bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Structures of Dipeptide–Palladium(II) Conjugated Complexes
Authors: Moriuchi Toshiyuki , Morimoto Kunihiro , Sakamoto Yuki , Hirao Toshikazu
Published: May 2012

The chiral tridentate 2,6‐pyridinedicarboxamide ligand L1H2 bearing two dipeptide chains (‐L‐Ala‐L‐Pro‐NHBu) was designed. Complexation of L1H2 with Pd(OAc)2 was demonstrated to afford the dipeptide–palladium(II) conjugated complex [(L1)Pd(MeCN)] (1) with an ancillary acetonitrile ligand. In the crystal packing of 1, a right‐handed helical‐like molecular arrangement was observed, wherein each assembly is connected through continuous intermolecular hydrogen bonds together with water molecules. The dipeptide–palladium(II) conjugated complex 1 was studied as a metalloreceptor through metal coordination to accommodate a guest ligand, 4‐aminopyridine, resulting in the formation of the dipeptide–palladium(II) conjugated complex [(L1)Pd(4APy)] (2). Each preorganized helical molecule of 2 is packed in a right‐handed helical‐like molecular arrangement in the crystal packing. The dipeptide–palladium(II) conjugated complex 2 was found to exhibit emission with a maximum at 652 nm in the solid state.
A Highly Luminescent Hexanuclear Molybdenum Cluster – A Promising Candidate toward Photoactive Materials
Authors: Kirakci Kaplan , Kubát Pavel , Dušek Michal , Fejfarová Karla , Šícha Václav , Mosinger Jiří , Lang Kamil
Published: May 2012

A new Mo6 cluster complex and its silica and polyurethane composites have been synthesized and characterized. These materials are highly luminescent with emission above 650 nm, produce singlet oxygen with high efficiency, are photostable, and can be excited up to 580 nm. These properties are desirable for the construction of luminescent probes of oxygen, photoactive materials for oxidation reactions with easily separable active carriers, and bactericidal textile surfaces upon daylight irradiation.
Synthesis of Cholic Acid Oligomer–Taurine Conjugates: A Study of Their Aggregation and Cholesterol Solubilization
Authors: Satyanarayana T. B. N. , Maitra Uday , Savyasachi A. J.
Published: May 2012

Taurine conjugates of two cholic acid derived oligomers with different spacers between the cholic acid units were synthesized. These molecules self‐assemble in aqueous media. The critical micelle concentration (CMC) values were measured by using fluorescence spectroscopic analysis and the aggregates were characterized by dynamic light scattering and electron microscopy. The cooperativity of the cholic acid units in these tetramers to solubilize cholesterol was investigated. The ability of these molecules to act as nanocarriers for liphophilic dyes was also studied.
Unusual Control of Reaction Selectivity through a Subtle Change in the Ligand: Proof of Concept and Application in Pd‐Catalyzed C–P Bond Formation
Authors: Ananikov Valentine P. , Ivanova Julia V. , Khemchyan Levon L. , Beletskaya Irina P.
Published: May 2012

A new concept for the design of ligands for transition‐metal‐catalyzed reactions is described. It was shown that the steric effect of triarylphosphanes upon coordination to a metal center can be controlled by switching between unrestricted and restricted rotation modes. The ligands studied were intrinsically tuned to possess characteristic signals in the 1H, 13C, 31P NMR and electrospray ionization mass spectrometry (ESI‐MS), thus allowing mechanistic studies to be easily carried out. The efficiency of the developed method was demonstrated in a study on the mechanistic pathways of Pd‐catalyzed hydrophosphorylation of alkynes. The catalytic cycle was explored step‐by‐step by using ESI‐MS and NMR methods. Several Pd species were detected under catalytic conditions and the nature of the intermediate metal complexes were evaluated. The process responsible for capturing the Pd catalyst in the inactive resting state and the routes leading to catalyst decomposition were identified and described. For the first time, the catalytic reaction mechanism of hydrophosphorylation of alkynes was revealed at a molecular level, which led to the design of a novel practical procedure for Pd‐mediated C–P bond formation. A new Pd/P[(MeO)nC6H5–n]3 catalytic system was proposed with the outstanding ability to control reaction selectivity simply by adjusting the methoxy substituents in the phosphane ligand.
A Convergent Hetero‐Diels–Alder Strategy for Asymmetric Access to a Lactone Containing Two Lipidic Chains
Authors: Vu Cong S. , Guisot Nicolas , Guillarme Stéphane , Martel Arnaud , Dujardin Gilles , Pipelier Muriel , Dubreuil Didier , Saluzzo Christine
Published: May 2012

Eu(fod)3‐catalyzed heterocycloaddition of chiral β‐alkyl‐N‐vinyl‐1,3‐oxazolidin‐2‐ones with a heterodiene bearing a lipidic chain led to heterocycloadducts in high yield with excellent endo and facial selectivities. An original lipidic lactone, a potent precursor of a ceramide analog, was obtained in seven steps from the adduct in a convergent manner after appropriate functionalization.
Bioavailability of cyanide and metal–cyanide mixtures to aquatic life
Authors: Redman Aaron , Santore Robert
Published: May 2012

