bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on inherently radiopaque acrylate copolymers for biomedical applications
Authors: Dawlee S. , Jayabalan M.
Published: January 2012

Poly(glycidyl methacrylate‐co‐ethyl methacrylate) and poly(glycidyl methacrylate‐co‐butyl methacrylate) random copolymers (with 50–50 mol % of monomers) were made radiopaque by grafting iodine moieties through the ring opening reaction of the epoxy groups. The percentage weight of grafted iodine in the copolymers was found to be as high as 19%. The iodinated copolymers showed higher glass transition temperature and thermal stability in comparison with the parent copolymers. Iodinated copolymer of poly(glycidyl methacrylate‐co‐ethyl methacrylate) has improved glass transistion temperature than iodinated poly(glycidyl methacrylate‐co‐butyl methacrylate). Radiographic analysis of these iodinated copolymers showed excellent radiopacity. The in vitro cytotoxicity tests revealed cytocompatibility with cells. These radiopaque copolymers are expected to find application as dental and orthopedic cements. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Miscibility and crystallization behavior of poly(ethylene‐co‐vinylalcohol)/poly(maleic anhydride‐alt‐ethylene) blend
Authors: Aouak Taieb , AlArifi Abdullah Saad , Ouladsmane Mohamed
Published: January 2012

The miscibility of poly(vinylalcohol‐co‐ethylene) (PEVA) with poly(ethylene‐alt‐maleic anhydride) (PEMAH) blends was investigated over a wide range of compositions by viscosimetry and DSC analyses using Krigbaum–Wall and Kwei approaches. The results revealed that the blends were completely miscible in all proportions due to the specific interactions between the hydroxyl groups of PEVA and the carbonyl groups of PEMAH. From Nishi equation, the interaction parameter of Flory was found to be −0.89. The nonisothermal crystallization behavior and kinetics of this system were also investigated and compared with those of the pure PEVA. There were strong dependencies of the degree of crystallinity (XT), peak crystallization temperature (Tp), half time of crystallization (t1/2), and Ozawa exponent (m) on PEMAH content and cooling rate. The crystallization activation energy (Ec) that was calculated from Kissinger model increased with increasing PEMAH composition in the blend. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
BNC1 is required for maintaining mouse spermatogenesis
Authors: Zhang Xiaohong , Chou Weichin , Haig‐Ladewig Lisa , Zeng Wenxian , Cao Wenlei , Gerton George , Dobrinski Ina , Tseng Hung
Published: January 2012

Basonuclin (BNC1) is a zinc finger protein expressed primarily in gametogenic cells and proliferative keratinocytes. Our previous work suggested that BNC1 is present in spermatogonia, spermatocytes, and spermatids, but absent in the Sertoli cells. BNC1′s role in spermatogenesis is unknown. Here, we show that BNC1 is required for the maintenance of spermatogenesis. Bnc1‐null male mice were sub‐fertile, losing germ cells progressively with age. The Bnc1‐null seminiferous epithelia began to degenerate before 8 weeks of age and eventually became Sertoli cell‐only. Sperm count and motility also declined with age. Furthermore, Bnc1 heterozygotes, although fertile, showed a significant drop in sperm count and in testis weight by 24 weeks of age, suggesting a dosage effect of Bnc1 on testis development. In conclusion, our data demonstrate for the first time BNC1′s essential role in maintaining mouse spermatogenesis. genesis 50:517–524, 2012. © 2012 Wiley Periodicals, Inc.
Comparison of limited‐volume perioperative high‐dose‐rate brachytherapy and wide‐field external irradiation in resected head and neck cancer
Authors: Gaztañaga Miren , Pagola María , Cambeiro Mauricio , Ruiz Maria E. Rodriguez , Aristu Javier , Montesdeoca Néstor , Alcalde Juan , Martínez‐Monge Rafael
Published: January 2012

Background

This study aimed to test the safety of using perioperative high‐dose‐rate brachytherapy (PHDRB) in resected head and neck cancer.

Methods

From 2000 to 2008, 97 patients received PHDRB after complete macroscopic resection. Group 1 (previously irradiated patients) received 32 to 40 Gray (Gy) of PHDRB in 8 to 10 twice‐daily (bid) treatments (R0–R1 resections). Group 2 (unirradiated patients) received 16 to 24 Gy of PHDRB in 4 to 6 bid treatments (R0–R1 resections) followed by external beam irradiation (EBRT) of 45 Gy/25 daily fractions ± concomitant chemotherapy.

Results

The median follow‐up was 4.3 years. The cumulative hazard of 2‐year grade ≥ 3 complications in group 1 was 45.9%, and the rate of grade ≥ 3 complications in group 2 was 24.6%. Actuarial locoregional control at 2 and 5 years for group 1 was 60.9% and for group 2, 84.1% and 79.4%.

Conclusions

Complications and locoregional failure rates were similar to those reported in the reference standards despite a much smaller treatment volume. © 2012 Wiley Periodicals, Inc. Head Neck, 2012
Minor salivary gland malignancies in the pediatric population
Authors: Galer Chad , Santillan Alfredo A. , Chelius Daniel , Huh Winston , El‐Naggar Adel , Hanna Ehab. , Weber Randal S. , Kupferman Michael E.
Published: January 2012

Background

Minor salivary gland malignancies in children are rare and data on treatment and outcomes are limited.

Methods

A retrospective chart review of all pediatric patients with the pathologic diagnosis of minor salivary gland malignancy at a tertiary care cancer hospital was used to conduct this review.

