bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of cationic magnetic nanoparticles and evaluation of their gene delivery efficacy in Hep G2 cells
Authors: Chen Jui‐Tse , Ahmed Marya , Liu Qingxia , Narain Ravin
Published: April 2012

Well‐defined cationic polymers were synthesized via the reversible addition fragmentation chain transfer polymerization and were subsequently used as stabilizer for the synthesis of cationic iron‐oxide magnetic nanoparticles via the coprecipitation method. The surface‐coated iron‐oxide nanoparticles made stable suspension in water and were characterized by a range of techniques such as dynamic light scattering, transmission electron microscopy, and thermogravimetric analysis. The presence of protonated amine and carbohydrate residues onto the surface of the nanoparticles allowed their facile complexation with DNA and the resulting nanocomplexes were then studied for their efficacy as DNA carriers in Hep G2 cells. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A: 2342–2347, 2012.
Calculation of the relative free energy of oxidation of azurin at pH 5 and pH 9
Authors: Steiner Denise , Oostenbrink Chris , van Gunsteren Wilfred F.
Published: April 2012

Free energy calculations are described for the small copper‐containing redox protein Azurin fromPseudomonas aeruginosa. A thermodynamic cycle connecting the reduced and oxidized states at pH 5 and pH 9 is considered, allowing for an assessment of convergence in terms of hysteresis and cycle closure. Previously published thermodynamic integration (TI) data is compared to Hamiltonian replica exchange TI (RE‐TI) simulations using different simulation setups. The effects of varying simulation length, initial structure, position restraints on particular atoms, and the strength of temperature coupling are studied. Although the overall simulation times are too short to observe an experimentally described peptide plane rotation, it is found that RE‐TI simulations do stimulate the distribution of conformational changes over the relevant values of the TI coupling parameter λ. This results in significantly improved values for hysteresis and cycle closure when compared to regular TI. © 2012 Wiley Periodicals, Inc.
Efficient treatment of solvation shells in 3D molecular theory of solvation
Authors: Gusarov Sergey , Pujari Bhalchandra S. , Kovalenko Andriy
Published: April 2012

We developed a technique to decrease memory requirements when solving the integral equations of three‐dimensional (3D) molecular theory of solvation, a.k.a. 3D reference interaction site model (3D‐RISM), using the modified direct inversion in the iterative subspace (MDIIS) numerical method of generalized minimal residual type. The latter provides robust convergence, in particular, for charged systems and electrolyte solutions with strong associative effects for which damped iterations do not converge. The MDIIS solver (typically, with 2 × 10 iterative vectors of argument and residual for fast convergence) treats the solute excluded volume (core), while handling the solvation shells in the 3D box with two vectors coupled with MDIIS iteratively and incorporating the electrostatic asymptotics outside the box analytically. For solvated systems from small to large macromolecules and solid–liquid interfaces, this results in 6‐ to 16‐fold memory reduction and corresponding CPU load decrease in MDIIS. We illustrated the new technique on solvated systems of chemical and biomolecular relevance with different dimensionality, both in ambient water and aqueous electrolyte solution, by solving the 3D‐RISM equations with the Kovalenko–Hirata (KH) closure, and the hypernetted chain (HNC) closure where convergent. This core–shell‐asymptotics technique coupling MDIIS for the excluded volume core with iteration of the solvation shells converges as efficiently as MDIIS for the whole 3D box and yields the solvation structure and thermodynamics without loss of accuracy. Although being of benefit for solutes of any size, this memory reduction becomes critical in 3D‐RISM calculations for large solvated systems, such as macromolecules in solution with ions, ligands, and other cofactors. © 2012 Wiley Periodicals, Inc.
Myelinating and demyelinating phenotype of Trembler‐J mouse (a model of Charcot–Marie–Tooth human disease) analyzed by atomic force microscopy and confocal microscopy
Authors: Rosso Gonzalo , Negreira Carlos , Sotelo José R. , Kun Alejandra
Published: April 2012

The accumulation of misfolded proteins is associated with various neurodegenerative conditions. Mutations in PMP‐22 are associated with the human peripheral neuropathy, Charcot–Marie–Tooth Type 1A (CMT1A). PMP‐22 is a short‐lived 22 kDa glycoprotein, which plays a key role in the maintenance of myelin structure and compaction, highly expressed by Schwann cells. It forms aggregates when the proteasome is inhibited or the protein is mutated. This study reports the application of atomic force microscopy (AFM) as a detector of profound topographical and mechanical changes in Trembler‐J mouse (CMT1A animal model). AFM images showed topographical differences in the extracellular matrix and basal lamina organization of Tr‐J/+ nerve fibers. The immunocytochemical analysis indicated that PMP‐22 protein is associated with type IV collagen (a basal lamina ubiquitous component) in the Tr‐J/+ Schwann cell perinuclear region. Changes in mechanical properties of single myelinating Tr‐J/+ nerve fibers were investigated, and alterations in cellular stiffness were found. These results might be associated with F‐actin cytoskeleton organization in Tr‐J/+ nerve fibers. AFM nanoscale imaging focused on topography and mechanical properties of peripheral nerve fibers might provide new insights into the study of peripheral nervous system diseases. Copyright © 2012 John Wiley & Sons, Ltd.
Muscle excursion does not correlate with increased serial sarcomere number after muscle adaptation to stretched tendon transfer
Authors: Takahashi Mitsuhiko , Ward Samuel R. , Fridén Jan , Lieber Richard L.
Published: April 2012

