bluuebunny/crossref_metadata_2025 huggingface dataset:
Orientational Behavior of Ellipsoidal Silica‐Coated Hematite Nanoparticles Integrated within an Elastomeric Matrix and its Mechanical Reinforcement
Authors: Sánchez‐Ferrer Antoni , Mezzenga Raffaele , Dietsch Hervé
Published: January 2011

The mechanical and orientational properties of IOENs consisting of integrated ellipsoidal SCH spindle‐type nanoparticles within an elastomeric matrix are reported. The influence of the SCH surface chemistry, leading either to dispersed nanoparticles or crosslinked nanoparticles within the surrounding elastomeric matrix, is studied by mechanical uniaxial deformation (stress‐strain) and SAXS measurements under stress. Without surface modifications, the SCH nanoparticles act as defects, and the Young's modulus of the elastomeric matrix remains unmodified. Surface‐modified SCH nanoparticles acting as crosslinkers increase Young's modulus by a factor 1.2. SAXS measurements demonstrate that the integrated ellipsoidal nanoparticles orient upon a deformation larger than 50% independently of the specific integration strategy.

magnified image
Compact Mixing Using Multiple Splitting, Stretching, and Recombining Flows
Authors: Neerincx Peter E. , Denteneer Roel P. J. , Peelen Sven , Meijer Han E. H.
Published: January 2011

The working principle of static mixers is based on repeated stretching, cutting, and stacking operations. Two‐way splitting (cutting) elements are most commonly used. Multiple splitting elements increase the compactness of the mixer, but an issue is the pressure consumption. Here we first investigate how to improve existing two way splitting and recombining flows. We use the serpentine channel geometry which relevance is that it is easy to fabricate on the interface between two halves of a mold or device. Next a parallel multiple splitting method is developed which is compact and efficient in terms of pressure consumption and uniformity of the resulting layer distribution. The final design represents a fully parallel multiple mixer, circularly shaped, that uses fan shaped channels (for a uniform flow length distribution) to guide the flow to its splitting channels, where it is turned and recollected in a second fan shaped channel. Because of its twelve‐way parallel splitting design, the device produces 24 layers in one mixing element and 288 layers in the second element and so on. Prototypes are fabricated, tested on performance, and compared with some existing static mixers using mixing speed, volume, length, and pressure drop as criteria. The new mixer outperforms the other designs, with an exception of the volume used.

magnified image
A Simple Method for the Reinforcement of UV‐Cured Coatings via Sol‐Gel Photopolymerization
Authors: Belon Cindy , Chemtob Abraham , Croutxé‐Barghorn Céline , Rigolet Séverinne , Le Houérou Vincent , Gauthier Christian
Published: January 2011

A difunctional methacrylate oligomer was mixed with a variable amount of a MAPTMS precursor in the presence of both a radical and a cationic photoinitiator. The simultaneous photolysis of both photosensitive molecules upon UV irradiation allowed the single‐step generation of a type‐II polymethacrylate/polysiloxane nanocomposite film. Methacrylate and methoxysilyl conversions during irradiation were efficiently monitored by FTIR spectroscopy. The inorganic structure of the resulting silica‐based hybrid films was characterized using 29Si solid‐state NMR. Finally, the reinforcement ability of the resulting hybrid films was also assessed by using a unique range of characterization techniques: DMA, scratch test, and nanoindentation.

magnified image
The composition in multidimensional Triebel–Lizorkin spaces
Authors: Moussai Madani
Published: January 2011

We will establish that the composition operator Tf:g → f○g takes the intersections of Triebel–Lizorkin spaces \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$ F_{{p},{q}}^{s}({\mathbb R}^n) $\end{document} with a certain space of bounded and continuous functions to \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$ F_{{p},{q}}^{s}({\mathbb R}^n) $\end{document}, under some conditions on the parameters n, s, p and q. Also, a similar partial result corresponding to the Besov spaces \documentclass{article}\usepackage{amssymb}\pagestyle{empty}\begin{document}$ B_{{p},{q}}^{s}({{\mathbb R}}^n) $\end{document} will be given. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Histological evaluation of microsurgical revascularized bone in the intraoral cavity: Does it remain alive?
Authors: Jacobsen Christine , Lübbers Heinz‐Theo , Obwegeser Joachim , Soltermann Alex , Grätz Klaus‐Wilhelm
Published: January 2011

Introduction:

Microsurgical revascularized fibula graft is a standard for the reconstruction of mandible or maxilla after major resection. Usually, screwed implants are inserted as a second procedure for dental rehabilitation. A lot has been published about the advantages of vascularized bone grafts, but until now there is only little information about long‐term viability of inserted bone grafts.

Material and Methods:

In this study, previously inserted vascularized fibula bone grafts were examined histologically. Bone biopsies were taken during dental implant insertion procedure in average of 19 months after insertion of bone grafts from 10 patients.

Results:

All bone biopsies showed partially or totally necrotic bone, although clinical examination and postoperative monitoring of the revascularized bone remained unremarkable.

Conclusion:

The results of histological examination are surprising, due to the fact of previous insertion of a vascularized bone graft and pretended osseointegration of inserted dental implants with satisfying primary stability. Therefore, one would expect vital bone. For better understanding how much viability is really necessary for sufficient remodeling of inserted bone grafts for adequate functional load, further studies should be performed. © 2011 Wiley‐Liss, Inc. Microsurgery, 2011.
ERETIC implemented in diffusion‐ordered NMR as a diffusion reference: a clarification
Authors: Van Lokeren Luk , Kerssebaum Rainer , Willem Rudolph , Denkova Pavletta
Published: January 2011

Additional information as to the objectives of our previous paper entitled ‘ERETIC implemented in diffusion‐ordered NMR as a diffusion reference’ (Magn. Reson. Chem. 2008, 46, S63) is provided. The need for an optimal instrumental stability for the method proposed to be reliably applicable in view of these objectives is emphasized and illustrated. Copyright © 2011 John Wiley & Sons, Ltd.
1H and 13C NMR spectral study of some 3‐aryl‐5r‐aryl‐6t‐carbethoxycyclohex‐2‐enones—a study of four‐bond 1H1H couplings
Authors: Yuvaraj C. , Pandiarajan K.
Published: January 2011