Cyanide can be toxic to aquatic organisms, and the U.S. Environmental Protection Agency has developed ambient water-quality criteria to protect aquatic life. Recent work suggests that considering free, rather than total, cyanide provides a more accurate measure of the biological effects of cyanides and provides a basis for water-quality criteria. Aquatic organisms are sensitive to free cyanide, although certain metals can form stable complexes and reduce the amount of free cyanide. As a result, total cyanide is less toxic when complexing metals are present. Cyanide is often present in complex effluents, which requires understanding how other components within these complex effluents can affect cyanide speciation and bioavailability. The authors have developed a model to predict the aqueous speciation of cyanide and have shown that this model can predict the toxicity of metal–cyanide complexes in terms of free cyanide in solutions with varying water chemistry. Toxicity endpoints based on total cyanide ranged over several orders of magnitude for various metal–cyanide mixtures. However, predicted free cyanide concentrations among these same tests described the observed toxicity data to within a factor of 2. Aquatic toxicity can be well-described using free cyanide, and under certain conditions the toxicity was jointly described by free cyanide and elevated levels of bioavailable metals. Environ. Toxicol. Chem. 2012; 31: 1774–1780. © 2012 SETAC
Phosphorylation of signal transducer and activator of transcription 3 in soft tissue leiomyosarcoma is associated with a better prognosis
Authors: Setsu Nokitaka , Kohashi Kenichi , Endo Makoto , Yamamoto Hidetaka , Tamiya Sadafumi , Takahashi Yusuke , Yamada Yuichi , Ishii Takeaki , Matsuda Shuichi , Yokoyama Ryohei , Iwamoto Yukihide , Oda Yoshinao
Published: May 2012

Signal transducer and activator of transcription (STAT) 3 mediates a broad range of biological processes, including cell survival and proliferation, and STAT3 has generally been regarded as a pro‐oncogenic transcription factor. We investigated the phosphorylation status of STAT3 and the protein expression of the suppressor of cytokine signaling 3 (SOCS3) by immunohistochemistry in 145 formalin‐fixed, paraffin‐embedded samples of soft tissue leiomyosarcoma (LMS), including 129 primary tumors. Eight benign soft tissue smooth muscle tumors were also examined. Thirteen frozen LMS samples, which were paired with normal tissue samples, were assessed by Western blot analysis for the phosphorylation of STAT3 and SOCS3 expression. Immunohistochemical study showed that the phosphorylation of STAT3 was not a major event in LMS (37%). Moreover, phosphorylated STAT3 (pSTAT3) expression was significantly correlated with a better prognosis. Overexpression of SOCS3 was recognized in 52% of the cases and negatively correlated with pSTAT3 expression. Among the benign tumors, 63 and 25% were positive for pSTAT3 and SOCS3, respectively. Immunoblotting detected pSTAT3 in all tumor samples, but at lower levels than in non‐neoplastic tissue. SOCS3 was detected in 92% (12 out of 13) of tumor tissues, but in none of the normal tissues. Contrary to the previous investigations of many other malignant tumors, STAT3 was inactivated in most LMS cases, likely owing to SOCS3 overexpression. STAT3 might not contribute to the progression of soft tissue LMS, and the phosphorylation status of STAT3 has the potential to be a favorable prognostic marker of LMS.
Reduction of Fe(II)EDTA‐NO using Paracoccus denitrificans and changes of Fe(II)EDTA in the system
Authors: Li Ning , Zhang Yu , Li Yanmei , Chen Mingxiang , Dong Xiyang , Zhou Jiti
Published: May 2012

BACKGROUND: In the BioDeNOX technology for NOX removal from flue gas, bioreduction of Fe(II)EDTA‐NO and Fe(III)EDTA are core processes. In this study, a newly isolated strain, Paracoccus denitrificans, was used to reduce Fe(II)EDTA‐NO with glucose and Fe(II)EDTA as donor electrons. To better understand the change law of Fe(II)EDTA, the process of Fe(II)EDTA‐NO reduction by P. denitrificans with glucose and Fe(II)EDTA as electron donors was investigated, and the factors that might affect Fe(II)EDTA concentration were studied.

RESULTS: For the bioreduction process of Fe(II)EDTA‐NO, P. denitrificans could use glucose and Fe(II)EDTA as electron donors. At different stages, primary electron donors were different, thereby affecting the concentration of Fe(II)EDTA in the system. It was also proved that this strain not only reduced Fe(III)EDTA with glucose as the electron donor but also secreted several substances that reacted with Fe(III)EDTA, resulting in increased Fe(II)EDTA concentration in the solution.

CONCLUSIONS: This work has shown that P. denitrificans can reduce Fe(II)EDTA‐NO and Fe(III)EDTA simultaneously to regenerate NOX absorption solution. © 2012 Society of Chemical Industry
Harmonic optical microscopy and fluorescence lifetime imaging platform for multimodal imaging
Authors: Pelegati Vitor B. , Adur Javier , De Thomaz André A. , Almeida Diogo B. , Baratti Mariana O. , Andrade Liliana A. L. A. , Bottcher‐luiz Fátima , Cesar Carlos. L.
Published: May 2012

In this work, we proposed and built a multimodal optical setup that extends a commercially available confocal microscope (Olympus VF300) to include nonlinear second harmonic generation (SHG) and third harmonic generation (THG) optical (NLO) microscopy and fluorescence lifetime imaging microscopy (FLIM). We explored all the flexibility offered by this commercial confocal microscope to include the nonlinear microscopy capabilities. The setup allows image acquisition with confocal, brightfield, NLO/multiphoton and FLIM imaging. Simultaneously, two‐photon excited fluorescence (TPEF) and SHG are well established in the biomedical imaging area, because one can use the same ultrafast laser and detectors set to acquire both signals simultaneously. Because the integration with FLIM requires a separated modulus, there are fewer reports of TPEF+SHG+FLIM in the literature. The lack of reports of a TPEF+SHG+THG+FLIM system is mainly due to difficulties with THG because the present NLO laser sources generate THG in an UV wavelength range incompatible with microscope optics. In this article, we report the development of an easy‐to‐operate platform capable to perform two‐photon fluorescence (TPFE), SHG, THG, and FLIM using a single 80 MHz femtosecond Ti:sapphire laser source. We described the modifications over the confocal system necessary to implement this integration and verified the presence of SHG and THG signals by several physical evidences. Finally, we demonstrated the use of this integrated system by acquiring images of vegetables and epithelial cancer biological samples. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.
Ultrastructure of differentiating oocytes and vitellogenesis in the giant freshwater prawn, Macrobrachium rosenbergii (de man)
Authors: Soonklang Nantawan , Wanichanon Chaitip , Stewart Michael J. , Stewart Praphaporn , Meeratana Prasert , Hanna Peter J. , Sobhon Prasert
Published: May 2012

