bluuebunny/crossref_metadata_2025 huggingface dataset:
Better performance with bone‐anchored hearing aid than acoustic devices in patients with severe air‐bone gap
Authors: de Wolf Maarten J. F. , Hendrix Sander , Cremers Cor W. R. J. , Snik Ad F. M.
Published: August 2010

Objectives/Hypothesis:

A study performed in the 1990s with analogue linear hearing aids showed that in patients with mixed hearing loss and an air‐bone gap that exceeded 25 to 30 dB, speech perception was better with a bone‐anchored hearing aid (Baha) than with a conventional behind‐the‐ear (BTE) device. The objective of the present study was to investigate whether this conclusion applies to today's digital BTEs with feedback cancellation and whether the crossover point still occurs at an air‐bone gap of 25 to 30 dB.

Study Design:

Case control.

Methods:

Experienced unilateral Baha users with the latest digital Baha processors were fitted with a powerful BTE with feedback cancellation. After an acclimatization period of 4 weeks, aided thresholds and speech recognition scores were determined and compared to those recorded previously with the Baha. To obtain patients' opinions, a disability‐specific questionnaire was used. Participants comprised 16 subjects with bilateral mixed hearing loss participated

Results:

Audiometric and speech recognition data showed similar trends to those described previously, but the crossover point had shifted to an air‐bone gap of 30 to 35 dB. In the questionnaire, the BTE was rated higher than the Baha, except by the patients with an air‐bone gap that exceeded an average of 45 dB.

Conclusions:

In patients with mixed hearing loss whose air‐bone gap exceeded 35 dB, speech recognition is likely to be better with a Baha than with a BTE. Therefore, the Baha should receive greater consideration when mixed hearing loss is combined with a significant air‐bone gap, even when there are no contraindications for BTEs. Laryngoscope, 2011
Land abandonment, landscape evolution, and soil erosion in a Spanish Mediterranean mountain region: The case of Camero Viejo
Authors: Arnaez J. , Lasanta T. , Errea M. P. , Ortigosa L.
Published: August 2010

The Spanish Mediterranean mountains have played an important social and economic role for many centuries. However, since the 1950s these regions have been considered of little economic interest, and this has led to the abandonment of villages, reduced productive activity, and significant changes in the landscape. In the last 50 years the Camero Viejo region (Iberian System, northeast Spain) has been subject to these changes, and was selected as our study area. Landscape evolution and soil erosion, as a result of agricultural abandonment, were studied using different analysis techniques: photointerpretation, geographic information systems and rainfall simulation. The results showed that a large proportion of previously cultivated land has been subject to plant recolonization processes. From 1956 to 2001, woodlands area increased from 10·1 per cent to 37 per cent, and scrubland increased from 42 per cent to 60 per cent. Changes in landscape structure in the same period suggest that the Camero Viejo is in a transitional stage from a highly humanized landscape to a more natural landscape. Although plant cover expansion is evident on most Camero Viejo hillslopes, in some terraced areas erosion processes are active. The generalized abandonment of agricultural terraces has favored the collapse of the stone walls of the terraces, with sliding of the soil. Surface runoff on abandoned terraces is also important. These erosion processes are related to the hydrological functioning of slopes following abandonment, neglect, and in some areas the intensification of grazing. Terrace destruction has a negative impact on the landscape and represents the loss of fertile soils. Landscape diversity should be preserved as an essential element of the economic potential of the Camero Viejo. Copyright © 2010 John Wiley & Sons, Ltd.
Primary sclerosing cholangitis in genetically diverse populations listed for liver transplantation: Unique clinical and human leukocyte antigen associations
Authors: Bowlus Christopher L. , Li Chin-Shang , Karlsen Tom H. , Lie Benedicte A. , Selmi Carlo
Published: August 2010

Primary sclerosing cholangitis (PSC) is well characterized in European populations. We aimed to characterize clinical characteristics and human leukocyte antigen (HLA) associations in a population of European American, Hispanic, and African American PSC patients listed for liver transplantation (LT). Population-stratified demographic, clinical, and HLA data from 6767 LT registrants of the United Network for Organ Sharing who had a diagnosis of PSC (4.7% of the registrants) were compared to data from registrants with other diagnoses. Compared to European Americans and Hispanics, African Americans were significantly younger (46.6 ± 13.7, 42.3 ± 15.9, and 39.7 ± 13.1 years, respectively; P = 0.002) and were listed with a higher Model for End-Stage Liver Disease score (15.2 ± 7.5, 14.9 ± 7.6, and 18.1 ± 9.3, respectively; P = 0.001); they were also less frequently noted to have inflammatory bowel disease in comparison with European Americans (71.4% versus 60.5%, P < 0.01). In multivariate analysis, African origin was a significant factor associated with listing for LT with PSC (odds ratio with respect to European Americans = 1.325, 95% confidence interval = 1.221-1.438). HLA associations in European Americans, Hispanics, and African Americans with PSC versus alcoholic liver disease were detected for HLA-B8, HLA-DR13, and protective HLA-DR4. However, HLA-DR3, which is in linkage disequilibrium with HLA-B8, showed associations only in European Americans and Hispanics. In conclusion, African Americans with PSC who are listed for LT differ clinically from European Americans and Hispanics. The association with HLA-B8 but not HLA-DR3 in African Americans should make possible the refinement of the HLA associations in PSC. Liver Transpl 16:1324-1330, 2010. © 2010 AASLD.
Impact of obesity on children undergoing liver transplantation
Authors: Dick André A. S. , Perkins James D. , Spitzer Austin L. , Lao Oliver B. , Healey Patrick J. , Reyes Jorge D.
Published: August 2010