Results

From 1952 to 2006, 35 children with minor salivary gland cancers were treated at The University of Texas MD Anderson Cancer Center. Mean age was 15.2 +/‐ 2.9 years with a slight female predominance. Recurrence occurred in 4 patients and was significantly associated with positive margins, advanced stage, and high histologic grade. Overall survival (OS) and disease‐specific survival (DSS) were 89.3% and 88.4%, respectively, at 5 years. Advanced stage, positive margins, and high grade were associated with adverse survival.

Conclusion

Minor salivary gland malignancies in children are rare. Surgical resection with clear margins yields excellent outcomes in patients with low‐intermediate grade and early stage tumors. Patients with high‐grade malignancies do poorly despite multimodality therapy. © 2012 Wiley Periodicals, Inc. Head Neck, 2012
Volumetric change of human papillomavirus–related neck lymph nodes before, during, and shortly after intensity‐modulated radiation therapy
Authors: Sanguineti Giuseppe , Ricchetti Francesco , Wu Binbin , Agrawal Nishant , Gourin Christine , Agbahiwe Harold , Marur Shanthi , Clemente Stefania , McNutt Todd , Forastiere Arlene
Published: January 2012

Background

To assess volumetric changes of human papillomavirus (HPV)‐related lymph nodes (LN) before, during, and after a course of intensity‐modulated radiation therapy (IMRT) ± chemotherapy.

Methods

Each “pathologic” LN (≥1 cm) was contoured on the available diagnostic/planning CTs before, during each week, and after treatment.

Results

Seventy‐nine LNs in 50 patients were identified. Beyond the first week of treatment, 3 patterns of LN change were recorded: consistently shrinking LN (n = 33; 41.8%), inconsistently shrinking LN with temporary enlargement limited to the first week (n = 14; 17.7%), or also during the subsequent weeks (n = 32; 40.5%). Nodal density at planning is highly predictive of group assignment, with a larger mean density for consistently over inconsistently shrinking LNs (p = .009). Also, this grouping predicts the response at the end of treatment.

Conclusion

HPV‐related LN behavior during IMRT is extremely variable but somewhat predictable on the basis of nodal density at planning. © 2012 Wiley Periodicals, Inc. Head Neck, 2012
Molecular targeting agents in the context of primary chemoradiation strategies
Authors: Laban Simon , Wang Chia Jung , Münscher Adrian , Tribius Silke , Schafhausen Philippe , Knecht Rainald
Published: January 2012

Background

Demands for organ preservation and increasing knowledge in molecular tumor biology have lead to the development of molecular targeting agents. These substances have also been incorporated into concomitant and sequential chemoradiation protocols.

Methods

This study was conducted using a systematic literature review.

Results

In head and neck squamous cell carcinoma (HNSCC), the inhibition of epidermal growth factor receptor (EGFR) signaling as a central step in carcinogenesis, progression, and metastasis is the predominant approach. Although EGFR targeting substances are commonly used, the specific influence of molecular targeting therapies on patient outcome remains unclear. In this review, results from recent clinical trials in the area of primary chemoradiation in the combination with EGFR targeting agents are discussed.

Conclusion

Encouraging results from recent trials need to be confirmed in larger patient cohorts and cost‐effectiveness analyses have to be undertaken. Phase III studies need to confirm these results before, time and again, new phase II studies are initiated. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Pattern and predictive factors of regional lymph node metastasis in papillary thyroid carcinoma: A prospective study
Authors: Nam Inn Chul , Park Jun Ook , Joo Young Hoon , Cho Kwang Jae , Kim Min Sik
Published: January 2012

Background

Most of the reports about lymph node (LN) metastasis in papillary thyroid carcinoma (PTC) are retrospective studies.

Methods

We prospectively evaluated the pattern and predictive factors of LN metastasis of 176 patients with PTC who underwent total thyroidectomy and bilateral central LN dissection with or without therapeutic lateral LN dissection.

Results

Ipsilateral central LNs were involved even in early T classification, and contralateral central LNs were infrequently involved even in late T classification. Most of the lateral LN metastases were in levels II, III, and IV. Male sex was predictive of LN metastasis. Ipsilateral central LN metastasis and central LN metastasis were associated with contralateral central LN metastasis and lateral LN metastasis, respectively.

Conclusions

Ipsilateral central neck dissection is recommended for all PTC patients. Careful inspection for LN metastasis should be performed when evaluating male patients with PTC, and if central LNs are involved, carefully inspect lateral LNs. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
CO2 laser surgery in elderly patients with glottic carcinoma: Univariate and multivariate analyses of results
Authors: Lucioni Marco , Bertolin Andy , Rizzotto Giuseppe , Accordi Daria , Giacomelli Luciano , Marioni Gino
Published: January 2012

Background

There are limited data on the role of laser‐assisted surgery for early glottic cancer in elderly patients.

Methods

This retrospective study was conducted on a series of 130 consecutive cases of early glottic carcinoma occurring in elderly patients (>65 years old) treated with CO2 laser surgery.

Results

The overall and disease‐specific survival rates were 87.7% and 99.2%, respectively. The rates of local disease control after primary laser surgery, ultimate local control with laser alone, and laryngeal preservation were 84.6%, 93.8%, and 96.9%, respectively. A shorter disease‐free survival (DFS) was associated with the involvement of 1 or more specific laryngeal regions (arytenoids, ventricle, anterior commissure, vocal muscle, subglottis) (p = .01) and the status of the surgical margins (p = .002); on multivariate analysis, only the latter remained prognostically significant vis‐à‐vis the DFS (p = .002).

