bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of the formin cappuccino is critical for polarity of Drosophila oocytes
Authors: Bor Batbileg , Bois Justin S. , Quinlan Margot E.
Published: December 2014

The Drosophila formin Cappuccino (Capu) creates an actin mesh‐like structure that traverses the oocyte during midoogenesis. This mesh is thought to prevent premature onset of fast cytoplasmic streaming which normally happens during late‐oogenesis. Proper cytoskeletal organization and cytoplasmic streaming are crucial for localization of polarity determinants such as osk, grk, bcd, and nanos mRNAs. Capu mutants disrupt these events, leading to female sterility. Capu is regulated by another nucleator, Spire, as well as by autoinhibition in vitro. Studies in vivo confirm that Spire modulates Capu's function in oocytes; however, how autoinhibition contributes is still unclear. To study the role of autoinhibition in flies, we expressed a Capu construct that is missing the Capu Inhibitory Domain, CapuΔN. Consistent with a gain of activity due to loss of autoinhibition, the actin mesh was denser in CapuΔN oocytes. Further, cytoplasmic streaming was delayed and fertility levels decreased. Localization of osk mRNA in early stages, and bcd and nanos in late stages, were disrupted in CapuΔN‐expressing oocytes. Finally, evidence that these phenotypes were due to a loss of autoinhibition comes from coexpression of the N‐terminal half of Capu with CapuΔN, which suppressed the defects in actin, cytoplasmic streaming and fertility. From these results, we conclude that Capu can be autoinhibited during Drosophila oocyte development. © 2014 Wiley Periodicals, Inc.
Two‐factor authentication scheme using attribute and password
Authors: Wei Jianghong , Hu Xuexian , Liu Wenfen
Published: December 2014

In this study, based on attribute and password, we introduce a new kind of two‐factor authentication protocol that has various applications such as anonymous authentication and privacy protection. Specifically, our proposal is constructed by introducing password authentication into the generic framework of attribute‐based authentication. Consequently, it not only achieves two‐factor authentication, but also enjoys the advantages of attribute authentication and password authentication simultaneously. Furthermore, to formally evaluate the security of the proposed protocol, we present the corresponding security model, within which the detailed security proof of the proposal is given. Copyright © 2014 John Wiley & Sons, Ltd.
Altitude training causes haematological fluctuations with relevance for the Athlete Biological Passport
Authors: Bonne Thomas Christian , Lundby Carsten , Lundby Anne Kristine , Sander Mikael , Bejder Jacob , Nordsborg Nikolai Baastrup
Published: December 2014

The impact of altitude training on haematological parameters and the Athlete Biological Passport (ABP) was evaluated in international‐level elite athletes. One group of swimmers lived high and trained high (LHTH, n = 10) for three to four weeks at 2130 m or higher whereas a control group (n = 10) completed a three‐week training camp at sea‐level. Haematological parameters were determined weekly three times before and four times after the training camps. ABP thresholds for haemoglobin concentration ([Hb]), reticulocyte percentage (RET%), OFF score and the abnormal blood profile score (ABPS) were calculated using the Bayesian model. After altitude training, six swimmers exceeded the 99% ABP thresholds: two swimmers exceeded the OFF score thresholds at day +7; one swimmer exceeded the OFF score threshold at day +28; one swimmer exceeded the threshold for RET% at day +14; and one swimmer surpassed the ABPS threshold at day +14. In the control group, no values exceeded the individual ABP reference range. In conclusion, LHTH induces haematological changes in Olympic‐level elite athletes which can exceed the individually generated references in the ABP. Training at altitude should be considered a confounding factor for ABP interpretation for up to four weeks after altitude exposure but does not consistently cause abnormal values in the ABP. Copyright © 2014 John Wiley & Sons, Ltd.
Comparison of reduced and sulfided CoMo/γ‐Al2O3 catalyst on hydroprocessing of pretreated bio‐oil in a continuous packed‐bed reactor
Authors: Parapati Divya R. , Guda Vamshi K. , Penmetsa Venkata K. , Tanneru Sathish K. , Mitchell Brian , Steele Philip H.
Published: December 2014

Pretreated bio‐oil was hydroprocessed with conventional sulfided CoMo/γ‐Al2O3 catalyst in a continuous packed‐bed reactor. Hydroprocessing experiments were performed at a temperature of 350 to 400°C, 1500 psig hydrogen pressure, using a hydrogen flow rate of 500 mL/min at a liquid hourly space velocity of 0.2 h−1. The results from sulfided catalytic experiments were compared with our prior studies on hydroprocessing pretreated bio‐oil with reduced CoMo/γ‐Al2O3 catalyst. sulfided CoMo/γ‐Al2O3 catalyst demonstrated higher catalytic activity and resulted in increased hydrocarbon fraction yields. Moreover, the quality of the hydrocarbon fraction, as determined by the acid value, higher heating value, and water content analysis, also improved. Sulfided CoMo/γ‐Al2O3 catalyst produced a hydrocarbon fraction having a higher heating value of 44.4 MJ/kg, acid value of 0.5 mg KOH/g oil, and a total water content of 0.1%. Use of sulfided catalyst for hydroprocessing pretreated bio‐oil decreased the oxygen content from 47.8 wt % in the pretreated bio‐oil to nondetectable limits (∼0 wt %) in the hydrocarbon fraction. The hydrocarbon fraction was also analyzed by detailed hydrocarbon analysis and simulated distillation. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 1174–1179, 2015
Hydration characteristics of cement for co‐sintered from washed‐fly ash and waste sludge
Authors: Lin Kae‐Long , Lo Kang‐Wei , Shie Je‐Lueng , Tuan Bui Le Anh , Hwang Chao‐lung , Chang Yu‐Min
Published: December 2014

