bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Chlorophenols in Water and Methods of Their Determination.
Authors: KORBA T. , POPL M.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Preparation of enantiomerically enriched α‐aminoorganostannanes and their applications in stereoselective synthesis
Authors: Coeffard Vincent , Beaudet Isabelle , Quintard Jean‐Paul , le Grognec Erwan
Published: September 2010

This review deals with the preparation of chiral, nonracemic α‐aminoorganostannanes and their applications in asymmetric synthesis. The pioneering works in this field date back almost 20 years ago and since then extensive research has been carried out to develop efficient and selective routes to highly enantioenriched α‐aminoorganostannanes. The facile Sn/Li transmetalation of these compounds by n‐BuLi has led to various applications in stereoselective synthesis. Selected examples using chiral α‐aminoorganostannanes as starting materials will be reported. Chirality, 2010. © 2010 Wiley‐Liss, Inc.
Development of Peptide and Small‐Molecule HIV‐1 Fusion Inhibitors that Target gp41
Authors: Cai Lifeng , Jiang Shibo
Published: September 2010

It has been 25 years since the development of the first efficient HIV‐1/AIDS treatment. Scientists now know more about the HIV‐1 infection life cycle, and more than 30 antiretroviral drugs have been developed, including HIV‐1 fusion inhibitors. Fundamental work was begun in the early 1990s and led to the development of a novel class of anti‐HIV‐1 drugs, culminating in a peptide known as T20, which is currently the only HIV‐1 fusion inhibitor approved by the US Food and Drug Administration. However, more work needs to be done to perfect the development of peptide and small‐molecule HIV fusion inhibitors, particularly those that target gp41. Herein we present a brief overview of the development of this class of anti‐HIV‐1 drug by focusing on the achievements, challenges, and lessons learned. We cite hallmark studies of the past and comment on future drug development.
Treatment of pituitary neoplasms with temozolomide
Authors: Syro Luis V. , Ortiz Leon D. , Scheithauer Bernd W. , Lloyd Ricardo , Lau Queenie , Gonzalez Ricardo , Uribe Humberto , Cusimano Michael , Kovacs Kalman , Horvath Eva
Published: September 2010

Temozolomide, an orally administered alkylating agent, is used to treat malignant gliomas. Recent reports also have documented its efficacy in the treatment of pituitary adenomas and carcinomas. Temozolomide methylates DNA and thereby exhibits an antitumor effect. O6‐methylguanine‐DNA methyltransferase (MGMT), a DNA repair enzyme, removes alkylating adducts induced by temozolomide, counteracting its effects. The authors of this review conducted a Medline database search regarding temozolomide in the treatment of pituitary tumors. Demographic characteristics, tumor types, and therapeutic responses were noted in all patients. Data regarding MGMT immunoexpression, which was documented in some studies, were correlated with information regarding clinical and radiologic responses. To date, there have been 19 reported cases of adenohypophyseal tumors treated with temozolomide, including 13 adenomas and 6 carcinomas. Ten of those 13 adenomas responded favorably, and 2 nonresponsive tumors had high‐level MGMT immunoexpression. All 6 carcinomas responded to therapy, but data regarding MGMT expression were available for only 3 patients, and each had low MGMT expression. In 2 adenomas, morphologic studies were performed both before and after the patients received temozolomide. The responsive tumor had necrosis, hemorrhage, fibrosis, and neuronal differentiation. The nonresponsive tumor had no changes. There have been no reported complications attributable to temozolomide. The current results indicated that temozolomide is efficacious in the treatment of aggressive pituitary adenomas and pituitary carcinomas. Evidence indicated that low‐level MGMT immunoexpression is correlated with a favorable response. A significant proportion of pituitary adenomas and carcinomas had low MGMT immunoexpression. Cancer 2011. © 2010 American Cancer Society.
Local control after craniospinal irradiation, intensity‐modulated radiotherapy boost, and chemotherapy in childhood medulloblastoma
Authors: Paulino Arnold C. , Mazloom Ali , Teh Bin S. , South Michael , Okcu M. Fatih , Su Jack , Butler E. Brian , Chintagumpala Murali
Published: September 2010

BACKGROUND:

The current study was conducted to determine whether the use of cochlear‐sparing intensity‐modulated radiotherapy (IMRT) boost results in excess local failures in children with medulloblastoma.

METHODS:

Fifty children with a median age of 7.8 years underwent resection, craniospinal irradiation (CSI), IMRT posterior fossa (PF) and/or tumor bed (TB) boost, and cisplatin‐based chemotherapy for medulloblastoma. For standard‐risk patients, the CSI dose was 18 to 23.4 grays (Gy) and was followed either by an IMRT PF boost to 36 Gy and a TB boost of 54 to 55.8 Gy (n = 29) or by an IMRT TB boost to 55.8 Gy (n = 4). For high‐risk patients, the CSI dose was 36 to 39.6 Gy followed by an IMRT PF boost to 54 to 55.8 Gy (n = 8), an IMRT PF boost to 45 Gy and a TB boost to 55.8 Gy (n = 2), or an IMRT TB boost to 55.8 Gy (n = 7). For the TB boost, a 2‐cm margin around the surgical bed was treated in most patients.