Nine 3‐aryl‐5r‐aryl‐6t‐carbethoxycyclohex‐2‐enones 2a–2i have been synthesized. For all these compounds, 1H and 13C NMR spectra have been recorded. For two compounds, 2D spectra have been recorded. The spectral data suggest that these compounds adopt sofa conformation in solution with H‐5, H‐6 and H‐4t occupying axial‐like positions and H‐4c occupying equatorial‐like positions. In 3‐phenyl‐5r‐(o‐chlorophenyl)‐6t‐carbethoxycylohex‐2‐enone (2b), the o‐chlorophenyl group is oriented such that the chlorine atom is in between H‐4c and H‐5. Allylic coupling of H‐2 is observed only with H‐4t. Evidence has been obtained for four‐bond coupling between 1,3‐diaxial and 1,3‐axial–equatorial protons. Copyright © 2011 John Wiley & Sons, Ltd.
Determination of substitution sites in monosubstituted five‐membered aromatic heterocycles
Authors: Schraml Jan , Kubec Roman , Kučerová Petra
Published: January 2011

Similar magnitudes of proton–proton couplings across three, four, and five bonds and proton–carbon couplings across two and three bonds combined with difficult to predict substituent effects make the results of an indiscriminate use of routine (COSY, HSQC, HMBC, etc.) techniques for substitution site determination in C‐monosubstituted five‐membered heteroaromatics suspect. As demonstrated on two examples of natural products, the use of 1,1‐ADEQUATE leads to unambiguous substitution site determination lending thus further support to suggested inclusion of 1,1‐ADEQUATE data into computer‐assisted structure elucidation (CASE) protocols. Copyright © 2011 John Wiley & Sons, Ltd.
Comparative intermolecular cross‐relaxation studies of human hemoglobin in red blood cells and bovine serum albumin in solution
Authors: Era Seiichi , Sogami Masaru , Uyesaka Nobuhiro , Kato Kazuo , Murakami Masataka , Matsushima Shigeru , Kinosada Yasutomi
Published: January 2011

Intermolecular cross‐relaxation rate (CR) spectra [1/TIS(HDO) or 1/TIS(H2O) vs f2(ppm) profiles] for bovine serum albumin [BSA; molecular weight (MW), 66 kDa] solution, partially hydrolyzed BSA gel (BSA*gel) and packed human red blood cells (RBCs) with normal or unstable hemoglobin (Hb; MW, 65 kDa) were studied using f2 irradiation ranging from – 100 to 100 ppm at γH2/2π of 250 Hz. The CR spectra for BSA*gel (pD 4.01, 0.10 M NaCl, 4.83 and 14.39%) exhibited different features in the off‐resonance region (below – 2.00 and above 12.0 ppm) relative to that for BSA solution (pD 7.14, 0.10 M NaCl, 14.39%), indicating the association of BSA* molecules in the gel state. The CR spectrum for packed RBCs was compared with those for BSA*gel and BSA solution (14.39%) by correcting for differences in protein concentration. The corrected CR spectrum for packed normal RBCs in the off‐resonance region was similar to that for BSA solution, indicating that the physical characteristics of Hb in normal RBCs may be in a solution‐like state. Our results on normal RBCs were approximately consistent with the previously reported thermodynamic and hydrodynamic findings that Hb in RBCs and/or in concentrated solution seems to be in a suspension of hard scaled particles. Copyright © 2011 John Wiley & Sons, Ltd.
Exploiting the tumor microenvironment for theranostic imaging
Authors: Stasinopoulos Ioannis , Penet Marie‐France , Chen Zhihang , Kakkad Samata , Glunde Kristine , Bhujwalla Zaver M.
Published: January 2011

The integration of chemistry and molecular biology with imaging is providing some of the most exciting opportunities in the treatment of cancer. The field of theranostic imaging, where diagnosis is combined with therapy, is particularly suitable for a disease as complex as cancer, especially now that genomic and proteomic profiling can provide an extensive ‘fingerprint’ of each tumor. Using this information, theranostic agents can be shaped for personalized treatment to target specific compartments, such as the tumor microenvironment (TME), whilst minimizing damage to normal tissue. These theranostic agents can also be used to target multiple pathways or networks by incorporating multiple small interfering RNAs (siRNAs) within a single agent. A decade ago genetic alterations were the primary focus in cancer research. Now it is apparent that the tumor physiological microenvironment, interactions between cancer cells and stromal cells, such as endothelial cells, fibroblasts and macrophages, the extracellular matrix (ECM), and a host of secreted factors and cytokines, influence progression to metastatic disease, aggressiveness and the response of the disease to treatment. In this review, we outline some of the characteristics of the TME, describe the theranostic agents currently available to target the TME and discuss the unique opportunities the TME provides for the design of novel theranostic agents for cancer therapy. Copyright © 2011 John Wiley & Sons, Ltd.
Painting a picture of America's nonprofit foundations: a content analysis of public relations photographs distributed through online wire services
Authors: Waters Richard D. , Wang Weijia
Published: January 2011

Studies have shown that nearly 75% of news coverage in print publications stem from public relations information subsidies, such as news releases, fact sheets, and position papers. Often, organizations send photographs along with these materials in hopes that the media will publish these pictures; thereby, increasing readership of the news story and maximizing the organization's exposure to key audiences. This study examines 339 randomly sampled photographs distributed by American nonprofit foundations through online news wire services from 2006 to 2009. The results indicate that the majority of photographs are staged rather than more intriguing live‐action photographs. The implications of these results are further discussed with formal suggestions for improving this element of media relations. Copyright © 2011 John Wiley & Sons, Ltd.
State mortgage foreclosure policies and lender interventions: Impacts on borrower behavior in default
Authors: Collins J. Michael , Lam Ken , Herbert Christopher E.
Published: January 2011