Conclusions

Even in elderly patients with early glottic carcinoma, endoscopic laser surgery is an effective treatment. © 2012 Wiley Periodicals, Inc. Head Neck, 2012
Distant metastases from cutaneous squamous cell carcinoma—analysis of AJCC stage IV
Authors: Brunner Markus , Veness Michael J. , Ch'ng Sydney , Elliott Michael , Clark Jonathan R.
Published: January 2012

Background

The seventh edition of the American Joint Committee on Cancer (AJCC) Staging Manual introduced a more detailed system to stage regional lymph node metastases for disease with cutaneous squamous cell carcinoma (SCC). The purpose of this study was to determine if the inclusion of disease staged N2 and N3 together with disease staged M1 is an appropriate grouping within stage IV.

Methods

A retrospective multicenter analysis was conducted of 603 patients with metastatic cutaneous SCC to compare survival data for regional (N2 and N3) versus distant metastases.

Results

Disease specific survival (DSS) and overall survival (OS) were much poorer for patients with distant disease compared to those with different stages of regional disease. After 5 years, only 25% of patients with N2 disease and 35% of patients with N3 disease died from their cancer compared with 89% of patients with distant metastases.

Conclusion

Our results indicate that in cutaneous SCC, stage IV represents a very heterogeneous group. Therefore, N2 and N3 disease should not be grouped with M1 together within AJCC stage IV. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Improved outcomes in buccal squamous cell carcinoma
Authors: Lin Chun–Shu , Jen Yee–Min , Kao Woei–Yau , Ho Ching–Liang , Dai Ming–Shen , Shih Chia–Lin , Cheng Jen–Chan , Chang Ping–Ying , Huang Wen–Yen , Su Yu–Fu
Published: January 2012

Background

The treatment results of buccal squamous cell carcinoma before and after 2002 were compared.

Methods

Two hundred forty‐five patients with buccal cancer who underwent curative treatment were retrospectively reviewed.

Results

The 5‐year overall survival rate was 30.0% before 2002 and 53.5% after 2002 (p = .004). On multivariate analysis, T classification, surgical margins, and treatment modality significantly affected overall survival, and N classification and histologic grade had trends to affect it. Invasion depth had a trend to influence locoregional control. For patients with early‐stage disease without adverse factors, the locoregional control was similar between surgery alone group and surgery + radiotherapy group.

Conclusion

The survival of patients with buccal cancer was improved after 2002, which represented the start of intensity‐modulated radiotherapy (IMRT) in our institute. Ipsilateral neck alone irradiation was recommended for T1‐2N0‐1 and small T3N0 disease, and bilateral neck irradiation could be reserved for advanced disease. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Relation between the dimensions and intraluminal pressure of the pharyngoesophageal segment and tracheoesophageal voice and speech proficiency
Authors: Takeshita Telma Kioko , Zozolotto Henrique Ceretta , Ribeiro Eduardo Alvarez , Ricz Hilton , de Azevedo‐Marques Paulo Mazzoncini , Dantas Roberto Oliveira , Aguiar‐Ricz Lílian
Published: January 2012

Background

The objective of the present study was to relate the dimensions and the intraluminal pressure of the pharyngoesophageal segment (PES) to the voice and speech proficiency of total laryngectomees with a tracheoesophageal prosthesis (TEP).

Methods

Twenty total laryngectomees with secondary TEP insertion underwent evaluation of voice and speech, manometry, and videofluoroscopy.

Results

Most laryngectomees (65%) were moderate speakers. The poorer speakers presented a lower intraluminal pressure in the PES at rest (4.44 mmHg) and a higher value (40.46 mmHg) during phonation. Good speakers presented a significant difference in the anteroposterior distance between prominence of the PES and the posterior pharyngeal wall (PPES‐PPW) in the rest (6.09 mm) to phonation (3.24 mm).

Conclusions

The poorer speakers presented a lower intraluminal pressure in the PES at rest and a higher value during phonation compared with moderate speakers. Good speakers showed a significant difference in the PPES‐PPW dimension. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Coupled‐cluster theory for the polarizable continuum model. III. A response theory for molecules in solution
Authors: Cammi R.
Published: January 2012

A coupled‐cluster (CC) response functions theory for molecular solutes described with the framework of the polarizable continuum model (PCM) is presented. The theory is an extension to the dynamical molecular properties of the PCM‐CC analytic derivatives recently proposed for the calculation of static molecular properties (Cammi, Jr Chem Phys 2009, 131, 164104). The theory is presented for linear and quadratic response functions, and the operative expressions of these response functions can accurately account for the nonequilibrium solvation effects. The excitation energies and transition moments of the solvated chromophores have been determined from the linear response functions. Accurate expressions for gradients of excitation energies for the evaluation of the excited state properties have been also discussed. © 2012 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Direct detection of additives and degradation products from polymers by liquid extraction surface analysis employing chip‐based nanospray mass spectrometry
Authors: Paine Martin R. L. , Barker Philip J. , Maclauglin Shane A. , Mitchell Todd W. , Blanksby Stephen J.
Published: January 2012

RATIONALE

Polymer‐based surface coatings in outdoor applications experience accelerated degradation due to exposure to solar radiation, oxygen and atmospheric pollutants. These deleterious agents cause undesirable changes to the aesthetic and mechanical properties of the polymer, reducing its lifetime. The use of antioxidants such as hindered amine light stabilisers (HALS) retards these degradative processes; however, mechanisms for HALS action and polymer degradation are poorly understood.