RESULTS:

The 5‐year overall and progression‐free survival rates (±standard deviation) were 72% ± 6.6% and 68.3% ± 6.8%, respectively, for all patients; 77.8% ± 7.4% and 75.1% ± 7.6%, respectively, for standard‐risk patients; and 60.8% ± 12.8% and 55.4% ± 12.8%, respectively, for high‐risk patients. The 5‐year PF control rate was 90.5% ± 4.6%. TB failures occurred in 3 patients (including 2 patients who had distant failure), whereas an isolated non‐TB PF failure occurred in 1 patient.

CONCLUSIONS:

The use of IMRT was associated with excellent local control and did not result in excess PF failures outside of the TB. Cancer 2011. © 2010 American Cancer Society.
Glucose metabolism gene polymorphisms and clinical outcome in pancreatic cancer
Authors: Dong Xiaoqun , Tang Hongwei , Hess Kenneth R. , Abbruzzese James L. , Li Donghui
Published: September 2010

BACKGROUND:

Altered glucose metabolism is the most common metabolic hallmark of malignancies. The authors tested the hypothesis that glucose metabolism gene variations affect clinical outcome in pancreatic cancer.

METHODS:

The authors retrospectively genotyped 26 single nucleotide polymorphisms from 5 glucose metabolism genes in 154 patients with localized disease and validated the findings in 552 patients with different stages of pancreatic adenocarcinoma. Association between genotypes and overall survival (OS) was evaluated using multivariate Cox proportional hazard regression models with adjustment for clinical predictors.

RESULTS:

Glucokinase (GCK) IVS1 + 9652C > T and hexokinase 2 (HK2) N692N homozygous variants were significantly associated with reduced OS in the training set of 154 patients (P < .001). These associations were confirmed in the validation set of 552 patients and in the combined dataset of all 706 patients (P ≤ .001). In addition, HK2 R844K variant K allele was associated with a better survival in the validation set and the combined dataset (P ≤ .001). When data were further analyzed by disease stage, glutamine‐fructose‐6‐phosphate transaminase (GFPT1) IVS14‐3094T>C, HK2 N692N and R844K in patients with localized disease and GCK IVS1 + 9652C>T in patients with advanced disease were significant independent predictors for OS (P ≤ .001). Haplotype CGG of GPI and GCTATGG of HK2 were associated with better OS, respectively, with P values of .004 and .007.

CONCLUSIONS:

The authors demonstrated that glucose metabolism gene polymorphisms affect clinical outcome in pancreatic cancer. These observations support a role of abnormal glucose metabolism in pancreatic carcinogenesis. Cancer 2011. © 2010 American Cancer Society.
Large deviations of interacting particle systems in infinite volume
Authors: Landim Claudio , Yau Horng‐Tzer
Published: September 2010

We prove a large deviation theorem from the hydrodynamical limit for the empirical measure of Ginzburg‐Landau and zero range processes in infinite volume starting from deterministic initial configurations. In the Ginzburg‐Landau case the main tool is the study of the evolution of the H−1 norm and in the zero range case the attractiveness which allows couplings.
Regulation of Tbx22 during facial and palatal development
Authors: Fuchs Alisa , Inthal Andrea , Herrmann David , Cheng Shuofei , Nakatomi Mitsushiro , Peters Heiko , Neubüser Annette
Published: September 2010

Mutations in the gene encoding the T‐box transcription factor TBX22 cause X‐linked cleft palate and ankyloglossia in humans. Here we show that Tbx22 expression during facial and palatal development is regulated by FGF and BMP signaling. Our results demonstrate that FGF8 induces Tbx22 in the early face while BMP4 represses and thus restricts its expression. This regulation is conserved between chicken and mouse, although the Tbx22‐expression patterns differ considerably between these two species. We suggest that these species‐specific differences may result at least in part from differences in the spatiotemporal patterns of BMP activity, but we exclude a direct repression of Tbx22 by the BMP‐inducible transcriptional repressor MSX1. Together these findings help to integrate Tbx22 into the molecular network of factors regulating facial development. Developmental Dynamics 239:2860–2874, 2010. © 2010 Wiley‐Liss, Inc.
The use of technical knowledge in European water policy‐making
Authors: van Overveld Perry J. M. , Hermans Leon M. , Verliefde Arne R. D.
Published: September 2010

Environmental policy‐making often involves a mix of technical knowledge, normative choice and uncertainty. Numerous actors, each with their own distinct objectives, are involved in these policy‐making processes. One question these actors face, is how they can effectively communicate their technical knowledge and represent their interests in policy‐making. The objective of this paper is to identify the factors that influence the use of technical knowledge and its impact on decision‐making in the European Union. This is done for case of water policy‐making for organic micropollutants, such as pesticides and pharmaceuticals. These pollutants enter the surface water in many ways and although concentrations are low, adverse effects cannot be ruled out. Via the EU Water Framework Directive, legislation has been developed to reduce the emissions of pollutants that pose a risk to ecology or public health. Using the advocacy coalition framework, the formal EU decision‐making processes are analyzed for the identification of priority pollutants (Priority Substances) and the derivation of maximum allowable concentrations (Environmental Quality Standards). To enable a detailed analysis, the focus is on three specific micropollutants that pose health risks via drinking water supply. The findings show the extent to which actors can influence the decision‐making process with technical knowledge. Early involvement in the drafting process that is led by the European Commission is important to influence decision‐making outcomes. For this, organizational capacity in coalitions to mobilize and coordinate the required targeted contribution of technical knowledge is crucial. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Initial Stages in the Rhodium(III)‐Catalyzed C–H Bond Activation of Primary Alcohols in Aqueous Solution
Authors: Eriksen Jette , Mønsted Lene , Mønsted Ole , Olsen Carl Erik , Schäffer Susan J. Cline
Published: September 2010