Controversies exist with respect to the mortality of patients undergoing liver transplantation at the extremes of the body mass index (BMI). For pediatric liver transplantation, weight is usually the only factor considered in survival analysis. A review of the United Network for Organ Sharing database (1987-2007) revealed 9701 pediatric patients (<18 years old) who underwent primary liver transplantation. Patients were stratified into 5 BMI categories established by the World Health Organization according to their Z score, which was based on age, gender, and BMI: −3, −2, 0, +2, and +3. The survival rates in these 5 categories were compared with Kaplan-Meier survival curves and log-rank testing. Patients with thinness (Z score = −2) and severe thinness (Z score = −3) had significantly (P < 0.0001) lower survival at 1 year (84.4%) versus the survival (88.7%) of the normal and overweight groups (Z score = 0 and Z score = + 2, respectively). For patients with obesity (Z score = +3), there was no significant difference in survival early after transplantation, but their mortality gradually increased in the later years after transplantation. By 12 years after liver transplantation, the obese group had significantly (P = 0.04) lower survival (72%) than the normal and overweight groups (77%). In conclusion, liver transplantation holds increased risk for obese pediatric patients. Thin pediatric patients experience early mortality after liver transplantation, and obese pediatric patients experience late mortality after liver transplantation. Transplant management can be modified to optimize the care of these patients. Liver Transpl 16:1296-1302, 2010. © 2010 AASLD.
Hepatitis C recurrence is not adversely affected by the use of donation after cardiac death liver allografts
Authors: Tao Ran , Ruppert Kristine , Cruz Ruy J. , Malik Shahid M. , Shaikh Obaid , Ahmad Jawad , DiMartini Andrea , Humar Abhinav , Fontes Paulo A. , de Vera Michael E.
Published: August 2010

Many factors can worsen a recurrent hepatitis C virus (HCV) infection after liver transplantation (LT). We sought to determine whether the use of donation after cardiac death (DCD) livers affects HCV recurrence. From January 2000 to June 2008, 37 HCV patients underwent LT with DCD allografts. The outcomes and severity of HCV recurrence were analyzed along with those for 74 matched control patients with HCV who received donation after brain death (DBD) livers. The 2 groups had similar donor and recipient characteristics, immunosuppression regimens, rates of acute cellular rejection (ACR), and HCV profiles. DCD patients had a higher incidence of primary nonfunction (19% versus 3%, P = 0.006) and significantly higher peak aspartate aminotransferase levels in comparison with DBD subjects, suggesting a greater degree of ischemia/reperfusion injury. Although the survival rates were not significantly different, DCD recipients had lower 1- and 5-year patient survival rates (83% and 69% versus 84% and 78%, respectively, P = 0.75) and graft survival rates (70% and 61% versus 82% and 74%, respectively, P = 0.24). Three hundred fourteen protocol and clinically indicated liver biopsy procedures were performed within 6 years after transplantation, and mixed modeling analysis showed that fibrosis progression rates were similar for the 2 groups (0.6 fibrosis units/year according to the Ishak modified staging system). The rates of severe HCV recurrence (retransplantation or death due to recurrent hepatitis C and/or the development of stage 4/6 fibrosis or worse within 2 years) were similar [3 DCD patients (8%) versus 11 DBD patients (15%), P = 0.38], and cytomegalovirus infection (hazard ratio = 7.9, P = 0.002, 95% confidence interval = 2.1-28.9) and ACR (hazard ratio = 6.2, P = 0.002, 95% confidence interval = 2.0-19.7) were the only independent risk factors for severe recurrence. In summary, although there was a trend of poorer overall outcomes in DCD patients, the use of DCD livers did not appear to adversely affect HCV recurrence after LT. Liver Transpl 16:1288-1295, 2010. © 2010 AASLD.
Risk of transmission of systemic transthyretin amyloidosis after domino liver transplantation
Authors: Lladó Laura , Baliellas Carme , Casasnovas Carlos , Ferrer Isidre , Fabregat Joan , Ramos Emilio , Castellote Jose , Torras Jaume , Xiol Xavier , Rafecas Antoni
Published: August 2010