The ultrastructure of oogenesis in Macrobrachium rosenbergii, with reference to vitellogenesis, has not been reported. We used light and electron microscopy, as well as vitellin (Vn) purification and antibody production, to study the temporal and spatial production of Vn in the ovary by immunofluorescence. Histologically, the ovary is subdivided into cone‐shaped ovarian pouches with a central core containing layers of oogonia. These divide to produce oocytes that migrate outwardly and differentiate into mature oocytes. During the course of differentiation, oocytes undergo modifications, including the rearrangement of nuclear chromatin, the accumulation of ribosomes, rough endoplasmic reticulum (RER), and lipid, and the formation of secretory and yolk granules, resulting in four stages. Ultrastructurally, early previtellogenic oocytes (Oc1) are characterized by the accumulation of new ribosomal aggregates, translocated from the nucleus. Late previtellogenic oocytes (Oc2) show nuclear heterochromatin with a “clock face” pattern, the presence of RER, and three types of secretory granules. Follicular cells occupy the intercellular spaces and surround the Oc2. Early vitellogenic oocytes (Oc3) are larger, with nuclei containing predominantly decondensed euchromatin, and cytoplasm with yolk and secretory granules, and few lipid droplets. Late vitellogenic oocytes (Oc4) are characterized by completely euchromatic nuclei, an indistinct plasma membrane, yolk platelets and secretory granules, and abundant lipid. Vitellogenin (Vg) in ovaries of M. rosenbergii consist of two main bands at MW 90 and 102 kDa. Our data indicates that Vn is present, and probably synthesized in Oc3 and Oc4, but there may be some undetected exogenous Vg production. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.
Developing a global leadership perspective through the use of student‐created reusable learning objects
Authors: Sandlin M'Randa R. , Odom Summer F. , Lindner James R. , Dooley Kim E.
Published: May 2012

Study abroad programs have been identified as one of the most effective methods of globalizing curricula and students. The purpose of this study was to examine the current framework of the Leading Change in Costa Rica Study Abroad Program and its ability to diffuse leadership theory to the participating students and to students who are not able to take part in a study abroad opportunity. This study abroad program used reusable learning objects (RLOs) as an assignment to develop global leadership competencies by applying the learned leadership theory in an international context. Students were impacted by the experience. They gained knowledge of the course content, developed and expanded their cultural competencies, and expanded their views of developing countries. The Leading Change in Costa Rica Study Abroad Program also made an effort to develop the intercultural competencies and global leadership abilities of students who are unable to study abroad. The student‐created RLOs have been used in class presentations and made available to interested faculty to use in classrooms across disciplines.
The effects of local vanadium treatment on angiogenesis and chondrogenesis during fracture healing
Authors: Paglia David N. , Wey Aaron , Park Andrew G. , Breitbart Eric A. , Mehta Siddhant K. , Bogden John D. , Kemp Francis W. , Benevenia Joseph , O'Connor J. Patrick , Lin Sheldon S.
Published: May 2012

This study quantified the effects of local intramedullary delivery of an organic vanadium salt, which may act as an insulin‐mimetic on fracture healing. Using a BB Wistar rat femoral fracture model, local vanadyl acetylacetonate (VAC) was delivered to the fracture site and histomorphometry, mechanical testing, and immunohistochemistry were performed. Callus percent cartilage was 200% higher at day 7 (p < 0.05) and 88% higher at day 10 (p < 0.05) in the animals treated with 1.5 mg/kg of VAC. Callus percent mineralized tissue was 37% higher at day 14 (p < 0.05) and 31% higher at day 21 (p < 0.05) in the animals treated with 1.5 mg/kg of VAC. Maximum torque to failure was 104% and 154% higher at 4 weeks post‐fracture (p < 0.05) for the healing femurs from the VAC‐treated (1.5 and 3.0 mg/kg) animals. Animals treated with other VAC doses demonstrated increased mechanical parameters at 4 weeks (p < 0.05). Immunohistochemistry detected 62% more proliferating cells at days 7 (p < 0.05) and 94% more at day 10 (p < 0.05) in the animals treated with 1.5 mg/kg VAC. Results showed 100% more vascular endothelial growth factor‐C (VEGF‐C) positive cells and 80% more blood vessels at day 7 (p < 0.05) within the callus subperiosteal region of VAC‐treated animals (1.5 mg/kg) compared to controls. The results suggest that local VAC treatment affects chondrogenesis and angiogenesis within the first 7–10 days post‐fracture, which leads to enhanced mineralized tissue formation and accelerated fracture repair as early as 3–4 weeks post‐fracture. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1971–1978, 2012
Laryngeal cancer: Quantitative and qualitative assessment of research output, 1945–2010
Authors: Glynn Ronan W. , Lowery Aoife J. , Scutaru Cristian , O'Dwyer Tadhg , Keogh Ivan
Published: May 2012

Objectives/Hypothesis:

To provide an in‐depth evaluation of research yield in laryngeal cancer from 1945 to 2010, using large‐scale data analysis, employment of bibliometric indicators of production and quality, and density equalizing mapping.

