bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, Photophysical and Electrophosphorescent Properties of Fluorene‐Based Platinum(II) Complexes
Authors: Yuen Mai‐Yan , Kui Steven C. F. , Low Kam‐Hung , Kwok Chi‐Chung , Chui Stephen Sin‐Yin , Ma Chun‐Wah , Zhu Nianyong , Che Chi‐Ming
Published: October 2010

A series of platinum(II) complexes bearing tridentate cyclometalated C^N^N (C^N^N=6‐phenyl‐2,2'‐bipyridine and π‐extended R‐C^N^N=3‐[6'‐(naphthalen‐2''‐yl)pyridin‐2'‐yl]isoquinoline) ligands with fluorene units have been synthesised and their photophysical properties have been studied. The fluorene units are incorporated into the cyclometalated ligands by a Suzuki coupling reaction. An increase in the π‐conjugation of the cyclometalated ligands confers favourable photophysical properties compared to the 6‐phenyl‐2,2'‐bipyridine analogues. The fluorene‐based platinum(II) complexes display vibronic‐structured emission bands with λmax=558–601 nm, and high emission quantum yields up to 0.76 in degassed dichloromethane. Their emissions are tentatively assigned to excited states with mixed 3IL/3MLCT parentage (IL=intraligand, MLCT=metal‐to‐ligand charge transfer). The crystal structures of these platinum(II) complexes reveal extensive PtII⋅⋅⋅π and/or π–π interactions. The fluorene‐based platinum(II) complexes are soluble in organic solvents, have high thermal stability with decomposition temperature >350 °C, and can be thermally vacuum‐sublimed or solution‐processed as phosphorescent dopants for the fabrication of organic light‐emitting diodes (OLEDs). A monochromic OLED with 3 d as dopant (2 wt %) fabricated by vacuum deposition gave a current efficiency of 14.7 cd A−1 and maximum brightness of 27000 cd m−2. A high current efficiency (9.2 cd A−1) has been achieved in a solution‐processed OLED using complex 3 f (5 wt %) doped in a PVK (poly(9‐vinylcarbazole)) host.
An estimated‐score approach for dealing with missing covariate data in matched case–control studies
Authors: Sinha Samiran
Published: October 2010

Matched case–control designs are commonly used in epidemiological studies for estimating the effect of exposure variables on the risk of a disease by controlling the effect of confounding variables. Due to retrospective nature of the study, information on a covariate could be missing for some subjects. A straightforward application of the conditional logistic likelihood for analyzing matched case–control data with the partially missing covariate may yield inefficient estimators of the parameters. A robust method has been proposed to handle this problem using an estimated conditional score approach when the missingness mechanism does not depend on the disease status. Within the conditional logistic likelihood framework, an empirical procedure is used to estimate the odds of the disease for the subjects with missing covariate values. The asymptotic distribution and the asymptotic variance of the estimator when the matching variables and the completely observed covariates are categorical. The finite sample performance of the proposed estimator is assessed through a simulation study. Finally, the proposed method has been applied to analyze two matched case–control studies.The Canadian Journal of Statistics38: 680–697; 2010 © 2010 Statistical Society of Canada
Comparison of Immediate vs Early Invasive Strategy in Patients With First Acute Non–ST‐Elevation Myocardial Infarction
Authors: Sciahbasi Alessandro , Madonna Mariapina , De Vita Maria , Agati Luciano , Scioli Roberto , Summaria Francesco , Romagnoli Enrico , Patrizi Roberto , Lanzillo Chiara , Pendenza Gianluca , Canali Emanuele , Penco Maria , Lioy Ernesto
Published: October 2010

Background:

The best timing for coronary angiography (immediate vs early) in patients with acute non–ST‐elevation myocardial infarction (NSTEMI) is controversial.

Hypothesis:

Evaluate in NSTEMI patients the effects of an immediate compared to an early invasive strategy on microvascular damage, myocardial perfusion, and infarct size.

Methods:

We randomized 54 consecutive patients with first episode of NSTEMI: 27 patients (22 males, age 58.8 ± 9.4 years, group A) underwent immediate (≤6 hours) percutaneous coronary intervention (PCI) with a double bolus of eptifibatide, and 27 patients (24 males, age 59.7 ± 9.8 years, P = 0.72, group B) underwent early (7–72 hours) PCI with upstream eptifibatide. Microvascular damage was evaluated at predischarge by myocardial contrast echocardiography, and the contrast defect length was calculated.

Results:

There were no significant differences in pre‐PCI myocardial blush grade (MBG) (41% MBG 0 or 1 in group A vs 37% MBG 0 or 1 in group B, P = 0.78), in post‐PCI MBG (7.4% MBG 0 or 1 in both groups, P = 1.00), and in contrast defect length (4.5% in group A vs 2.8% in group B, P = 0.56). However, group A showed a significant reduction in creatine kinase myocardial band isoenzyme peak (26 ± 26 ng/mL in group A vs 69 ± 79 ng/mL in group B, P = 0.01) and in troponin T peak (0.84 ± 1.2 ng/mL in group A vs 1.8 ± 2.1 ng/mL in group B, P = 0.048).

Conclusions:

In patients with NSTEMI treated with eptifibatide, immediate PCI is associated with less increase in myonecrosis markers compared with PCI within 72 hours. There were no significant differences in myocardial perfusion between the 2 strategies. Copyright © 2010 Wiley Periodicals, Inc.