Recent reports of the transmission of systemic transthyretin (TTR) amyloidosis after domino liver transplantation (DLT) using grafts from patients with familial amyloid polyneuropathy (FAP) have raised concerns about the procedure. The aim of this study was to evaluate the transmission incidence of systemic TTR amyloidosis after DLT with a complete clinical, neurological, and pathological assessment. At our institution, DLT has been performed 31 times with livers from patients with FAP. Seventeen of the 19 patients still alive in 2008 agreed to enter the study. This cross-sectional study of this cohort of patients included clinical assessments, rectal biopsy, and electroneuromyography (as well as sural nerve biopsy when it was indicated). The mean follow-up at the time of the study was 62.6 ± 2.9 months. Clinically, 3 patients complained of weak dysesthesia. When a focused study was performed, 8 patients reported some kind of neurological and/or gastrointestinal disturbance. Six of the rectal biopsy samples showed amyloid deposits (TTR-positive). Electromyography (EMG) showed signs of mild sensorimotor neuropathy in 3 cases and moderate to severe sensorimotor neuropathy in 1 case. Only 2 of the 4 patients with EMG signs of polyneuropathy showed amyloid deposits in their rectal biopsy samples. Sural nerve biopsy revealed amyloid deposits (TTR-positive) in all 4 patients with EMG signs of polyneuropathy. Two patients with normal EMG findings had TTR-positive amyloid deposits in their sural nerve biopsy samples. In conclusion, de novo systemic amyloidosis after DLT may be more frequent and appear earlier than was initially thought. In our opinion, however, the graft shortage still justifies DLT in selected patients, despite the risk of de novo systemic amyloidosis. Sural nerve biopsy with EMG and clinical correlation is mandatory for confirming the disease. Indeed, other causes of neuropathy should be excluded. Liver Transpl 16:1386–1392, 2010. © 2010 AASLD.
Identification of new donor variables associated with graft survival in a single-center liver transplant cohort
Authors: Nafidi Otmane , Marleau Denis , Roy André , Bilodeau Marc
Published: August 2010

We currently face the more widespread use of marginal livers for organ transplantation. Therefore, it is imperative to adequately identify the factors affecting early and late graft survival in that setting. The objective of this study was to determine the donor variables associated with graft survival in the liver transplant program of the University of Montreal. We retrospectively studied the survival of 634 grafts transplanted into 634 recipients between 1990 and 2008. The variables associated with 1- and 5-year graft survival were identified with the Cox proportional hazards regression model. The donor population was characterized by a mean age of 45.24 ± 18.15 years; 52.8% had at least 1 of the currently recognized extended criteria donor factors. The recipients had a mean age of 52.51 ± 10.80 years and a mean Child-Pugh score of 9.58 ± 2.32. Liver grafts were considered inadequate with respect to their gross appearance in 16 cases (2.5%). The 1- and 5-year graft survival rates were 78.7% and 71.1%, respectively. According to a Cox regression multivariate analysis, the independent determining factors associated with graft survival were (1) the graft appearance (P < 0.001 at 1 and 5 years), (2) the donor partial pressure of oxygen/fraction of inspired oxygen ratio (P = 0.005 at 1 year and P < 0.005 at 5 years), and (3) the donor hemoglobin level (P = 0.008 at 1 year and P = 0.005 at 5 years). In conclusion, the gross graft appearance, the presence of donor lung diffusion abnormalities, and the donor hemoglobin levels were significantly associated with graft survival. These observations, if they are confirmed, could improve our ability to select marginal organs. Liver Transpl 16:1393–1399, 2010. © 2010 AASLD.
Incidental intracardiac thromboemboli during liver transplantation: Incidence, risk factors, and management
Authors: Xia Victor W. , Ho Jonathan K. , Nourmand Hamid , Wray Christopher , Busuttil Ronald W. , Steadman Randolph H.
Published: August 2010

Even though numerous cases of massive thromboemboli have been reported in the literature, intracardiac thromboemboli (ICTs) incidentally found during orthotopic liver transplantation (OLT) have not been examined. In this study, we retrospectively examined the incidence, risk factors, and management of incidental ICTs during OLT. After institutional review board approval, adult patients who underwent OLT between January 2004 and December 2008 at our center were reviewed. ICTs were identified and confirmed by the examination of OLT datasheets, anesthesia records, and recorded transesophageal echocardiography (TEE) clips. The clinical presentation, management, and outcomes of the patients with ICTs were reviewed. Risk factors were analyzed by multivariate logistic regression. During the study period, 426 of the 936 adult OLT patients (45.5%) underwent intraoperative TEE monitoring. Incidental ICTs were identified in 8 of these 426 patients (1.9%). Two ICTs occurred before reperfusion, and 6 ICTs occurred after reperfusion. The treatment was at the discretion of the treating physicians; however, none of the patients received an anticoagulant or thrombolytics. Multivariate analysis identified 2 independent risk factors for intraoperative incidental ICTs: the presence of symptomatic or surgically treated portal hypertension (a history of gastrointestinal bleeding, a transjugular intrahepatic portosystemic shunt procedure, or portocaval shunt surgery) before OLT and intraoperative hemodialysis (odds ratios of 4.05 and 7.29, respectively; P < 0.05 for both). In conclusion, incidental ICTs during OLT occurred at a rate of 1.9% and were associated with several preoperative and intraoperative risk factors. The use of TEE allows early identification, which may be important. Our management for incidental ICTs is described; however, no conclusions can be made about the optimal therapy. Liver Transpl 16:1421–1427, 2010. © 2010 AASLD.
Solid Peptide Nanoparticles – Structural Characterization and Quantification of Cargo Encapsulation
Authors: Dittrich Christian , Meier Wolfgang
Published: August 2010