Study Design:

Bibliometic analysis incorporating the Web of Science Database.

Methods:

The search strategy employed was as follows; “TS = ((Laryngeal Neoplasm$) OR (Larynx Neoplasm$) OR (Larynx Cancer$) OR (Laryngeal Cancer$)).” Author and journal data and cooperation networks were computed following analysis of combinations of countries and institutions that registered cooperation during the study period. Mapping was performed as described by Groneberg‐Kloft in 2004.

Results:

A total of 8,658 items relating to laryngeal cancer were published over the study period, accounting for 139,700 citations. The United States was the most prolific country, accounting for 28.83% (n = 2,496) of total output. Other prolific nations included Italy (n = 794) and Germany (n = 792). There were 973 items published as a consequence of international cooperation; this practice increased steadily over time and accounted for 15.58% (88 of 565) of output in 2010. There were 1,073 different journals publishing articles on laryngeal cancer, although the top 20 (1.8%) most prolific titles were together responsible for more than 43% of the total output; these were led by Laryngoscope (n = 368) and Head and Neck, Journal of the Scientific Specialties (n = 364). A total of 24,682 authors contributed to the literature on laryngeal cancer; the leading author by output was Alfio Ferlito (n = 120); Carlo La Vecchia recorded the highest h‐index (h = 32).

Conclusions:

This work represents the first attempt to provide quantitative and qualitative analysis of laryngeal cancer research output, whilst in tandem identifying the key bibliometric benchmarks to which those involved in the production of that output might aspire.
Bio‐inspired algorithms for the optimization of offshore oil production systems
Authors: Vieira Ian Nascimento , de Lima Beatriz Souza Leite Pires , Jacob Breno Pinheiro
Published: May 2012

This work describes the development, implementation, and assessment of enhanced variants of three different groups of bio‐inspired methodologies: genetic algorithms, particle swarm optimization, and artificial immune system. The algorithms are implemented on a computational tool for the synthesis and optimization of offshore oil production risers that connect a floating platform at the sea surface to the wellheads at the sea bottom. Optimization procedures using bio‐inspired algorithms for such real‐world engineering problems require the calculation of the objective function through a large number of time‐consuming finite element nonlinear dynamic analyses, for the evaluation of the structural behavior of each candidate configuration. Therefore, the performance of the algorithms may be measured by the smaller number of objective function evaluations associated to a given target fitness value. The results indicate that the artificial immune system approach, incorporating some enhancements presented in this work, is more effective than the genetic algorithms and particle swarm optimization methods, requiring a smaller number of evaluations to obtain better solutions. Copyright © 2012 John Wiley & Sons, Ltd.
Up‐regulated expression of sulfatases (SULF1 and SULF2) as prognostic and metastasis predictive markers in human gastric cancer
Authors: Hur Keun , Han Tae‐Su , Jung Eun‐Jung , Yu Jieun , Lee Hyuk‐Joon , Kim Woo Ho , Goel Ajay , Yang Han‐Kwang
Published: May 2012

Gastric cancer (GC) is the fourth most common cancer worldwide. In spite of the mortality incidence associated with GC, no reliable prognostic biomarkers are currently available for this malignancy. The sulfatases (or SULFs), SULF1 and SULF2, play a critical role in the pathogenesis of a variety of human cancers. We sought to evaluate the potential of SULFs as biomarkers for GC. Thirty pairs of GC and corresponding normal tissues were analysed for the expression and methylation status of SULFs. Furthermore, the functional role of SULF overexpression was investigated in GC cell lines and tumour xenograft animal models. Lastly, we validated the expression of SULF1 protein in a large cohort of 450 GC patients. GC tissues showed conspicuously higher expression of SULF1 (p = 0.0002) and SULF2 (p = 0.001) compared to normal mucosa, which was correlated with its promoter hypomethylation. Furthermore, high expression of SULFs caused marked acceleration in the growth of xenograft tumours in nude mice. The expression of SULF1 protein significantly correlated with higher recurrence rates (p = 0.0002) and worse overall survival (p < 0.0001) in GC patients. Multivariate analysis revealed that SULF1 is an independent prognostic (p = 0.0123) and lymph node metastasis predictive factor (p = 0.0003) in patients with GC. We provide novel evidence that hypomethylation of promoter CpG islands within SULF genes imparts them with oncogenic potential in GC. Moreover, our data suggest that SULF1 may serve as a promising biomarker for patients with GC. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Impaired decidual natural killer cell regulation of vascular remodelling in early human pregnancies with high uterine artery resistance
Authors: Fraser Rupsha , Whitley Guy StJ , Johnstone Alan P , Host Amanda J , Sebire Neil J , Thilaganathan Baskaran , Cartwright Judith E
Published: May 2012