METHODS

Detection of the HALS TINUVIN®123 (bis(1‐octyloxy‐2,2,6,6‐tetramethyl‐4‐piperidyl) sebacate) and the polymer degradation products directly from a polyester‐based coil coating was achieved by liquid extraction surface analysis (LESA) coupled to a triple quadrupole QTRAP® 5500 mass spectrometer. The detection of TINUVIN®123 and melamine was confirmed by the characteristic fragmentation pattern observed in LESA‐MS/MS spectra that was identical to that reported for authentic samples.

RESULTS

Analysis of an unstabilised coil coating by LESA‐MS after exposure to 4 years of outdoor field testing revealed the presence of melamine (1,3,5‐triazine‐2,4,6‐triamine) as a polymer degradation product at elevated levels. Changes to the physical appearance of the coil coating, including powder‐like deposits on the coating's surface, were observed to coincide with melamine deposits and are indicative of the phenomenon known as polymer 'blooming'.

CONCLUSIONS

For the first time, in situ detection of analytes from a thermoset polymer coating was accomplished without any sample preparation, providing advantages over traditional extraction‐analysis approaches and some contemporary ambient MS methods. Detection of HALS and polymer degradation products such as melamine provides insight into the mechanisms by which degradation occurs and suggests LESA‐MS is a powerful new tool for polymer analysis. Copyright © 2012 John Wiley & Sons, Ltd.
Correcting for nonlinearity effects of continuous flow isotope ratio mass spectrometry across a wide dynamic range
Authors: Kornfeld Ari , Horton Travis W. , Yakir Dan , Turnbull Matthew H.
Published: January 2012

RATIONALE

Environmental and biological investigations may require samples that vary over a wide range of concentrations and isotope ratios, making measurements using continuous flow isotope ratio mass spectrometry (CF‐IRMS) problematic due to nonlinear signal response. We therefore developed a mathematical approach for correcting nonlinearities over a wide range of sample concentrations and actual δ values.

METHODS

Dilution series for two standards were prepared in septum‐capped vials and introduced into the mass spectrometer via the standard sampling pathway. Parameters for a nonlinear signal correction were determined by regression on measured isotope ratio vs. both signal strength and actual isotope ratio. We further extended the dynamic range by adjusting the position of an open split based on analyte concentration. Effects of the open split setting required additional mathematical correction.

RESULTS

The nonlinearities were corrected over a 100‐fold range of sample concentrations and across a 600‰ change in isotope ratios (for δO2/N2 values). The precision, measured as standard deviation, across the upper 90% of the concentration range was ±0.08‰, ±0.05‰, and ±2.6‰ for δ18O, δ15N, and δO2/N2 values, respectively; the precision across the lower 10% of the range was ±0.22‰, ±0.07‰, and ±7.6‰, respectively. In all cases the linearity correction represented only a small fraction of these precision values.

CONCLUSIONS

The empirical correction described here provides a relatively simple yet effective way to increase the usable signal range for CF‐IRMS applications. This improvement in dynamic range should be especially helpful for environmental and biological field studies, where sampling methods may be constrained by external factors. Copyright © 2012 John Wiley & Sons, Ltd.
Holography for Einstein-Maxwell-dilaton theories from generalized dimensional reduction
Authors: Goutéraux Blaise , Smolic Jelena , Smolic Milena , Skenderis Kostas , Taylor Marika
Published: January 2012

Abstract

We show that a class of Einstein-Maxwell-Dilaton (EMD) theories are re- lated to higher dimensional AdS-Maxwell gravity via a dimensional reduction over com- pact Einstein spaces combined with continuation in the dimension of the compact space to non-integral values (‘generalized dimensional reduction’). This relates (fairly complicated) black hole solutions of EMD theories to simple black hole/brane solutions of AdS-Maxwell gravity and explains their properties. The generalized dimensional reduction is used to infer the holographic dictionary and the hydrodynamic behavior for this class of theories from those of AdS. As a specific example, we analyze the case of a black brane carrying a wave whose universal sector is described by gravity coupled to a Maxwell field and two neutral scalars. At thermal equilibrium and finite chemical potential the two operators dual to the bulk scalar fields acquire expectation values characterizing the breaking of con- formal and generalized conformal invariance. We compute holographically the first order transport coefficients (conductivity, shear and bulk viscosity) for this system.
Distinguishing among technicolor/warped scenarios in dileptons
Authors: Banerjee Piyali , Martin Adam , Sanz Veronica
Published: January 2012

Abstract

Models of dynamical electroweak symmetry breaking usually include new spin-1 resonances, whose couplings and masses have to satisfy electroweak precision tests. We propose to use dilepton searches to probe the underlying structure responsible for satisfying these. Using the invariant mass spectrum and charge asymmetry, we can determine the number, parity, and isospin of these resonances. We pick three models of strong/warped symmetry breaking, and show that each model produces specific features that reflect this underlying structure of electroweak symmetry breaking and cancellations.
Holographic Fermi and non-Fermi liquids with transitions in dilaton gravity
Authors: Iizuka Norihiro , Kundu Nilay , Narayan Prithvi , Trivedi Sandip P.
Published: January 2012