Chronic skeletal muscle stretch typically increases serial muscle fiber sarcomere number. Since serial sarcomere number correlates with functional excursion in normal muscle, observed changes in sarcomere number are often extrapolated to their new assumed function. However, this has not been well demonstrated experimentally. Thus, we measured the functional properties of muscles stretched due to tendon transfer surgery. Muscle active and passive length–tension curves were measured 1 week and 4 weeks after surgery, and then each muscle was further examined to determine structural adaptation as well as single fiber and fiber bundle passive mechanical properties. We found a disconnect between the functional and structural muscle properties. Specifically, muscle excursion was significantly lower in the transferred muscle compared to controls, even though serial sarcomere number had increased. Furthermore, maximum tetanic tension was significantly reduced, though the two groups had similar physiological cross sectional areas. Passive tension increased in the transferred muscle, which was deemed to be due to proliferation of extracellular matrix. These data are the first to report that muscle morphological adaptation after chronic stretch does not accurately predict the muscle's functional properties. These data have significant implications for examining muscle physiological properties under surgical interventions. © 2012 Orthopaedic Research Society. This article is a US Government work and, as such, is in the public domain in the United States of America. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1774–1780, 2012
Endoscopy and role of endoscopic resection in gastric cancer
Authors: Hoppo Toshitaka , Jobe Blair A.
Published: April 2012

Patient selection for endoscopic resection is based on meticulous endoscopic examination and histological assessment so as to avoid performing this procedure on patients with a high risk of lymph node involvement or metastatic disease. Currently, endoscopic mucosal resection (EMR) is used for tumors <2 cm, and endoscopic submucosal dissection (ESD) should be considered for tumors >2 cm. The advantage of ESD is that it achieves en‐bloc resection of larger tumors, potentially reducing the risk of disease recurrence. J. Surg. Oncol. 2013;107:243–249. © 2012 Wiley Periodicals, Inc.
Management of advanced carcinoma of the base of tongue
Authors: Karatzanis Alexander D. , Psychogios Georgios , Mantsopoulos Konstantinos , Zenk Johannes , Velegrakis George A. , Waldfahrer Frank , Iro Heinrich
Published: April 2012

Background and Objective

Base‐of‐tongue carcinoma is a relatively rare disease with aggressive behavior and poor prognosis. Up to date no consensus exists regarding the ideal management strategy for each stage of the disease. This study aims to evaluate the experience of a single head and neck oncology center in the management of advanced stage base‐of‐tongue cancer.

Methods

A retrospective evaluation of cases primarily treated for stage III/IVA–B base‐of‐tongue carcinoma, between 1980 and 2007, at a tertiary referral center.

Results

A total of 366 cases were studied. Five‐year disease specific survival (DSS) was 42% and local control (LC) 80%. Regional and distal control estimates were 91.3 and 84%, respectively. Prognosis was significantly superior for cases receiving surgery plus adjuvant treatment compared to cases solely managed with non‐surgical modalities. Positive surgical margins and regional disease significantly worsened prognosis. Satisfactory retention of pharyngeal function and no fatal complications were noted in surgical cases.

Conclusion

Although no consensus exists regarding ideal therapy for advanced base‐of‐tongue carcinoma, combined strategies with the use of surgery and adjuvant chemoradiotherapy (CRT) seem to offer the best possibility for a positive outcome. J. Surg. Oncol. 2012; 106:713–718. © 2012 Wiley Periodicals, Inc.
Role of radiation therapy in the management of pancreatic cancer
Authors: Goodman Karyn A. , Hajj Carla
Published: April 2012

Local failure remains a major issue for patients with both resectable and locally advanced pancreatic cancer. The role of radiation therapy in the management of this disease is less clear and represents an area of some controversy. The objective of this review is to present the rationale for radiation therapy in pancreatic cancer, as well as to discuss the potential limitations and caveats of the currently available studies. J. Surg. Oncol. 2013;107:86–96. © 2012 Wiley Periodicals, Inc.
Determination of 4‐methylpiperaine‐1‐carbodithioc acid 3‐cyano‐3,3‐diphenylpropyl ester hydrochloride in rats’ plasma by online‐SPE‐HPLC‐DAD: Application to a pharmacokinetic study
Authors: Zhang Jianmei , Lin Wensi , Li Xiaona , Yu Ning , Ling Xiaomei , Fu Ge , Li Runtao , Cui Jingrong
Published: April 2012

A specific, simple, and fast online‐solid‐phase extraction‐high performance liquid chromatography‐diode array detector (SPE‐HPLC‐DAD) method was developed and validated to quantify 4‐methylpiperaine‐1‐carbodithioc acid 3‐cyano‐3,3‐diphenylpropyl ester hydrochloride (TM208) in small volume samples of rats’ plasma for the first time. In this method, the 50‐μL plasma sample was taken to perform protein precipitation with 75 μL methanol, and then 50 μL supernatant containing the target analytes was injected and concentrated automatically in a C18 solid‐phase extraction (SPE) cartridge. After that the sample was separated on a C18 RP analytical column and analyzed by DAD. The run cycle time is 6.0 min for each sample, and the calibration curve over the range of 0.03 to 25.00 μg/mL has a good linear relationship (r > 0.9998). The recoveries of the quality control samples were all greater than 90%. The limit of detection and the lowest limit of quantification were 0.01 and 0.03 μg/mL, respectively. Finally, this method was successfully applied to a pharmacokinetic study of TM208 in rats.
Selectivity of two types of sulfadimidine‐imprinted monolithic polymer‐based fibers
Authors: Wang Lihua , Shao Guang , Gan Feng
Published: April 2012