During human pregnancy, natural killer (NK) cells accumulate in the maternal decidua, but their specific roles remain to be determined. Decidual NK (dNK) cells are present during trophoblast invasion and uterine spiral artery remodelling. These events are crucial for successful placentation and the provision of an adequate blood supply to the developing fetus. Remodelling of spiral arteries is impaired in the dangerous pregnancy complication pre‐eclampsia. We studied dNK cells isolated from pregnancies at 9–14 weeks' gestation, screened by uterine artery Doppler ultrasound to determine resistance indices which relate to the extent of spiral artery remodelling. dNK cells were able to promote the invasive behaviour of fetal trophoblast cells, partly through HGF. Cells isolated from pregnancies with higher resistance indices were less able to do this and secreted fewer pro‐invasive factors. dNK cells from pregnancies with normal resistance indices could induce apoptotic changes in vascular smooth muscle and endothelial cells in vitro, events of importance in vessel remodelling, partly through Fas signalling. dNK cells isolated from high resistance index pregnancies failed to induce vascular apoptosis and secreted fewer pro‐apoptotic factors. We have modelled the cellular interactions at the maternal‐fetal interface and provide the first demonstration of a functional role for dNK cells in influencing vascular cells. A potential mechanism contributing to impaired vessel remodelling in pregnancies with a higher uterine artery resistance is presented. These findings may be informative in determining the cellular interactions contributing to the pathology of pregnancy disorders where remodelling is impaired, such as pre‐eclampsia. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Prevalence of germline TP53 mutations and history of Li–Fraumeni syndrome in families with childhood adrenocortical tumors, choroid plexus tumors, and rhabdomyosarcoma: A population‐based survey
Authors: Magnusson Susanne , Gisselsson David , Wiebe Thomas , Kristoffersson Ulf , Borg Åke , Olsson Håkan
Published: May 2012

Purpose

Whether childhood adrenocortical tumors (ACTs), choroid plexus tumors (CPTs), and rhabdomyosarcoma (RMS) are early manifestation of Li–Fraumeni syndrome (LFS) is uncertain. In this study, we evaluated the frequency of germline TP53 mutations and family history in a population‐based series of patients.

Patients and Methods

We identified children (≤18 years) diagnosed between 1958 and 2008 with ACT (n = 3) or CPT (n = 7), or children ≤5 years with RMS (n = 29). Registry‐based pedigree expansion was performed.

Results

No patients had a family history of classic LFS but 17 fulfilled Chompret or Eeles criteria. TP53 mutations were found in 1/3 ACT patients and 1/18 RMS patients; both were novel mutations. Of five tested CPT patients none had a detectable mutation. No excess of LFS associated tumors was observed, except for breast cancer in families of CPT patients. An overall increased cancer incidence was observed in families of patients with CPT [standardized incidence ratio (SIR) = 2.0; 95% CI: 1.1–3.5] due to excess of breast and female kidney cancer and in families of patients with RMS (SIR = 1.2; 95% CI: 0.9–1.7), due to excess of early‐onset melanoma and male stomach cancer.

Conclusion

Relatives of patients with childhood ACTs, CPTs, and RMSs showed no increased risk of LFS associated tumors. However, TP53 mutations could be found in these children irrespective of family history. Absence of LFS associated tumors may suggest the presence of other cancer syndromes. Improved knowledge about relatives' cancer risks could be helpful in counseling family members of children with cancer. Pediatr Blood Cancer 2012; 59: 846–853. © 2012 Wiley Periodicals, Inc.
Polyamide‐6 structure modification by combined solid‐phase extrusion
Authors: Beloshenko V.A. , Voznyak A.V. , Voznyak Yu.V. , Glasunova V.A. , Konstantinova T.E.
Published: May 2012

Methods of wide‐angle X‐ray analysis and transmission electron microscopy were performed to investigate structural and phase transformation occurring in polyamide‐6 (PA‐6) by combined solid‐phase processing including extrusion through a conical die (ED) and the following equal‐channel multiple‐angular extrusion (ECMAE). It was shown that high level of plastic and strength characteristics of extruded PA‐6 is determined by the formation of a duplex structure consisting of elongated disoriented fiber‐like entities and fragmented globular formations. Conservation of high values of plasticity of deformed PA‐6 is also controlled by the transition of the crystals of α‐form to the crystals of γ‐form with higher plasticity reserve. We have established rational technology parameters of PA‐6 processing by ED‐ECMAE processes (the deformation degree εED at ED, deformation intensity ΔΓ and the value of accumulated deformation εECMAE at ECMAE). POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Development of a multimicroinjection molding system for thermoplastic polymer
Authors: Zhang Panpan , Xie Pengcheng , Wang Jian , Ding Yumei , Yang Weimin
Published: May 2012

A novel concept of microinjection molding system was designed and presented. The system was designed as a multimicroinjection module, which is matched with a vertical injection molding machine (IMM) and can be applied on commercial IMMs. A planetary gear pump was integrated in this system to complete the multi microinjection molding (MμIM). The module is fixed between the stationary platen and the mold of IMM. The plasticizing unit of the IMM provides the melt and initial pressure for the multi microinjection molding system. With this system, a commercial IMM could be upgraded to a precise microinjection machine and has the capability of precise metering for the microinjection molding. Melt flowing behavior was predicted through the 3D injection molding simulation and experiments were carried out to testify the performance of the MμIM. The injection molding performance was evaluated and the results revealed that the MμIM system could effectively realize the microinjection molding. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Modification of surface wettability of sodium ionomer sheets via atmospheric plasma treatment
Authors: España J.M. , García D. , Sánchez L. , López J. , Balart R.
Published: May 2012