The mechanism of the catalytic H/D exchange in primary alcohol substrates derived from aldopentoses, promoted by a macrocyclic rhodium(III) complex, has been shown to occur by a reversible redox reaction that gives aldehyde and a rhodium–hydride complex. Hydride exchange in the latter complex promotes the introduction of solvent hydrogen in the primary alcohol formed by the reverse reaction. The hydride complex has been crystallographically characterized as a trifluoromethanesulfonate salt that contains the trans‐[Rh(cycb)(H)(OH2)]2+ (cycb = rac‐5,5,7,12,12,14‐hexamethyl‐1,4,8,11‐tetraazacyclotetradecane) cation. The hydride complex is stable for extended periods of time in acidic solution in the absence of oxidants. In basic solutions a series of base‐catalyzed reactions take place to yield ultimately the same mixture of [Rh(cycb)(OH)2]+ isomers as produced by base hydrolysis of the trans‐[Rh(cycb)(Cl)2]+ complex.
Prediction of quality of intact olives by near infrared spectroscopy
Authors: Cayuela José Antonio , Camino María del Carmen Pérez
Published: September 2010

In this work we investigated the intact olive fruit quality prediction parameters measured directly by visible and near infrared spectroscopy (Vis/NIRS); the usefulness of a portable spectrometer is also assessed. The analysed parameters of the olive fruits were moisture, dry matter, oil content, oil free acidity and fruit maturity index. It was also studied whether NIR prediction of dry matter on olives may be more useful than NIR moisture measurement. Likewise, the results from the NIR prediction of olive oil contents related to dry matter as well as to fresh weight, were compared. Models for oil content were developed using Soxhlet extraction from dried olive paste as the reference analysis. Results indicate a good prediction potential of the models for the olive quality parameters analysed, with RPD ratios from 2.51 to 3.18. The successful NIR predictions of these quality parameters are reported for the first time.

Practical applications: The technique presented here can expedite the milling procedure by allowing early detection of the olive quality and a quick calculation of the economic returns to the producers becomes possible. Furthermore, since oil quality depends largely on the optimal harvesting date when the olives should be taken to the mill, techniques that enable the monitoring of the oil content in olive fruit at different stages of maturity, even while still on the tree, become a useful and practical tool. This technique could allow monitoring the quality attributes of large amounts of the olive fruit entering the mill without the need of laboratory analysis that can only be conducted on a small number of olive fruit samples.
Evaluation of Qualidem: a dementia‐specific quality of life instrument for persons with dementia in residential settings; scalability and reliability of subscales in four Dutch field surveys
Authors: Bouman A. I. E. , Ettema T. P. , Wetzels R. B. , van Beek A. P. A. , de Lange J. , Dröes R. M.
Published: September 2010

Objective

To evaluate the scalability and reliability of Qualidem, a quality of life observation instrument rated by professional caregivers of persons with mild to very severe dementia living in residential settings.

Method

Data from four field surveys in the Netherlands were used. The instrument consists of nine subscales for mild to severe dementia; of which six can be applied in very severe dementia. The Mokken scaling model was used to compute scalability and reliability coefficients for each subscale and dementia group.

Results

Seven hundred fifty nine persons with mild to severe dementia and 214 persons with very severe dementia residing in 36 nursing homes and 4 homes for the elderly were included. In general, the subscales for the mild to severely demented group were scalable and (moderate) sufficiently reliable; the results confirmed the results of previous research to develop Qualidem. For the very severe demented group, four out of six subscales were scalable (Care relationship, H = 0.56; Positive affect, H = 0.55; Restless tense behavior, H = 0.42; and Social isolation, H = 0.34); they were also sufficiently reliable to measure quality of life (0.57 ≤ ρ ≤ 0.82). From the other two measured subscales, Social relations was considered not scalable (H = 0.26) and Negative affect was scalable (H = 0.36), but insufficiently reliable (ρ = 0.40).

Conclusion

Qualidem is an easy to administer and overall moderately sufficient reliable rating scale that provides a quality of life profile of persons with mild to even very severe dementia living in residential settings. Copyright © 2010 John Wiley & Sons, Ltd.
Electrocorticographic correlates of cognitive control in a stroop task—intracranial recording in epileptic patients
Authors: Koga Shinichiro , Rothermel Robert , Juhász Csaba , Nagasawa Tetsuro , Sood Sandeep , Asano Eishi
Published: September 2010