The authors have no funding, financial relationships, or conflicts of interest to disclose.
A Cardiac Catheterization Laboratory Is Not Just an Angiographic Suite
Authors: Richard Conti C.
Published: October 2010

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When I began my cardiology training in 1965, my instructors in the cardiac catheterization laboratory made it clear to me that many things other than anatomic assessment by angiography could be accomplished in the cardiac catheterization laboratory. For example, at that time cardiac output, pressure gradients, valvar insufficiency, shunts, assessment of contractility, assessment of myocardial blood flow using radioactive techniques, lactate metabolism, and assessment of ventricular function were the principal physiologic parameters measured.Copyright © 2010 Wiley Periodicals, Inc.
Cumulative incidence of cancer among individuals with acquired immunodeficiency syndrome in the United States
Authors: Simard Edgar P , Pfeiffer Ruth M , Engels Eric A.
Published: October 2010

BACKGROUND:

The overall burden of cancer may increase as individuals with acquired immunodeficiency syndrome (AIDS) live longer because of highly active antiretroviral therapy (HAART), which has been widely available since 1996.

METHODS:

A population‐based, record‐linkage study identified cancers in 472,378 individuals with AIDS from 1980 to 2006. By using nonparametric competing‐risk methods, the cumulative incidence of cancer was estimated across 3 calendar periods (AIDS onset in 1980‐1989, 1990‐1995, and 1996‐2006).

RESULTS:

Measured at 5 years after AIDS onset, the cumulative incidence of AIDS‐defining cancer (ADC) declined sharply across the 3 AIDS calendar periods (from 18% in 1980‐1989, to 11% in 1990‐1995, to 4.2% in 1996‐2006 [ie, the HAART era]). The cumulative incidence of Kaposi sarcoma declined from 14.3% during 1980 to 1989, to 6.7% during 1990 to 1995, and to 1.8% during 1996 to 2006. The cumulative incidence of non‐Hodgkin lymphoma (NHL) declined from 3.8% during 1990 through 1995 to 2.2% during 1996 through 2006; during the HAART era, NHL was the most common ADC (53%). The cumulative incidence of non‐AIDS‐defining cancer (NADC) increased from 1.1% to 1.5% with no change thereafter (1%; 1996‐2006), in part because of declines in competing mortality. However, cumulative incidence increased steadily over time for specific NADCs (anal cancer, Hodgkin lymphoma, and liver cancer). The cumulative incidence of lung cancer increased from 0.14% during 1980 to 1989 to 0.32% during 1990 to 1995, and no change was observed thereafter.

CONCLUSIONS:

Dramatically declining cumulative incidence was noted in 2 major ADCs (Kaposi sarcoma and NHL), and increases were observed in some NADCs (specifically, cancers of the anus, liver, and lung and Hodgkin lymphoma). As HIV/AIDS is increasingly managed as a chronic disease, greater attention should be focused on cancer screening and prevention. Cancer 2011. Published 2010 by American Cancer Society.
Conditional survival of extremity soft‐tissue sarcoma
Authors: Parsons Helen M. , Habermann Elizabeth B. , Tuttle Todd M. , Al‐Refaie Waddah B.
Published: October 2010

BACKGROUND:

With increasing interest in adult cancer survivorship, currently available prognostic estimates for long‐term survivors of extremity soft‐tissue sarcoma (ESTS) are limited. We assessed determinants of survival in adults surgically treated for nonmetastatic ESTS, conditional on specific survival periods.

Methods:

We identified 6215 persons aged >18 in the Surveillance Epidemiology and End Results program who were surgically treated for nonmetastatic ESTS from 1991 to 2006. We used Cox proportional hazards regression to assess demographic, tumor, and treatment factors associated with 10‐year sarcoma‐specific survival (SSS) at diagnosis and conditional on surviving 3 and 5 years postdiagnosis.

RESULTS:

At the time of diagnosis, age, tumor, and treatment factors predicted SSS. Although older age significantly predicted worse SSS for all age groups at diagnosis (HR 3.78 for age >81 vs 18‐35; P < .05 for all), the effect of age became nonsignificant as survival time increased, except for the oldest group (>80 years). Tumor size, grade, and histologic subtypes continued to be important predictors of SSS for all periods of conditional survival. Persons who underwent limb amputation were at 3 times the risk of mortality for all conditional survival periods.

CONCLUSIONS:

In this large population‐based experience of ESTS survivors, age >80, tumor, and treatment factors continued to affect long‐term survival, whereas the effect of age dampened over time. These estimates provide important counseling information for changing risk factors as survival time increases, help to streamline future surveillance programs, and provide insights into the design of adult survivorship care. Cancer 2011. © 2010 American Cancer Society.
Trends, patterns, and outcomes in the management of malignant colonic polyps in the general population of the United States
Authors: Wasif Nabil , Etzioni David , Maggard Melinda A , Tomlinson James S , Ko Clifford Y
Published: October 2010

BACKGROUND:

Colonoscopic screening has increased detection of malignant colonic polyps (MPs). The goal of this study was to analyze trends and patterns in the surgical treatment of MPs and to assess outcomes as measured by lymph node retrieval and patient survival.

METHODS:

The Surveillance, Epidemiology, and End Results (SEER) registry was queried to identify 19,743 patients with MPs from 1988 to 2003.