In this study, atmospheric plasma treatment has been used to modify the wetting properties of ethylene‐methacrylic acid sodium ionomer. The effects of the plasma treatment on surface properties of this ionomer have been followed by contact angle measurements, Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM). With the use of these techniques, the overall effects on activation–functionalization and surface topography changes have been determined in terms of the processing parameters of the atmospheric plasma treatment (rate and distance). The obtained results show a remarkable increase of the wetting properties and optimum balanced behavior is obtained for atmospheric plasma treatment with a rate of 100 mm/s and a distance of 6 mm; in this case, surface free energy is increased from 33 mJ/m2 (untreated ionomer) up to 62 mJ/m2, maintaining good transparency. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Block copolymer alignment method for mobility anisotropy and enhancement of poly(3‐hexylthiophene) thin‐film transistors
Authors: Cheng J.‐W. John , Ho Jeng‐Rong , Tseng Yu‐Wei , Su Hung‐Jie , Chien Chi‐Horng , Tsiang Raymond C.‐C. , Hsu Chia Chen , Chen Ting‐Ray , Chiang Cheng‐Yi
Published: May 2012

In this article, a new alignment‐layer approach based on block copolymers (BCPs) is proposed for mobility anisotropy and enhancement of organic thin‐film transistors (OTFTs). In particular, the poly(3‐hexylthiophene) (P3HT) TFT with polystyrene‐block‐poly(methyl methacrylate) alignment layer was studied. With max dichroic ratio 1.23 in polarized absorption spectra of P3HT and corresponding device mobility anisotropy 4.63, taking place at the highest annealing temperature of 230°C, the BCP alignment approach proved to be an effective tool for orientation control of polymers such as the P3HT. However, because of negative effect of thermal annealing that causes twisting in P3HT backbones, the achieved mobility enhancement was only a meager 41%. Nevertheless, with rich varieties in the composition and complexity of BCPs, the proposed BCP alignment design represents an interesting alternative to existing alignment approaches to orientation control of P3HT and mobility anisotropy and enhancement of the resultant OTFTs. Besides, the phase‐alternate surface morphology of the BCP alignment layer was confirmed through a series of atomic force microscopy, X‐ray photoelectron microscopy, and field‐emission scanning electron microscopy. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Diallyl‐1,12‐diaminododecane‐based cyclopolymers and their use as inhibitors for mild steel corrosion
Authors: Ali Shaikh A. , Saeed M.T. , El‐Sharif Asma M.Z.
Published: May 2012

A variety of N,N‐diallyl compounds, capable of undergoing cyclopolymerization, are prepared from 1,12‐dodecanediamine. Selective monoformylation followed by allylation of the parent diamine afforded N,N‐diallyl‐N′‐formyl‐1,12‐dodecanediamine which was converted into quaternary ammonium monomers N,N‐diallyl‐N‐benzyl (or p‐methoxybenzyl)‐N′‐formyl‐1,12‐dodecanediamine by reacting with benzyl‐ or p‐methoxybenzyl chloride. The monomers on homo‐ and co‐cyclopolymerization (with SO2) afforded the cationic polyelectrolytes which on acidic hydrolysis of the formyl group gave water‐soluble polyelctrolytes. All the synthesized monomers, polymers, and the starting 1,12‐dodecanediamine were used to study the corrosion inhibition of mild steel by gravimetry and electrochemical methods in acidic and saline media at 60°C. The inhibitor molecules (at a concentration of 400 ppm) exhibited inhibition efficiencies (%IE) in the ranges 62%–99% in 1 M HCl, 95%–99% in 4 M HCl, 13%–91% in 7.7 M HCl, 13%–91% in 0.5 M H2SO4, and 75%–90% in 3.5% NaCl. There is a dramatic increase in the IEs by the monomers and polymers in comparison to the parent diamine. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Preparation of polymer nanoparticles from renewable biobased furfuryl alcohol and maleic anhydride by stabilizer‐free dispersion polymerization
Authors: Luo Wei , Liu Jianxin , Ma Yuhong , Zhang Bing , Yang Wantai
Published: May 2012

The spherical polymer nanoparticles of biobased renewable monomers, furfuryl alcohol (FA) and maleic anhydride (MAn), with diameters (Dn) in the range of 120 to 500 nm have been prepared by stabilizer‐free dispersion copolymerization. In acetate or its mixture, the conversion of the monomers greatly depended on the concentration of AIBN. When the molar ratio of AIBN/monomers was 3.6% (wt), the monomer conversion could be as high as 80%. The aggregations of the solvated polymer chains formed the nuclei of the polymer particles. After the nucleation stage, both the monomer conversions and particle sizes increased steadily, while the coefficient of variation of the particle size decreased. The almost linear relationship between the Dn3 and the weight of polymer suggested that there is no significant secondary nucleation. The copolymer of FA and MAn could not dissolve in common organic solvents. Elemental analyses, FTIR and 13CP‐MAS spectra showed that the copolymer was close to the alternative copolymer of FA and MAn irrespective to the molar ratios of FA/MAn in monomer feed. Furthermore, the two 2,5‐ and 3,4‐dihydrofuran ring configurations exist in the copolymer and the later is the major one. The reaction of copolymer particles with triethylenetetramine confirmed the reactivity of the succinic anhydride groups at the surface of copolymer particles. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Synthesis of soluble single‐walled carbon nanotubes with poly (1,3‐cyclohexadiene): Grafting poly(1,3‐cyclohexadienyl)lithium onto a solid surface
Authors: Natori Itaru , Natori Shizue
Published: May 2012

The first‐ever grafting of poly(1,3‐cyclohexadiene) (PCHD) onto single‐walled carbon nanotubes (SWNTs) was accomplished by reaction with poly(1,3‐cyclohexadienyl)lithium. The rate of this reaction was especially slow due to the heterogeneous nature of the reaction system. The concentration of active carbons available for reaction with PCHDLi on the solid surface of the SWNTs was found to be approximately 2.0 mol %. The mass of PCHD attached to the SWNTs was effectively controlled by varying the molecular weight of the PCHD. The resulting PCHD‐grafted SWNTs exhibited excellent solubility in organic solvent, maintaining a highly stable homogeneous dispersion even after 3 months. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
The conserved arginine 380 of Hsp90 is not a catalytic residue, but stabilizes the closed conformation required for ATP hydrolysis
Authors: Cunningham Christian N. , Southworth Daniel R. , Krukenberg Kristin A. , Agard David A.
Published: May 2012