Molecularly imprinted polymeric monolithic fiber is a new technique of solid‐phase microextraction that focuses on selectivity. However, the inner mechanism of increasing the selectivity is not well understood. Here, a new approach to improve the selectivity is shown through controlling the surface of a molecular imprinted polymeric monolithic fiber. Sulfadimidine‐imprinted polymeric monolithic fibers were fabricated using two kinds of molds, the polytetrafluoroethylene capillary and the silica capillary. A mixture of sulfadimidine, sulfamerazine, sulfadiazine, and sulfametoxypirydazine was used to test the selectivity of the fibers to sulfadimidine. This paper demonstrates that the extraction ratio for sulfadimidine in mixture is increased to more than 150% in sulfadimidine‐imprinted polymeric monolithic fiber compared to nonimprinted polymeric monolithic fiber. The extraction ratio is increased to about 30% in sulfadimidine‐imprinted polymeric monolithic fiber fabricated from silica capillary than in the counterpart from nonimprinted polymeric monolithic fiber. The sulfadimidine‐imprinted polymeric monolithic fibers were also applied to extract standard mixtures spiked into Pearl River water and milk. The results indicated that polytetrafluoroethylene‐sulfadimidine imprinted polymeric monolithic fiber showed highest selectivity to sulfadimidine in complex samples.
Impact of substituent position in monosubstituted α‐cyclodextrins on enantioselectivity in capillary electrophoresis
Authors: Řezanka Michal , Řezanka Pavel , Sýkora David , Jindřich Jindřich , Král Vladimír
Published: April 2012

In this study, our three recently synthesized regiospecifically monosubstituted carboxymethyl‐α‐cyclodextrins (CMACDs) were successfully applied for the enantiomeric separation of several biologically important low‐molecular weight compounds by capillary electrophoresis. The enantioselectivity of the individual monosubstituted CMACDs added into the background electrolyte (BGE) was studied and compared with the mixture of three monosubstituted CMACDs and with native α‐cyclodextrin at pH of the BGE ranging from 2.5 to 11. Our experiments revealed a significant influence of the position of the carboxymethyl group on the α‐cyclodextrin skeleton on the enantioselectivity for all the studied analytes. Interestingly, the least common 3I‐O regioisomer was revealed as the most effective chiral selector.
Combined application of macroporous resin and high speed counter‐current chromatography for preparative separation of three flavonoid triglycosides from the leaves of Actinidia valvataDunn
Authors: Qu Liping , Xin Hailiang , Su Yonghua , Zheng Guoyin , Ling Changquan
Published: April 2012

In this paper, the combined techniques of macroporous resin column chromatography and high speed counter‐current chromatography were applied for preparative separation of flavonoid triglycosides from the leaves of Actinidia valvata Dunn, a famous Chinese medicinal herb. Twelve kinds of macroporous resins were investigated by adsorption and desorption tests. HPD‐300 resin showed the maximum effectiveness and thus was selected for the first cleaning‐up, in which 20% ethanol was used to remove the undesired constituents and 60% ethanol to elute the targets. The crude extract was then purified by high speed counter‐current chromatography with the solvent system composed of ethyl acetate‒n‐butanol‒water (2:1:3 and 4:1:5, v/v). Three flavonoid triglycosides, namely, kaempferol 3‐O‐α‐l‐rhamnopyranosyl‐(1→3)‐α‐l‐rhamnopyranosyl‐(1→6)‐β‐d‐galactopyranoside, kaempferol 3‐O‐α‐l‐rhamnopyranosyl‐(1→3)‐(4‐O‐acetyl‐α‐l‐rhamnopyranosyl)‐(1→6)‐β‐d‐galactopyranoside and kaempferol 3‐O‐α‐l‐rhamnopyranosyl‐(1→3)‐(2,4‐di‐O‐acetyl‐α‐l‐rhamnopyranosyl)‐(1→6)‐β‐d‐galactopyranoside, were obtained. The purities of the separated compounds were all over 95% as determined by HPLC area normalization method. Their chemical structures were confirmed by UV, MS, NMR, and the standards.
Behavioral markers of coping and psychiatric symptoms among sexually abused children
Authors: Shapiro Danielle N. , Kaplow Julie B. , Amaya‐Jackson Lisa , Dodge Kenneth A.
Published: April 2012

The current study examined coping and psychiatric symptoms in a longitudinal sample of sexually abused children. Coping was behaviorally coded from children's forensic interviews in the aftermath of sexual abuse. Using principal components analysis, coping behaviors were found to cluster into 3 categories: avoidant, expressive, and positive affective coping. Avoidant coping had predictive utility for a range of psychiatric symptoms, including depressive, posttraumatic stress, anxiety, and dissociative symptoms as well as aggression and attention problems measured 8–36 months following the forensic interview. Specific behaviors, namely fidgetiness and distractibility, were also found to be associated with future symptoms. These findings suggest the predictive utility of avoidant behaviors in general, and fidgetiness and distractibility in particular, among sexually abused children.
Stepped early psychological intervention for posttraumatic stress disorder, other anxiety disorders, and depression following serious injury
Authors: O'Donnell Meaghan L. , Lau Winnie , Tipping Susannah , Holmes Alexander C. N. , Ellen Steven , Judson Rodney , Varker Tracey , Elliot Peter , Bryant Richard A. , Creamer Mark C. , Forbes David
Published: April 2012