RESULTS:

The majority of MPs were present in the sigmoid and descending colon (54%), and 38% were tubular, 40% were tubulovillous, and 22% were villous. During the study period, the incidence of MPs increased from 29% to 42% and surgical resection (SR) was increasingly used for treatment, from 54% to 70%. Predictors of SR were aged <70 years (odds ratio [OR], 1.3; 95% confidence interval [95% CI], 1.2‐1.4), high‐grade tumors (OR, 1.5; 95% CI, 1.2‐1.9), diagnosis in 1999 through 2003 (OR, 1.7; 95% CI, 1.5‐1.9), villous subtype (OR, 2.3; 95% CI, 2.0‐2.6), and right colon location (OR, 8.1; 95% CI, 7.0‐9.4). In patients undergoing SR, the mean and median number of lymph nodes was only 4 and 1, respectively. A significant percentage of patients (49%) had no lymph nodes retrieved and a worse overall survival at 5 years compared with patients who had at least 1 lymph node examined (64% vs 74%; P <.001).

CONCLUSIONS:

MPs appear to be increasing in incidence, and there is a trend toward increased use of SR for treatment. However, patients undergoing SR for MPs undergo suboptimal assessment of lymph nodes, with a detrimental impact on survival. Adequate lymphadenectomy and lymph node evaluation are crucial to improve outcomes in patients with these potentially curable lesions. Cancer 2011. © 2010 American Cancer Society.
Serotonin receptor diversity in the human colon: Expression of serotonin type 3 receptor subunits 5‐HT3C, 5‐HT3D, and 5‐HT3E
Authors: Kapeller Johannes , Möller Dorothee , Lasitschka Felix , Autschbach Frank , Hovius Ruud , Rappold Gudrun , Brüss Michael , Gershon Michael D. , Niesler Beate
Published: October 2010

Since the first description of 5‐HT3receptors more than 50 years ago, there has been speculation about the molecular basis of their receptor heterogeneity. We have cloned the genes encoding novel 5‐HT3 subunits 5‐HT3C, 5‐HT3D, and 5‐HT3E and have shown that these subunits are able to form functional heteromeric receptors when coexpressed with the 5‐HT3A subunit. However, whether these subunits are actually expressed in human tissue remained to be confirmed. In the current study, we performed immunocytochemistry to locate the 5‐HT3A as well as the 5‐HT3C, 5‐HT3D, and 5‐HT3E subunits within the human colon. Western blot analysis was used to confirm subunit expression, and RT‐PCR was employed to detect transcripts encoding 5‐HT3receptor subunits in microdissected tissue samples. This investigation revealed, for the first time, that 5‐HT3C, 5‐HT3D, and 5‐HT3E subunits are coexpressed with 5‐HT3A in cell bodies of myenteric neurons. Furthermore, 5‐HT3A and 5‐HT3D were found to be expressed in submucosal plexus of the human large intestine. These data provide a strong basis for future studies of the roles that specific 5‐HT3receptor subtypes play in the function of the enteric and central nervous systems and the contribution that specific 5‐HT3receptors make to the pathophysiology of gastrointestinal disorders such as irritable bowel syndrome and dyspepsia. J. Comp. Neurol. 519:420–432, 2011. © 2010 Wiley‐Liss, Inc.
Acute myeloid leukemia with myelodysplasia‐related changes with erythroid differentiation involving pleural fluid: A case report and brief cytopathologic review
Authors: Stoll Lisa Marie , Duffield Amy S. , Johnson Michael W. , Ali Syed Z.
Published: October 2010

The vast majority of malignant pleural effusions are caused by metastatic adenocarcinoma, most frequently from breast or lung primaries. However, a minority of cases show evidence of involvement by a hematopoietic neoplasm such as lymphoma or leukemia. We report a rare case of a 54‐year‐old male with a prior diagnosis of acute myeloid leukemia with myelodysplastic‐related changes (AML‐MDS) with erythroid differentiation having new onset pleural effusions containing leukemic blasts. The pleural specimen was comprised of blast forms having large round nuclei with finely dispersed chromatin and prominent nucleoli, with scattered binucleate forms. The blasts expressed CD45 and CD34 and were negative for epithelial and mesothelial markers. Previous bone marrow biopsies had shown that the blasts exhibited strong staining for hemoglobin and lacked expression of Factor VIII and myeloperoxidase, consistent with erythroid differentiation. Although rare, this case indicates the need for consideration of unusual disease states presenting within a pleural fluid and highlights the differential diagnosis and immunohistochemical profile of AMLs with erythroid differentiation. Diagn. Cytopathol. 2011. © 2010 Wiley‐Liss, Inc.
Follicular lesions of the thyroid: A retrospective study of 1,348 fine needle aspiration biopsies
Authors: Wu ShouJin , DeMay Richard M. , Papas Pamela , Yan Benjamin , Reeves Ward
Published: October 2010