Abstract

We study the two-point function for fermionic operators in a class of strongly coupled systems using the gauge-gravity correspondence. The gravity description includes a gauge field and a dilaton which determines the gauge coupling and the potential energy. Extremal black brane solutions in this system typically have vanishing entropy. By analyzing a charged fermion in these extremal black brane backgrounds we calculate the two-point function of the corresponding boundary fermionic operator. We find that in some region of parameter space it is of Fermi liquid type. Outside this region no well-defined quasi-particles exist, with the excitations acquiring a non-vanishing width at zero frequency. At the transition, the two-point function can exhibit non-Fermi liquid behaviour.
Influence of a triazine derivative-based biocide on microbial biofilms of cutting fluids in contact with different substrates
Authors: Lucchesi Eliane G , Eguchi Sílvia Y , Moraes Ângela M
Published: January 2012

Although biofilms are often associated with hospital infection problems owing to their high resistance to antimicrobial agents, in recent years biofilms have also been studied in the industrial sector, mainly because they are a major cause of contamination outbreaks in facilities and products. The aim of this study was to investigate whether different materials commonly found in the metalworking industries have different biofilm formation characteristics when in contact with contaminated cutting fluid as well as to establish an optimal concentration of a triazine-based antimicrobial agent to protect the oil/water emulsion and also to delay or interrupt the development of biofilms. Biofilms grown on the surface of carbon steel, stainless steel, aluminum, polyvinyl chloride, and glass were analyzed in terms of cell growth and susceptibility to the tested biocide. The results showed that the type of material used had little influence on cell adhesion or on the microbicide concentration required to control and eradicate microorganisms suspended in the emulsion and in the biofilms.
Pharmaco-écho-doppler pénien: méthodologie, critères diagnostiques et indications actuelles dans l’exploration d’une dysfonction érectile
Authors: Bonnin C. , Bouilly P.
Published: January 2012

La dysfonction érectile (DE) est une pathologie multifactorielle fréquente, dont l’origine organique ou mixte est considérée actuellement comme dominante chez l’homme après 50 ans. La plupart des DE vasculotissulaires sont liées à une dysfonction endothéliale, en relation avec les principaux facteurs de risque cardiovasculaires (FRCV). La DE représente un indicateur de la santé vasculaire en général. Elle est aussi prédictive d’événements cardiovasculaires (ECV), notamment de coronaropathies. Elle a également été associée aux artériopathies des membres inférieurs et aux accidents vasculaires cérébraux. Le pharmaco-écho-doppler pénien (PEDP) est un examen assez peu utilisé aujourd’hui dans la prise en charge d’une DE, la recherche étiologique n’étant encore le plus souvent pas considérée comme nécessaire à la prise en charge thérapeutique, mais également en raison de l’absence de standardisation. Cependant, de nombreuses publications ont mis récemment en évidence que l’origine vasculotissulaire d’une DE, établie sur des critères vélocimétriques enregistrés après injection intracaverneuse (IIC) de substances vasoactives, renforçait la valeur prédictive de la DE concernant les événements et la mortalité cardiovasculaires (CV), justifiant un intérêt accru pour réaliser cet examen.
Resonant dynamics for the quintic nonlinear Schrödinger equation
Authors: Grébert Benoît , Thomann Laurent
Published: January 2012

We consider the quintic nonlinear Schrödinger equation (NLS) on the circle

i\partial _{t}u + \partial _{x}^{2}u = \pm \nu |u|^{4}u,\:\nu \ll 1,\:x \in \mathbb{S}^{1},\:t \in \mathbb{R}.

We prove that there exist solutions corresponding to an initial datum built on four Fourier modes which form a resonant set (see Definition 1.1), which have a nontrivial dynamic that involves periodic energy exchanges between the modes initially excited. It is noticeable that this nonlinear phenomenon does not depend on the choice of the resonant set.

The dynamical result is obtained by calculating a resonant normal form up to order 10 of the Hamiltonian of the quintic NLS and then by isolating an effective term of order 6. Notice that this phenomenon cannot occur in the cubic NLS case for which the amplitudes of the Fourier modes are almost actions, i.e. they are almost constant.

Nous considérons lʼéquation de Schrödinger non linéaire (NLS) quintique sur le cercle

i\partial _{t}u + \partial _{x}^{2}u = \pm \nu |u|^{4}u,\:\nu \ll 1,\:x \in \mathbb{S}^{1},\:t \in \mathbb{R}.

Nous montrons quʼil existe des solutions issues dʼune condition initiale construite sur quatre modes de Fourier formant un ensemble résonant (voir définition 1.1) ont une dynamique non triviale mettant en jeu des échanges périodiques dʼénergie entre ces quatre modes initialement excités. Il est remarquable que ce phénomène non linéaire soit indépendant du choix de lʼensemble résonant.

Le résultat dynamique est obtenu en mettant dʼabord sous forme normale résonante jusquʼà lʼordre 10 lʼHamiltonien de NLS quintique puis en isolant un terme effectif dʼordre 6. Il est à noter que ce phénomène ne peut pas se produire pour NLS cubique pour lequel les amplitudes des modes de Fourier sont des presque-actions et donc ne varient quasiment pas au cours du temps.
Utrophin ABD binds to F‐actin in an open conformation
Authors: Broderick Mike J.F. , Bobkov Andrey , Winder Steve J.
Published: January 2012

Structural analyses of actin binding regions comprising tandem calponin homology domains alone and when bound to F‐actin have revealed a number of different conformations with calponin homology domains in ‘open’ and ‘closed’ positions. In an attempt to resolve these issues we have examined the properties of the utrophin actin binding domain in open and closed conformations in order to verify the conformation when bound to F‐actin. Locking the actin binding domain in a closed conformation using engineered cysteine residues in each calponin homology domain reduced the affinity for F‐actin without affecting the stoichiometry furthermore differential scanning calorimetry experiments revealed a reduction in melting temperature on binding to actin. The data suggest the amino‐terminal utrophin actin binding domain is in an open conformation in solution and when bound to F‐actin.
Subunit architecture of general transcription factor TFIIH
Authors: Gibbons Brian J. , Brignole Edward J. , Azubel Maia , Murakami Kenji , Voss Neil R. , Bushnell David A. , Asturias Francisco J. , Kornberg Roger D.
Published: January 2012