The purpose of this study is to co‐sinter washed‐fly ash, limestone sludge, stone sludge, and iron‐oxide sludge to fabricate 4 types of eco‐cement clinkers. The compound raw materials were burned for 2 h at 1400°C to form the eco‐cement clinkers, all of which met the toxicity characteristic leaching procedure requirements. The results show that the major components of ordinary Portland cement (OPC), C3S, C2S, C3A, and C4AF, were present in the eco‐cement clinkers. The compressive strength development indicated that the EcoA pastes were similar to those of commercial OPC products. The compressive strength in the EcoG pastes decreased because of the amount the α‐C2S increased. The mercury intrusion porosimetry results showed that the pore volume in the pastes gradually decreased when the curing time increased. Additionally, from the X‐ray diffraction results, all the eco‐cements produced Ca(OH)2 during hydration, which also increased with curing age. The scanning electron microscopy images of OPC and EcoA pastes showed that the pore volume decreased and the denser structural increased with the curing time increased. In addition, adding higher amounts of 1% washed‐fly ash caused to increase the content of α‐C2S. The result show that this co‐sintered process from 1% washed‐fly ash and 99% waste sludge (77% limestone sludge, 19.51% stone sludge and 2.49% iron‐oxide sludge) to produce eco‐cement with excellent mechanical characteristics. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 964–972, 2015
Structural covariance networks of striatum subdivision in patients with Parkinson's disease
Authors: Chou Kun‐Hsien , Lin Wei‐Che , Lee Pei‐Lin , Tsai Nai‐Wen , Huang Yung‐Cheng , Chen Hsiu‐Ling , Cheng Kuei‐Yueh , Chen Pei‐Chin , Wang Hung‐Chen , Lin Tsu‐Kung , Li Shau‐Hsuan , Lin Wei‐Ming , Lu Cheng‐Hsien , Lin Ching‐Po
Published: December 2014

Parkinson's disease (PD) is a neurodegenerative disorder associated with the striatum. Previous studies indicated that subdivisions of the striatum with distinct functional connectivity profiles contribute to different pathogeneses in PD. Segregated structural covariance (SC) pattern between the striatum and neocortex observed in healthy subjects, however, remain unknown in PD. The purpose of this study is to map and compare the subregional striatal SC network organization between 30 healthy controls and 48 PD patients and to investigate their association with the disease severity. The striatal SC network was statistically inferred by correlating the mean gray matter (GM) volume of six striatal subdivisions (including the bilateral dorsal caudate, superior ventral striatum, inferior ventral striatum, dorsal caudal putamen, dorsal rostral putamen, and ventral rostral putamen) with the entire neocortical GM volume in voxel‐wise manner. The PD patients revealed marked atrophy in the striatum, cerebellum, and extra‐striatum neocortices. As predicted, segregated striatal SC network patterns were observed in both groups. This suggests that in PD, pathological processes occurring in the striatum affect the same striato‐cortical networks that covary with the striatum in healthy brains. The PD patients further demonstrated atypical striatal SC patterns between the caudate, parahippocampus temporal cortices, and cerebellum, which corresponded to dopaminergic associated network. The areas with significant group differences in SC were further associated with disease severity. Our findings support previous studies indicating that PD is associated with altered striato‐cortical networks, and suggest that structural changes in the striatum may result in a cascade of alterations in multiple neocortices. Hum Brain Mapp 36:1567–1584, 2015. © 2014 Wiley Periodicals, Inc.
Crystal Clear? The Relationship Between Methamphetamine Use and Sexually Transmitted Infections
Authors: Mialon Hugo M. , Nesson Erik T. , Samuel Michael C.
Published: December 2014

Public health officials have cited methamphetamine control as a tool with which to decrease HIV and other sexually transmitted infections, based on previous research that finds a strong positive correlation between methamphetamine use and risky sexual behavior. However, the observed correlation may not be causal, as both methamphetamine use and risky sexual behavior could be driven by a third factor, such as a preference for risky behavior. We estimate the effect of methamphetamine use on risky sexual behavior using monthly data on syphilis diagnoses in California and quarterly data on syphilis, gonorrhea, and chlamydia diagnoses across all states. To circumvent possible endogeneity, we use a large exogenous supply shock in the US methamphetamine market that occurred in May 1995 and a later shock stemming from the Methamphetamine Control Act, which went into effect in October 1997. While the supply shocks had large negative effects on methamphetamine use, we find no evidence that they decreased syphilis, gonorrhea, or chlamydia rates. Our results have broad implications for public policies designed to decrease sexually transmitted infection rates. Copyright © 2014 John Wiley & Sons, Ltd.
Trends in human papillomavirus–related oropharyngeal cancer in Israel
Authors: Amit Moran , Ilana Kaplan , Avraham Sharon Pelles , Binenbaum Yoav , Bachar Gideon , Billan Salem , Zaarura Suliman , Czerninski Rakefet , Bar‐Tov Matan , Maly Alexander , Akrish Sharon , Gil Ziv
Published: December 2014

Background

The role of human papillomavirus (HPV) infection in oropharyngeal cancer (SCC) is well established. The annual incidence of oropharyngeal SCC in Israel is considerably lower than that in the United States. The purpose of this study was to assess the rate of HPV‐related oropharyngeal SCC in Israel.