CD3ac, an uncharged and strongly hydrophobic 10 amino acid peptide (Ac‐LK(Ac)‐LK(Ac)‐LK(Ac)‐LW‐DL‐LW‐DL‐LW‐DL‐LW‐NH2) was synthesized and purified. The peptide readily dissolves in ethanol and – upon solvent exchange to water – assembles into solid spherical particles with diameters of around 500 nm and low size‐polydispersity. CD3ac self‐assembles in a convenient one‐step‐process in the absence of a templating two‐phase solvent system or any other templating agents. Circular dichroism reveals a gramicidin‐like secondary structure, which can be attributed to the presence of D‐leucine, whereas LCD3ac, a peptide of identical constitution yet composed entirely of L‐amino acids precipitates amorphously. The unacetylated derivative of LCD3ac (LCD3) displays α‐helical character in circular dichroism. During the process of bead formation, CD3ac can take up and enrich water‐soluble and – insoluble cargo compounds, which is exemplified by the encapsulation of rose bengal (RB) and 5‐carboxy‐fluorescein (CF), two xanthene derivatives. We confirmed their presence in CD3ac beads by confocal fluorescence microscopy and quantified the encapsulation efficiency by absorption measurements of dissolved RB‐containing peptide bead suspensions. Loaded CD3ac beads consist of up to 40 mol‐% RB, which corresponds to a logarithmic partition coefficient of 2.95. To the best of our knowledge CD3ac is the first peptide synthesized by Fmoc chemistry which forms solid particles in the nano‐ and micrometer size range and holds promise for drug delivery applications.

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Equilibrium Constants and Activation Rate Coefficients for Atom Transfer Radical Polymerizations at Pressures up to 2 500 Bar
Authors: Buback Michael , Morick Joachim
Published: August 2010

Equilibrium constants, KATRP, and activation rate coefficients, kact, have been measured up to 2 500 bar and used for estimating reaction volumes, ΔVR, and activation volumes, ΔV‡act, respectively. Quantitative analysis of binary copper‐ligand–alkyl bromide initiator systems, without monomer being present, has been carried out in a solution of acetonitrile by high‐pressure online‐FT‐NIR/VIS spectroscopic monitoring of the CuII ligand species. The numbers for ΔVR and ΔV‡act are close to each other and reflect the characteristics of ligand complexation. Whereas ΔVR is almost insensitive to the type of initiator, the absolute KATRP clearly depends on this alkyl bromide species.

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Functional Dendritic Polymers for the Development of Hybrid Materials for Water Purification
Authors: Arkas Michael , Tsiourvas Dimitris , Paleos Constantinos M.
Published: August 2010

Dendritic polymers can, depending on their polarity and the interaction ability of their interior, encapsulate water contaminants. By appropriate functionalization of their external groups and following integration with ceramics, hybrid devices bearing nanosized sorbents are developed. In a first strategy, hydrophobic dendritic polymers were non‐covalently attached on the surface of ceramic filter modules, while in a second, dendritic polymers were covalently bound on these surfaces. In another method, dendritic polymers act as templates and induce the formation of silica/dendritic polymer nanospheres. In all cases, the property of dendritic polymers to encapsulate impurities remains intact, leading to effective filtration/purification systems.

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Photoinduced Controlled Radical Polymerization
Authors: Tasdelen Mehmet Atilla , Uygun Mustafa , Yagci Yusuf
Published: August 2010

Well‐controlled radical polymerization of methyl methacrylate can be achieved by in situ photochemical generation of copper (I) complex from air‐stable copper (II) species without using any reducing agent at room temperature. The living character of this polymerization was confirmed by both the linear tendency of molecular weight evolution with conversion and a chain extension experiment.

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Distinct basal ganglia hyperechogenicity in idiopathic basal ganglia calcification
Authors: Brüggemann Norbert , Schneider Susanne A. , Sander Thurid , Klein Christine , Hagenah Johann
Published: August 2010

We report a 67‐year‐old patient with idiopathic basal ganglia calcification (IBGC). He presented with progressive cognitive impairment, frontal lobe dysfunction, mild leg spasticity, and levodopa (L‐dopa)‐responsive parkinsonism. Transcranial sonography (TCS) revealed marked hyperechogenicity of the basal ganglia and periventricular spaces bilaterally. The detected signal alterations showed a fairly symmetric distribution and corresponded to the hyperintense calcifications depicted on the computer tomography brain scan. The combination of symmetric hyperechogenic areas adjacent to the lateral ventricles and of the basal ganglia may serve as an imaging marker characteristic of IBGC. Hyperechogenicity due to extended basal ganglia calcification as presented here is distinct from the pattern of hyperechogenicity caused by heavy metal accumulation, which is described to be less striking. In addition to atypical parkinsonian syndromes such as progressive supranuclear palsy and multiple system atrophy, IBGC is thus another differential diagnosis of parkinsonism with basal ganglia hyperechogenicity. © 2010 Movement Disorder Society.
Advanced magnetic resonance imaging in benign hereditary chorea: Study of two familial cases
Authors: Maccabelli Gloria , Pichiecchio Anna , Guala Andrea , Ponzio Michela , Palesi Fulvia , Maranzana, RT Diego , Poloni Guy Umberto , Bastianello Stefano , Danesino Cesare
Published: August 2010

No brain abnormalities are usually detected on conventional magnetic resonance imaging (MRI) in benign hereditary chorea (BHC); there are currently no studies with advanced techniques in literature. We investigated whether conventional and advanced MRI techniques could depict regional brain abnormalities in two familial BHC patients and 24 healthy controls. No brain abnormalities on conventional scans were detectable; also, no significant differences in fractional anisotropy of the basal nuclei were observed. Volumetric analysis showed a decreased volume of the striatum bilaterally compared with controls, whereas spectroscopy demonstrated a significant increased myoinositol/creatine ratio bilaterally, a reduction of choline/creatine ratio bilaterally, and of N‐acetyl‐aspartate/creatine in the right putamen. With the limits of the small sample size in the patient group, these data show that, despite the absence of macroscopic changes on conventional MRI, volumetric and metabolic abnormalities are present in the basal nuclei of BHC patients. © 2010 Movement Disorder Society.
What is the functional significance of nondominant arm tremor in essential tremor?
Authors: Louis Elan D. , Gerbin Marina , Mullaney Mary M.
Published: August 2010