Fine needle aspiration (FNA) has proven to be an effective tool in management of patients with thyroid nodules. However, the diagnosis of follicular patterned lesions can be challenging. The surgical and cytopathology computer database at a large referral medical center was searched for cases that had both cytologic and histologic thyroid accessions from January 2004 to November 2008. A total of 1,255 histologic thyroid specimens and 2,776 thyroid FNA biopsies were retrieved for review. Histologically, 272 overt malignancies were identified; 20 (7.4%) were follicular carcinomas. Cytologically, 1,348 cases were follicular‐patterned lesions, comprising 1,044 cases of “benign follicular nodules” (BFN), 137 cases of “follicular lesions of undetermined significance” (FLUS), and 167 cases of “suspicious for follicular neoplasm” (SFN). Seventy‐nine (7.5%) of BFN, 23 (16.8%) of FLUS, and 65 (38.9%) of SFN cases had histologic follow‐up. Overt malignancy, a cystic papillary carcinoma, was identified histologically in only one case of BFN, for a negative predictive value of 98.7%. Overt malignancy was identified histologically in two cases of FLUS, both follicular variant of papillary carcinoma, for a positive predictive value of 8.7%. Overt malignancy was identified histologically in 14 cases of SFN, for a positive predictive value of 21.5%. Five follicular carcinomas were identified histologically in the SFN category, all minimally invasive. Incidental (“occult”) papillary microcarcinoma were identified histologically in all three categories. In this study, the risk of overt malignancy increases from 1.3%, to 8.7%, to 21.5% for BFN, FLUS, and SFN, respectively. All follicular carcinomas identified histologically occurred in the SFN category and all were minimally invasive. Papillary microcarcinomas can occur in any of the three diagnostic categories. Diagn. Cytopathol. 2012;40:E8–E12. © 2010 Wiley Periodicals, Inc.
A novel null allele of mouse Dscam survives to adulthood on an inbred C3H background with reduced phenotypic variability
Authors: Fuerst Peter G. , Harris Belinda S. , Johnson Kenneth R. , Burgess Robert W.
Published: October 2010

Rod bipolar cells (green; PKCa+), a subset of retinal bipolar cells (red; CHX10+) span the two synaptic layers of the mouse retina, Nuclei in the three nuclear layers of the mouse retina are blue (Hoechst stain). A new mutant mouse allele of Down syndrome cell adhesion molecule (Dscam) was used to study the role of this gene in synaptic lamination of the mouse retina. See the article by Fuerst et al. in this issue.
FGF receptor gene expression and its regulation by FGF signaling during early zebrafish development
Authors: Ota Satoshi , Tonou‐Fujimori Noriko , Tonou‐Fujimori Noriko , Nakayama Yukiko , Ito Yuki , Kawamura Akinori , Yamasu Kyo
Published: October 2010

The expression of all four fgfr genes was extensively examined throughout early embryogenesis of the zebrafish (Danio rerio). fgfr1 alone was expressed maternally throughout the blastoderm, and then zygotically in the anterior neural plate and presomitic mesoderm. fgfr4 expression was first detected in late blastulae and was gradually restricted to the brain. fgfr2 and fgfr3 expression were initiated in early and late gastrulae, respectively; fgfr2 was expressed in the anterior neural plate and somitic mesoderm, whereas fgfr3 was activated in the axial mesoderm and then in the midbrain and somitic mesoderm. During somitogenesis, each of these fgfr genes was expressed in a characteristic manner in the brain. Using an FGF signal inhibitor, dominant‐negative FGF receptors and fgf8.1/fgf8a mutants, we found that fgfr expression is directly or indirectly regulated by FGF signaling during epiboly and at the end of somitogenesis, revealing the presence of an autoregulatory mechanism. genesis 48:707–716, 2010. © 2010 Wiley‐Liss, Inc.
A Combined Experimental and Density Functional Theory Study on the Pd‐Mediated Cycloisomerization of o‐Alkynylnitrobenzenes – Synthesis of Isatogens and Their Evaluation as Modulators of ROS‐Mediated Cell Death (Eur. J. Org. Chem. 31/2010)
Authors: Ramana Chepuri V. , Patel Pitambar , Vanka Kumar , Miao Benchun , Degterev Alexei
Published: October 2010

The cover picture shows the historical details of the nitro–alkyne cycloisomerization leading to isatogens. Since the first documentation of this reaction by Baeyer (picture of Baeyer and the corresponding literature citation are shown) in the late 19th century, a mild and general method for the synthesis of isatogens has been sought. The electrophilic PdII halide complexes are found to bring about this cyclization to provide the desired isatogens and accommodate both aryl and alkyl substituents as well as tolerate commonly employed protecting groups/functional units. Details of the course of the reaction through advanced theoretical studies and the utility of isatogens as new ROS (reactive oxygen species) scavengers are discussed in the article by C. V. Ramana, K. Vanka, A. Degterev et. al. on p. 5955 ff.
Conceptualizing the cross‐cultural gaps in managing international aid: HIV/AIDS and TB project delivery in Southern Africa
Authors: Jackson Terence
Published: October 2010

There appears to be a gap between the billions of dollars inputted into fighting HIV/AIDS and TB and outcomes. This in part can be attributed to the lack of attention in International Development to managing programmes and projects within complex levels of cross‐cultural interactions. International Development often ignores management issues, yet Management Studies is left wanting through a lack of engagement with development issues including the fight against disease and poverty. This paper attempts to link these two disciplines towards mutual benefit, through a critical cross‐cultural approach. It provides contextualization of international development policies/strategies; conceptualization of dominant paradigms; structural analysis of how a programme/project fits into the global governance structure; analysis of complexities and levels of cross‐cultural interaction and their consequences and the process and implications of knowledge transfer across cultural distances. It concludes with implications for policy and practice, as well as what is needed from cross‐disciplinary research. This includes how feedback loops can be strengthened from local to global, how indigenous knowledge may be better understood and integrated, how power relations within the global governance structure could be managed, how cross‐cultural interaction could be better understood, and how knowledge transfer/sharing should be critically managed. Copyright © 2010 John Wiley & Sons, Ltd.
Computerized evaluation of mean residence times in multicompartmental linear system and pharmacokinetics
Authors: Villalba J. M. , Barbero A. J. , Diaz‐Sierra R. , Arribas E. , Garcia‐Meseguer M. J. , Garcia‐Sevilla F. , Garcia‐Moreno M. , De Labra J. A. Vidal , Varon R.
Published: October 2010