Structures of complete 10-subunit yeast TFIIH and of a nested set of subcomplexes, containing 5, 6, and 7 subunits, have been determined by electron microscopy (EM) and 3D reconstruction. Consistency among all the structures establishes the location of the “minimal core” subunits (Ssl1, Tfb1, Tfb2, Tfb4, and Tfb5), and additional densities can be specifically attributed to Rad3, Ssl2, and the TFIIK trimer. These results can be further interpreted by placement of previous X-ray structures into the additional densities to give a preliminary picture of the RNA polymerase II preinitiation complex. In this picture, the key catalytic components of TFIIH, the Ssl2 ATPase/helicase and the Kin28 protein kinase are in proximity to their targets, downstream promoter DNA and the RNA polymerase C-terminal domain.
pH-controlled delivery of luminescent europium coated nanoparticles into platelets
Authors: Davies Amy , Lewis David J. , Watson Stephen P. , Thomas Steven G. , Pikramenou Zoe
Published: January 2012

Water soluble, luminescent gold nanoparticles are delivered into human platelets via a rapid, pH-controlled mechanism using a pH low insertion peptide,
pHLIP
. The approach introduces cocoating of gold nanoparticles with a europium luminescent complex,
EuL
and the
pHLIP
peptide to give
pHLIP
•
EuL
•
Au
. The 13-nm diameter gold nanoparticles act as a scaffold for the attachment of both the luminescent probe and the peptide to target delivery. Their size allows delivery of approximately 640 lanthanide probes per nanoparticle to be internalized in human platelets, which are not susceptible to transfection or microinjection. The internalization of
pHLIP
•
EuL
•
Au
in platelets, which takes just minutes, was studied with a variety of imaging modalities including luminescence, confocal reflection, and transmission electron microscopy. The results show that
pHLIP
•
EuL
•
Au
only enters the platelets in low pH conditions, pH 6.5, mediated by the
pHLIP
translocation across the membrane, and not at pH 7.4. Luminescence microscopy images of the treated platelets show clearly the red luminescence signal from the europium probe and confocal reflection microscopy confirms the presence of the gold particles. Furthermore, transmission electron microscopy gives a detailed insight of the internalization and spatial localization of the gold nanoparticles in the platelets. Thus, we demonstrate the potential of the design to translocate multimodal nanoparticle probes into cells in a pH dependent manner.
Host-targeting protein 1 (SpHtp1) from the oomycete
Saprolegnia parasitica
translocates specifically into fish cells in a tyrosine-O-sulphate–dependent manner
Authors: Wawra Stephan , Bain Judith , Durward Elaine , de Bruijn Irene , Minor Kirsty L. , Matena Anja , Löbach Lars , Whisson Stephen C. , Bayer Peter , Porter Andrew J. , Birch Paul R. J. , Secombes Chris J. , van West Pieter
Published: January 2012

The eukaryotic oomycetes, or water molds, contain several species that are devastating pathogens of plants and animals. During infection, oomycetes translocate effector proteins into host cells, where they interfere with host-defense responses. For several oomycete effectors (i.e., the RxLR-effectors) it has been shown that their N-terminal polypeptides are important for the delivery into the host. Here we demonstrate that the putative RxLR-like effector, host-targeting protein 1 (SpHtp1), from the fish pathogen
Saprolegnia parasitica
translocates specifically inside host cells. We further demonstrate that cell-surface binding and uptake of this effector protein is mediated by an interaction with tyrosine-O-sulfate–modified cell-surface molecules and not via phospholipids, as has been reported for RxLR-effectors from plant pathogenic oomycetes. These results reveal an effector translocation route based on tyrosine-O-sulfate binding, which could be highly relevant for a wide range of host–microbe interactions.
Phasic D1 and tonic D2 dopamine receptor signaling double dissociate the motivational effects of acute nicotine and chronic nicotine withdrawal
Authors: Grieder Taryn E. , George Olivier , Tan Huibing , George Susan R. , Le Foll Bernard , Laviolette Steven R. , van der Kooy Derek
Published: January 2012

Nicotine, the main psychoactive ingredient of tobacco smoke, induces negative motivational symptoms during withdrawal that contribute to relapse in dependent individuals. The neurobiological mechanisms underlying how the brain signals nicotine withdrawal remain poorly understood. Using electrophysiological, genetic, pharmacological, and behavioral methods, we demonstrate that tonic but not phasic activity is reduced during nicotine withdrawal in ventral tegmental area dopamine (DA) neurons, and that this pattern of signaling acts through DA D2 and adenosine A2A, but not DA D1, receptors. Selective blockade of phasic DA activity prevents the expression of conditioned place aversions to a single injection of nicotine in nondependent mice, but not to withdrawal from chronic nicotine in dependent mice, suggesting a shift from phasic to tonic dopaminergic mediation of the conditioned motivational response in nicotine dependent and withdrawn animals. Either increasing or decreasing activity at D2 or A2A receptors prevents the aversive motivational response to withdrawal from chronic nicotine, but not to acute nicotine. Modification of D1 receptor activity prevents the aversive response to acute nicotine, but not to nicotine withdrawal. This double dissociation demonstrates that the specific pattern of tonic DA activity at D2 receptors is a key mechanism in signaling the motivational effects experienced during nicotine withdrawal, and may represent a unique target for therapeutic treatments for nicotine addiction.
Identification of residues defining phospholipid flippase substrate specificity of type IV P-type ATPases
Authors: Baldridge Ryan D. , Graham Todd R.
Published: January 2012