Due to the rise in foreclosure filings, policymakers are increasingly concerned with helping families in financial distress keep their homes. This paper tests the extent to which distressed mortgage borrowers benefit from three types of state foreclosure polices: (1) judicial foreclosure proceedings, (2) statutory rights of redemption, and (3) statewide foreclosure‐prevention initiatives. Based on an analysis of borrowers in default who reside in 22 cross‐state metropolitan statistical area pairs, state policies generally have weak effects. Both judicial foreclosure proceedings and foreclosure prevention initiatives are associated with modest increases in loan modification rates. Using a matching procedure, a lender's letter promoting mortgage default counseling was associated with increases in loan modifications, decreases in loan cures, and decreases in foreclosure starts. The effects of the letter were also stronger in states with judicial proceedings. © 2011 by the Association for Public Policy Analysis and Management.
Multilevel analysis of the effects of antidiscrimination policies on earnings by sexual orientation
Authors: Klawitter Marieka
Published: January 2011

This study uses the 2000 U.S. Census data to assess the impact of antidiscrimination policies for sexual orientation on earnings for gays and lesbians. Using a multilevel model allows estimation of the effects of state and local policies on earnings and of variation in the effects of sexual orientation across local labor markets. The results suggest that gay men face an earnings penalty that varies significantly (though not sizably) across local areas, and that state antidiscrimination policies may decrease that penalty in private sector employment. There is, however, no evidence that lesbians in any sector average higher earnings or wages in areas with antidiscrimination policies. The strongest evidence of effects for antidiscrimination policies is for weeks of employment and for gay men who are in the private sector, white, and in the upper half of the earnings distribution. © 2011 by the Association for Public Policy Analysis and Management.
A review on flame retardant technology in China. Part II: flame retardant polymeric nanocomposites and coatings
Authors: Lu Hongdian , Song Lei , Hu Yuan
Published: January 2011

The progress of flame retarded polymer nanocomposites and coatings in China over the past decades are described in this review. Emphasis on flammability performance of polymer nanocomposites containing nanofillers, mainly layered inorganic compounds, nanofibers and nanoparticles, combined with conventional flame retardant additives are addressed based on the open literature. Polymeric coatings with improved flame retardancy prepared using a wide variety of additives and UV‐curing technology are also introduced. Derived from this research, the combination of multiple methods and technologies including catalyst and nanotechnology, is predicted to have a high probability to enhance char formation and improve the flame retardancy of polymeric materials. Copyright © 2011 John Wiley & Sons, Ltd.
Reactive modifications of some chain‐ and step‐growth polymers with phosphorus‐containing compounds: effects on flame retardance—a review
Authors: Joseph Paul , Tretsiakova‐Mcnally Svetlana
Published: January 2011

This article reviews the recent developments in the synthetic strategies to chemically modify several chain‐growth polymers that were primarily developed in our laboratories, with a view to improve their flame retardance. In addition, it also incorporates the corresponding methodologies for the step‐growth thermoplastics and thermoset materials. For chain‐growth polymers, this involves primarily copolymerization reactions, under radical initiation, of acrylic or styrenic monomers with phosphorus‐containing comonomers, or optionally, by post‐modification reactions on preformed olefinic polymeric substrates with appropriate phosphorus‐containing reagents. In the case of step‐growth polymers, generally, an appropriate phosphorus‐bearing moiety is employed, as one of the reactive components, during the step‐growth synthetic process. The relative predominance of vapor‐ and condensed‐phase mechanisms of flame retardance in the modified systems was evaluated through a combination of various analytical techniques. It was found that incorporation of phosphorus, through chemical modification reactions, on to the various thermoplastics resulted in substantial increases in the flame retardation. Furthermore, mechanistic aspects of flame retardation revealed both vapor‐phase and condensed‐phase elements depending on the chemical nature of the parent polymer in question and to a lesser extent on the chemical environment of the phosphorus‐bearing moiety. Copyright © 2011 John Wiley & Sons, Ltd.
Safety assessment of intensive induction therapy in childhood anaplastic large cell lymphoma: Report of the ALCL99 randomised trial
Authors: Wrobel Grazyna , Mauguen Audrey , Rosolen Angelo , Reiter Alfred , Williams Denise , Horibe Keizo , Brugières Laurence , Le Deley Marie‐Cécile ,   on behalf of European Inter‐Group for Childhood, Non‐Hodgkin Lymphoma (EICNHL)
Published: January 2011

Background

ALCL99 protocol including six courses of chemotherapy derived from the NHL‐BFM protocol is widely used for the treatment of paediatric anaplastic large‐cell lymphoma. In the ALCL99 trial, patients were randomised to receive MTX 1 g/m2 in 24 hr with intrathecal injection (MTX1) versus MTX 3 g/m2 in 3 hr without intrathecal (MTX3); then to receive or not vinblastine (high‐risk patients). The present study provides information about the acute adverse reactions (ARs) during the six courses of the ALCL99 treatment, assesses risk factors for ARs and evaluates the risk of overweight related to treatment.

Methods

Data concerning ARs were assessed using CTCv2 and analysed overall and according to the type of course.

Results

Between 1999 and 2005, 352 patients were recruited. Toxicity assessed after 2050 courses included grade 4 neutropaenia (70% of courses), grade 3–4 stomatitis (13%), grade 3–4 transaminase elevation (10%) and grade 3–4 infection (5%). Four patients (1%) died of toxicity. The toxicity profile differed between courses‐A (significantly more haematological toxicity) and courses‐B (significantly more stomatitis). The percentage of ARs was higher after the first course than after subsequent courses. Severe toxicity was more frequent after MTX1 than after MTX3 courses but did not differ between courses with or without vinblastine. Overall 20% of patients had a weight gain exceeding 20%.