Tremor in the dominant arm is often the focus of clinical attention in essential tremor (ET) yet many daily activities require both arms. The functional relevance of nondominant arm tremor has rarely been studied. In 181 right‐handed patients with ET, action tremor in each arm was rated using a clinical rating scale. Tremor disability was self‐reported and a performance‐based test of function was administered. Independently of tremor on the right, greater tremor severity on the left was associated with greater self‐reported disability (P = 0.02) and greater performance‐based dysfunction (P < 0.001). In 5.0% of patients, tremor was largely restricted to the nondominant arm. Nondominant arm tremor, independent of dominant arm tremor, had a significant functional correlate, contributing to both greater perceived and greater observable functional difficulty. In 5% of patients, tremor in the nondominant arm was the likely motivator for seeking care, which is another indication of its functional significance. © 2010 Movement Disorder Society.
POLG, but not PEO1, is a frequent cause of cerebellar ataxia in Central Europe
Authors: Schicks Julia , Synofzik Matthis , Schulte Claudia , Schöls Ludger
Published: August 2010

Nuclear genes, in particular mitochondrial polymerase gamma (POLG) and PEO1, have been increasingly recognized to cause mitochondrial diseases. Both genes assume a complementary role as part of the mitochondrial DNA (mtDNA) replication fork and, accordingly, seem to present with largely overlapping phenotypical spectra. We assessed the frequency and phenotypic spectrum of PEO1 compared to POLG mutations in a cohort of 80 patients with cerebellar ataxia for which common repeat expansion diseases had been excluded. Patients were selected to present additional features previously described for PEO1 mutations, namely early age of onset, progressive external ophthalmoplegia (PEO), or epilepsy. Whereas PEO1 mutations were not found in our cohort, POLG frequently caused ataxia with PEO (47%), psychiatric comorbidities (20%) and, more rarely, with epilepsy (14%). Thus, PEO1 is rare in Central Europe even in those patients displaying characteristic phenotypic features. In contrast, POLG is rather common in Central European ataxia patients. It should be particularly considered in ataxia patients with PEO, psychiatric comorbidities, and/or sensory neuropathy, even if characteristic mitochondrial extra‐CNS features are absent. © 2010 Movement Disorder Society.
Free Energy Calculations of Mutations Involving a Tightly Bound Water Molecule and Ligand Substitutions in a Ligand‐Protein Complex
Authors: García‐Sosa Alfonso T. , Mancera Ricardo L.
Published: August 2010

The accurate calculation of the free energy of interaction of protein‐water‐ligand systems has an important role in molecular recognition and drug design that is often not fully considered. We report free energy thermodynamic integration calculations used to evaluate the effects of inclusion, neglect, and targeting and removal (i.e., systematic substitution by ligand functional groups) of an important, tightly bound, water molecule in the SH3 domain of Abl tyrosine kinase. The effects of this water molecule on the free energies of interaction of several Abl‐SH3 domain‐ligand systems reveal that there is an unfavourable free energy change associated with its removal into the bulk solvent. Only three substitutions by an additional functional group (out of methyl, ethyl, hydroxyl, amino, and amide groups) in the phenyl ring of a tyrosine in the peptide ligand resulted in a favourable change in the free energy of binding upon replacement of the ordered water molecule. This computational approach provides a direct route to the systematic and rigorous prediction of the thermodynamic influence of ordered, structural water molecules on ligand modification and optimization in drug design by calculating free energy changes in protein‐water‐ligand systems.
The One‐Class Classification Approach to Data Description and to Models Applicability Domain
Authors: Baskin Igor I. , Kireeva Natalia , Varnek Alexandre
Published: August 2010

In this paper, we associate an applicability domain (AD) of QSAR/QSPR models with the area in the input (descriptor) space in which the density of training data points exceeds a certain threshold. It could be proved that the predictive performance of the models (built on the training set) is larger for the test compounds inside the high density area, than for those outside this area. Instead of searching a decision surface separating high and low density areas in the input space, the one‐class classification 1‐SVM approach looks for a hyperplane in the associated feature space. Unlike other reported in the literature AD definitions, this approach: (i) is purely “data‐based”, i.e. it assigns the same AD to all models built on the same training set, (ii) provides results that depend only on the initial descriptors pool generated for the training set, (iii) can be used for the huge number of descriptors, as well as in the framework of structured kernel‐based approaches, e.g., chemical graph kernels. The developed approach has been applied to improve the performance of QSPR models for stability constants of the complexes of organic ligands with alkaline‐earth metals in water.
Terpolymerization of Ethylene/Propylene/Diene Monomers Using (2‐PhInd)2ZrCl2 Metallocene Catalysts
Authors: Ahmadjo Saeid , Arabi Hassan , Nekoomanesh Mehdi , Zohuri Gholam Hossein , Mortazavi Mohammad Mehdi , Naderi Ghasem
Published: August 2010

(2‐PhInd)2ZrCl2 was synthesized and used for the first time in the terpolymerization of ethylene, propylene and 5‐ethylidiene‐2‐norbornene (ENB). It showed appropriate activity, high incorporation ability of the comonomers and good workup in terpolymerization. Increasing the [Al]/[Zr] ratio up to 188:1 increased ethylene content and decreased the ENB content of the terpolymer. The higher the polymerization temperature, the lower the ethylene content and higher the ENB content that was obtained. A higher propylene content in the P/E feed ratio and ENB concentration led to higher ENB content of the EPDM product. A compounded EPDM showed good curing properties compared to a commercial EPDM.