Type IV P-type ATPases (P4-ATPases) catalyze translocation of phospholipid across a membrane to establish an asymmetric bilayer structure with phosphatidylserine (PS) and phosphatidylethanolamine (PE) restricted to the cytosolic leaflet. The mechanism for how P4-ATPases recognize and flip phospholipid is unknown, and is described as the “giant substrate problem” because the canonical substrate binding pockets of homologous cation pumps are too small to accommodate a bulky phospholipid. Here, we identify residues that confer differences in substrate specificity between Drs2 and Dnf1,
Saccharomyces cerevisiae
P4-ATPases that preferentially flip PS and phosphatidylcholine (PC), respectively. Transplanting transmembrane segments 3 and 4 (TM3-4) of Drs2 into Dnf1 alters the substrate preference of Dnf1 from PC to PS. Acquisition of the PS substrate maps to a Tyr618Phe substitution in TM4 of Dnf1, representing the loss of a single hydroxyl group. The reciprocal Phe511Tyr substitution in Drs2 specifically abrogates PS recognition by this flippase causing PS exposure on the outer leaflet of the plasma membrane without disrupting PE asymmetry. TM3 and the adjoining lumenal loop contribute residues important for Dnf1 PC preference, including Phe587. Modeling of residues involved in substrate selection suggests a novel P-type ATPase transport pathway at the protein/lipid interface and a potential solution to the giant substrate problem.
The diverse effects of mechanical loading on active hair bundles
Authors: Ó Maoiléidigh Dáibhid , Nicola Ernesto M. , Hudspeth A. J.
Published: January 2012

Hair cells in the auditory, vestibular, and lateral-line systems of vertebrates receive inputs through a remarkable variety of accessory structures that impose complex mechanical loads on the mechanoreceptive hair bundles. Although the physiological and morphological properties of the hair bundles in each organ are specialized for detecting the relevant inputs, we propose that the mechanical load on the bundles also adjusts their responsiveness to external signals. We use a parsimonious description of active hair-bundle motility to show how the mechanical environment can regulate a bundle’s innate behavior and response to input. We find that an unloaded hair bundle can behave very differently from one subjected to a mechanical load. Depending on how it is loaded, a hair bundle can function as a switch, active oscillator, quiescent resonator, or low-pass filter. Moreover, a bundle displays a sharply tuned, nonlinear, and sensitive response for some loading conditions and an untuned or weakly tuned, linear, and insensitive response under other circumstances. Our simple characterization of active hair-bundle motility explains qualitatively most of the observed features of bundle motion from different organs and organisms. The predictions stemming from this description provide insight into the operation of hair bundles in a variety of contexts.
Tumor suppressor function of Liver kinase B1 (Lkb1) is linked to regulation of epithelial integrity
Authors: Partanen Johanna I. , Tervonen Topi A. , Myllynen Mikko , Lind Essi , Imai Misa , Katajisto Pekka , Dijkgraaf Gerrit J. P. , Kovanen Panu E. , Mäkelä Tomi P. , Werb Zena , Klefström Juha
Published: January 2012

Although loss of epithelial integrity is a hallmark of advanced cancer, it remains poorly understood whether genetic alterations corrupting this integrity causally facilitate tumorigenesis. We show that conditional deletion of tumor suppressor gene Lkb1 (Par-4) in the mammary gland compromises epithelial integrity manifested by mislocalization of cell polarity markers, lateralization of tight junctions, deterioration of desmosomes and basement membrane (BM), and hyperbranching of the mammary ductal tree. We identify the desmosomal BM remodelling serine protease Hepsin as a key factor mediating Lkb1 loss-induced structural alterations in mammary epithelium and BM fragmentation. Although loss of Lkb1 alone does not promote mammary tumorigenesis, combination of Lkb1 deficiency with oncogenic c-Myc leads to dramatic acceleration in tumor formation. The results coupling Lkb1 loss-mediated epithelial integrity defects to mislocalization of serine protease Hepsin and to oncogenic synergy with c-Myc imply that Lkb1 loss facilitates oncogenic proliferation by releasing epithelial cells from structural BM boundaries.
Mining and integration of pathway diagrams from imaging data
Authors: Kozhenkov Sergey , Baitaluk Michael
Published: January 2012

Motivation: Pathway diagrams from PubMed and World Wide Web (WWW) contain valuable highly curated information difficult to reach without tools specifically designed and customized for the biological semantics and high-content density of the images. There is currently no search engine or tool that can analyze pathway images, extract their pathway components (molecules, genes, proteins, organelles, cells, organs, etc.) and indicate their relationships.

Results: Here, we describe a resource of pathway diagrams retrieved from article and web-page images through optical character recognition, in conjunction with data mining and data integration methods. The recognized pathways are integrated into the BiologicalNetworks research environment linking them to a wealth of data available in the BiologicalNetworks' knowledgebase, which integrates data from >100 public data sources and the biomedical literature. Multiple search and analytical tools are available that allow the recognized cellular pathways, molecular networks and cell/tissue/organ diagrams to be studied in the context of integrated knowledge, experimental data and the literature.

Availability: BiologicalNetworks software and the pathway repository are freely available at www.biologicalnetworks.org.