The human brain executes cognitive control, such as selection of relevant information in the presence of competing irrelevant information, and cognitive control is essential for us to yield a series of optimal behaviors in our daily life. This study assessed electrocorticographic γ‐oscillations elicited by cognitive control in the context of the Stroop color‐naming paradigm, with a temporal resolution of 10 msec and spatial resolution of 1 cm. Subjects were instructed to overtly read a color word printed in an incongruent color in the reading task, and to overtly name the ink color of a color word printed in an incongruent color in the Stroop color‐naming task. The latter task specifically elicited larger γ‐augmentations in the dorsolateral‐premotor, dorsolateral‐prefrontal and supplementary motor areas with considerable inter‐subject spatial variability. Such Stroop color‐naming‐specific γ‐augmentations occurred 500 to 200 msec prior to overt responses. Electrical stimulation of the sites showing Stroop color‐naming‐specific γ‐augmentations resulted in temporary naming impairment more frequently than that of the remaining sites. This study has provided direct evidence that a critical process of cognitive control in the context of Stroop color‐naming paradigm consists of recruitment of neurons essential for naming located in variable portions of the dorsolateral premotor and prefrontal areas. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Photochemical crosslinking of soluble wool keratins produces a mechanically stable biomaterial that supports cell adhesion and proliferation
Authors: Sando Lillian , Kim Misook , Colgrave Michelle L. , Ramshaw John A. M. , Werkmeister Jerome A. , Elvin Christopher M.
Published: September 2010

Keratins extracted from various “hard tissues” such as wool, hair, and nails are increasingly being investigated as a source of abundant, biocompatible materials. In this study we explored a recent photochemical method to crosslink solubilized wool keratoses, with the aim of producing a mechanically favorable biomaterial. Wool proteins were isolated by oxidizing the disulfides and extracting the resulting soluble keratoses. The α‐ and γ‐keratose fractions were analyzed by liquid chromatography–mass spectrometry to identify their constituent proteins. Hydrogels were produced by covalent crosslinking of the α‐keratoses via a photo‐oxidative process catalyzed by blue light, a ruthenium complex, and persulfate. The presence of dityrosine crosslinks was demonstrated by high performance liquid chromatography and mass spectrometry analyses. The crosslinked α‐keratose material had moderate tensile strength and elasticity, and high adhesive strength. The material displayed modest shrinking after crosslinking, however the shrinking could be prevented by crosslinking in the presence of 2.5% glycerol, resulting in gels that did not shrink or swell. Small solutes such as Tris and glycerol influenced the crosslink density and elastic modulus of the crosslinked material. The α‐keratose was able to support adhesion and growth of NIH/3T3 fibroblasts in vitro. The fabrication of mechanically stable keratin biomaterials by this facile photo‐crosslinking method may be useful for various tissue engineering applications. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Effects of exogenous phosphorus and silicon on osteoblast differentiation at the interface with bioactive ceramics
Authors: Gupta Gautam , Kirakodu Sreenatha , El‐Ghannam Ahmed
Published: September 2010

In this study, we have investigated the effects of dissolved phosphorus and silicon on osteoblast differentiation in vitro. Neonatal rat calvarial osteoblasts were seeded on silica–calcium phosphate composites (SCPCS), hydroxyapatite (HA‐200), and tissue culture polystyrene (TCPS) and incubated over 4 days in media containing 0 {minimal essential medium [MEM] (−)} or 3 mM β‐glycerophosphate [MEM (+)]. Inductively coupled plasma analysis showed that P‐content in original MEM (+) was 225% higher than that in MEM (−). Moreover, P‐content in MEM (+) significantly increased to 3.4–4.4 mM and 3.6–4.7 mM after 2 and 4 days incubation with SCPC, respectively, owing to material dissolution and exogenous phosphate supplementation. In contrast, P‐content in MEM (+) showed no change upon incubation with HA or TCPS. The P‐content in MEM (−) incubated with SCPC was considerably lower than that in MEM (+). SCPC exhibited controlled Si‐release in cell culture media [MEM (−) or MEM (+)], with Si‐rich SCPC showing a significantly greater dissolution than Si‐poor SCPC. Moreover, SCPC, unlike HA, demonstrated a cell‐ and solution‐mediated dissolution over 4 days. Quantitative real‐time PCR showed that in MEM (−), osteocalcin and osteopontin mRNA expression on Si‐rich SCPC was significantly greater than that on HA, suggesting that Si plays an important role in enhancing bone‐cell differentiation. However, osteoblast phenotypic expression on SCPC was significantly decreased after 4 days incubation in MEM (+), indicating that sustained exposure to elevated P‐levels in the media can downregulate osteoblast function. Our results demonstrate that the controlled dissolution of SCPC provides a natural stimulus for bone‐cell differentiation in vitro and could obviate the need of exogenous phosphate supplementation. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Modifications of a calcium phosphate cement with biomolecules—Influence on nanostructure, material, and biological properties
Authors: Vater Corina , Lode Anja , Bernhardt Anne , Reinstorf Antje , Nies Berthold , Gelinsky Michael
Published: September 2010

Calcium phosphate cements (CPC), forming hydroxyapatite during the setting reaction, are characterized by good biocompatibility and osteoconductivity, however, their remodeling into native bone tissue is slow. One strategy to improve remodeling and bone regeneration is the directed modification of their nanostructure. In this study, a CPC was set in the presence of cocarboxylase, glucuronic acid, tartaric acid, α‐glucose‐1‐phosphate, L‐arginine, L‐aspartic acid, and L‐lysine, respectively, with the aim to influence formation and growth of hydroxyapatite crystals through the functional groups of these biomolecules. Except for glucuronic acid, all these modifications resulted in the formation of smaller and more agglomerated hydroxyapatite particles which had a positive impact on the biological performance indicated by first experiments with the human osteoblast cell line hFOB 1.19. Moreover, adhesion, proliferation, and osteogenic differentiation of human bone marrow‐derived mesenchymal stem cells (hBMSC) as well as binding of the growth factors BMP‐2 and VEGF was investigated on CPC modified with cocarboxylase, arginine, and aspartic acid. Initial adhesion of hBMSC was improved on these three modifications and proliferation was enhanced on CPC modified with cocarboxylase and arginine whereas osteogenic differentiation remained unaffected. Modification of the CPC with arginine and aspartic acid, but not with cocarboxylase, led to a higher BMP‐2 binding. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Enhancement of the blood compatibility of dialyzer membranes by the physical adsorption of human thrombomodulin (ART‐123)
Authors: Omichi Masaaki , Matsusaki Michiya , Kato Shinya , Maruyama Ikuro , Akashi Mitsuru
Published: September 2010