Methods

The cohort included patients with oropharyngeal SCC who were treated during 1999 to 2011 in Israel. HPV typing was carried out using reverse hybridization and immunohistochemistry.

Results

Of the 74 patients analyzed, 25 (33.7%) had detectable HPV DNA. Patients in the HPV‐positive group tended to be younger, with a higher rate of nodal metastases, and no history of smoking (p < .02).

Conclusion

This study demonstrated a rate of HPV‐related oropharyngeal SCC in Israel as approximately 3‐fold lower than in Western countries. Low exposure to HPV‐16, a lower rate of transformation, to cancer or protective genetic factors may contribute to the lower rate of oropharyngeal SCC in Israel. © 2015 Wiley Periodicals, Inc. Head Neck 38: E274–E278, 2016
Metacognition and Mentalizing in the Psychotherapy of Patients With Psychosis and Personality Disorders
Authors: Dimaggio Giancarlo , Lysaker Paul H.
Published: December 2014

Many adults with significant forms of mental illness, including psychosis and personality disorders, experience deficits in metacognition that are reflected in a limited ability to describe and think about their own mental states and those of others. Above and beyond experiencing symptoms specific to their disorder, they may be unaware of their own emotions, unable to see their own thoughts as subjective and fallible, and struggle to form complex self‐representations of themselves as unique beings in the world. Similarly, they have difficulties grasping the thoughts, feelings, and intentions underlying the behavior of others. Moreover, these patients may be relatively unable to use knowledge about themselves and others to respond to psychological and interpersonal challenges. In this introduction to this JCLP: In Session issue on metacognition and mentalizing, we detail different ways to understand these deficits and discuss three unique challenges these present to treating clinicians.
The Quest for Tailored Treatments: A Meta‐Discussion of Six Social Cognitive Therapies
Authors: Kongerslev Mickey , Simonsen Sebastian , Bo Sune
Published: December 2014

In this commentary on the 6 articles comprising this In Session issue on metacognition and mentalizing in the psychotherapeutic treatment of severe mental disorders, we strive to contextualize and bring together salient issues reflected in these articles. In the foreground of our discussion is the point that the commonalities of these and related social cognitive treatments far outweigh their differences. We attempt to pinpoint some of the more specific tailored treatment elements described by the authors and relate these to empirical findings and theoretical and practical problems. Among the key issues addressed in this commentary are conceptual fallacies, therapist transparency, personality disorder and self‐harm in adolescence, therapeutic alliance, and a metacognitive‐informed group psychotherapy practice for patients with avoidant personality disorder or alexithymia.
Neighbor Distinguishing Edge Colorings Via the Combinatorial Nullstellensatz Revisited
Authors: Przybyło Jakub , Wong Tsai‐Lien
Published: December 2014

Consider a simple graph and its proper edge coloring c with the elements of the set . We say that c is neighbor set distinguishing (or adjacent strong) if for every edge , the set of colors incident with u is distinct from the set of colors incident with v. Let us then consider a stronger requirement and suppose we wish to distinguishing adjacent vertices by sums of their incident colors. In both problems the challenging conjectures presume that such colorings exist for any graph G containing no isolated edges if only . We prove that in both problems is sufficient. The proof is based on the Combinatorial Nullstellensatz, applied in the “sum environment.” In fact the identical bound also holds if we use any set of k real numbers instead of as edge colors, and the same is true in list versions of the both concepts. In particular, we therefore obtain that lists of length ( in fact) are sufficient for planar graphs.
Evaluation of portal vein invasion of distal cholangiocarcinoma as borderline resectability
Authors: Miura Fumihiko , Sano Keiji , Amano Hodaka , Toyota Naoyuki , Wada Keita , Yoshida Masahiro , Hayano Koichi , Matsubara Hisahiro , Takada Tadahiro
Published: December 2014

Background

The concept of borderline resectability has not yet been introduced for extrahepatic cholangiocarcinoma (ECC). In this study, the surgical results of ECC patients were analyzed to clarify the implications of surgery for distal ECC with portal vein (PV) invasion as a preliminary step for the introduction of the concept of borderline resectability.

Methods

The clinicopathological data of 129 patients who had undergone pancreatoduodenectomy of distal ECC were reviewed retrospectively. Combined PV resection was performed in 10 patients. The clinicopathological variables were evaluated using univariate and multivariate analyses.

Results

Pathological PV invasion was observed in eight of the 129 patients. The survival rates of patients with PV invasion were significantly poorer than those of patients without PV invasion: 3 and 5 years after surgery, 17% and 0% versus 50% and 39% (P < 0.001), respectively. Presence of pancreatic or PV invasion, tumor progression, nodal status, and residual tumor were significant prognostic factors on univariate analysis. On multivariate analysis, PV invasion was the only significant independent predictive factor of a poor prognosis.

Conclusions

PV invasion of distal ECC should be regarded as indicating borderline resectability.
Huanglongbing modifies quality components and flavonoid content of ‘Valencia’ oranges
Authors: Massenti Roberto , Lo Bianco Riccardo , Sandhu Amandeep K , Gu Liwei , Sims Charles
Published: December 2014

BACKGROUND

In order to evaluate the effect of citrus greening disease, or Huanglongbing (HLB), on quality components and flavonoid contents of ‘Valencia’ oranges, fruit from non‐infected trees (control), from infected trees but symptom‐less (asymptomatic) and from infected trees and showing clear HLB symptoms (symptomatic) were harvested in March and in May, 2013. Fruit peel, pulp and juice were separated, the main quality components were determined, and hesperidin, nobiletin, tangeretin, narirutin and didymin were quantified using liquid chromatography.