Contact: baitaluk@sdsc.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
A Boolean network model of the FA/BRCA pathway
Authors: Rodríguez Alfredo , Sosa David , Torres Leda , Molina Bertha , Frías Sara , Mendoza Luis
Published: January 2012

Motivation:

Fanconi anemia (FA) is a chromosomal instability syndrome originated by inherited mutations that impair the Fanconi Anemia/Breast Cancer (FA/BRCA) pathway, which is committed to the repair of DNA interstrand cross-links (ICLs). The disease displays increased spontaneous chromosomal aberrations and hypersensitivity to agents that create DNA interstrand cross-links. In spite of DNA damage, FA/BRCA-deficient cells are able to progress throughout the cell cycle, probably due to the activity of alternative DNA repair pathways, or due to defects in the checkpoints that monitor DNA integrity.

Results: We propose a Boolean network model of the FA/BRCA pathway, Checkpoint proteins and some alternative DNA repair pathways. To our knowledge, this is the largest network model incorporating a DNA repair pathway. Our model is able to simulate the ICL repair process mediated by the FA/BRCA pathway, the activation of Checkpoint proteins observed by recurrent DNA damage, as well as the repair of DNA double-strand breaks and DNA adducts. We generated a series of simulations for mutants, some of which have never been reported and thus constitute predictions about the function of the FA/BRCA pathway. Finally, our model suggests alternative DNA repair pathways that become active whenever the FA/BRCA pathway is defective.

Contact:  sarafrias@yahoo.com; lmendoza@biomedicas.unam.mx

Supplementary information:  Supplementary data are available at Bioinformatics online.
Under the Counter, Under the Radar? The Business and Regulation of the Pornographic Press in Sweden 1950–1971
Authors: Arnberg Klara
Published: January 2012

In this article, the process leading to decriminalization of pornography in Sweden in 1971 is analyzed. The interplay between the structural institutional level and company behavior is stressed, with an emphasis on business strategies. The article shows that the division between hard-core and soft-core pornographic magazines in Sweden was quite different than the development in the United Kingdom and the United States. It also shows how the business strategies used by hard-core pornographers challenged the obscenity legislation and regulation of national distribution, making them obsolete. Even though there was fierce competition between the pornography companies, producers formed joint alternative distribution channels crucial to the survival of the industry.
Ventricular assist device support as a bridge to heart transplantation in patients with giant cell myocarditis
Authors: Murray Lindsay K. , González‐Costello Jose , Jonas Samual N. , Sims Daniel B. , Morrison Kerry A. , Colombo Paolo C. , Mancini Donna M. , Restaino Susan W. , Joye Evan , Horn Evelyn , Takayama Hiroo , Marboe Charles C. , Naka Yoshifumi , Jorde Ulrich P. , Uriel Nir
Published: January 2012

Aims

Giant cell myocarditis (GCM) carries a poor prognosis and many patients require end‐stage therapies. This study sought to determine the outcome of patients bridged with ventricular assist devices (VAD) to orthotopic heart transplantation (OHT).

Methods and results

A retrospective data collection of all patients with GCM was performed. Diagnosis was determined by endomyocardial or explanted heart biopsy. Eight patients were found, but two of those patients went directly to OHT and were excluded. The remaining six patients received VADs, and these patients, aged 44 ± 18 years, were included. Five of the six patients were bridged with biventricular support and one patient was supported by left ventricular assist device (LVAD) alone. Two patients died on device support. Four patients were bridged to OHT 77 ± 42 days after device implantation. All four patients bridged with a VAD are alive, with a mean follow‐up of 5.7 ± 4.1 years. Two patients were found to have recurrent GCM in the transplanted heart and were treated successfully with immunosuppression. Three patients had high grade (2R) rejection at 66 ± 52 days post‐OHT. Cardiac function was preserved in all patients, and only one patient had cardiac allograft vasculopathy.

Conclusion

Patients with end‐stage GCM can be successfully bridged with VADs to OHT with very good post‐OHT survival. The proper immunosuppressive regimen for this group needs further investigation given the frequency of rejection and GCM recurrence.
Measuring the vertical distributional variability of pelagic fauna in Monterey Bay
Authors: Urmy Samuel S. , Horne John K. , Barbee David H.
Published: January 2012

Urmy, S. S., Horne, J. K., and Barbee, D. H. 2012. Measuring the vertical distributional variability of pelagic fauna in Monterey Bay. – ICES Journal of Marine Science, 69: 184–196. Temporal variability is an important feature of aquatic ecosystems that can be difficult to measure. A stationary, upward-facing scientific echosounder was used to record the vertical distribution of pelagic fauna in Monterey Bay, CA, for 18 months. To characterize the distributions, a suite of metrics, including measures of density, abundance, location, dispersion, occupancy, evenness, and aggregation, was developed and tested. An algorithm to detect and count the number of acoustic backscatter layers was developed using image-analysis techniques. The metrics recorded a strong seasonal cycle, with total backscatter reaching a minimum during the spring upwelling season and peaking in autumn and winter. Variability in the vertical distribution of animals was greatest at long time-scales and decreased as a power (−1.050 to −1.585) of signal frequency. There were significant peaks in the power spectrum at 12- and 24-h periods, corresponding to the semi-diurnal tide and diel vertical migration. The diel signal was strongest in late winter and weakest during the spring upwelling season. Active acoustics are a useful addition to ocean observatories, and the metrics presented provide a useful set of tools to quantify the distribution and temporal variability of pelagic fauna.