The best approach for implementing early psychological intervention for anxiety and depressive disorders after a traumatic event has not been established. This study aimed to test the effectiveness of a stepped model of early psychological intervention following traumatic injury. A sample of 683 consecutively admitted injury patients were screened during hospitalization. High‐risk patients were followed up at 4‐weeks postinjury and assessed for anxiety and depression symptom levels. Patients with elevated symptoms were randomly assigned to receive 4–10 sessions of cognitive–behavioral therapy (n = 24) or usual care (n = 22). Screening in the hospital identified 89% of those who went on to develop any anxiety or affective disorder at 12 months. Relative to usual care, patients receiving early intervention had significantly improved mental health at 12 months. A stepped model can effectively identify and treat injury patients with high psychiatric symptoms within 3 months of the initial trauma.
Translocation as a conservation tool for Agassiz's desert tortoises: Survivorship, reproduction, and movements
Authors: Nussear K. E. , Tracy C. R. , Medica P. A. , Wilson D. S. , Marlow R. W. , Corn P. S.
Published: April 2012

We translocated 120 Agassiz's desert tortoises to 5 sites in Nevada and Utah to evaluate the effects of translocation on tortoise survivorship, reproduction, and habitat use. Translocation sites included several elevations, and extended to sites with vegetation assemblages not typically associated with desert tortoises in order to explore the possibility of moving animals to upper elevation areas. We measured survivorship, reproduction, and movements of translocated and resident animals at each site. Survivorship was not significantly different between translocated and resident animals within and among sites, and survivorship was greater overall during non‐drought years. The number of eggs produced by tortoises was similar for translocated and resident females, but differed among sites. Animals translocated to atypical habitat generally moved until they reached vegetation communities more typical of desert tortoise habitat. Even within typical tortoise habitat, tortoises tended to move greater distances in the first year after translocation than did residents, but their movements in the second or third year after translocation were indistinguishable from those of resident tortoises. Our data show that tortoises translocated into typical Mojave desert scrub habitats perform well; however, the large first‐year movements of translocated tortoises have important management implications. Projects that employ translocations must consider how much area will be needed to contain translocated tortoises and whether roads need fencing to prevent the loss of animals. © 2012 The Wildlife Society.
Transnasal tracheoscopy
Authors: Verma Sunil P. , Smith Marshall E. , Dailey Seth H.
Published: April 2012

Objectives/Hypothesis:

Unsedated transnasal tracheoscopy (TNT) has emerged as a technique in otolaryngology–head and neck surgery for an awake airway examination in the office setting. This study investigates the safety, procedural success rate, indications, and findings of TNTs performed over a 3‐year period at an academic medical center.

Study Design:

Retrospective chart review.

Methods:

After institutional review board approval, billing records were reviewed for patients who underwent TNT from 2007–2009 in the University of Wisconsin–Madison Department of Otolaryngology–Head and Neck Surgery. Hospital charts for these patients were obtained, and data regarding patient demographics, complications, procedural success rate, indications, and findings were recorded.

Results:

Sixty‐eight TNTs were performed on 44 patients over the last 3 years (25 males, 19 females; age range, 16–91 years). No complications were noted. Ninety‐one percent of procedures were able to be completed. Indications for TNT were to: 1) detect airway stenosis or pathology, 2) evaluate the larynx and trachea prior to airway surgery, 3) monitor postoperative results of airway interventions, and 4) evaluate the airway prior to tracheotomy tube decannulation.

Conclusions:

TNT is a safe procedure that can be performed on the unsedated patient using only topical anesthesia and is an attractive alternative to rigid bronchoscopy. The procedural success rate was high, indicating good patient tolerance. The indications for TNT, including its use as a tool for surgical planning, have become better defined. TNT has become a standard tool in the management of patients with airway pathology in our practices.
Cystic fibrosis transmembrane conductance regulator modulation by the tobacco smoke toxin acrolein
Authors: Alexander Nathan S. , Blount Angela , Zhang Shaoyan , Skinner Daniel , Hicks Stephen B. , Chestnut Michael , Kebbel Frederick A. , Sorscher Eric J. , Woodworth Bradford A.
Published: April 2012

Objectives/Hypothesis:

Evidence indicates that decreased mucociliary clearance (MCC) is a major contributing feature to chronic rhinosinusitis. Tobacco‐smoke exposure is thought to inhibit transepithelial Cl− secretion, a major determinant of airway surface liquid hydration and MCC. The objective of the current study was to evaluate the effects of acrolein exposure (a prominent tobacco smoke toxin) on vectorial Cl− transport through the major apical anion channel cystic fibrosis transmembrane conductance regulator (CFTR) in sinonasal epithelium.

Study Design:

In vitro investigation.

Methods:

Primary murine nasal septal epithelia (MNSE; wild‐type and transgenic CFTR−/−) cultures were exposed to acrolein in Ussing chambers and the effects on Cl− secretion investigated using pharmacologic manipulation. Cellular cyclic adenosine monophosphate (cAMP) signaling and cytotoxicity were also investigated.