RESULTS

Peel colour, total soluble solids and citric acid were similar in control and asymptomatic fruits. Symptomatic fruits were smaller, yielded less juice, had higher acidity and lower sugar and peel colour than control fruits. In the peel, hesperidin, nobiletin, tangeretin, narirutin and didymin were higher in symptomatic than in asymptomatic and control fruits. Peel flavonoids decreased with fruit maturation. Also, in pulp and juice, flavonoid content was higher in symptomatic than in asymptomatic and control fruits.

CONCLUSIONS

These results show that asymptomatic fruits are similar to control fruits more than to symptomatic fruits, suggesting that secondary metabolism and physical properties of fruits are only affected at a later and more advanced stage of HLB infection. Despite the significant loss of quality, fruit with clear HLB symptoms accumulate high quantities of flavonoids in peel and pulp. © 2014 Society of Chemical Industry
Effects of preharvest ultraviolet‐C irradiation on fruit phytochemical profiles and antioxidant capacity in three strawberry (Fragaria × ananassa Duch.) cultivars
Authors: Xie Zhichun , Charles Marie Thérèse , Fan Jinshuan , Charlebois Denis , Khanizadeh Shahrokh , Rolland Daniel , Roussel Dominique , Deschênes Martine , Dubé Claudine
Published: December 2014

BACKGROUND

Ultraviolet‐C (UV‐C) has proven effective in extending shelf‐life, reducing disease incidence and increasing the levels of health‐promoting compounds in several crops. While most studies were conducted at the postharvest stage, our study examined the effect of preharvest UV‐C application in three strawberry cultivars (Fragaria × ananassa Duch. 'Albion', 'Charlotte' and 'Seascape'). UV‐C treatment was applied from the onset of flowering until the fruits reached commercial maturity on plants grown for two consecutive seasons under greenhouse conditions. The phytochemical profiles and antioxidant capacity of the fruits were assessed at harvest.

RESULTS

The ellagic acid and kaempferol‐3‐glucuronide contents were significantly increased only in fruits of the cultivar 'Albion' collected from UV‐C‐treated plants in season 1. UV‐C did not consistently affect the other phenolic compounds that were measured. Based on the results of the ferric‐reducing antioxidant power, oxygen radical absorbance capacity and total phenolic content assays, the antioxidant capacity of the three strawberry cultivars was not affected by UV‐C. Season and cultivar had a decisive impact on these parameters.

CONCLUSION

The effect of preharvest UV‐C on the levels of bioactive compounds in strawberry fruits appears to be cultivar‐ dependent, with season or growing conditions having a significant impact. © 2014 Society of Chemical Industry
A prospective study of mastectomy patients with and without delayed breast reconstruction: Long‐term psychosocial functioning in the breast cancer survivorship period
Authors: Metcalfe Kelly A. , Zhong Toni , Narod Steven A. , Quan May‐Lynn , Holloway Claire , Hofer Stefan , Bagher Shaghayegh , Semple John
Published: December 2014

Introduction

For women who have mastectomy, breast reconstruction is an option which may improve psychosocial functioning. The purpose of this study was to evaluate changes in psychosocial functioning over a long follow‐up period after mastectomy, specifically examining the differences between those with mastectomy alone and those who underwent postmastectomy delayed breast reconstruction (DBR).

Methods

This was a prospective longitudinal survey study of women with mastectomy in which a repeated measures design was used to compare psychosocial function scores over 3 timepoints: 1) pre‐mastectomy; 2) one year post‐mastectomy; and 3) long‐term post‐mastectomy (mean 6.3 years). In addition, psychosocial functioning was compared between the mastectomy alone group and the group who elected for DBR.

Results

67 women who completed questionnaires at all three time points were included. The long‐term follow‐up time post‐mastectomy was 75.2 months (6.3 years). Twenty‐eight women (41.8%) underwent DBR in the study period. For the entire cohort, between one‐year and long‐term post‐mastectomy, there were significant improvements in scores for body concerns (P = 0.03), cancer‐related distress (P = 0.01), and total distress (P = 0.04). At long‐term follow‐up, women with DBR had significantly higher levels of total distress (P = 0.01), obsessiveness (P = 0.03), and cancer‐related distress (P = 0.02) compared to those with mastectomy alone. There were no differences in quality of life between the two groups at any time point.

Conclusions

Psychosocial functioning improves over time in patients treated with mastectomy in the long‐term breast cancer survivorship period, which may be related to the effect of time post‐treatment, rather than an effect of choice for or against DBR. J. Surg. Oncol. 2015 111:258–264. © 2014 Wiley Periodicals, Inc.
3,3′‐Diamino‐N‐methyldipropylamine as a versatile affinity ligand
Authors: Silva Marta S. , Graça Vânia C. , Reis Lucinda V. , Santos Paulo F. , Silvestre Samuel , Granadeiro Luiza , Almeida Paulo , Queiroz João A. , Sousa Fani
Published: December 2014