Hsp90, a dimeric ATP‐dependent molecular chaperone, is required for the folding and activation of numerous essential substrate “client” proteins including nuclear receptors, cell cycle kinases, and telomerase. Fundamental to its mechanism is an ensemble of dramatically different conformational states that result from nucleotide binding and hydrolysis and distinct sets of interdomain interactions. Previous structural and biochemical work identified a conserved arginine residue (R380 in yeast) in the Hsp90 middle domain (MD) that is required for wild type hydrolysis activity in yeast, and hence proposed to be a catalytic residue. As part of our investigations on the origins of species‐specific differences in Hsp90 conformational dynamics we probed the role of this MD arginine in bacterial, yeast, and human Hsp90s using a combination of structural and functional approaches. While the R380A mutation compromised ATPase activity in all three homologs, the impact on ATPase activity was both variable and much more modest (2–7 fold) than the mutation of an active site glutamate (40 fold) known to be required for hydrolysis. Single particle electron microscopy and small‐angle X‐ray scattering revealed that, for all Hsp90s, mutation of this arginine abrogated the ability to form the closed “ATP” conformational state in response to AMPPNP binding. Taken together with previous mutagenesis data exploring intra‐ and intermonomer interactions, these new data suggest that R380 does not directly participate in the hydrolysis reaction as a catalytic residue, but instead acts as an ATP‐sensor to stabilize an NTD‐MD conformation required for efficient ATP hydrolysis.
Distribution of rodenticide resistance and zoonotic pathogens in Norway rats in Lower Saxony and Hamburg, Germany
Authors: Runge Martin , von Keyserlingk Michael , Braune Silke , Becker Detlef , Plenge‐Bönig Anita , Freise Jona F , Pelz Hans‐Joachim , Esther Alexandra
Published: May 2012

BACKGROUND: Genetically based resistance to anticoagulants has led to increasing difficulties in the control of rodents over recent decades. The possible impact of rodenticide‐resistant rats on the infection risk of humans and livestock by zoonotic pathogens is generally unknown. Hence, in a monitoring programme in the German federal states of Lower Saxony and Hamburg, more than 500 Norway rats were analysed for both Tyr139Cys polymorphisms within the VKORC1 gene and zoonotic agents.

RESULTS: Evidence of resistance was almost completely restricted to the known resistance area in southern Lower Saxony. Homozygous mutations were only found in urban areas sampled owing to the occurrence of rat control problems and were missing in bycatches of rats by muskrat trappers in rural areas. In more than 25% of the rats, zoonotic bacteria (Leptospira, Salmonella, Yersinia and Coxiella) were detected. There was no obvious correlation between the occurrence of rats carrying zoonotic pathogens and anticoagulant resistance.

CONCLUSION: Zoonotic agents and genetically based resistance conferred by the Tyr139Cys polymorphism are both unevenly distributed in Lower Saxony. The study provides the basis for further studies focusing on districts with high levels of pathogens and resistance to assess the potential health risk of their combined occurrence. © 2012 Society of Chemical Industry
Insecticide resistance profiles can be misleading in predicting the survival of Myzus persicae genotypes on potato crops following the application of different insecticide classes
Authors: van Toor Ron F , Malloch Gaynor L , Anderson Eric A , Dawson Greg , Fenton Brian
Published: May 2012

BACKGROUND: The accuracy of predicting the survival of insecticide‐resistant aphids following the application of commonly used insecticides from the carbamate, the pyrethroid, a mix of the two or the neonicotinoid chemical classes was evaluated in a potato field in Scotland. Equal proportions of five genotypes of the peach‐potato aphid, Myzus persicae (Sulzer), with none, resistance to dimethyl‐carbamates, resistance to pyrethroids or combinations conferring resistance to both chemical classes were released into potato field plots. The insecticides were sprayed separately onto these plots, the aphid populations were analysed after 6–8 days and the process repeated.

RESULTS: For each assessment after the three separate spray events, plots treated with the carbamate had 48, 147 and 28%, those treated with pyrethroid 53, 210 and 89%, those treated with carbamate/pyrethroid 28, 108 and 64% and those treated with neonicotinoid 43, 55 and 11% of the numbers of M. persicae by comparison with untreated controls. Only the proportions of surviving aphids from the genotype containing no insecticide resistance traits and the genotype containing elevated carboxylesterases matched ratios predicted from the selective advantage afforded by the resistance traits alone. Survival of aphids from the other three genotypes that carried 1–3 of the insecticide resistance traits differed from expectations in all cases, possibly owing to physiological differences, including their vulnerability to predators and hymenopterous parasitoids present at the site and/or their carrying unknown insecticide resistance mechanisms.