Results:

Acrolein stimulated Cl− secretion (ΔISC—change in short‐circuit current in μA/cm2) at concentrations similar to smoker's airways (100 μM, 15.8 ± 2.2 vs. 2.4 ± 0.8 [control]; P < .0001), suppressed forskolin‐stimulated C− transport at 300 μM (13.3 ± 1.2 vs. 19.9 ± 1.0; P < .01), and completely abolished all transport at 500 μM (−1.1 ± 1.6). Stimulated Cl− secretion was solely reliant upon the presence of CFTR (confirmed in transgenic CFTR−/− MNSE), but independent of cAMP signaling. Inhibition at higher concentrations was not secondary to cellular cytotoxicity.

Conclusions:

The present study demonstrates that acrolein has complex but pronounced interaction with the major apical Cl− transport mechanism that uses CFTR. Further investigations are required to determine acrolein's impact as a tobacco smoke constituent on mucociliary transport.
Variability of standard liver volume estimation versus software-assisted total liver volume measurement
Authors: Pomposelli James J. , Tongyoo Assanee , Wald Christoph , Pomfret Elizabeth A.
Published: April 2012

The estimation of the standard liver volume (SLV) is an important component of the evaluation of potential living liver donors and the surgical planning for resection for tumors. At least 16 different formulas for estimating SLV have been published in the worldwide literature. More recently, several proprietary software-assisted image postprocessing (SAIP) programs have been developed to provide accurate volume measurements based on the actual anatomy of a specific patient. Using SAIP, we measured SLV in 375 healthy potential liver donors and compared the results to SLV values that were estimated with the previously published formulas and each donor's demographic and anthropomorphic data. The percentage errors of the 16 SLV formulas versus SAIP varied by more than 59% (from −21.6% to +37.7%). One formula was not statistically different from SAIP with respect to the percentage error (−1.2%), and another formula was not statistically different with respect to the absolute liver volume (18 mL). More than 75% of the estimated SLV values produced by these 2 formulas had percentage errors within ±15%, and the formulas provided good predictions within acceptable agreement (±15%) on scatter plots. Because of the wide variability, care must be taken when a formula is being chosen for estimating SLV, but the 2 aforementioned formulas provided the most accurate results with our patient demographics. Liver Transpl, 2012. © 2012 AASLD.
Banded Spherulitic Morphology in Blends of Poly (propylene fumarate) and Poly(ϵ‐caprolactone) and Interaction with MC3T3‐E1 Cells
Authors: Wang Kan , Jesse Stephen , Wang Shanfeng
Published: April 2012

The thermal properties, morphological development, crystallization behavior, and miscibility of semicrystalline PCL and its 25, 50, and 75 wt% blends with amorphous PPF in spin‐coated thin films crystallized at various crystallization temperatures (Tc) from 25 to 52 °C are investigated. The surface roughness of PPF/PCL (ϕPCL = 75%) films increases with increasing Tc and consequently the adsorption of serum proteins is also increased. No significant variance is found in surface hydrophilicity or in mouse MC3T3‐E1 cell attachment, spreading, and proliferation on PPF/PCL (ϕPCL = 75%) films crystallized isothermally at 25, 37, and 45 °C, because of low ridge height, nonuniformity in structures, and PPF surface segregation.
Imidazolium End‐Functionalized ATRP Polymers as Directing Agents for CNT Dispersion and Confinement
Authors: Dervaux Bart , Meyer Franck , Raquez Jean‐Marie , Olivier Aurore , Du Prez Filip E. , Dubois Philippe
Published: April 2012

Imidazolium end‐functionalized poly(butyl acrylate) and polystyrene (co)polymers (Im‐PnBuA, Im‐PSty, and Im‐PnBuA‐b‐PSty are synthesized via ATRP. The controlled character of the polymerization reactions is highlighted by SEC and MALDI‐TOF MS analyses. Subsequently, the polymers are tested as dispersing/compatibilizing agents for CNTs in polymer matrices. When CNTs are challenged with a mixture of Im‐PnBuA and Im‐PSty, the CNTs are mainly located in the PnBuA phase. In contrast, the Im‐PnBuA‐b‐PSty block copolymer enables CNT confinement in the PSty phase. By selecting the proper ω‐imidazolium polymer, it is possible to direct the CNT confinement toward a specific polymer phase within polymer mixtures.
Structuring and Molding of Electrospun Nanofibers: Effect of Electrical and Topographical Local Properties of Micro‐Patterned Collectors
Authors: Lavielle Nicolas , Hébraud Anne , Mendoza‐Palomares Carlos , Ferrand Alice , Benkirane‐Jessel Nadia , Schlatter Guy
Published: April 2012

The controlled deposition of electrospun nanofibers at the micro‐scale is studied. Several collectors with microscopic patterns are prepared using photolithography. Nanofiber deposition is influenced by the geometry, the size, and the distance between micro‐patterns. Within certain conditions, membranes with multiple “micro spider‐webs” or perpendicularly interconnected microgrids are obtained. Dielectric micro‐holes having a conductive bottom can be filled by the nanofiber. This kind of micro‐molding is rationalized using simulations that show the influence of the collector relative permittivity on the electric field at the pattern vicinity. “Micro‐woven” membranes of PCL with good mechanical properties can be produced, allowing their use for biomedical applications in tissue engineering.