Deriving mean residence times (MRTs) is an important task both in pharmacokinetics and in multicompartmental linear systems. Taking as starting point the analysis of MRTs in open or closed (Garcia‐Meseguer et al., Bull Math Biol 2003, 65, 279) multicompartmental linear systems, we implement a versatile software, using the Visual Basic 6.0 language for MS‐Windows, that is easy to use and with a user‐friendly format for the input of data and the output of results. For any multicompartmental linear system of up to 512 compartments, whether closed or open, with traps or without traps and with zero input in one or more of the compartments, this software allows the user to obtain the symbolic expressions, in the most simplified form, and/or the numerical values of the MRTs in any of its compartments, in the entire system or in a part of the system. As far as we known from the literature, such a software has not been implemented before. The advantage of the present software is that it reduces on the work time needed and minimizes the human errors that are frequent in compartmental systems even those that are relatively staightforward. The software bioCelTer, along with instructions, can be downloaded from http://oretano.iele‐ab.uclm.es/∼fgarcia/bioCelTer/. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
Temperature gradient interaction chromatography of polymers: A molecular statistical model
Authors: Radke Wolfgang , Lee Sekyung , Chang Taihyun
Published: October 2010

A new model describing the retention in temperature gradient interaction chromatography of polymers is developed. The model predicts that polymers might elute in temperature gradient interaction chromatography in either an increasing or decreasing order or even nearly independent of molar mass, depending on the rate of the temperature increase relative to the flow rate. This is in contrast to solvent gradient elution, where polymers elute either in order of increasing molar mass or molar mass independent. The predictions of the newly developed model were verified with the literature data as well as new experimental data.
Separation of linear and star‐shaped polystyrenes by phase distribution chromatography
Authors: Boye Susanne , Scharfenberg Linda , Lederer Albena
Published: October 2010

The phase distribution chromatographic technique was optimized and applied for the separation of linear and star‐shaped polystyrene (PS). For this purpose non‐crosslinked, ultra high molecular weight PS coated on different supporting materials was used. The stability of the coating under chromatographic conditions was tested by thermo gravimetric analysis and microscopic techniques. The modification of different column packing materials was tested. Separation according to branching was indicated for different molecular weights of linear and star‐shaped PS. The resolution of the separation was improved by changing the density of the stationary phase and the temperature. The separation results were supported by cloud point measurements and the determination of the critical conditions for linear and star‐polymers at the same molecular weight.
Influence of Screw Speed on Electrical and Rheological Percolation of Melt‐Mixed High‐Impact Polystyrene/MWCNT Nanocomposites
Authors: McClory Caroline , Pötschke Petra , McNally Tony
Published: October 2010

The influence of screw speed on the electrical and rheological percolation of HIPS/MWCNT composites prepared via melt mixing was investigated. Microscopic examination of these composites using POM, FESEM and HRTEM revealed optimum MWCNT dispersion was achieved at intermediate screw speeds. On addition of MWCNTs to HIPS, the electrical conductivity of HIPS increased by up to 12 orders of magnitude. At screw speeds up to 100 rpm an electrical percolation of 1–3 wt.‐% was achieved. This increased to 3–5 wt.‐% when the screw speed was increased to 150 rpm. The onset of a rheological percolation was detected for an MWCNT loading of 5 wt.‐%, irrespective of screw speed employed. An up‐shift in the Raman G‐band of 24 cm−1 was observed, implying strong interfacial interaction between HIPS and MWCNTs.

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Rapid Photocrosslinkable Thermoresponsive Injectable Polyphosphazene Hydrogels
Authors: Potta Thrimoorthy , Chun ChangJu , Song Soo‐Chang
Published: October 2010

Rapidly photocrosslinkable and thermosensitive polyphosphazene polymers have been prepared to overcome the limitations associated with long UV exposure. Short UV exposure on the thermosensitive gels under mild conditions leads to quick photocrosslinking of the acrylate groups in the polymer network, and results in a dual crosslinked network with enhanced mechanical strength. The accelerated photocrosslinking can be attributed to the high reactivity of the acrylate double bond and hydrophobic interactions in the polymer network. The effects on the degree of photocrosslinking of the UV light intensity and the concentration of the photoinitiator were studied. In vitro and in vivo photocrosslinkings were accomplished within 120 and 180 s of exposure times, respectively. The degradation rate of the polymers depended on the degree of acrylate substitution in the polymer network. These results demonstrate that the injectable hydrogels with desired mechanical properties and degradation rates can be created in situ under mild photocrosslinkable conditions, and the dual crosslinkable acrylated poly(organophosphazenes) may hold great promise for biomedical delivery applications of biological molecules, cells, and drugs.

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Cell Uptake and Trafficking Behavior of Non‐covalent, Coiled‐coil Based Polymer–Drug Conjugates
Authors: Apostolovic Bojana , Deacon Samuel P.E. , Duncan Ruth , Klok Harm‐Anton
Published: October 2010

This paper reports on the cell uptake and trafficking properties of a series of non‐covalent polymer–drug conjugates. These nanomedicines are composed of a poly(N‐(2‐hydroxypropyl)methacrylamide) backbone functionalized with multiple copies of a drug. The drug moieties are attached to the polymer via a non‐covalent, so called coiled coil motif, which is formed by heterodimerization of two complementary peptide strands, one of which is attached to the polymer carrier and the other to the drug. Cytotoxicity and FACS experiments, which were carried out with model anticancer drug or fluorophore conjugates, provided insight into the cell uptake and trafficking behavior of these conjugates.