Currently, in biomedicine and biotechnology fields, there is a growing need to develop and produce biomolecules with a high degree of purity. To accomplish this goal, new purification methods are being developed looking for higher performance, efficiency, selectivity, and cost‐effectiveness. Affinity chromatography is considered one of the most highly selective methods for biomolecules purification. The purpose of this work is to explore a new type of a structurally simple ligand immobilized onto an agarose matrix to be used in affinity chromatography. The ligand in this study, 3,3′‐diamino‐N‐methyldipropylamine has shown low toxicity and low cost of preparation. Moreover, the ability of the ligand to be used in affinity chromatography to purify proteins and nucleic acids was verified. An increasing sodium chloride gradient, using salt concentrations up to 500 mM, was suitable to accomplish the purification of these biomolecules, meaning that the new support allows the recovery of target biomolecules under mild conditions. Thus, the 3,3′‐diamino‐N‐methyldipropylamine ligand is shown to be a useful and versatile tool in chromatographic experiments, with very good results either for proteins or supercoiled plasmid isoform purification.
Combinatorial Screening for Specific Drug Solubilizers with Switchable Release Profiles
Authors: Wieczorek Sebastian , Vigne Sara , Masini Tiziana , Ponader Daniela , Hartmann Laura , Hirsch Anna K. H. , Börner Hans G.
Published: December 2014

Polymer‐block‐peptide conjugates are tailored to render hydrophobic small molecule drugs water soluble. The combinatorial strategy selects for bioconjugates that exhibit sequence‐specific solubilization and switchable release profiles of the cargo through incorporation of a disulfide linker moiety into the peptide‐library design. While the study focused on the photosensitizer m‐THPC and reductive carrier cleavage, the approach is generic and might be expanded toward a broad range of poorly soluble small‐molecule drugs and other selective cleavage mechanisms to disassemble a peptide binding domain of the bioconjugate‐based solubilizer.
Quantitative muscle ultrasonography in the follow‐up of juvenile dermatomyositis
Authors: Habers G. Esther A. , Van Brussel Marco , Bhansing Kavish J. , Hoppenreijs Esther P. , Janssen Anjo J.W.M. , Van Royen‐Kerkhof Annet , Pillen Sigrid
Published: December 2014

Introduction: We explored the use of quantitative muscle ultrasonography (QMUS) for follow‐up of juvenile dermatomyositis (JDM). Methods: Seven JDM patients were evaluated at diagnosis and 1, 3, 6, 12, and 24 months using the Childhood Myositis Assessment Scale (CMAS) and QMUS. Muscle thickness (MT) and quantitative muscle echo intensity (EI) were assessed with QMUS in 4 muscles. Results: Six patients experienced a monocyclic course. At diagnosis EI was slightly increased, and MT was relatively normal. After start of treatment MT first decreased and EI increased, with normalization of EI within 6–12 months (n = 4). One patient had higher EIs at diagnosis and slower normalization, indicating fibrosis, despite early normalization of CMAS. One patient experienced a chronic course, with high EIs and atrophy during follow‐up. Conclusions: QMUS can provide additional information for follow‐up of JDM regarding disease severity and residual muscle damage, particularly after normalization of CMAS. Muscle Nerve 52: 540–546, 2015
Unstructured, curved elements for the two‐dimensional high order discontinuous control‐volume/finite‐element method
Authors: Stipcich G. , Piller M.
Published: December 2014

Quadrilateral and triangular elements with curved edges are developed in the framework of spectral, discontinuous, hybrid control‐volume/finite‐element method for elliptic problems. In order to accommodate hybrid meshes, encompassing both triangular and quadrilateral elements, one single mapping is used. The scheme is applied to two‐dimensional problems with discontinuous, anisotropic diffusion coefficients, and the exponential convergence of the method is verified in the presence of curved geometries. Copyright © 2014 John Wiley & Sons, Ltd.
Efficient photoinduced In situ preparation of clay/poly(glycidyl methacrylate) nanocomposites using hydrogen‐donor silane
Authors: Jlassi Khouloud , Benna‐Zayani Mémia , Chehimi Mohamed M. , Yagci Yusuf
Published: December 2014

Clay/poly(glycidyl methacrylate) nanocomposites (clay/PGMA) were prepared by in situ radical photopolymerization using N,N‐dimethylaminopropyltrimethoxysilane(DMA)‐modified bentonite clay acting as hydrogen donor for benzophenone in solution. This initiating system permits to photopolymerize glycidyl methacrylate between the lamellae of the DMA‐modified clay. The approach provides exfoliated nanocomposites as judged by the measurements of X‐ray diffraction. However, a low fraction of persistent intercalated clay regions was visible by transmission electron microscopy. X‐ray photoelectron spectra analyses indicate that the nanocomposites have PGMA‐rich surface. The clay/PGMA nanocomposites can be readily dispersed in ethanol. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 800–808
Structure of sodium carboxymethyl cellulose aqueous solutions: A SANS and rheology study
Authors: Lopez Carlos G. , Rogers Sarah E. , Colby Ralph H. , Graham Peter , Cabral João T.
Published: December 2014

We report a small angle neutron scattering (SANS) and rheology study of cellulose derivative polyelectrolyte sodium carboxymethyl cellulose with a degree of substitution of 1.2. Using SANS, we establish that this polymer is molecularly dissolved in water with a locally stiff conformation with a stretching parameter
. We determine the cross sectional radius of the chain (
3.4 Å) and the scaling of the correlation length with concentration (ξ = 296 c−1∕2Å for c in g/L) is found to remain unchanged from the semidilute to concentrated crossover as identified by rheology. Viscosity measurements are found to be in qualitative agreement with scaling theory predictions for flexible polyelectrolytes exhibiting semidilute unentangled and entangled regimes, followed by what appears to be a crossover to neutral polymer concentration dependence of viscosity at high concentrations. Yet those higher concentrations, in the concentrated regime defined by rheology, still exhibit a peak in the scattering function that indicates a correlation length that continues to scale as
. © 2014 The Authors. Journal of Polymer Science Part B: Polymer Physics Published by Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 492–501
Influence of Tetramethyldisiloxane‐Oxygen Mixtures on the Physical Properties of Microwave PECVD Coatings and Subsequent Post‐Plasma Reactions
Authors: Hall Colin J. , Murphy Peter J. , Griesser Hans J.
Published: December 2014