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Nonperiodic preventive maintenance for repairable systems
Authors: Lin Zu‐Liang , Huang Yeu‐Shiang
Published: August 2010

As a complex system with multiple components usually deteriorates with age, preventive maintenance (PM) is often performed to keep the system functioning in a good state to prolong its effective age. In this study, a nonhomogeneous Poisson process with a power law failure intensity is used to describe the deterioration of a repairable system, and the optimal nonperiodic PM schedule can be determined to minimize the expected total cost per unit time. However, since the determination of such optimal PM policies may involve numerous uncertainties, which typically make the analyses difficult to perform because of the scarcity of data, a Bayesian decision model, which utilizes all available information effectively, is also proposed for determining the optimal PM strategies. A numerical example with a real failure data set is used to illustrate the effectiveness of the proposed approach. The results show that the optimal schedules derived by Bayesian approach are relatively more conservative than that for non‐Bayesian approach because of the uncertainty of the intensity function, and if the intensity function are updated using the collected data set, which indicates more severe deterioration than the prior belief, replacing the entire system instead of frequent PM activities before serious deterioration is suggested. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010
Some elementary ideas concerning the complexity of system structure
Authors: Li Shuang , Lynch James
Published: August 2010

A system of iid Bernoulli components is the starting point in the statistical theory of reliability. This simplification allows for the development of a rich, though elementary, theory for the structure of the system. Two representations play a prominent role in the study of structural reliability. One is the minimal path set representation and the other is the signature representation. By combining the two representations with the Gibbs measure for the state of components, one obtains terms that can be interpreted as the complexity of the system structure. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010
An extensible modeling framework for dynamic reassignment and rerouting in cooperative airborne operations
Authors: Murray Chase C. , Karwan Mark H.
Published: August 2010

Unmanned aerial vehicles (UAVs), increasingly vital to the success of military operations, operate in a complex and dynamic environment, sometimes in concert with manned aircraft. We present an extensible modeling framework for the solution to the dynamic resource management (DRM) problem, where airborne resources must be reassigned to time‐sensitive tasks in response to changes in battlespace conditions. The DRM problem is characterized by diverse tasks with time windows, heterogeneous resources with fuel‐ and payload‐capacity limitations, and multiple competing objectives. We propose an integer linear programing formulation for this problem, where mathematical feasibility is guaranteed. Although motivated by airborne military operations, the proposed general modeling framework is applicable to a wide array of settings, such as disaster relief operations. Additionally, land‐ or water‐based operations may be modeled within this framework, as well as any combination of manned and unmanned vehicles. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010
Finding cancer stem cells: are aldehyde dehydrogenases fit for purpose?
Authors: Alison Malcolm R , Guppy Naomi J , Lim Susan ML , Nicholson Linda J
Published: August 2010

Despite many years of intensive effort, there is surprisingly little consensus on the most suitable markers with which to locate and isolate stem cells from adult tissues. By comparison, the study of cancer stem cells is still in its infancy; so, unsurprisingly, there is great uncertainty as to the identity of these cells. Stem cell markers can be broadly categorized into molecular determinants of self‐renewal, clonogenicity, multipotentiality, adherence to the niche, and longevity. This review assesses the utility of recognizing cancer stem cells by virtue of high expression of aldehyde dehydrogenases (ALDHs), probably significant determinants of cell survival through their ability to detoxify many potentially cytotoxic molecules, and contributing to drug resistance. Antibodies are available against the ALDH enzyme family, but the vast majority of studies have used cell sorting techniques to enrich for cells expressing these enzymes. Live cells expressing high ALDH activity are usually identified by the ALDEFLUOR kit and sorted by fluorescence activated cell sorting (FACS). For many human tumours, but notably breast cancer, cell selection based upon ALDH activity appears to be a useful marker for enriching for cells with tumour‐initiating activity (presumed cancer stem cells) in immunodeficient mice, and indeed the frequency of so‐called ALDHbri cells in many tumours can be an independent prognostic indicator. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Pin1 acts as a modulator of cell proliferation through alteration in NF‐κB but not β‐catenin/TCF4 signalling in a subset of endometrial carcinoma cells
Authors: Saegusa Makoto , Hashimura Miki , Kuwata Takeshi
Published: August 2010