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Preventing galvanic corrosion – Systematic development of a magnesium car body component
Authors: Schreckenberger H. , Izquierdo P. , Klose S. G. , Blawert C. , Heitmann Volker , Höche D. , Kainer K. U.
Published: October 2010

Die Rückwandtür des neuen Mercedes‐Benz E‐Klasse T‐Modells ist ein Beispiel für eine Hybridbauweise bestehend aus einem Innenteil aus Magnesiumdruckguss und einer Beplankung aus Aluminiumblech. Dabei muss das Bauteil eine Reihe von Anforderungen hinsichtlich Maßhaltigkeit, Gewicht, Steifigkeit, Crash‐ und Korrosionsverhalten erfüllen. Das Hybridkonzept im Allgemeinen, diverse Anbindungspunkte und Berührungsflächen erfordern eine sorgfältige Konstruktion, um Bimetallkorrosion zu vermeiden. Kritische Punkte werden angesprochen und anhand von zwei Beispielen (Gasdruckfeder und Türscharnier) werden die konstruktiven Kriterien diskutiert. Abschließend wird das Konzept der Korrosionsschutzmaßnahmen vorgestellt und Ergebnisse von verschiedenen Korrosions‐ und Funktionserprobungen präsentiert.

The hatch back of the new Mercedes‐Benz E‐Class T‐Model is one example for a hybrid design with inner magnesium high pressure die casting liner and outer aluminium sheet. The hybrid lift gate has to fulfil a variety of requirements corresponding to dimensional stability, weight, stiffness, crash and corrosion performance. The hybrid concept in general as well as various interfaces and connecting points require a careful design to prevent galvanic corrosion. Critical points are introduced and for two examples (gas pressure spring and hinge) the constructive criterions are discussed. Finally, the concept of corrosion protection measures and results of various testing trials of the component are presented.
Interhemispheric motor networks are abnormal in patients with Gilles de la Tourette syndrome
Authors: Bäumer Tobias , Thomalla Götz , Kroeger Johan , Jonas Melanie , Gerloff Christian , Hummel Friedhelm Christoph , Müller‐Vahl Kirsten , Schnitzler Alfons , Siebner Hartwig Roman , Orth Michael , Münchau Alexander
Published: October 2010

Brain imaging has shown altered corpus callosum (CC) morphology in patients with Gilles de la Tourette syndrome (GTS). Yet it is unclear whether these morphological changes are associated with altered interhemispheric interactions. Here, we combined transcranial magnetic stimulation (TMS) with diffusion tensor magnetic resonance imaging (DTI) to explore functional and structural interhemispheric connections between the left and right motor hand areas. We studied 14 unmedicated GTS patients without psychiatric comorbidity (2 women, mean age 35.5 years) and 15 healthy volunteers (3 women, mean age 35 years). Left‐to‐right and right‐to‐left interhemispheric inhibitions (IHIs) were measured in hand muscles with TMS. In 13 GTS patients and all healthy controls, we measured fractional anisotropy (FA) with DTI to examine the relation between functional measures of interhemispheric connectivity as derived by TMS and structural properties of the CC region that carries fibers interconnecting both motor cortices. In GTS patients, left‐to‐right IHI was weaker than right‐to‐left IHI. Left‐to‐right IHI in GTS patients was also reduced compared with healthy controls. Voxel‐based morphometric analysis revealed that FA in the motor region of the CC did not differ between groups. However, there was a significant interaction between groups and the relation between regional FA and left‐to‐right IHI in the motor region of the CC. A negative linear relation between FA and left‐to‐right IHI was present in control subjects but not in patients. Our combined TMS‐DTI approach demonstrates abnormal functional interhemispheric connectivity in GTS accompanied by an altered structure–function relationship in the motor CC. © 2010 Movement Disorder Society.
Simplified modeling approach suggests structural mechanisms for constitutive activation of the C5a receptor
Authors: Nikiforovich Gregory V. , Marshall Garland R. , Baranski Thomas J.
Published: October 2010

Molecular modeling of conformational changes occurring in the transmembrane region of the complement factor 5a receptor (C5aR) during receptor activation was performed by comparing two constitutively active mutants (CAMs) of C5aR, NQ (I124N/L127Q), and F251A, to those of the wild‐type C5aR and NQ‐N296A (I124N/L127Q/N296A), which have the wild‐type phenotype. Modeling involved comprehensive sampling of various rotations of TM helices aligned to the crystal template of the dark‐adapted rhodopsin along their long axes. By assuming that the relative energies of the spontaneously activated states of CAMs should be lower or at least comparable to energies characteristic for the ground states, we selected the plausible models for the conformational states associated with constitutive activation in C5aR. The modeling revealed that the hydrogen bonds between the side chains of D82–N119, S85–N119, and S131–C221 characteristic for the ground state were replaced by the hydrogen bonds D82‐N296, N296‐Y300, and S131‐R134, respectively, in the activated states. Also, conformational transitions that occurred upon activation were hindered by contacts between the side chains of L127 and F251. The results rationalize the available data of mutagenesis in C5aR and offer the first specific molecular mechanism for the loss of constitutive activity in NQ‐N296A. Our results also contributed to understanding the general structural mechanisms of activation in G‐protein‐coupled receptors lacking the “ionic lock”, R3.50and E/D6.30. Importantly, these results were obtained by modeling approaches that deliberately simplify many elements in order to explore potential conformations of GPCRs involving large‐scale molecular movements. Proteins 2011. © 2010 Wiley‐Liss, Inc.
Exciton in a strained (001)‐oriented zinc‐blende GaN/AlxGa1‐xN ellipsoidal finite‐potential quantum dot under hydrostatic pressure
Authors: Shi Lei , Yan Zu Wei
Published: October 2010