Conclusions

The high rate of acute toxicity should be considered when using the ALCL99 protocol. Chemotherapy including MTX 3 g/m2 in 3 hr was less toxic than the same regimen with MTX 1 g/m2 in 24 hr. Adding vinblastine did not increase the risk of toxicity. Pediatr Blood Cancer 2011;56:1071–1077. © 2011 Wiley‐Liss, Inc.
Outcomes of informed consent among parents of children in cancer clinical trials
Authors: Truong Tony H. , Weeks Jane C. , Cook E. Francis , Joffe Steven
Published: January 2011

Background

Clinical trials are central to pediatric oncology, yet the process and outcomes of informed consent are poorly understood. We evaluated correlates of understanding among parents of pediatric trial participants, and explored differences in the process and outcome of informed consent between parents and a comparison group of adult participants.

Procedure

We administered the Quality of Informed Consent (QuIC) to parents of children who were newly enrolled onto a cancer trial. We identified independent correlates of knowledge among parents, and compared parents' knowledge to that of a contemporaneous group of adult participants, using multiple linear regression models.

Results

Parents (n = 47) were less likely than adult participants (n = 204) to report having enough time to learn about the trial (64% vs. 87%, P = 0.001) or sufficient opportunity for questions (79% vs. 93%, P = 0.01), and reported lower overall satisfaction with the consent process (71% vs. 90%, P = 0.002). The mean parental knowledge score was 73.6 (95% confidence interval [CI] 69.5–77.8, theoretical maximum 100). Knowledge did not differ between parents and adult trial participants. In multivariate analysis, two predictors were significantly associated with higher parent knowledge scores: consent sought by the study's principal investigator (increment 13.6, CI 2.7–24.6) and physician‐reported poor prognosis (increment 13.8, 95% CI 5.4–22.1).

Conclusions

Although we observed no differences in knowledge between parents of pediatric cancer trial participants and their adult counterparts, parents report more problems with the informed consent process for their trials. The increased prevalence of problems is likely due to clinical and contextual differences between pediatric and adult trials. Pediatr Blood Cancer 2011; 57: PPL–1004. © 2011 Wiley‐Liss, Inc.
1H NMR study of the hetero‐association of non‐symmetrical diols with pyridine; GIAO/DFT calculations on diols
Authors: Lomas John S. , Maurel François , Adenier Alain
Published: January 2011

The 1H NMR titration method is used to investigate the association of non‐symmetrical 1,2‐ and 1,3‐diols with pyridine in benzene. These diols give well‐defined titration curves for the two non‐equivalent OH protons, but it is not possible to determine individual association constants. Only the sum of the first association constants for the two protons and the product of the first and second association constants are accessible. The sum is significantly higher than that of the association constants of the corresponding primary and secondary alcohols, but close to an estimate based on symmetrical diols. The product leads to second association constants similar to those found for symmetrical diols. The sum of the chemical shifts of the associated and non‐associated OH protons in either 1:1 pyridine complex is higher than that of the shifts in the free diol and the 2:1 complex. These features are consistent with small cooperative effects, amounting to an average increase in the reaction free energy of 1.3 kJ mol−1 compared to monohydric alcohols. Infrared (IR) spectra of non‐symmetrical diols and quantum mechanical (QM) calculation of the energies and 1H NMR shifts of the OH protons in several conformers of propan‐1,2‐ and butan‐1,3‐diols indicate that both the primary and the secondary OH groups act as “donor” or “acceptor” in the free molecule. Gauche interactions in propan‐1,2‐diol enhance chemical shifts considerably less than does the intramolecular hydrogen bond in butan‐1,3‐diol. Copyright © 2011 John Wiley & Sons, Ltd.
Analysis of the upper airway by the acoustic reflection method in children with mucopolysaccharidosis
Authors: Leboulanger Nicolas , Louis Bruno , Vialle Raphaël , Heron Bénédicte , Fauroux Brigitte
Published: January 2011

Background

Upper airway obstruction is common in children with mucopolysaccharidosis. The acoustic reflection method is a noninvasive technique that can analyze the caliber of the upper airways. The aim of the study was to evaluate the feasibility of the acoustic reflection method in children with mucopolysaccharidosis, and to compare the characteristics of the upper airways evaluated by the acoustic reflection method in patients with mucopolysaccharidosis to matched healthy counterparts.

Methods

Open, single center, prospective, study.

Results

Accurate acoustic reflection measurements could be obtained in 7 of 10 patients (mean age: 10.4 ± 3.9 years; mucopolysaccharidosis type II (n = 3); type IV (n = 2), type VI (n = 1), and fucosidosis (n = 1)). The mean minimum cross‐sectional area was lower in mucopolysaccharidosis patients (1.6 ± 0.3 cm2) as compared to 14 healthy counterparts (1.8 ± 0.3 cm2; P = 0.03). The mean resistance of the airways was significantly higher in the MPS group (7.9 ± 1.8 cmH2O l−1 sec) as compared to the controls (5.5 ± 1.2 cmH2O l−1 sec; P = 0.006).

Conclusion

This study is the first to analyze the upper airways by the noninvasive acoustic reflection method in children with mucopolysaccharidosis. Due to a lack of cooperation, reliable measurements could only be obtained in 70% of a selected group of patients. Children with mucopolysaccharidosis have significant upper airway obstruction as assessed by the reduction of the minimal cross‐sectional area of the upper airways and the increase in airway resistance. Pediatr. Pulmonol. 2011; 46:587–594. © 2011 Wiley‐Liss, Inc.
Thermal and acid denaturation of bovine lens α‐crystallin
Authors: Rasmussen Tue , van de Weert Marco , Jiskoot Wim , Kasimova Marina R.
Published: January 2011