ART‐123 is a recombinant soluble human thrombomodulin (hTM) with excellent anticoagulant activity. We focused on improving the blood compatibility of the polysulfone ‐ polyvinylpyrrolidone dialyzer surface by the physical adsorption of ART‐123 onto the surface. The blood compatibility of the dialyzer with the hTM adsorbed membrane was evaluated by measuring the differential pressure between the arterial and the venous pressures and by blood parameters during blood circulation. The hTM adsorbed dialyzer membrane inhibited blood clot formation without heparin administration due to the anticoagulant activity of hTM for over 4 h. The physically adsorbed hTM was stable during blood circulation, and it did not affect activated clotting time, which is significant drawback of heparin administration, and blood cell counts of RBC, WBC, or platelets. The physical adsorption of hTM onto the dialyzer membrane will be a simple and safe method to prevent blood coagulation during dialysis instead of heparin administration. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Evaluating the suitability of highly cross‐linked and remelted materials for use in posterior stabilized knees
Authors: Huot J. Caitlin , Van Citters Douglas W. , Currier John H. , Currier Barbara H. , Mayor Michael B. , Collier John P.
Published: September 2010

Posterior stabilized (PS) knee designs are a popular choice for cruciate sacrificing knee arthroplasty procedures. The introduction of PS inserts fabricated from highly cross‐linked and remelted Ultra High Molecular Weight Polyethylene (UHMWPE) has recently generated concern as these materials have been shown to possess reduced mechanical properties. This study investigated whether highly cross‐linked and remelted UHMWPE material (referred to as XRP) can be expected to perform similarly to historical gamma‐air polyethylene, which has suffered few reported incidences of tibial post failure. Never‐implanted gamma‐air PS tibial inserts shelf‐aged 14 years were examined and compared to XRP materials. Evaluation of oxidation levels, impact toughness, and fatigue strength demonstrated never‐implanted gamma‐air PS tibial inserts to possess nonuniform mechanical properties. Despite severe oxidation along the exterior of gamma‐air tibial posts, comparatively low oxidation levels at the center of the tibial posts corresponded to sufficiently high mechanical properties. XRP material (75 kGy) showed superior impact toughness over shelf aged gamma‐air material; however, tibial post fatigue testing demonstrated XRP material (100 kGy) to be less resistant to fatigue failure than historical gamma‐air material. Results from this study indicate that XRP materials (100 kGy) may demonstrate an inferior resistance to tibial post failure than historical polyethylene. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Thermochemical stabilities, electronic structures, and optical properties of C56X10 (X = H, F, and Cl) fullerene compounds
Authors: Tang Shu‐Wei , Feng Jing‐Dong , Qiu Yong‐Qing , Sun Hao , Wang Feng‐Di , Su Zhong‐Min , Chang Ying‐Fei , Wang Rong‐Shun
Published: September 2010

Stimulated by the recent isolation and characterization of C56Cl10 chlorofullerene (Tan et al., J Am Chem Soc 2008, 130, 15240), we perform a systematic study on the geometrical structures, thermochemistry, and electronic and optical properties of C56X10 (X = H, F, and Cl) on the basis of density functional theory (DFT). Compared with pristine C56, the equatorial carbon atoms in C56X10 are saturated by X atoms and change to sp3 hybridization to release the large local strains. The addition reactions C56 + 5X2 → C56X10 are highly exothermic, and the optimal temperature for synthesizing C56X10 should be ranged between 500 and 1000 K. By combining 10 X atoms at the abutting pentagon vertexes and active sites, C56X10 molecules exhibit large energy gaps between the highest occupied and lowest unoccupied molecular orbitals (from 2.84 to 3.00 eV), showing high chemical stabilities. The C56F10 and C56Cl10 could be excellent electron acceptors for potential photonic/photovoltaic applications in consequence of their large vertical electron affinities. The density of states is also calculated, which suggest that the frontier molecular orbitals of C56X10 are mainly from the carbon orbitals of two separate annulene subunits, and the contributions derived from X atoms are secondary. In addition, the ultraviolet–visible spectra and second‐order hyperpolarizabilities of C56X10 are calculated by means of time‐dependent DFT and finite field approach, respectively. Both the average static linear polarizability 〈α〉 and second‐order hyperpolarizability 〈γ〉 of these compounds are larger than those of C60 due to lower symmetric structures and high delocalization of π electron density on the two separate annulene subunits. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
In‐plane deformations of the heme group in native and nonnative oxidized cytochrome c probed by resonance Raman dispersion spectroscopy
Authors: Alessi Maria , Hagarman Andrew M. , Soffer Jonathan B. , Schweitzer‐Stenner Reinhard
Published: September 2010

