, and ELel+Hb appear to be more relevant to the biological activity. These findings can be meaningful for developing QSAR studies and for designing new antituberculosis agents. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
MRCI study of the photoelectron spectrum of GeC and GeSi and their GeC+ and GeSi+ ions
Authors: Ueno Leonardo T. , Marim L. R. , Dal Pino Jr. A. , Machado Francisco B. C.
Published: June 2006

The lowest‐lying states of the species GeC, GeC+, GeSi, and GeSi+ were studied using the multireference configuration interaction (MRCI) method and the aug‐cc‐pVQZ basis set. For the first time, the GeC+ molecule was characterized. The dissociation energy (D0) of the ground state (X3∏) of GeC is equal to 3.70 eV, showing good agreement with the theoretical result (3.90 eV) of Sari and colleagues. These results, however, are considerably smaller than the experimental value of 4.72 eV. The dissociation energy of the ground state (X3∑−) of GeSi is equal to 2.90 eV, and it is in very good agreement with the experimental value (3.08 eV). The most favorable transitions are A3∑− (GeC) → X4∑− (GeC+), A3∑− (GeC) → b2∏ (GeC+) and X3∑− (GeSi) → X4∑− (GeSi+), which present very few peaks in the spectra. © 2006 Wiley Periodicals, Inc. J Quantum Chem, 2006
Measurement of paclitaxel and its metabolites in human plasma using liquid chromatography/ion trap mass spectrometry with a sonic spray ionization interface
Authors: Gréen Henrik , Vretenbrant Karin , Norlander Björn , Peterson Curt
Published: June 2006

A quantitative liquid chromatography/ion trap mass spectrometry method for the simultaneous determination of paclitaxel, 6α‐hydroxypaclitaxel and p‐3′‐hydroxypaclitaxel in human plasma has been developed and validated. 6α‐,p‐3′‐Dihydroxypaclitaxel was also quantified using paclitaxel as a reference and docetaxel as an internal standard. The substances were extracted from 0.500 mL plasma using solid‐phase extraction. The elution was performed with acetonitrile and the samples were reconstituted in the mobile phase. Isocratic high‐performance liquid chromatography analysis was performed by injecting 50 µL of reconstituted material onto a 100 × 3.00 mm C12 column with a methanol:1% trifluoroacetic acid/ammonium trifluoroacetate in H2O 70:30 mobile phase at 350 µL/min. The [M+H]+ ions generated in the sonic spray ionization interface were isolated and fragmented using two serial mass spectrometric methods: one for paclitaxel (transition 854 → 569 & 551) and the dihydroxymetabolite (transition 886 → 585 & 567) and one for the hydroxy metabolites (transition 870 → 585 & 567; transition 870 → 569 & 551) and docetaxel ([M+Na]+, transition 830 → 550). Calibration curves were created ranging between 0.5 and 7500 ng/mL for paclitaxel, 0.5 and 750 ng/mL for 6α‐hydroxypaclitaxel, and 0.5 and 400 ng/mL for p‐3′‐hydroxypaclitaxel. Adduct ion formation was noted and investigated during method development and controlled by mobile phase optimization. In conclusion, a sensitive method for simultaneous quantification of paclitaxel and its metabolites suitable for analysis in clinical studies was obtained. Copyright © 2006 John Wiley & Sons, Ltd.
Liquid chromatography/electrospray ionization tandem mass spectrometry analysis of octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX)
Authors: Pan Xiaoping , Zhang Baohong , Tian Kang , Jones Lindsey E. , Liu Jun , Anderson Todd A. , Wang Jia‐Sheng , Cobb George P.
Published: June 2006

A quantitative liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) method was developed for the analysis of the explosive, octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX). In negative ionization mode, HMX forms an acetate adduct ion [M + CH3COO]−, m/z 355, in the presence of a small amount of acetic acid in the mobile phase. The ESI collision‐induced dissociation (CID) spectrum of m/z 355 was acquired and the transitions m/z 355 → 147 and m/z 355 → 174 were chosen for the determination of HMX in samples. Using this quantification technique, the method detection limit was 1.57 µg/L and good linearity was achieved in the range 5–500 µg/L. This method will help to unambiguously analyze environmentally relevant concentrations of HMX. Copyright © 2006 John Wiley & Sons, Ltd.
A novel approach for in‐process monitoring and managing cross‐contamination in a high‐throughput high‐performance liquid chromatography assay with tandem mass spectrometric detection
Authors: Chang Min S. , Kim Elaine J. , El‐Shourbagy Tawakol A.
Published: June 2006