The chaperone‐like protein α‐crystallin is a ∼35 subunit hetero‐oligomer consisting of αA and αB subunits in a 3:1 molar ratio and has the function of maintaining eye lens transparency. We studied the thermal denaturation of α‐crystallin by differential scanning calorimetry (DSC), circular dichroism (CD), and dynamic light scattering (DLS) as a function of pH. Our results show that between pH 7 and 10 the protein undergoes a reversible thermal transition. However, the thermodynamic parameters obtained by DSC are inconsistent with the complete denaturation of an oligomeric protein of the size of α‐crystallin. Accordingly, the CD data suggest the presence of extensive residual secondary structure above the transition temperature. Within the pH range from 4 to 7 the increased aggregation propensity around the isoelectric point (pI ∼ 6) precludes observation of a thermal transition. As pH decreases below 4 the protein undergoes a substantial unfolding. The secondary structure content of the acid‐denatured state shows little sensitivity to heating. We propose that the thermal transition above pH 7 and the acid‐induced transition at ambient temperature result in predominant denaturation of the αB subunit. Although the extent of denaturation of the αA subunit cannot be estimated from the current data, the existence of a native‐like conformation is suggested by the preserved association of the subunits and the chaperone‐like activity. A key difference between the thermal and the acid denaturation is that the latter is accompanied by dissociation of αB subunits from the remaining αA‐oligomer, as supported by DLS studies. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Molecular dynamics simulations reveal structural coordination of Ffh‐FtsY heterodimer toward GTPase activation
Authors: Yang Ming‐Jun , Zhang Xin
Published: January 2011

Two homologous GTPases (guanine‐triphosphatases) in the signal recognition particle (SRP) and its receptor (SR) use their cumulative energy during GTP (guanine‐triphosphate) hydrolysis to control the co‐translational protein targeting process. Distinct from classical GTPases, which rely on external factors to hydrolyze GTP, SRP GTPases stimulate one another's activity in a self‐sufficient manner upon SRP–SR complex association. Although both ground‐state and putative transition‐state GTP analogs have been used to recapitulate the state of GTPase activation, the underlying mechanism of the activated state still remains elusive. In particular, several residues that were placed in pending positions have been shown to be important to GTP hydrolysis in biochemical studies. Here, we examined the stability and dynamics of three interaction networks involving these residues and discovered that they contribute to the GTPase activation via well‐tuned conformational changes. The crystallographically identified pending residues Ffh:R191/FtsY:R195 undergo extensive conformational rearrangements to form persisted interactions with FtsY:E284/Ffh:E274, explaining the biochemically observed defective effect of R191 mutant to the activation of both GTPases. In addition, the side chain of FtsY:R142, one of the most important catalytic residues, rotates to an extended conformation that could more efficiently maintain the electrostatic balance for GTP hydrolysis. Finally, the invariant residues Ffh:G190 and FtsY:G194, instead of the supposed auxiliary water molecules, are proposed to stabilize the nucleophilic waters during GTPase activation. In complementary to experimental observations, these findings suggest a more favorable interaction model for SRP GTPase activation and would thus benefit to our understanding of how SRP GTPases regulate the protein targeting pathway. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Predictive skill of a subset of models participating in D‐PHASE in the COPS region
Authors: Bauer Hans‐Stefan , Weusthoff Tanja , Dorninger Manfred , Wulfmeyer Volker , Schwitalla Thomas , Gorgas Theresa , Arpagaus Marco , Warrach‐Sagi Kirsten
Published: January 2011

The unique combination of observing and modelling efforts during the Convective and Orographically‐induced Precipitation Study (COPS) and D‐PHASE (Demonstration of the Probabilistic Hydrological and Atmospheric Simulation of flood Events in the alpine region) allows the systematic evaluation of models participating in D‐PHASE with observations collected during COPS. This study verifies a subset of the D‐PHASE models in the COPS region, including convection‐permitting models as well as models with convection parametrization. Observations from the Joint D‐PHASE/COPS (JDC) dataset are applied and processed with the Vienna Enhanced Resolution Analysis (VERA). The focus is set on monthly accumulated sums of the 12‐hourly precipitation between 0600 and 1800 UTC and includes comparisons of horizontal distributions, averaged diurnal cycles and neighbourhood verification techniques. Two fuzzy verification scores were applied: The Fractions Skill Score (FSS) and Upscaling.

The FSS analysis shows that all models are capable of forecasting the correct distribution of precipitation, especially for low precipitation thresholds. Low scores in the upscaling analysis reveal weaknesses in predicting the amounts of precipitation. The high‐resolution models usually outperform their lower‐resolution counterparts. This is true for the skill score analysis as well as the comparison of the horizontal distribution and the diurnal cycle averaged over the COPS period. Large differences between the models and the observations occur in regions with complex terrain, especially for models applying a convection scheme. Copyright © 2011 Royal Meteorological Society
Long‐range transport of Saharan dust and its radiative impact on precipitation forecast: a case study during the Convective and Orographically‐induced Precipitation Study (COPS)
Authors: Chaboureau Jean‐Pierre , Richard Evelyne , Pinty Jean‐Pierre , Flamant Cyrille , Di Girolamo Paolo , Kiemle Christoph , Behrendt Andreas , Chepfer Hélène , Chiriaco Marjolaine , Wulfmeyer Volker
Published: January 2011

A Saharan dust event affected the Rhine valley in southwestern Germany and eastern France on 1 August 2007 during the Convective and Orographically‐induced Precipitation Study (COPS) experiment. Prior to an episode of intense convection, a layer of dry, clean air capped by a moist, dusty layer was observed using Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and airborne and ground‐based lidar observations from North Africa to western Europe. The origin of the different layers was investigated using the regional model Meso‐NH. For the purpose of modelling evaluation, a lidar simulator was developed for direct comparison of observed and simulated vertical structures of the lidar backscattered signal. Overall, the model reproduced the vertical structure of dust probed several times by the different lidar systems during its long‐range transport. From Lagrangian back trajectories it was found that the dust was mobilized from sources in Mauritania six days earlier, while the dry layer subsided over the north Atlantic. Off the Moroccan coasts, the dry layer folded down beneath the dusty air mass and the two‐layer structure was advected to the Rhine valley in about two days. By heating the atmosphere, the dust layer changed the static stability of the atmosphere and thus the occurrence of convection. A study of sensitivity to the radiative effect of dust showed a better prediction of precipitation when a dust prognostic scheme was used rather than climatology or when dust effects were ignored. This result suggests that dust episodes that occur prior to convective events might be important for quantitative precipitation forecasts. Copyright © 2011 Royal Meteorological Society
Prediction of delivery mode with transperineal ultrasound in women with prolonged first stage of labor
Authors: Torkildsen E. A. , Salvesen K. Å. , Eggebø T. M.
Published: January 2011

Objective

To investigate if fetal head–perineum distance and angle of progression measured with two‐dimensional (2D) and three‐dimensional (3D) transperineal ultrasound could predict outcome of labor in primiparous women with prolonged first stage of labor.