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Noncontrast‐enhanced three‐dimensional (3D) intracranial MR angiography using pseudocontinuous arterial spin labeling and accelerated 3D radial acquisition
Authors: Wu Huimin , Block Walter F. , Turski Patrick A. , Mistretta Charles A. , Johnson Kevin M.
Published: April 2012

Pseudocontinuous arterial spin labeling (PCASL) can be used to generate noncontrast magnetic resonance angiograms of the cerebrovascular structures. Previously described PCASL‐based angiography techniques were limited to two‐dimensional projection images or relatively low‐resolution three‐dimensional (3D) imaging due to long acquisition time. This work proposes a new PCASL‐based 3D magnetic resonance angiography method that uses an accelerated 3D radial acquisition technique (VIPR, spoiled gradient echo) as the readout. Benefiting from the sparsity provided by PCASL and noise‐like artifacts of VIPR, this new method is able to obtain submillimeter 3D isotropic resolution and whole head coverage with a 8‐min scan. Intracranial angiography feasibility studies in healthy (N = 5) and diseased (N = 5) subjects show reduced saturation artifacts in PCASL‐VIPR compared with a standard time‐of‐flight protocol. These initial results show great promise for PCASL‐VIPR for static, dynamic, and vessel selective 3D intracranial angiography. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Topology optimization with geometric uncertainties by perturbation techniques
Authors: Lazarov B. S. , Schevenels M. , Sigmund O.
Published: April 2012

The aim of this paper was to present a topology optimization methodology for obtaining robust designs insensitive to small uncertainties in the geometry. The variations are modeled using a stochastic field. The model can represent spatially varying geometry imperfections in devices produced by etching techniques. Because of under‐etching or over‐etching parts of the structure may become thinner or thicker than a reference design supplied to the manufacturer. The uncertainties are assumed to be small and their influence on the system response is evaluated using perturbation techniques. Under the above assumptions, the proposed algorithm provides a computationally cheap alternative to previously introduced stochastic optimization methods based on Monte Carlo sampling. The method is demonstrated on the design of a minimum compliance cantilever beam and a compliant mechanism. Copyright © 2012 John Wiley & Sons, Ltd.
Inverse extraction of cohesive zone laws by field projection method using numerical auxiliary fields
Authors: Kim Hyun‐Gyu , Chew Huck Beng , Kim Kyung‐Suk
Published: April 2012

The cohesive zone law relates the cohesive tractions with the cohesive separations within the fracture process zone of a material and is used to quantify the strength and toughness of the material. Determining the material's cohesive zone law, however, is a nontrivial inverse problem of finding unknown tractions and separations from measurement data. Previously, a field projection method was established to extract the cohesive zone laws from far‐field data using interaction J‐integrals between the physical field of interest and auxiliary analytical probing fields. Here, we extend the universality of the field projection method and its ease of numerical implementation by using numerical auxiliary fields. These numerical fields are generated by systematically imposing uniform surface tractions element‐by‐element along the crack faces in finite element models. Then, interaction J‐ and M‐integrals between these auxiliary probing fields and the measurement field are used to reconstruct the traction and separation relationship along the crack faces. The effectiveness of this method in extracting the cohesive zone law from measured displacements in the far‐field region is demonstrated through numerical experiments. Copyright © 2012 John Wiley & Sons, Ltd.
CTC1 Mutations in a patient with dyskeratosis congenita
Authors: Keller Rachel B. , Gagne Katelyn E. , Usmani G. Naheed , Asdourian George K. , Williams David A. , Hofmann Inga , Agarwal Suneet
Published: April 2012

Dyskeratosis congenita (DC) is a rare inherited bone marrow failure syndrome caused by mutations in seven genes involved in telomere biology, with approximately 50% of cases remaining genetically uncharacterized. We report a patient with classic DC carrying a compound heterozygous mutation in the CTC1 (conserved telomere maintenance component 1) gene, which has recently implicated in the pleiotropic syndrome Coats plus. This report confirms a molecular link between DC and Coats plus and expands the genotype–phenotype complexity observed in telomere‐related genetic disorders. Pediatr Blood Cancer 2012;59:311–314. © 2012 Wiley Periodicals, Inc.
Evaluation of Different Pulverisation Methods for RNA Extraction in Squash Fruit: Lyophilisation, Cryogenic Mill and Mortar Grinding
Authors: Román Belén , González‐Verdejo Clara I. , Peña Francisco , Nadal Salvador , Gómez Pedro
Published: April 2012

Introduction

Quality and integrity of RNA are critical for transcription studies in plant molecular biology. In squash fruit and other high water content crops, the grinding of tissue with mortar and pestle in liquid nitrogen fails to produce a homogeneous and fine powered sample desirable to ensure a good penetration of the extraction reagent.

Objective

To develop an improved pulverisation method to facilitate the homogenisation process of squash fruit tissue prior to RNA extraction without reducing quality and yield of the extracted RNA.

Methodology

Three methods of pulverisation, each followed by the same extraction protocol, were compared. The first approach consisted of the lyophilisation of the sample in order to remove the excess of water before grinding, the second one used a cryogenic mill and the control one a mortar grinding of frozen tissue. The quality of the isolated RNA was tested by carrying out a quantitative real time downstream amplification.

Results

In the three situations considered, mean values for A260/A280 indicated minimal interference by proteins and RNA quality indicator (RQI) values were considered appropriate for quantitative real‐time polymerase chain reaction (qRT‐PCR) amplification. Successful qRT‐PCR amplifications were obtained with cDNA isolated with the three protocols.