Cross‐contamination among wells of a high‐throughput, high‐density assay is a risk that cannot be detected or controlled by the performance of calibration standards and quality control samples. In the current practice, carryover and cross‐contamination is detected only when analytes are detected in blank, zero, placebo, pre‐dose samples, in a low standard or low quality control sample. There is no mechanism that allows bioanalytical scientists to determine if cross‐contamination has occurred among other samples. As a result, erroneous results can be released to clients even though a batch meets the acceptance criteria. We tested a new approach that quantifies the cross‐contamination of each sample and allows the scientist to make quality decisions with documentation. The approach will also detect carryover in over 90% of the wells. Briefly, two additional analytes were added as contamination markers. The markers were added to a multi‐well plate alternatively creating a pattern of a checkerboard. The spiked multi‐well plate was then used to perform the assay. If both markers were detected in a well, the sample was considered contaminated. The amount of the unexpected marker detected in a well measures the degree of contamination and may be used to make deactivation decisions. Depending on the relative impact of the contamination, a scientist can choose to tolerate the bias, reject the sample, reject the batch or raise the lower limit of quantitation for the batch. A guideline for rejection decisions is presented for discussion. Copyright © 2006 John Wiley & Sons, Ltd.
A deflection system to reduce the interference from post‐source decay product ions in photodissociation tandem time‐of‐flight mass spectrometry
Authors: Yoon So Hee , Moon Jeong Hee , Choi Kyung Mi , Kim Myung Soo
Published: June 2006

A deflection system consisting of four deflectors was designed and used to reduce the interference from post‐source decay (PSD) product ions in photodissociation (PD) tandem time‐of‐flight (TOF) mass spectrometry. For simple protonated peptides generated by matrix‐assisted laser desorption/ionization, the presence of PSD product ions at the laser irradiation spot was found to noticeably alter the minor peaks in the PD spectra even though the major ones were hardly affected. Other benefits from the use of the deflection system such as the improvement in the resolving power in PSD tandem mass spectra are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
UPLC/MSE; a new approach for generating molecular fragment information for biomarker structure elucidation
Authors: Plumb Robert S. , Johnson Kelly A. , Rainville Paul , Smith Brian W. , Wilson Ian D. , Castro‐Perez Jose M. , Nicholson Jeremy K.
Published: June 2006

The original article to which this Addendum refers was published in Rapid Commun. Mass Spectrom. 2006; 20: 1989–1994
A combined superiority and non‐inferiority approach to multiple endpoints in clinical trials
Authors: Bloch Daniel A. , Lai Tze Leung , Su Zheng , Tubert‐Bitter Pascale
Published: June 2006

Treatment comparisons in clinical trials often involve multiple endpoints. By making use of bootstrap tests, we develop a new non‐parametric approach to multiple‐endpoint testing that can be used to demonstrate non‐inferiority of a new treatment for all endpoints and superiority for some endpoint when it is compared to an active control. It is shown that this approach does not incur a large multiplicity cost in sample size to achieve reasonable power and that it can incorporate complex dependencies in the multivariate distributions of all outcome variables for the two treatments via bootstrap resampling. Copyright © 2006 John Wiley & Sons, Ltd.
A score test for overdispersion in zero‐inflated poisson mixed regression model
Authors: Xiang Liming , Lee Andy H. , Yau Kelvin K. W. , McLachlan Geoffrey J.
Published: June 2006

Count data with extra zeros are common in many medical applications. The zero‐inflated Poisson (ZIP) regression model is useful to analyse such data. For hierarchical or correlated count data where the observations are either clustered or represent repeated outcomes from individual subjects, a class of ZIP mixed regression models may be appropriate. However, the ZIP parameter estimates can be severely biased if the non‐zero counts are overdispersed in relation to the Poisson distribution. In this paper, a score test is proposed for testing the ZIP mixed regression model against the zero‐inflated negative binomial alternative. Sampling distribution and power of the test statistic are evaluated by simulation studies. The results show that the test statistic performs satisfactorily under a wide range of conditions. The test procedure is applied to pancreas disorder length of stay that comprised mainly same‐day separations and simultaneous prolonged hospitalizations. Copyright © 2006 John Wiley & Sons, Ltd.
Qualitative and quantitative analysis and comparison of Java distributed architectures
Authors: Rozman Ivan , Juric Matjaz B. , Golob Izidor , Hericko Marjan
Published: June 2006