Methods

This was a prospective observational study of 110 primiparous women with singleton cephalic presentation at term diagnosed with prolonged first stage of labor. Digital assessment of fetal station was related to the ischial spine. Fetal head descent was measured with transperineal ultrasound as the shortest distance from the fetal head to the perineum, and the angle between the pubic symphysis and the fetal head. Receiver–operating characteristics (ROC) curves were constructed and 2D and 3D data acquisitions were compared. The stored 3D volumes were assessed by an examiner blinded to all other data. Vaginal delivery vs. Cesarean section was the primary outcome.

Results

Cesarean section was performed in 25% of the women. Areas under the ROC curves for prediction of vaginal delivery were 81% (95% confidence interval (CI), 71–91%) (P < 0.01) and 76% (95% CI, 66–87%) (P < 0.01) for fetal head–perineum distance and angle of progression, respectively, as measured by 2D ultrasound and 66% (95% CI, 54–79%) for digital assessment of fetal station (P = 0.01). In 50% of women fetal head–perineum distance was ⩽ 40 mm and 93% (95% CI, 83–97%) of them delivered vaginally vs. 18% (95% CI, 5–48%) with distance > 50 mm. In 48% of women the angle of progression was ≥ 110° and 87% (95% CI, 75–93%) of them delivered vaginally vs. 38% (95% CI, 21–57%) with angle < 100°. Results from 2D and 3D acquisitions were similar.

Conclusion

Fetal head–perineum distance and angle of progression measured with 2D or 3D ultrasound can predict labor outcome, with similar predictive values for the two techniques. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
The thymic–thoracic ratio in fetal heart defects: a simple way to identify fetuses at high risk for microdeletion 22q11
Authors: Chaoui R. , Heling K.‐S. , Sarut Lopez A. , Thiel G. , Karl K.
Published: January 2011

Objectives

To establish reference ranges for the fetal thymic–thoracic ratio (TT‐ratio) and to compare results with those from fetuses with congenital heart defects (CHD) with and without microdeletion 22q11 (del.22q11), a condition known to be associated with a hypoplastic thymus.

Methods

TT‐ratio was defined as the quotient of the anteroposterior thymic to the intrathoracic mediastinal diameters measured in the three vessels and trachea view. This ratio was measured in a prospective cross‐sectional study of 302 normal healthy fetuses between 15 and 39 weeks' gestation. The study group comprised two groups: one group (CHDn) consisted of 90 fetuses with CHD and a normal karyotype with no del.22q11 and the other group (CHD22) included 20 fetuses with CHD and a normal karyotype but with proven del.22q11.

Results

The TT‐ratio of the normal fetuses did not show any statistically significant change during gestation, with a mean value of 0.44. The values of all 90 fetuses of the CHDn group were within the normal range and no different from normal fetuses. However, 19 of the 20 (95%) fetuses in the CHD22 group had a significantly smaller TT‐ratio (P < 0.001) compared with both the CHDn group and the normal fetuses, having a mean value of 0.25.

Conclusions

The TT‐ratio is reliable and easy to obtain during fetal echocardiography. Fetuses with CHD and a low TT‐ratio can be considered at high risk of having microdeletion del.22q11. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Robustness
Authors: Morgenthaler Stephan
Published: January 2011

That the conclusion based on a data analysis be robust and stable is not merely a desirable feature, it is essential. To merit this quality label, a conclusion must be supported by strong data‐based evidence and not simply be a discovery gleaned from a preconceived model and weakly supported by a part of the data. Robustness in statistics refers to the definition and investigation of procedures that lead to such stability. This article gives a brief overview of the concepts and procedures that are relevant in judging robustness. These have mostly been developed over the last five decades. WIREs Comp Stat 2011 3 85–94 DOI: 10.1002/wics.144

This article is categorized under:

Statistical Learning and Exploratory Methods of the Data Sciences > Exploratory Data Analysis

Statistical and Graphical Methods of Data Analysis > Nonparametric Methods

Statistical and Graphical Methods of Data Analysis > Robust Methods
Magnetoliposomes as magnetic resonance imaging contrast agents
Authors: Soenen Stefaan J. , Velde Greetje Vande , Ketkar‐Atre Ashwini , Himmelreich Uwe , De Cuyper Marcel
Published: January 2011

Among the wide variety in iron oxide nanoparticles which are routinely used as magnetic resonance imaging (MRI) contrast agents, magnetoliposomes (MLs) take up a special place. In the present work, the two main types (large and small MLs) are defined and their specific features are commented. For both types of MLs, the flexibility of the lipid coating allows for efficient functionalization, enabling bimodal imaging (e.g., MRI and fluorescence) or the use of MLs as theranostics. These features are especially true for large MLs, where several magnetite cores are encapsulated within a single large liposome, which were found to be highly efficient theranostic agents. By carefully fine‐tuning the number of magnetite cores and attaching Gd3+‐complexes onto the liposomal surface, the large MLs can be efficiently optimized for dynamic MRI. A special type of MLs, biogenic MLs, can also be efficiently used in this regard, with potential applications in cancer treatment and imaging. Small MLs, where the lipid bilayer is immediately attached onto a solid magnetite core, give a very high r2/r1 ratio. The flexibility of the lipid bilayer allows the incorporation of poly(ethylene glycol)–lipid conjugates to increase blood circulation times and be used as bone marrow contrast agents. Cationic lipids can also be incorporated, leading to high cell uptake and associated strong contrast generation in MRI of implanted cells. Unique for these small MLs is the high resistance the particles exhibit against intracellular degradation compared with dextran‐ or citrate‐coated particles. Additionally, intracellular clustering of the iron oxide cores enhances negative contrast generation and enables longer tracking of labeled cells in time. WIREs Nanomed Nanobiotechnol 2011 3 197–211 DOI: 10.1002/wnan.122