Coatings deposited by microwave plasma enhanced CVD have potential for applications as protective coatings against mechanical and environmental damage. The properties of plasma polymer coatings can, however, vary markedly with deposition conditions, and we report here that this is also the case for coatings deposited from mixtures of tetramethyldisiloxane (TMDSO) and oxygen. Hardness, modulus, stress, mass, and surface chemical compositions all varied considerably with the TMDSO/O2 ratio. Post‐plasma reactions led to changes in the physical properties of coatings, which were found to be dependent on the oxygen concentration at the time of deposition. Coatings deposited at low oxygen concentration lost mass, became more rigid, became less tensile in stress, and underwent a large increase in hardness and modulus. These coatings were found to craze over periods of up to six months. Coatings deposited at high oxygen concentrations were observed to gain mass, became less rigid, and showed reduced compressive stress. They were more stable but their mechanical mismatch with polymer substrates affects their performance as protective coatings.
Experimental and theoretical investigation of the superior contact properties of dielectrophoretically processed graphene and tantalum nitride electrodes
Authors: Pascon A. M. , Souza J. F. , Fonseca L. R. C. , Diniz J. A.
Published: December 2014

We have explored the dielectrophoretic process (DEP) to reach large scale integration of field effect transistors based on multilayer graphene (GraFET) deposited between source and drain metal electrodes. In our devices graphene lays on top of a TaOx gate dielectric deposited on an n+ silicon substrate, which is used as the back gate electrode, while the metal electrodes are made of TaN. These GraFETs reached a maximum transconductance of −19 mS/mm, which is higher than in silicon MOSFETs. To explain the origin of such good performance at the atomic level, ab initio calculations were conducted assuming two different models of the graphene/TaN interface: Ta‐ and N‐terminated δ‐TaN[111] surfaces with one, two, three, and four layers of graphene on top. We have found that all graphene layers are considerably deformed due to strong interaction with both metal surfaces, and remain non‐planar up to the fourth layer. We have also found that, except for the first graphene layer on TaN, all other layers display the Dirac cones in their locally projected density of states (PDOS). The reason for the absence of the Dirac cones in the first layer, an indication of poor conductance for monolayer graphene on TaN, is the metal induced surface states and not graphene deformation. Finally, due to the large work function of N‐terminated TaN, the first few graphene layers closest to the interface are strongly p‐doped, while for the Ta‐terminated TaN which has low work function the first few graphene layers are slightly n‐doped. The better adherence of graphene on N‐terminated TaN and the strong p‐doping of the interfacial graphene layers may explain the measured low contact resistance.
Carrier distributions in InGaN/GaN light‐emitting diodes
Authors: Hammersley Simon , Davies Matthew J. , Dawson Philip , Oliver Rachel A. , Kappers Menno J. , Humphreys Colin J.
Published: December 2014

The distribution of carriers in InGaN/GaN quantum well light‐emitting diodes is frequently calculated using drift‐diffusion models. Using this type of approach, it is found that the holes are preferentially captured into the quantum wells closest to the p‐type injection layer. This type of model, however, only deals with the initial capture of carriers into the quantum wells, and not any subsequent redistribution of carriers caused by carrier escape or tunnelling. However, thermally driven carrier redistribution in InGaN/GaN quantum wells has been reported, so in this work, we have studied the effects of carrier redistribution across the quantum well stack in a light‐emitting diode structure containing five quantum wells. We find that the holes are distributed amongst the available quantum wells with a more uniform population profile than would be predicted using a drift‐diffusion model.
A randomized two‐stage design for phase II clinical trials based on a Bayesian predictive approach
Authors: Cellamare Matteo , Sambucini Valeria
Published: December 2014

The rate of failure in phase III oncology trials is surprisingly high, partly owing to inadequate phase II studies. Recently, the use of randomized designs in phase II is being increasingly recommended, to avoid the limits of studies that use a historical control. We propose a two‐arm two‐stage design based on a Bayesian predictive approach. The idea is to ensure a large probability, expressed in terms of the prior predictive probability of the data, of obtaining a substantial posterior evidence in favour of the experimental treatment, under the assumption that it is actually more effective than the standard agent. This design is a randomized version of the two‐stage design that has been proposed for single‐arm phase II trials by Sambucini. We examine the main features of our novel design as all the parameters involved vary and compare our approach with Jung's minimax and optimal designs. An illustrative example is also provided online as a supplementary material to this article. Copyright © 2014 JohnWiley & Sons, Ltd.
Adjusting for time‐dependent sensitivity in an illness‐death model, with application to mother‐to‐child transmission of HIV
Authors: Teeple Elizabeth A. , Brown Elizabeth R.
Published: December 2014