Prolyl isomerase Pin1 is frequently up‐regulated in a variety of human malignancies, modulating signalling in several oncogenic pathways, including those involving NF‐κB and β‐catenin. Our previous study provided evidence that alterations in these signal pathways are essential events during trans‐differentiation of endometrial carcinoma (Em Ca) cells. Here we focused on the functional roles of Pin1. In normal endometrium, Pin1 expression showed a stepwise decrease from proliferative to secretory phases during the menstrual cycle, correlating positively with cell proliferation and expression of several cell cycle‐related molecules including E2F1 and pRb. Transfection of E2F1 caused transactivation of Pin1, indicating control by E2F1/Rb pathways. In Em Cas with morules, Pin1 expression was found to be significantly increased in glandular but not in morular components, correlating inversely with nuclear accumulation of β‐catenin. Overexpression also caused an increase in the stability of nuclear p65, leading to enhancement of NF‐κB‐mediated transactivation of the cyclin D1 gene, in contrast to minimal inhibition of β‐catenin/TCF4 transcription activity. These findings indicate that Pin1 may play an important role in preserving cell proliferative activity in glandular carcinoma components through enhancement of NF‐κB signalling, but its down‐regulation may be a key signal for induction of trans‐differentiation of Em Ca cells, contributing to a shift from NF‐κB to β‐catenin/TCF signalling pathways. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Preparation of nanocomposite dispersions based on cellulose whiskers and acrylic copolymer by miniemulsion polymerization: Effect of the silane content
Authors: Ben Mabrouk Ayman , Kaddami Hamid , Magnin Albert , Belgacem Mohamed Naceur , Dufresne Alain , Boufi Sami
Published: August 2010

A one‐step method was used to prepare stable aqueous nanocomposite dispersions based on cellulose whiskers extracted from the rachis of the date palm tree and a poly(styrene‐co‐2‐ethyl hexylacrylate) copolymer via miniemulsion polymerization. A reactive silane, i.e., methacryloxypropyl triethoxysilane was added to stabilize the dispersion and favor the anchoring of the whiskers on polymer particles. Dynamic light scattering was used to study the effect of the silane and whiskers contents on the average particle size of the polymer. Nanocomposites materials were prepared from these dispersions using a casting/evaporation method. The effect of the silane and whiskers contents on the thermal and mechanical properties were studied using differential scanning calorimetry and dynamic mechanical analysis. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Incorporation of reactive silver‐tricalcium phosphate nanoparticles into polyamide 6 allows preparation of self‐disinfecting fibers
Authors: Gerber Lukas C. , Mohn Dirk , Fortunato Giuseppino , Astasov‐Frauenhoffer Monika , Imfeld Thomas , Waltimo Tuomas , Zehnder Matthias , Stark Wendelin J.
Published: August 2010

Polymer fibers are used for a wide range of materials in contact with the human body. Since bacterial contamination may cause diseases, it is desirable to provide fibers with antimicrobial properties. This work investigates the ability of silver‐tricalcium phosphate nanoparticles (Ag/TCP) to build a reactive system when incorporated in polyamide fibers. In the presence of bacteria, the TCP carrier particles are biodegraded and trigger the release of silver. For this work, Ag/TCP nanoparticles (1.3 wt% silver) were produced by flame spray synthesis and subsequently processed with polyamide 6 to fibers (125‐μm thick, containing 260 ppm silver) with the aid of extrusion and melt‐spinning for subsequent antibacterial testing. The fibers were contaminated with the clinically relevant strains Escherichia coli or Streptococcus sanguinis, respectively. The reactive fibers demonstrated significantly reduced plate count within 24 h (the number of colony forming units was reduced by 99.999% with E. coli and 99.6% with S. sanguinis compared with pure PA6 reference fibers). These reactive properties of easily integrated antibacterial silver suggest an implementation of intelligent fibers to a wide range of applications. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Influence of molecular weight on rheological, thermal, and mechanical properties of PEEK
Authors: Yuan Mingjun , Galloway Jeffrey A. , Hoffman Richard J. , Bhatt Sanjiv
Published: August 2010

This study focuses on the influence of molecular weight on the rheological, thermal, and mechanical behavior of poly(ether‐ether‐ketone) (PEEK), a semicrystalline high‐performance polymer. The results show that the molecular weight of PEEK has significant influence on its rheological, thermal, and mechanical behavior. It was found that PEEK has the unique characteristic of two shear‐thinning regions. The shear viscosity and the stress relaxation time of PEEK increase significantly as molecular weight increases. In general, the Cox‐Merz rule is valid for all grades of PEEK. As molecular weight increases, the melting temperature of PEEK decreases slightly, but its isothermal and nonisothermal crystallization temperatures drop dramatically. As molecular weight increases, the crystallinity, the crystallization rate, and the magnitude of crystallization activation energy decrease. The crystallization kinetics study indicates that PEEK tends to form spherical crystalline structures, regardless of its molecular weight. As molecular weight increases, the tensile strength at yield, the tensile modulus, and the flexural modulus of PEEK decrease slightly, whereas the tensile strength at break, the tensile strain at break, the modulus of toughness, and the impact strength of PEEK increase significantly. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Silica/polystyrene and silica/polystyrene‐b‐polymethacryloxypropyltrimethoxysilane hybrid nanoparticles via surface‐initiated ATRP and comparison of their wettabilities
Authors: Yu Hai‐Jiang , Luo Zheng‐Hong
Published: August 2010