In this article we have undertaken a qualitative and quantitative comparison of common approaches used to develop distributed solutions in Java: RMI and Web services for regular unsecured communication, RMI‐SSL and WS‐Security for secure communication and authentication, and HTTP‐to‐port and HTTP‐to‐CGI/servlet tunnelling for RMI communication through firewalls and proxies. We have performed a functional comparison that helps with the selection of the most appropriate approach. We have also carried out a detailed performance analysis with the identification of major bottlenecks, identification of design and implementation guidelines for distributed applications, and specification of optimizations for distributed middleware. This article contributes to the understanding of different approaches for developing Java distributed applications, provides detailed performance analysis, presents design and implementation guidelines, and identifies the major performance overheads. Copyright © 2006 John Wiley & Sons, Ltd.
The application kernel approach—a novel approach for adding SMP support to uniprocessor operating systems
Authors: Kågström Simon , Grahn Håkan , Lundberg Lars
Published: June 2006

The current trend of using multiprocessor computers for server applications requires operating system adaptations to take advantage of more powerful hardware. However, modifying large bodies of software is very costly and time consuming, and the cost of porting an operating system to a multiprocessor might not be motivated by the potential performance benefits. In this paper we present a novel method, theapplication kernel approach, for adaption of an existing uniprocessor kernel to multiprocessor hardware. Our approach considers the existing uniprocessor kernel as a ‘black box’, to which no or very small changes are made. Instead, the original kernel runs operating system services unmodified on one processor whereas the other processors execute applications on top of a small custom kernel. We have implemented the application kernel for the Linux operating system, which illustrates that the approach can be realized with fairly small resources. We also present an evaluation of the performance and complexity of our approach, where we show that it is possible to achieve good performance while at the same time keeping the implementation complexity low. Copyright © 2006 John Wiley & Sons, Ltd.
Oxime palladacycles revisited: stone‐stable complexes nonetheless very active catalysts
Authors: Alacid Emilio , Alonso Diego A. , Botella Luis , Nájera Carmen , Pacheco Ma Carmen
Published: June 2006

Our review critically presents the main achievements, advantages, and limitations of oxime palladacycles as high‐turnover catalysts for Heck, as well as homo‐ and cross‐coupling reactions such as Suzuki–Miyaura, Stille, Ullmann‐type, Cassar–Heck–Sonogashira, sila‐Sonogashira, Glaser‐type, Hiyama, and alkoxycarbonylation reactions. New developments in this area are reviewed from a mechanistic and synthetic point of view. The role of oxime palladacycles as a source of highly active zero‐valent palladium species is also discussed. © 2006 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 117–132; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20077
Catalysts for new tasks: preparation and applications of tunable ruthenium catalysts for olefin metathesis
Authors: Grela Karol , Michrowska Anna , Bieniek Michał
Published: June 2006

A continuous survey across structures, made over the past decades, has led to the development of highly active olefin metathesis catalysts for sophisticated synthetic tasks and for polymer technology. In this paper, our efforts toward novel and improved ruthenium complexes with even better performance in olefin metathesis are described. Oxygen ether derivatives 3, pioneered by Hoveyda, exhibit high activity and possess excellent functional group tolerance. We have successfully fine‐tuned catalyst 3b to increase its activity and applicability by the introduction of electron‐withdrawing groups to diminish the donor properties of the oxygen atom. As a result, the stable and easily accessible nitro‐substituted catalyst 6 has found a number of successful applications in various research and industrial laboratories. We were intrigued by the possibility to further fine‐tune the Hoveyda‐type catalysts by combining two activating effects—steric and electronic—in a single catalyst. This was possible to achieve in so‐called scorpio carbenes, which are currently under investigation in our laboratory. These modifications can be used not only to control the catalyst activity, but also to alter its physical–chemical properties, such as solubility in a given medium or an affinity to silica gel. An example of immobilization strategy based on this concept is presented. © 2006 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 144–156; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20079