Conclusion

Both apparatus can improve and facilitate the grinding step in the RNA extraction process in zucchini, resulting in isolated RNA of high quality and integrity as revealed by qRT‐PCR downstream application. This is apparently the first time that a cryogenic mill has been used to prepare fruit samples for RNA extraction, thereby improving the sampling strategy because the fine powder obtained represents a homogeneous mix of the organ tissue. Copyright © 2012 John Wiley & Sons, Ltd.
Placebo‐controlled Randomized Clinical Trial on the Immunomodulating Activities of Low‐ and High‐Dose Bromelain after Oral Administration – New Evidence on the Antiinflammatory Mode of Action of Bromelain
Authors: Müller Silke , März Reinhard , Schmolz Manfred , Drewelow Bernd , Eschmann Klaus , Meiser Peter
Published: April 2012

Bromelain has been used for treatment of inflammatory diseases for decades. However, the exact mechanism of action remains poorly understood. While in vitro investigations have shown conflicting effects on the release of various cytokines, no in vivo data were available. In this study, the effects on inflammation‐related cytokines of two doses of bromelain were tested in a single dose placebo‐controlled 3 × crossover randomized clinical trial. Cytokine circadian profiles were used to investigate the effects of bromelain on the human immune system by using stimulated whole‐blood leukocytes. The effects seen in these cultures demonstrated a significant shift in the circadian profiles of the Th1 cell mediator interferon gamma (IFNγ; p < 0.043) after bromelain 3000 FIP (Fédération Internationale Pharmaceutique) units, and trends in those of the Th2‐type cytokine IL‐5 as well as the immunosuppressive cytokine interleukin (IL)‐10. This suggests a general effect on the antigen‐specific (T cell) compartment of the human immune system. This is the first time that bromelain has been shown to modulate the cellular responses of lymphocyte after oral use. It is postulated that the immunomodulating effect of bromelain observed in this trial is part of its known antiinflammatory activities. Further investigations will be necessary to verify the relevance of these findings to a diseased immune system. Copyright © 2012 John Wiley & Sons, Ltd.
Vasodilatory Effects of Cinnamic Acid via the Nitric Oxide–cGMP–PKG Pathway in Rat Thoracic Aorta
Authors: Kang Yun Hwan , Kang Jae Sook , Shin Heung Mook
Published: April 2012

Cinnamic acid (CA) and its derivatives have a broad therapeutic spectrum that includes antimicrobial, antifungal, and antitumoral activities. However, the vasodilative effect of CA has not been demonstrated. The present study characterizes the vasodilative activity and the mechanism of CA in rat thoracic aorta. The vasomotion of aortic strips following CA treatment was measured in an organ bath system. In addition, vascular strips and human umbilical vein endothelial cells (HUVECs) were used in organ bath, Western blot, nitrite, and cyclic guanosine monophosphate (cGMP) measurements. CA relaxed phenylephrine‐precontracted aortic strips in an endothelium‐dependent manner. Pretreatment of the endothelium‐intact aortic strips with NG‐nitro‐l‐arginine methyl ester (10−4 M), 1 H‐[1,2,4]‐oxadiazolole‐[4,3‐a] quinoxalin‐10‐one, (10−6 M) and methylene blue (10−5 M) inhibited CA‐induced vasorelaxation. CA also increased the phosphorylation of endothelial nitric oxide synthase and nitric oxide generation in a concentration‐dependent manner in HUVECs. In addition, cGMP generation and cGMP‐dependent protein kinase G (PKG) expression in aortic strips were increased by CA treatment. Furthermore, CA‐induced vasorelaxation was inhibited by the PKG inhibitor KT5823 (0.3 μM) and the Ca2+‐activated K+ channel inhibitor tetraethylammonium (10−3 M). These findings suggest that CA exerts an endothelium‐dependent vasodilation effect via the nitric oxide–cGMP–PKG‐mediated pathway in rat thoracic aorta. Copyright © 2012 John Wiley & Sons, Ltd.
A polar low observed over the Norwegian Sea on 3–4 March 2008: high‐resolution numerical experiments
Authors: Føre Ivan , Nordeng Thor Erik
Published: April 2012

A polar low (PL) observed over the Norwegian Sea by the IPY‐THORPEX research aircraft campaign during 3–4 March 2008 was studied by a series of fine‐mesh (3 km) experiments using the state‐of‐the‐art Weather Research and Forecasting (WRF) model. The full‐physics experiment simulated the PL intensity, baroclinic nature, surface wind speed and track rather well compared to dropsonde observations and satellite images. Two types of sensitivity experiments were designed to analyse the physical properties of the PL. First, physical processes such as condensational heating and sensible and/or latent heat fluxes were switched off throughout the whole simulation. In the second type, these processes were turned off at later times, which minimized the modification of the polar low environment caused by the absence of one or all of them over a long time period, making it suitable to study the direct effect of the physical processes on the PL itself. These two types of sensitivity experiments suggested the following: low‐level baroclinic energy conversion was of primary importance for the PL development, while other physical processes had a minor direct impact on the PL intensity. The surface latent heat fluxes, and to a lesser extent sensible heat fluxes, played an indirect role in the sense that they set up and supported the baroclinic environment vital for the PL development. Condensational heating, however, was essential to set up the initial baroclinic environment favourable for the PL intensification, while it had a modest indirect effect thereafter. The experiments indicated that in the late mature stage, after baroclinicity vanished, surface energy fluxes (sensible and/or latent heat) might have contributed to the PL energetics. How the variability in the simulated moist convection, the thermal structure of the PL core, and surface energy fluxes in each experiment affected the PL was difficult to answer. Copyright © 2012 Royal Meteorological Society
LINKING RIVER MANAGEMENT TO SPECIES CONSERVATION USING DYNAMIC LANDSCAPE‐SCALE MODELS
Authors: Freeman M. C. , Buell G. R. , Hay L. E. , Hughes W. B. , Jacobson R. B. , Jones J. W. , Jones S. A. , Lafontaine J. H. , Odom K. R. , Peterson J. T. , Riley J. W. , Schindler J. S. , Shea C. , Weaver J. D.
Published: April 2012