Both silica/polystyrene (SiO2/PS) and silica/polystyrene‐b‐polymethacryloxypropyltrimethoxysilane (SiO2/PS‐b‐PMPTS) hybrid nanoparticles were synthesized via surface‐initiated atom transfer radical polymerization (SI‐ATRP) from SiO2 nanoparticles. The growths of all polymers via ATRP from the SiO2 surfaces were well controlled as demonstrated by the macromolecular characteristics of the grafted chains. Their wettabilities were measured and compared by water contact angle (WCA) and surface roughness. The results show that the nanoparticles possess hydrophobic surface properties. The static WCA of SiO2/PS‐b‐PMPTS hybrid nanoparticles is smaller than that of SiO2/PS hybrid nanoparticles, meanwhile, the surface roughness of SiO2/PS‐b‐PMPTS hybrid nanoparticles is yet slightly rougher than that of SiO2/PS hybrid nanoparticles, which shows that the combination and competition of surface chemistry and roughness of a solid material can finally determine its wettability. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Comparison of the crystalline quality of homoepitaxially grown CVD diamond layer on cleaved and polished substrates
Authors: Araújo D. , Bustarret E. , Tajani A. , Achatz P. , Gutiérrez M. , García A. J. , Villar M. P.
Published: August 2010

A transmission electron microscopy (TEM) study, comparing homoepitaxial diamond layers grown on different substrate surface preparation states and crystallographic orientation is presented. Quality of epilayers grown on {111} cleaved surface and on {001} polished one is evaluated in terms of crystalline defects. Focused ion beam (FIB‐dual beam) sample preparations are observed by TEM using the {111}, {400} and {022} reflections of the [011] pole. Burgers vector analysis allowed to conclude the presence of 60° dislocations oriented along all the different 〈110〉 directions in the cleaved sample, while no dislocations are observed on the polished one. A complete dislocation analysis is performed for that sample. The presence of dislocations in an undoped (i.e. fully lattice matched) epilayer is surprising; and is probably induced by atomic steps, generated by the cleavage process. This notes down the importance of the substrate if high quality diamond epilayers want to be grown.
Effect of the substrate morphology on the adsorption of Ru‐bipyridyl sensitizers on anatase TiO2
Authors: León Carmen Pérez , Kador Lothar , Peng Bin , Thelakkat Mukundan
Published: August 2010

The effects of the morphology of anatase TiO2 substrates on the adsorption nature of Ru‐bipyridyl complexes with carboxylate groups as anchoring moieties have been investigated with infrared absorption spectroscopy and electron microscopy. The investigated dyes were the recently synthesized [Ru(dcbpyH2)2(bpy‐TPA2)](PF6)2, Ru‐TPA2, and the well‐known (Bu4N)2[Ru(dcbpyH)2(NCS)2], N719, complexes. As substrates, TiO2 paste films and pristine anatase nanopowder were used. Scanning electron microscopy images show big differences in the grain size, shape, and dispersity of the titania nanoparticles. The attenuated total reflection Fourier transform infrared spectra suggest that the coordination of both complexes on the TiO2 paste films occurs via bidentate or bridging linkage. The adsorption of the dyes on pristine anatase nanopowder appears to be via bridging or bidentate chelate linkage for the dye N719 as well, however, the Ru‐TPA2 complex appears to bind via unidentate or ester‐like linkage or by direct physisorpion via H‐bonding.
Laser direct writing: Enabling monolithic and hybrid integrated solutions on the lithium niobate platform
Authors: Thomas Jens , Heinrich Matthias , Zeil Peter , Hilbert Vinzenz , Rademaker Katja , Riedel Robert , Ringleb Stefan , Dubs Carsten , Ruske Jens‐Peter , Nolte Stefan , Tünnermann Andreas
Published: August 2010

Applications in life sciences and information technology require all‐optical solutions. In the inevitable race towards miniaturized optical circuits, all‐integrated solutions will prevail against bulk setups. Because of its outstanding nonlinear properties, lithium niobate (LiNbO3) emerged as the key platform for integrated optics. In this paper, we discuss the direct femtosecond (fs) laser inscription technique whose flexibility enables the realization of two‐ and three‐dimensional embedded optical waveguides in various optical materials.

Linear and nonlinear components for monolithic and hybrid waveguide devices are characterized and their perspectives are reviewed, e.g. couplers, Bragg reflectors, frequency converters, amplitude modulators and gain modules. Finally, we demonstrate a monolithic LiNbO3waveguide chip that combines a frequency doubling and a modulating unit.

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Schematic of a hybrid fs laser written chip that comprises a rare‐earth‐doped laser section (a), a frequency doubling unit (b), Bragg reflectors (c), waveguide splitters (d) and an amplitude modulator (e).
Single electron tunnelling through high‐Q single‐wall carbon nanotube NEMS resonators
Authors: Hüttel A. K. , Meerwaldt H. B. , Steele G. A. , Poot M. , Witkamp B. , Kouwenhoven L. P. , van der Zant H. S. J.
Published: August 2010

By first lithographically fabricating contact electrodes and then as last step growing carbon nanotubes with chemical vapour deposition across the ready‐made chip, many potential contamination mechanisms for nanotube devices can be avoided. Combining this with pre‐defined trenches on the chip, such that the nanotubes are freely suspended above the substrate, enables the formation of highly regular electronic systems. We show that, in addition, such suspended nanotubes provide excellent high‐frequency and low‐dissipation mechanical resonators. The motion detection mechanism of our experiment is discussed, and we measure the effect of Coulomb blockade and the back‐action of single electron tunnelling on the mechanical motion. In addition data on the mechanical higher modes is presented.

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(a) Sketch of the basic experimental setup, with a nanotube nano‐electromechanical resonator being driven contact‐free via the electric field of a suspended radio‐frequency antenna. (b) Gate voltage dependence of the observed mechanical resonance frequency for the fundamental bending mode of the nanotube resonator as well as higher modes.