We determined the dispersion of the depolarization ratio (DPR) of several Raman bands of ferricytochrome c at different pH values using low‐ionic‐strength conditions. The experimental data predominantly cover the pre‐resonance and resonance region of Q‐band excitation. The selected pH values 7.5, 9.0, 10.0 and 11.0 correspond to the conformational states III, III*, IV, and V of the protein. While the existence of the states III, IV, and V is known for nearly 70 years, the nativelike state III* has only recently been obtained from optical measurements at low ionic strength [D. Verbaro, A. Hagarman, J. B. Soffer and R. Schweitzer‐Stenner, Biochemistry, 48, 2990, 2009]. We used group‐theoretical arguments to obtain in‐plane symmetry‐lowering deformations from the obtained DPRs of various Raman bands in the high‐wavenumber region of the obtained spectra. Thus, we found that a comparatively strong rhombic deformation along the B1g mode, ν18, is maintained at all pH values investigated. It most likely arises from static Jahn‐Teller distortion of the E‐symmetry ground state. While this distortion depends on the existence of a strong sixth ligand, its occurrence is rather independent of the nature of this ligand as long as a low‐spin configuration is maintained. The III → III* transition was found to modify A1g‐type perturbations of the heme macrocycle. This is likely to reflect a decrease in nonplanar distortions such as ruffling and saddling. This drop in nonplanarity is slightly reversed by the subsequent transitions into states IV and V. Circular dichroism (CD) spectra of the Q‐band region suggest that the III → III* transition reduces the electronic contribution to the Q‐band splitting, which could reflect either a weakening or a reorientation of the internal electric field in the heme pocket. Our results underscore the relevance of state III* as a thermodynamic intermediate of the alkaline transition between states III and IV. Copyright © 2010 John Wiley & Sons, Ltd.
Relationship of protein tyrosine phosphorylation state with tolerance to frozen storage and the potential to undergo cyclic AMP‐dependent hyperactivation in the spermatozoa of Japanese Black bulls
Authors: Harayama Hiroshi , Nishijima Kazuhiro , Murase Tetsuma , Sakase Mitsuhiro , Fukushima Moriyuki
Published: September 2010

The aim of this study was to elucidate the relationship between protein tyrosine phosphorylation state and sperm characteristics in frozen‐stored spermatozoa of Japanese Black bulls. The spermatozoa were washed with PBS containing polyvinyl alcohol and then incubated with cell‐permeable cAMP analog cBiMPS to induce flagellar hyperactivation. Before and after incubation, the spermatozoa were used for immunodetection of tyrosine‐phosphorylated proteins, assessment of morphological acrosome condition and evaluation of motility. In bulls whose frozen‐stored spermatozoa were classified as having a high‐grade acrosome condition before incubation, sperm tyrosine‐phosphorylated proteins, including the 33‐kDa tyrosine‐phosphorylated SPACA1 protein, were localized in the anterior region of the acrosome and equatorial subsegment. The immunodetection level of the 41‐ and 33‐kDa sperm tyrosine‐phosphorylated proteins in the Western blots and the immunofluorescence of tyrosine‐phosphorylated proteins and SPACA1 proteins in the anterior region of the sperm acrosome were lower in bulls whose frozen‐stored sperm were classified as having a low‐grade acrosome condition. On the other hand, after incubation with cBiMPS, immunodetection levels of at least 10 tyrosine‐phosphorylated proteins increased in the connecting and principal pieces of spermatozoa, coincident with the induction of flagellar hyperactivation. Many of the spermatozoa also exhibited detection patterns similar to those of boar hyperactivated spermatozoa. These results are consistent with the suggestion that immunodetection levels of tyrosine‐phosphorylated proteins are valid markers that can predict the level of tolerance to frozen storage and the potential to undergo cAMP‐dependent hyperactivation for the spermatozoa of individual Japanese Black bulls. Mol. Reprod. Dev. 77:910–921, 2010. © 2010 Wiley‐Liss, Inc.
Fluorine (19F) MRS and MRI in biomedicine
Authors: Ruiz‐Cabello Jesús , Barnett Brad P. , Bottomley Paul A. , Bulte Jeff W.M.
Published: September 2010

Shortly after the introduction of 1H MRI, fluorinated molecules were tested as MR‐detectable tracers or contrast agents. Many fluorinated compounds, which are nontoxic and chemically inert, are now being used in a broad range of biomedical applications, including anesthetics, chemotherapeutic agents, and molecules with high oxygen solubility for respiration and blood substitution. These compounds can be monitored by fluorine (19F) MRI and/or MRS, providing a noninvasive means to interrogate associated functions in biological systems. As a result of the lack of endogenous fluorine in living organisms, 19F MRI of ‘hotspots’ of targeted fluorinated contrast agents has recently opened up new research avenues in molecular and cellular imaging. This includes the specific targeting and imaging of cellular surface epitopes, as well as MRI cell tracking of endogenous macrophages, injected immune cells and stem cell transplants. Copyright © 2010 John Wiley & Sons, Ltd.
Diffuse idiopathic skeletal hyperostosis cases found in Joseon Dynasty Human Sample Collection of Korea
Authors: Kim M. J. , Lee I. S. , Kim Y.‐S. , Oh C. S. , Park J. B. , Shin M. H. , Shin D. H.
Published: September 2010