In mother‐to‐child transmission of HIV, identifying infected infants relies on a diagnostic test with imperfect sensitivity that is administered at scheduled visits. Under this scenario, a participant's true state may be unknown at the start and end times of the study, and the detection of transitions into illness may be delayed or missed altogether. This could lead to biased estimates of the risk of transmission and covariate associations. When a test has imperfect sensitivity, but perfect specificity, the additional uncertainty can be captured as a random variable measuring delay in detection. The cumulative distribution then defines a time‐dependent sensitivity function that increases over time. We present a maximum likelihood based illness‐death model that accounts for imperfect sensitivity by including the delay as an exponential distribution. We specify transition rates as penalized B‐splines to allow for nonhomogeneity of risk and discuss the model under Markov and semi‐Markov assumptions. We apply this method to our motivating data set, a study of 1499 mother and infant pairs at three sites in Africa. Copyright © 2014 John Wiley & Sons, Ltd.
Estimation of ROC curve with complex survey data
Authors: Yao Wenliang , Li Zhaohai , Graubard Barry I.
Published: December 2014

The receiver operating characteristic (ROC) curve can be utilized to evaluate the performance of diagnostic tests. The area under the ROC curve (AUC) is a widely used summary index for comparing multiple ROC curves. Both parametric and nonparametric methods have been developed to estimate and compare the AUCs. However, these methods are usually only applicable to data collected from simple random samples and not surveys and epidemiologic studies that use complex sample designs such as stratified and/or multistage cluster sampling with sample weighting. Such complex samples can inflate variances from intra‐cluster correlation and alter the expectations of test statistics because of the use of sample weights that account for differential sampling rates. In this paper, we modify the nonparametric method to incorporate sampling weights to estimate the AUC and employ leaving‐one‐out jackknife methods along with the balanced repeated replication method to account for the effects of the complex sampling in the variance estimation of our proposed estimators of the AUC. The finite sample properties of our methods are evaluated using simulations, and our methods are illustrated by comparing the estimated AUC for predicting overweight/obesity using different measures of body weight and adiposity among sampled children and adults in the US Hispanic Health and Nutrition Examination Survey. Copyright © 2014 John Wiley & Sons, Ltd.
Verantwortlichkeiten bei Stahlbauprojekten
Authors: Kranz Bernd , Wagner Steffen , Keitel Steffen
Published: December 2014

Die Handelnden in der Kette beginnend beim Entwurf über die Bemessung, die Konstruktion bis hin zur Fertigung und Montage haben entsprechende Verantwortlichkeiten zu übernehmen. Bereits beim Entwurf einer Konstruktion sind fertigungsrelevante Vorgaben zu beachten. Aber auch in der Fertigung ist auf Erfordernisse einzugehen, die sich aus der Bemessung ergeben. Auf dem Stahlbausektor existiert dafür mit den Normenreihen DIN EN 1990, DIN EN 1991, DIN EN 1993 ff. und DIN EN 1090 ein in sich geschlossenes Regelwerk, wobei die Erstgenannte für den Bereich der Bemessung und der Konstruktion und die zweite für die Fertigung und die Montage steht. Seit Einführung der DIN EN 1090 sind nun auch die Bemessung und die Konstruktion in die Überprüfung hinsichtlich der Konformität zum aktuell geltenden Regelwerk einzubeziehen. Nach zweijähriger Erfahrung in diesem Bereich ist festzustellen, dass die Vorschriften hinsichtlich der Bemessung und Konstruktion weitgehend beherrscht werden. Die fertigungsrelevanten Vorgaben aus der DIN EN 1090 werden hingegen noch häufig nur unzureichend berücksichtigt. Mit diesem Beitrag sollen die sich daraus ergebenden Probleme dargestellt aber auch Lösungsmöglichkeiten für eine entsprechende Aus‐ und Weiterbildung aufgezeigt werden.

Responsibility for steel construction projects. The actors in the chain beginning with the design via calculation, construction to manufacturing and assembling have to assume corresponding responsibilities. The fabrication‐relevant design specifications have to be considered already in the design. Responding to requirements that arise from the design is important in the production, too. A self‐contained set of rules exists in the steel construction sector. The standard series DIN EN 1990, DIN EN 1991 and DIN EN 1993 et seqq. are the base for structural designers and constructing engineers, and DIN EN 1090 is the base for the manufacturers and assembly operators. With the introduction of DIN EN 1090 the design and construction are also included in checking for conformity at the currently applicable regulations. After two years of experience in this area it is to be noted that the rules have largely been mastered in terms of design and construction. The fabrication‐related requirements of DIN EN 1090 are, however, often still insufficiently taken into account. The resulting problems are presented as well as solutions. A contribution of an appropriate education and training will be presented.
Feuerverzinken im Brückenbau
Authors: Ungermann Dieter , Rademacher Dennis , Oechsner Matthias , Simonsen Fabian , Friedrich Susanne , Lebelt Peter
Published: December 2014

In dem hier vorgestellten Forschungsprojekt wurden durch die TU Dortmund, die MPA Darmstadt und das Institut für Korrosionsschutz Dresden GmbH der wissenschaftliche und technische Nachweis eines sicheren Einsatzes der Feuerverzinkung im Stahl‐ und Verbundbrückenbau erbracht. Die Verwendung der Feuerverzinkung ermöglicht einen langlebigen, wartungsfreien und robusten Korrosionsschutz und bietet ökologische und ökonomische Vorteile gegenüber den aktuell eingesetzten Korrosionsschutzsystemen. Der Einsatz im Brückenbau mit zyklischen Belastungen war bislang – aufgrund fehlender wissenschaftlicher Untersuchungen zum Ermüdungsverhalten feuerverzinkten Stahls – nicht möglich. Die Ergebnisse dieses Forschungsprojekts ermöglichen den Nachweis des feuerverzinkten Stahls gegen Werkstoffermüdung nach EC 3‐1‐9 und weisen den sicheren Einsatz der Feuerverzinkung als Korrosionsschutzsystem nach.