Efforts to conserve stream and river biota could benefit from tools that allow managers to evaluate landscape‐scale changes in species distributions in response to water management decisions. We present a framework and methods for integrating hydrology, geographic context and metapopulation processes to simulate effects of changes in streamflow on fish occupancy dynamics across a landscape of interconnected stream segments. We illustrate this approach using a 482 km2 catchment in the southeastern US supporting 50 or more stream fish species. A spatially distributed, deterministic and physically based hydrologic model is used to simulate daily streamflow for sub‐basins composing the catchment. We use geographic data to characterize stream segments with respect to channel size, confinement, position and connectedness within the stream network. Simulated streamflow dynamics are then applied to model fish metapopulation dynamics in stream segments, using hypothesized effects of streamflow magnitude and variability on population processes, conditioned by channel characteristics. The resulting time series simulate spatially explicit, annual changes in species occurrences or assemblage metrics (e.g. species richness) across the catchment as outcomes of management scenarios. Sensitivity analyses using alternative, plausible links between streamflow components and metapopulation processes, or allowing for alternative modes of fish dispersal, demonstrate large effects of ecological uncertainty on model outcomes and highlight needed research and monitoring. Nonetheless, with uncertainties explicitly acknowledged, dynamic, landscape‐scale simulations may prove useful for quantitatively comparing river management alternatives with respect to species conservation. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
Characterization of Pd‐Ni‐Co alloy thin films by ED‐EPMA with application of the STRATAGEM software
Authors: Kühn Julius , Hodoroaba Vasile‐Dan , Linke Sebastian , Moritz Werner , Unger Wolfgang E. S.
Published: April 2012

Ternary thin film alloys based on Pd, Ni and Co on silicon wafers have been characterized in order to determine elemental composition and thickness. A broad variety of alloy compositions was obtained on one and the same substrate by magnetron dc‐co‐sputter deposition. Energy‐dispersive electron probe X‐ray microanalysis of these ‘multi’ alloy composition samples is performed in a non‐destructive, precise and, if optimized, also in a time‐saving way. The local thickness of the layers under study was in between 50 nm and 250 nm. Pure element bulk materials have been employed as reference specimens. The results attained in this study are compared to those obtained by other analytical methods as Auger electron spectroscopy and X‐ray photo electron spectroscopy. Copyright © 2012 John Wiley & Sons, Ltd.
Investigation of a Ferrite/Silicon Nitride Composite Concept Aimed at Automotive Applications
Authors: Van Landeghem Hugo Paul , Gouné Mohamed , Redjaïmia Abdelkrim
Published: April 2012

This paper presents the investigation of the behavior of a Fe–1.5 wt% Si thin sheet upon plasma‐assisted nitriding at 570°C. It had been confirmed that a very fine and intense precipitation of amorphous silicon nitride occurs as nitrogen diffuses into the sheet. The precipitates, the size of which is comprised between several and several tens of nanometer, display a cubic morphology in spite of their amorphous structure. These cubes adopt a particular morphology in relation to the matrix with their faces parallel to the {100} plane family. These precipitates cause a notable hardening of the alloy and it was possible to harden a 1 mm sheet across its whole thickness in under 8 h.
Are Therapeutic Human Mesenchymal Stromal Cells Compatible with Human Blood?
Authors: Moll Guido , Rasmusson-Duprez Ida , von Bahr Lena , Connolly-Andersen Anne-Marie , Elgue Graciela , Funke Lillemor , Hamad Osama A. , Lönnies Helena , Magnusson Peetra U. , Sanchez Javier , Teramura Yuji , Nilsson-Ekdahl Kristina , Ringdén Olle , Korsgren Olle , Nilsson Bo , Le Blanc Katarina
Published: April 2012

Multipotent mesenchymal stromal cells (MSCs) are tested in numerous clinical trials. Questions have been raised concerning fate and function of these therapeutic cells after systemic infusion. We therefore asked whether culture-expanded human MSCs elicit an innate immune attack, termed instant blood-mediated inflammatory reaction (IBMIR), which has previously been shown to compromise the survival and function of systemically infused islet cells and hepatocytes. We found that MSCs expressed hemostatic regulators similar to those produced by endothelial cells but displayed higher amounts of prothrombotic tissue/stromal factors on their surface, which triggered the IBMIR after blood exposure, as characterized by formation of blood activation markers. This process was dependent on the cell dose, the choice of MSC donor, and particularly the cell-passage number. Short-term expanded MSCs triggered only weak blood responses in vitro, whereas extended culture and coculture with activated lymphocytes increased their prothrombotic properties. After systemic infusion to patients, we found increased formation of blood activation markers, but no formation of hyperfibrinolysis marker D-dimer or acute-phase reactants with the currently applied dose of 1.0–3.0 × 106 cells per kilogram. Culture-expanded MSCs trigger the IBMIR in vitro and in vivo. Induction of IBMIR is dose-dependent and increases after prolonged ex vivo expansion. Currently applied doses of low-passage clinical-grade MSCs elicit only minor systemic effects, but higher cell doses and particularly higher passage cells should be handled with care. This deleterious reaction can compromise the survival, engraftment, and function of these therapeutic cells.