Diffuse idiopathic skeletal hyperostosis (DISH) is a disorder showing hyperostosis of the spinal column and ossification of extraspinal ligaments or tendons. The prevalence of DISH has been found to be higher in historic peoples of the upper‐ and ruling classes, and in fact was closely correlative with nutritional and high‐caloric diets. DISH is also known to be a function of genetic factors; as such, there have been very few cases of DISH found among the specimens of Asian skeletal collections. In our osteoarchaeological study on the Joseon Dynasty Human Sample Collection (JDHSC), we found four DISH instances among the 96 cases (4.17%) we examined. This prevalence is not so different from those discovered in already‐published studies on collections in Europe and other regions. However, as already stated, it must be considered that most of the JDHSC individuals we examined were remains of people from the highest social classes of 16th–18th century Joseon society. Therefore, when collections from medieval European monastic sites, the appropriate control from well‐fed populations, were used for comparison, the prevalence of DISH was found to be far lower among the JDHSC. Reports on DISH from examinations of collections in Asian countries have been spotty, leaving gaps in the social‐strata spectrum. Further researches into the prevalence of DISH among the different social strata of ancient or medieval Asian peoples are still required. Copyright © 2010 John Wiley & Sons, Ltd.
Is antibiotic use a risk factor for breast cancer? A meta‐analysis
Authors: Sergentanis Theodoros N. , Zagouri Flora , Zografos George C.
Published: September 2010

Purpose

Breast cancer is a disease integrating hormonal and non‐hormonal factors. Given the widespread antibiotic use, attention has been recently drawn upon the association between antibiotic use and breast cancer; however, the published studies have yielded contradictory results. In addition, various types of quantification in antibiotic use have been adopted. This meta‐analysis aims to examine whether antibiotic use is associated with breast cancer risk presenting two analyses: one on antibiotic ever‐use and one on the number of antibiotic prescriptions.

Methods

Eligible studies were retrieved by a search in MEDLINE, Cochrane, and EMBASE databases till July 2009. Odds ratios (OR) pertaining to antibiotic ever‐use were appropriately calculated. The random effects model was used to estimate the pooled OR. Publication bias was assessed through Begg's and Egger's tests. Meta‐regression with the number of antibiotic prescriptions was performed.

Results

Five case–control studies were eligible at the ever‐use versus never‐use analysis (13 069 cases and 73 920 controls). Antibiotic ever‐use was associated with slightly elevated breast cancer risk (pooled OR = 1.175, 95%CI: 0.994–1.387). No publication bias became apparent. Meta‐regression showed a borderline dose–response effect implicating the number of antibiotic prescriptions.

Conclusions

Antibiotic use seems associated with slightly elevated breast cancer risk. The underlying nature of the association remains elusive, as it may be direct or due to secondary associations, that is, causal or confounding. At any case, this is a finding with potentially important public health implications, which should be further examined in the literature. Copyright © 2010 John Wiley & Sons, Ltd.
Risk of hyperkalemia associated with selective COX‐2 inhibitors
Authors: Aljadhey Hisham , Tu Wanzhu , Hansen Richard A. , Blalock Susan , Brater D. Craig , Murray Michael D.
Published: September 2010

Background

Selective cyclooxygenase‐2 (COX‐2) inhibitors have been linked to cardiac death. The mechanism for this adverse effect appears to be by ischemic insult; however another mechanism could involve hyperkalemia. The objective of this study was to determine the effects of selective COX‐2 inhibitors and non‐selective nonsteroidal anti‐inflammatory drugs (NSAIDs) on serum potassium concentration and the electrocardiogram.

Methods

A retrospective cohort study was conducted using propensity score matching of patients from an inner‐city academic medical center at Indianapolis, Indiana. Two hundred and two patients prescribed selective COX‐2 inhibitors were matched to 202 patients prescribed non‐selective NSAIDs using propensity scores methods. Outcomes included change in serum potassium concentration from baseline and the risk of an abnormal electrocardiogram.

Results

Compared to patients prescribed non‐selective NSAIDs, those prescribed a selective COX‐2 inhibitor had a higher risk of serum potassium increase greater than 5 mEq/L (OR, 2.56; 95%CI, 1.03–6.36). However, patients prescribed selective COX‐2 inhibitors had no greater risk of electrocardiogram abnormality (OR, 1.16; 95%CI, 0.74–1.82).

Conclusions

Selective COX‐2 inhibitors may have a greater risk of hyperkalemia than non‐selective NSAIDs. This study was exploratory with small numbers of patients. Further studies are needed to confirm these results and any association with cardiovascular events. Copyright © 2010 John Wiley & Sons, Ltd.
Electronic structure of Mg studied by Compton scattering
Authors: Kontrym‐Sznajd Grażyna , Samsel‐Czekała Małgorzata , Pylak Maciej , Dobrzyński Ludwik , Brancewicz Marek , Andrejczuk Andrzej , Żukowski Eugeniusz , Kaprzyk Stanisław
Published: September 2010

The electronic structure of divalent hexagonal close packed Mg is investigated by means of the high‐resolution Compton scattering. Two‐dimensional (2D) electron momentum densities are reconstructed using their line integrals, derived from the plane integrals of three‐dimensional (3D) electron momentum densities measured directly in the Compton experiment. The analysis is performed both in the extended and reduced zone schemes. The results are compared with corresponding densities calculated within Korringa–Kohn–Rostoker in the local density approximation (KKR‐LDA) band structure theory and electron–positron densities measured in the angular correlation of annihilation radiation (ACAR) experiment.
Evading metal adduct formation during desorption‐ionization mass spectrometry
Authors: Chan Chang‐Ching , Bolgar Mark S. , Miller Scott A. , Attygalle Athula B.
Published: September 2010