This article is categorized under:

Diagnostic Tools > Diagnostic Nanodevices

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging
Synthese und Kristallstruktur von (Ph3PNPPh3)2[Cu(N3)4]
Authors: Hiller W. , Hösler K. , Dehnicke K.
Published: January 2011

Inhaltsübersicht. Die Titelverbindung entsteht neben CuN3 · PPh3 bei der Einwirkung von Natriumazid auf CuCl2 und Triphenylphosphan in siedendem Acetonitril bei Anwesenheit von 15‐Krone‐5 als Lösungsvermittler für NaN3. (Ph3PNPPh3)2[Cu(N3)4] bildet schwarze Kristalle, die wir durch das IR‐Spektrum und durch eine röntgenographische Strukturanalyse charakterisiert haben. Raumgruppe Pbca, Z = 4, (4245 beobachtete unabhängige Reflexe, R = 7,2%), Gitter‐abmessungen (20°C):a = 1980, 1;b = 1618,8; c = 2014,3 pm. Die Verbindung besteht aus Kationen [Ph3PNPPh3]+ und Anionen [Cu(N3)4]2– der Symmetrie Ci, in denen das Cu‐Atom planar von den α‐N‐Atomen der Azidgruppen mit Cu–N‐Abständen von 197,2(4) und 189,5(4) pm umgeben ist.

Synthesis and Crystal Structure of (Ph3PNPPh3)2[Cu(N3)4]

The title compound is prepared besides CuN3 · PPh3 by the reaction of sodium azide with CuCl2 and PPh3 in boiling acetonitrile in the presence of 15‐crown‐5. (Ph3PNPPh3)2[Cu(N3)4] forms black crystals, which have been characterized by their IR spectrum as well as by an X‐ray structure determination. Space group Pbca, Z = 4 (4245 observed independent reflexions, R = 0.072), lattice dimensions (20°C): A = 1980.1; b = 1618.8; c = 2014.3 pm. The compound consists of Ph3PNPPh3+ cations and anions [Cu(N3)4]2– with symmetry C1, in which the copper atom is planarly surrounded by the four nitrogen atoms of the azide groups with bond lengths Cu–N of 197.2(4) and 189.5(4) pm, respectively.
Chemie polyfunktioneller Moleküle. 103 [1]: Chrom‐, Molybdän‐ und Wolframtetra‐ sowie ‐tricarbonyl‐Komplexe eines Diphenylphosphin‐substituierten Cyclophosphamide
Authors: Eikermann J. , Moll M. , Will N.
Published: January 2011

Inhaltsübersicht. (Ph2PCH2CH2)2N‐P(O)N(H)CH2CH2CH2O (2) bildet mit cis‐M(CO)4(C7H8) bzw. fac‐M(CO)3(CH3CN)3 (M = Cr, Mo, W; C7H8 = Norbornadien) die Chelat‐komplexe cis‐M(CO)4(PPh2CH2CH2)2N‐P(O)N(H)CH2CH2CH2O (3a–c) bzw. fac‐M(CO)3(PPh2CH2CH2)2N–P(O)N(H)CH2CH2CH2O (4a–c). 3a kristallisiert mit einem Mol Methanol aus, während 4a–c jeweils ein halbes Mol THF als Solvat enthalten. Alle Verbindungen wurden, soweit möglich, durch IR‐, Raman‐, 1H‐NMR‐, 31P‐NMR‐, 13C‐NMR‐ und Massenspektren charakterisiert.

Chemistry of Polyfunctional Molecules. 103. Chromium, Molybdenum, and Tungsten Tetra‐ and Tricarbonyl Complexes of a Diphenylphosphine‐substituted Cyclophosphamide Abstract. (Ph2PCH2CH2)2N–P(O)N(H)CH2CH2CH2O (2) forms with cis‐M(CO)4(C7H8) or fac‐M(CO)3(CH3CN)3 (M = Cr, Mo, W; C7H8 = norbornadiene) the chelate complexes cis‐M(CO)4(PPh2CH2CH2)2N–P(O)N(H)CH2CH2CH3O (3a–c) or fac‐M(CO)3(PPh2CH2CH2)2N–P(O)N(H)CH2CH2CH2O (4a–c). 3a crystallizes with one mole of methanol whereas 4a–c contain 1/2 mole of THP as solvate. All compounds were, as far as possible, characterized by their IR, Raman, 1H NMR, 31P NMR, 13C NMR, and mass spectra.
Das erste quinquinäre Oxoaurat(I) K6Na[IO6][AuO]2 = K6[NaIO6][AuO2/2]2 [1]
Authors: Schneider J. , Hoppe R.
Published: January 2011

Inhaltsübersicht. Bei Versuchen zur Darstellung unbekannter Phasen im System A/Au/I/O (mit A = Alkalimetall) entstanden durch Erhitzen eines Gemenges (2,2 K2O + 1,0 NaIO4; Au‐Rohr; 700°C, 59 d) farblose, transparente Einkristalle von K6NaAu2IO8, das nach Einkristalldaten (Vierkreisdiffraktometerdaten, 2465 Io(hkl), AgKα, R = 6,8% und Rw = 5,6%) monoklin in P2/c mit a = 707,4 pm; b = 977,3 pm; c = 1199,4 pm; β = 122,9°; Z = 2 kristallisiert. Charakteristisch sind die hier erstmals gefundenen, HgO‐analogen Zickzackketten [AuO2/2] längs [001]. Daneben prägen, den NaIO6‐Teil der Struktur betreffend, Ketten aus [IO6]‐Oktaeder, über Na in prismatischer Koordination verknüpft, den Aufbau.