A variational method is used to discuss the binding energies of excitons in a strained zinc‐blende ellipsoidal quantum dot by considering the hydrostatic pressure effect. The analytic expressions for the Hamiltonian of the exciton have been obtained by using the Hylleraas coordinate system. The results indicate that the binding energies of excitons reach a peak value as the quantum dot radius increases and then diminish for the finite potential well. We show that the binding energies of excitons decrease with increasing ellipticity constant, but increase with pressure. In particular, it is found that the binding energies are more sensitive to the variations of the ellipticity constant for the small size of QD (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Probing the weakest bond and the cleavage ofp‐chlorobenzaldehyde diperoxide energetic molecule via quantum chemical calculations and theoretical charge density analysis
Authors: Stephen A. David , Revathi M. , Asthana S. N. , Pawar Rajesh B. , Kumaradhas P.
Published: October 2010

A high‐level ab initio Hartree‐Fock/Møller‐Plesset 2 and density functional theory quantum chemical calculations were performed onp‐chlorobenzaldehyde diperoxide energetic molecule to understand its bond topological, electrostatic, and energetic properties. The optimized molecular geometry for the basis set 6‐311G** exhibit chair diperoxide ring and planar aromatic side rings. Although the diperoxide ring bear same type of side rings, surprisingly, both the rings are almost perpendicular to each other, and the dihedral angle is 96.1°. The MP2 method predicts the OO bond distance as ∼1.466 Å. The charge density calculation reveals that the CC bonds of chlorobenzaldehyde ring have rich electron density and the value is ∼2.14 e Å−3. The maximum electron density of the OO bonds does not lie along the internuclear axes; in view of this, a feeble density is noticed in the ring plane. The high negative values of laplacian of CC bonds (approximately −22.4 e Å−5) indicate the solidarity of these bonds, whereas it is found too small (approximately −1.8 e Å−5for MP2 calculation) in OO bonds that shows the existence of high degree of bond charge depletion. The energy density in all the CC bonds are found to be uniform. A high electronegative potential region is found at the diperoxide ring which is expected to be a nucleophilic attack area. Among the bonds, the OO bond charge is highly depleted and it also has high bond kinetic energy density; in consequence of this, the molecular cleavage is expected to happen across these bonds when the material expose to any external stimuli such as heat or pressure treatment. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Human Embryonic Stem Cells Suffer from Centrosomal Amplification
Authors: Holubcová Zuzana , Matula Pavel , Sedláčková Miroslava , Vinarský Vladimír , Doležalová Dáša , Bárta Tomáš , Dvořák Petr , Hampl Aleš
Published: October 2010

Propagation of human embryonic stem cells (hESCs) in culture tends to alter karyotype, potentially limiting the prospective use of these cells in patients. The chromosomal instability of some malignancies is considered to be driven, at least in part, by centrosomal overamplification, perturbing balanced chromosome segregation. Here, we report, for the first time, that very high percentage of cultured hESCs has supernumerary centrosomes during mitosis. Supernumerary centrosomes were strictly associated with an undifferentiated hESC state and progressively disappeared on prolonged propagation in culture. Improved attachment to culture substratum and inhibition of CDK2 and Aurora A (key regulators of centrosomal metabolism) diminished the frequency of multicentrosomal mitoses. Thus, both attenuated cell attachment and deregulation of machinery controlling centrosome number contribute to centrosomal overamplification in hESCs. Linking the excessive number of centrosomes in mitoses to the ploidy indicated that both overduplication within a single cell cycle and mitotic failure contributed to generation of numerical centrosomal abnormalities in hESCs. Collectively, our data indicate that supernumerary centrosomes are a significant risk factor for chromosome instability in cultured hESCs and should be evaluated when new culture conditions are being implemented.
Local translation of mRNAs in neural development
Authors: Jung Hosung , Holt Christine E.
Published: October 2010

Growing axons encounter numerous developmental signals to which they must promptly respond in order to properly form complex neural circuitry. In the axons, these signals are often transduced into a local increase or decrease in protein levels. Contrary to the traditional view that the cell bodies are the exclusive source of axonal proteins, it is becoming increasingly clear not only that de novo protein synthesis takes place in axons, but also that it is required for the axons to respond to certain signals. Here we review the current knowledge of local mRNA translation in developing neurons with a special focus on protein synthesis occurring in axons and growth cones. WIREs RNA 2011 2 153–165 DOI: 10.1002/wrna.53

This article is categorized under:

Translation > Translation Regulation

RNA Export and Localization > RNA Localization

RNA in Disease and Development > RNA in Development
N‐Acylated Bacteriohopanehexol‐Mannosamides from the Thermophilic Bacterium Alicyclobacillus acidoterrestris
Authors: Řezanka Tomáš , Siristova Lucie , Melzoch Karel , Sigler Karel
Published: October 2010