CONCLUSION: Control strategies based on knowledge of the genetically determined insecticide resistance profile of an M. persicae population alone are insufficient. Hence, other important factors contributing to aphid survival under insecticide pressure need to be considered. Copyright © 2012 Society of Chemical Industry
Green nanoemulsion‐laden glyphosate isopropylamine formulation in suppressing creeping foxglove (A. gangetica), slender button weed (D. ocimifolia) and buffalo grass (P. conjugatum)
Authors: Lim Chaw Jiang , Basri Mahiran , Omar Dzolkhifli , Abdul Rahman Mohd Basyaruddin , Salleh Abu Bakar , Raja Abdul Rahman Raja Noor Zaliha
Published: May 2012

BACKGROUND: Pesticides are developed with carriers to improve their physicochemical properties and, accordingly, the bioefficacy of the applied formulation. For foliar‐applied herbicide, generally less than 0.1% of the active ingredient reaching the target site could reduce pesticide performance. Recently, a carrier of nanoemulsion consisting of oil, surfactant and water, with a particle size of less than 200 nm, has been shown to enhance drug permeability for skin penetration in pharmaceutical delivery systems. In the present work, the aim was to formulate a water‐soluble herbicide, glyphosate isopropylamine (IPA), using a green nanoemulsion system for a biological activity study against the weeds creeping foxglove, slender button weed and buffalo grass.

RESULTS: The nanoemulsion formulations displayed a significantly lower spray deposition on creeping foxglove (2.9–3.5 ng cm−2), slender button weed (2.6–2.9 ng cm−2) and buffalo grass (1.8–2.4 ng cm−2) than Roundup® (3.7–5.1 ng cm−2). The visible injury rates of weeds treated with the nanoemulsion formulations were statistically equivalent to those relating to Roundup® at 14 days after treatment, with a control range of 86.67–96.67%.

CONCLUSION: It was hypothesised that the significant difference in spray deposition with equal injury rates can be attributed to enhanced bioactivity of the nanoemulsion formulations. This initial discovery could be the platform for developing better penetration of agrochemical formulations in the future. Copyright © 2012 Society of Chemical Industry
Thiamethoxam acts as a target‐site synergist of spinosad in resistant strains of Frankliniella occidentalis
Authors: Guillén Juan , Bielza Pablo
Published: May 2012

BACKGROUND: Previous studies have suggested that the resistance mechanism towards spinosad in Frankliniella occidentalis (Pergande) is an altered target site. Like the neonicotinoids, the spinosyns act on nicotinic acetylcholine receptors (nAChRs) in insects, but at a distinct site. The changes in nAChRs related to spinosad resistance in thrips might involve interaction with neonicotinoids. In this study, the efficacy of spinosad and neonicotinoids, alone and in combination, was evaluated in susceptible and spinosad‐resistant thrips strains.

RESULTS: The neonicotinoids tested were imidacloprid, thiacloprid, acetamiprid, thiamethoxam and clothianidin. No cross‐resistance was shown between spinosad and any of the neonicotinoids. However, an increased toxicity was observed when a mixture of spinosad with thiamethoxam or clothianidin was tested. No synergism was found in the susceptible strains. The more spinosad‐resistant the thrips strain, the stronger was the synergism.

CONCLUSION: Data suggest that spinosad and thiamethoxam may interact at the nAChRs in spinosad‐resistant thrips, facilitating enhanced insecticidal action. Copyright © 2012 Society of Chemical Industry
The benefits of herbicide‐resistant crops
Authors: Green Jerry M
Published: May 2012

Since 1996, genetically modified herbicide‐resistant crops, primarily glyphosate‐resistant soybean, corn, cotton and canola, have helped to revolutionize weed management and have become an important tool in crop production practices. Glyphosate‐resistant crops have enabled the implementation of weed management practices that have improved yield and profitability while better protecting the environment. Growers have recognized their benefits and have made glyphosate‐resistant crops the most rapidly adopted technology in the history of agriculture. Weed management systems with glyphosate‐resistant crops have often relied on glyphosate alone, have been easy to use and have been effective, economical and more environmentally friendly than the systems they have replaced. Glyphosate has worked extremely well in controlling weeds in glyphosate‐resistant crops for more than a decade, but some key weeds have evolved resistance, and using glyphosate alone has proved unsustainable. Now, growers need to renew their weed management practices and use glyphosate with other cultural, mechanical and herbicide options in integrated systems. New multiple‐herbicide‐resistant crops with resistance to glyphosate and other herbicides will expand the utility of existing herbicide technologies and will be an important component of future weed management systems that help to sustain the current benefits of high‐efficiency and high‐production agriculture. Copyright © 2012 Society of Chemical Industry
In‐plane dielectric and magnetoelectric studies of BiFeO3
Authors: Kumar Ashok , Scott J. F. , Martínez R. , Srinivasan G. , Katiyar R. S.
Published: May 2012

In‐plane temperature dependent dielectric behavior of BiFeO3 (BFO) as‐grown thin films show diffuse but prominent phase transitions near 450 (±10) K and 550 K with dielectric loss temperature dependences that suggest skin layer effects. The 450 K anomalies are near the “transition” first reported by Polomska et al. [Phys. Status Solidi 23, 567 (1974)]. The 550 K anomalies coincide with the surface phase transition recently reported [Marti et al., Phys. Rev. Lett. 106, 236101 (2011)]. In addition, anomalies are found at low temperatures: After several experimental cycles, the dielectric loss shows a clear relaxor‐like phase transition near what was previously suggested to be a spin reorientation transition (SRT) temperature (∼201 K) for frequencies 1 kHz < f < 1 MHz which follow a nonlinear Vogel–Fulcher (V–F) relation; an additional sharp anomaly is observed near ∼180 K at frequencies below 1 kHz. As emphasized recently by Cowley et al. [Adv. Phys. 60, 229 (2011)], skin effects are expected for all relaxor ferroelectrics. Using the interdigital electrodes, experimental data and a theoretical model for in‐plane longitudinal and transverse direct magnetoelectric (ME) coefficient are presented.