Hot‐dip galvanizing in bridge construction – Part 1: Using hot‐dip galvanized mild steel for cyclic loaded structures. In the here presented research project the scientific and technical evidence for the safe use of hot‐dip galvanizing for steel and composite bridges were provided by TU Dortmund, MPA Darmstadt and Institut für Korrosionsschutz Dresden GmbH. The use of hot dip galvanizing offers a durable, maintenance‐free and robust corrosion protection and provides environmental and economic advantages over the corrosion protection systems currently in use. The use in bridge construction with cyclic loading was previously not possible – due to a lack of scientific studies on the fatigue behavior of hot‐dip galvanized steel. The results of this research allow the proof of hot‐dip galvanized steel against fatigue according to EC 3‐1‐9 and demonstrate the safe use of hot dip galvanizing as corrosion protection system.
Das Minarett der Großen Moschee von Algerien – Ein Tragwerk der besonderen Art
Authors: Constantinescu Dan , Köber Dietlinde , Akkermann Jan
Published: December 2014

Das Minarett der Großen Moschee von Algerien wird das höchste Minarett weltweit und das höchste Bauwerk Afrikas sein. Das Projekt wurde von deutschen Architekten und Ingenieuren geplant und befindet sich zurzeit im Bau. Das Bauwerk unterliegt einem extrem hohen Erdbebenrisiko. In Verbindung mit der extremen Schlankheit des Gebäudes und seinem außergewöhnlichen Aussteifungssystem hat dies zu einem Tragwerk im Verbundbau geführt, das einmalig ist. Zur Absicherung der notwendigen seismischen Sicherheit dieses Millennium‐Monuments mussten die aufwendigsten Verfahren der Planung in Erdbebengebieten angewandt werden. Der Aufsatz beschreibt das Bemessungskonzept der Aussteifung, die angewandten Bemessungsverfahren und einige relevante Tragwerkseigenschaften.

The Minaret of the Great Mosque of Algeria – A very special structure. The minaret of the Great Mosque of Algeria will be the highest minaret in the world and Africa’s highest skyscraper. The project designed by a German team of architects and engineers is under construction. The site is exposed to an extremely high seismic risk. This in conjunction with the buildings slenderness and its particular architectonical demands, have led to a composite structure with an unusual concept to withstand lateral loading. In order to ensure the necessary seismic safety of this millennium’s monument the most sophisticated seismic design procedures had to be used. The paper presents the design philosophy and analyses as well as some significant structural features and details of the minaret structure – see also [1].
Himmelstürmend – Bauten und Visionen der Hochhausstadt Frankfurt seit 1945
Authors: Möller Eberhard
Published: December 2014

Keine andere Stadt in Deutschland bietet eine solch spannende Hochhauskulisse wie die Bankenmetropole Frankfurt am Main, “analog zu Frankfurts Mainhattan Skyline wird Downtown New York oft als Manhattan bezeichnet“. Dieses treffende Bonmot des Schriftstellers Andreas Neumeister illustriert die städtebauliche, architektonische und baukonstruktive Bedeutung des hessischen Wolkenkratzer‐Ensembles. In Ergänzung zu den beinahe ausschließlich von außen erlebbaren etwa 530 Hochhäusern der Stadt, erläutert das Deutsche Architekturmuseum in Frankfurt am Main politische, gesellschaftliche aber auch bauliche Hintergründe und Entwicklungen. Die Ausstellung “Himmelstürmend – Hochhausstadt Frankfurt“ wird dort bis zum 19. April 2015 gezeigt.

Skyward ‐ Buildings and Visions of the Highrise City Frankfurt since 1945. No other city in Germany offers such an exciting skyscraper backdrop like the banking metropolis of Frankfurt am Main, “analogous to the Frankfurt Mainhattan skyline downtown New York often is referred as Manhattan”. This apt quip of the writer Andreas Neumeister illustrates the urban, the architectural but also the constructional importance of the Hessian skyscraper ensemble. In addition to the view from outside to the about 530 high‐rise buildings of the city, the exhibition of the Deutsches Architekturmuseum in Frankfurt am Main explores political and social as well as architectural backgrounds and developments. The exhibition “Skyward – Highrise City Frankfurt” is open till April 19, 2015.
Ermüdungsgerechte Fachwerke aus Rundhohlprofilen mit dickwandigen Gurten
Authors: Kuhlmann Ulrike , Euler Mathias , Hubmann Michael , Bucak Ömer , Fischl Andreas , Mangerig Ingbert , Hess Andreas , Kranz Bernd , Herrmann Jörg , Zschech Roland
Published: December 2014

Der Beitrag gibt einen Überblick über die Ergebnisse des ZUTECH‐Forschungsvorhabens FOSTA P815, das sich mit dem Ermüdungsverhalten von geschweißten K‐ und KK‐Knoten in Fachwerken aus Rundhohlprofilen mit dickwandigen Gurten beschäftigt hat. Im Mittelpunkt des Beitrags stehen die experimentellen und numerischen Untersuchungen, die zu Planungs‐, Fertigungs‐ und Bemessungsempfehlungen für die Praxis zusammengefasst wurden.

Fatigue‐resistant trusses of circular hollow sections with thick‐walled chords. This paper gives an overview about the results of the ZUTECH‐Research Project FOSTA P815 dealing with the fatigue behaviour of welded K‐ and KK‐joints in trusses made of circular hollow sections with thickwalled chords. The focus is laid on the experimental and numerical investigations that had been summarized to recommendations on planning, fabrication and design for practitioners.