An investigation into the propensity of metal adduct formation in the recently developed Desorption Ionization by Charge Exchange (DICE) mass spectrometric technique has demonstrated that this method could be utilized to minimize spectral complications caused by metal adducts. For example, peaks for sodium and other metal adducts were not observed in the mass spectra acquired by the ambient‐pressure DICE technique from samples deposited on a solid surface, even after the salt content of samples was deliberately increased. A mass spectrum recorded from a urine sample by this technique showed peaks only for the proton adducts of urea and creatinine. This technique employs a nebulized spray of charged toluene droplets for analyte desorption. Because of the non‐polar nature of the spray reagent, it neither contains any appreciable amount of cations nor provides any favored ‘pickup’ of metal cations from the sample matrix. Consequently, peaks for metal adducts that are commonly observed with other desorption techniques are minimal or absent in the spectra recorded by the DICE method. Copyright © 2010 John Wiley & Sons, Ltd.
Dynamic flow modelling of riverine amphibian habitat with application to regulated flow management
Authors: Yarnell S. M. , Lind A. J. , Mount J. F.
Published: September 2010

In regulated rivers, relicensing of hydropower projects can provide an opportunity to change flow regimes and reduce negative effects on sensitive aquatic biota. The volume of flow, timing and ramping rate of spring spills, and magnitude of aseasonal pulsed flows have potentially negative effects on the early life stages of amphibians, such as the Foothill yellow‐legged frog (Rana boylii). Two‐dimensional hydrodynamic modeling is one method to evaluate potential effects of flow variation on frog egg masses and tadpoles. We explored the usefulness of this technique by modeling habitat suitability under several pulsed flow scenarios in two river reaches in northern California, USA. We conducted analyses beyond simple weighted usable area calculations, such as quantifying the risk of scour or stranding, in order to quantify potential loss under different flow scenarios. The modeling results provided information on potential susceptibility to flow fluctuations as well as the influence of channel morphology on habitat suitability. Under each flow scenario, low percentages of suitable habitat remained suitable or were ‘buffered’ from the pulse, creating high potential for scour of egg masses or tadpoles. However, due to differences in channel morphologies, the wide, shallow study site provided 2‐3 times the buffering capacity of the entrenched study site.

Additional analyses suggested that limited buffering capacity and lack of connectivity between suitable egg mass and tadpole habitats may explain why some hydraulically suitable habitats are unoccupied. This type of model‐based analysis would be useful for managing foothill yellow‐legged frogs or similar aquatic species in regulated river systems. Copyright © 2010 John Wiley & Sons, Ltd.
Smoothed analysis of balancing networks
Authors: Friedrich Tobias , Sauerwald Thomas , Vilenchik Dan
Published: September 2010

In a balancing network each processor has an initial collection of unit‐size jobs (tokens) and in each round, pairs of processors connected by balancers split their load as evenly as possible. An excess token (if any) is placed according to some predefined rule. As it turns out, this rule crucially affects the performance of the network. In this work we propose a model that studies this effect. We suggest a model bridging the uniformly‐random assignment rule, and the arbitrary one (in the spirit of smoothed‐analysis). We start with an arbitrary assignment of balancer directions and then flip each assignment with probability α independently. For a large class of balancing networks our result implies that after
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rounds the discrepancy is
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with high probability. This matches and generalizes known upper bounds for α = 0 and α = 1/2. We also show that a natural network matches the upper bound for any α. © 2010 Wiley Periodicals, Inc. Random Struct. Alg., 39, 115–138, 2011
Anatomy of a young giant component in the random graph
Authors: Ding Jian , Kim Jeong Han , Lubetzky Eyal , Peres Yuval
Published: September 2010

We provide a complete description of the giant component of the Erdős‐Rényi random graph
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as soon as it emerges from the scaling window, i.e., for p = (1+ε)/n where ε3n →∞ and ε = o(1). Our description is particularly simple for ε = o(n‐1/4), where the giant component
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is contiguous with the following model (i.e., every graph property that holds with high probability for this model also holds w.h.p. for
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). Let Z be normal with mean
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and variance ε3n, and let
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be a random 3‐regular graph on
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vertices. Replace each edge of
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by a path, where the path lengths are i.i.d. geometric with mean 1/ε. Finally, attach an independent Poisson( 1‐ε )‐Galton‐Watson tree to each vertex. A similar picture is obtained for larger ε = o(1), in which case the random 3‐regular graph is replaced by a random graph with Nk vertices of degree k for k ≥ 3, where Nk has mean and variance of order εkn. This description enables us to determine fundamental characteristics of the supercritical random graph. Namely, we can infer the asymptotics of the diameter of the giant component for any rate of decay of ε, as well as the mixing time of the random walk on
\documentclass{article} \usepackage{mathrsfs} \usepackage{amsmath} \pagestyle{empty} \begin{document} \begin{align*}{\mathcal{C}_1}\end{align*} \end{document}. © 2010 Wiley Periodicals, Inc. Random Struct. Alg., 39, 139–178, 2011