The First Quinquinary Oxoaurate(I). K6Na[IO6][AuO]2 = K6[NaIO6][AuO2/2]2

Attempting to synthesize unknown phases in the system A/Au/I/O by heating a mixture of K2O and NaIO4 (K: Na = 2.2:1.0, sealed gold tube, 700°C) we obtained colourless, transparent single crystals of K6NaAu2IO6, a new type of Oxoaurate(I). According to single crystal data K6NaAu2IO8 crystallizes in a monoclinic form with a = 707.4 pm, b = 977.3 pm, c = 1199.4 pm β = 122.9° (Z = 2, space group P2/c). Essential part of the structure are chains NaIO6 and zigzag chains AuO2/2, both along [001]. The Madelung part of the lattice energy, MAPLE, and effective coordination numbers, ECoN, are calculated and discussed.
Neue Vertreter des K2Li14[Pb3O14]‐Typs Cs2Li14[Tb3O14] und K2Li14[Zr3O14] [1, 2]
Authors: Voigt S. , Werthmann R. , Hoppe R.
Published: January 2011

Inhaltsübersicht. Erstmals wurden klar durchscheinende, orange‐farbene Einkristalle von Cs2Li14[Tb3O14] aus Cs2TbO3 und Li2O (Tb: Li = 1:5) dargestellt [550°C, 21 d, verschlossenes AuRohr]. Es liegt der K2Li14[Pb3O14]‐Typ vor [Vierkreisdiffraktometerdaten, PW 1100, MoKä‐Strahlung, 660 Io(hkl), R = 4,8%, Rw = 3,4%, Immm, a = 1293,5(8), b = 792,6(3), c = 740,4(3) pm, Z = 2, drö = 4,65].

Ebenfalls neu wurde K2Li14[Zr3O14] in Form farbloser Einkristalle durch Tempern inniger Gemenge von K2O, Li2O und ZrO2 (K: Li: Zr = 1:4:1,5) dargestellt [900°C, 14 d, geschlossene Ni‐Bombe] und röntgenographisch untersucht. Die Strukturverfeinerung [612 Io(hkl), Vierkreisdiffraktometerdaten, PW 1100, MoKα‐Strahlung, R = 5,9%, Rw = 5,3%, Immm, a = 1244,6, b = 776,4, c = 724,3 pm, Z = 2] bestätigt die Isotypie mit K2Li14[Pb3O14]. Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECoN, diese über Mittlere Effektive Ionenradien, MEFIR, wurden berechnet. Für die nun bekannten Vertreter dieses Typs wurde ein Isotypievergleich vorgenommen.

New Compounds of the K2Li14[Pb3O14] Type: Cs2Li14[Tb8O14] and K2Li14[Zr3O14]

For the first time Cs2Li14[Tb3O14] has been prepared as orange single crystals from Cs2TbO3 and Li2O (Tb: Li = 1:5) [550°C, 21 d, sealed Au‐Tube]. Structure Refinement [four‐circle diffractometer data, PW 1100, MoKα radiation, 660 Io(hkl), R = 4.8%, Rw = 3.4%, Immm, a = 1293.5(8), b = 792.6(3), c = 740.4(3) pm, Z = 2, drö = 4.65] confirms isotypy with K2Li14[Pb3O14].

K2Li14[Zr3O14] has also been prepared as colorless single crystals from K2O, Li2O, and ZrO2 (K: Li: Zr = 1:4:1.5), [900°C, 14 d, closed Ni‐cylinder] and investigated by x‐ray [612 Io(hkl), four‐circle diffractometer data, PW 1100, MoKα radiation, R = 5.9%, Rw = 5.3%, Immm, a = 1244.6, b = 776.4, c = 724.3 pm, Z = 2].

The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, the latter derived from Mean Effective Fictive Ionic Radii, MEFIR, are calculated.

A detailed comparison of the structures is carried out.
Oxocuprate(I) mit CO2‐analogem Anion: Rb3[CuO2] [1]; (3. Mitteilung)
Authors: Carl W. , Hoppe R.
Published: January 2011

Inhaltsübersicht. Rb3[CuO2] wurde als dunkelgelbes Pulver bzw. erstmals in Form transparenter gelber, blockförmiger Einkristalle durch Tempern der binären Oxide (RbO0,63/Cu2O, Rb: Cu = 3,1:1 [Pulver] bzw. 4,2:1 [Einkristalle]) hergestellt (geschlossene Cu‐Bömbchen, 600°C/10 d, bzw. 560°C/14 d, dann langsam abgekühlt). Nach Strukturaufklärung (a = 930,9(1); b = 966,8(2); c = 675,5(1) pm, β = 110,1(1)°, P21/n–C52h, Z = 4, Vierkreisdiffraktometer AED2, MoKα, 1409 von 1573 Io(hkl), R = 14,6%, Rw = 10,0%) liegt ein neuer Strukturtyp vor (Parameter siehe Text). Strukturcharakteristisch sind die CO2‐analogen Hanteln [O–Cu–O] mit d(Cu–O) = 177 pm.

Die Struktur wird beschrieben. Der Madelunganteil der Gitterenergie, MAPLE, effektive Koordinationszahlen, ECoN, diese über mittlere fiktive Ionenradien, MEFIR, werden berechnet und diskutiert.

Oxocuprates(I) with CO2‐analogues Anions: Rb3[CuO2] (3rd Communication)

For the first time Rb3[CuO2] was prepared as dark yellow powder resp. yellow single crystals from the binary oxides (RbO0.63/Cu2O, Rb: Cu = 3.1:1 [powder] resp. 4.2:1 [single crystals], sealed Cu‐cylinders). The crystal structure (a = 930.9(1); b = 966.8(2); c = 675.5(1) pm, β = 110.1(1)°, P21/n–C52h, Z = 4, four circle diffractometer AED2, 1409 out of 1573 Io(hkl), R = 14.6%, Rw = 10.0%) was solved. The characteristic element is the CO2‐analogues group [O–Cu–O] with d(Cu–O) = 177 pm. The structure is described. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.