Identification of molecular species of various N‐acylated bacteriohopanehexol‐mannosamides from the thermophilic bacterium Alicyclobacillus acidoterrestris by semipreparative HPLC and by RP‐HPLC with ESI is described. We used triple‐quadrupole type mass spectrometer, 1H and 13C NMR for analyzing this complex lipid. CD spectra of two compounds (model compound—7‐deoxy‐d‐glycero‐d‐allo‐heptitol obtained by stereospecific synthesis, and an isolated derivative of hopane) were also measured and the absolute configuration of both compounds was determined. On the basis of all the above methods, we identified the full structure of a new class of bacteriohopanes, represented by various N‐acylated bacteriohopanehexol‐mannosamides.
Lessons from a Crisis: Reflections on Economic Governance for Europe
Authors: Van Rompuy Herman
Published: October 2010

Contrary to public perception, the European Union has dealt well with the Greek debt crisis. European institutions and Member States came together to face the crisis and managed to do so, thanks to coordination and resourcefulness. Now the bigger question looms: how to prevent the recurrence of such a crisis of confidence for as long as possible, and in the event of another crisis, how to manage it. The Task Force on Economic Governance is considering measures that will enforce budgetary discipline of Member States, establish effective crisis mechanisms and increase coordination and supervision of macroeconomic imbalances.
Trust, autonomy and relationships: The help‐seeking preferences of young people in secondary level schools in London (UK)
Authors: Leavey Gerard , Rothi Despina , Paul Rini
Published: October 2010

Help‐seeking among young people is complicated, often determined vicariously by the ability of adults, family or professionals, to recognize, and respond to, their difficulties. We know very little about the complex concerns of teenage young people and how they impact on help‐seeking preferences. We aimed to ascertain the help‐seeking preferences for a range of mental health problems among adolescents attending schools in an inner‐city area of London. In particular we sought to examine the relationship between such adolescents and their family doctor. Using a mixed methods approach we explored help‐seeking attitudes of young people. Emotional and mental health problems are not seen by young people as the domain of General practitioners. Moreover, there is a worrying lack of confidence and trust placed in family doctor and other professionals by young people. Young people do not tend easily to trust adults to help them with emotional difficulties.
Associations among sleep problems, learning difficulties and substance use in adolescence
Authors: Fakier Nuraan , Wild Lauren G.
Published: October 2010

This study investigated the relationships among sleep problems, learning difficulties and substance use in adolescence. Previous research suggests that these variables share an association with executive functioning deficits, and are intertwined. The sample comprised 427 adolescents (M age = 16 years) attending remedial schools and 276 adolescents (M age = 15 years) attending a mainstream school in Cape Town, South Africa. Participants completed anonymous self‐report questionnaires. Results indicated that adolescents without learning difficulties were more likely to use tobacco, methamphetamine and cannabis, whereas those with learning difficulties engaged in more inhalant use. Adolescents who had more sleep problems were more likely to use tobacco, alcohol, methamphetamine, cannabis, inhalants, cocaine, ecstasy and any other illegal drug. Adolescents with learning difficulties had more sleep problems than those without learning difficulties. However, sleep problems remained independently associated with tobacco, cannabis and inhalant use when learning difficulties were taken into account.
Developmental and metabolic brain alterations in rats exposed to bisphenol A during gestation and lactation
Authors: Kunz Nicolas , Camm Emily Jane , Somm Emmanuel , Lodygensky Gregory , Darbre Stéphanie , Aubert Michel Lucien , Hüppi Petra Susan , Sizonenko Stéphane Vladimir , Gruetter Rolf
Published: October 2010

In recent years, considerable research has focused on the biological effect of endocrine‐disrupting chemicals. Bisphenol A (BPA) has been implicated as an endocrine‐disrupting chemical (EDC) due to its ability to mimic the action of endogenous estrogenic hormones.

The aim of this study was to assess the effect of perinatal exposure to BPA on cerebral structural development and metabolism after birth.

BPA (1 mg/l) was administered in the drinking water of pregnant dams from day 6 of gestation until pup weaning. At postnatal day 20, in vivo metabolite concentrations in the rat pup hippocampus were measured using high field proton magnetic resonance spectroscopy. Further, brain was assessed histologically for growth, gross morphology, glial and neuronal development and extent of myelination.

Localized proton magnetic resonance spectroscopy (1H MRS) showed in the BPA‐exposed rat a significant increase in glutamate concentration in the hippocampus as well as in the Glu/Asp ratio. Interestingly these two metabolites are metabolically linked together in the malate–aspartate metabolic shuttle.

Quantitative histological analysis revealed that the density of NeuN‐positive neurons in the hippocampus was decreased in the BPA‐treated offspring when compared to controls. Conversely, the density of GFAP‐positive astrocytes in the cingulum was increased in BPA‐treated offspring.

In conclusion, exposure to low‐dose BPA during gestation and lactation leads to significant changes in the Glu/Asp ratio in the hippocampus, which may reflect impaired mitochondrial function and also result in neuronal and glial developmental alterations.
The mere association effect and brand evaluations
Authors: Dimofte Claudiu V. , Yalch Richard F.
Published: October 2010

The associative network model of memory proposes that each node (construct) belongs to specific networks of associations. These networks include nodes that share associations with a third (common) construct but are not themselves directly associated (merely associated nodes). The present research proposes that automatic associations between such indirectly related nodes can be primed in a single exposure and this may be sufficient to alter subsequent concept evaluations. An implicit cognition measure is used to demonstrate the automatic transfer of properties (both cognitive evaluations and affective responses) from a common associative node to seemingly unrelated objects. The effect is driven by individuals' inability to ignore activated but irrelevant associations. Results also show that the mere association effect and the underlying property transfer process (1) are more likely for consumers familiar with the concepts involved, (2) involve both cognitive and affective information, and (3) counterintuitively, occur more often for concepts from different categories rather than the same category.