bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of changes in sea ice advance on the large winter warming on the western Antarctic Peninsula
Authors: Turner John , Maksym Ted , Phillips Tony , Marshall Gareth J. , Meredith Michael P.
Published: April 2012

Over 1979–2007 near‐surface air temperatures on the maritime western side of the Antarctic Peninsula have increased throughout the year, with the greatest monthly temperature rise of 1.7 °C dec−1 occurring in July as recorded at Faraday/Vernadsky (F/V) station (65.4°S, 64.4°W). The warming trend in this month has been the result of a loss of very cold days at the station with the average number of days with mean temperature below − 15 °C decreasing from 7 during 1979–1988 to 0.6 over 1998–2007. There is a high anti‐correlation between temperatures at F/V and the extent of sea ice in July just to the west of the station. Passive microwave satellite imagery reveals that monthly ice concentrations here have decreased by up to 25% since the late 1970s creating a polynya‐like feature along the west coast of the peninsula. Sea ice extent over the southern Bellingshausen Sea has decreased markedly during the late summer and early autumn so that there has been a lengthening of the ice‐free season. Yet faster ice advance in June as a result of changes in the meridional component of the wind means that the overall ice extent in the Bellingshausen Sea in July (offshore of the F/V region) has not changed significantly. Years of extensive sea ice can occur as frequently now as in the earlier part of the record, but a combination of the changing nature of the ice advance and subtle shifts in the wind direction have led to the more frequent occurrence of the ice‐free area to the west of F/V in recent years. There are also indications of pre‐conditioning of the ice/ocean system to the west of F/V well before winter that is associated with the presence or absence of the ice anomaly that is observed in July. Copyright © 2012 Royal Meteorological Society
Interfacial shear strength of bioactive‐coated carbon fiber reinforced polyetheretherketone after in vivo implantation
Authors: Nakahara Ichiro , Takao Masaki , Goto Tomoyo , Ohtsuki Chikara , Hibino Shigeru , Sugano Nobuhiko
Published: April 2012

Despite the excellent osseointegration of carbon‐fiber‐reinforced polyetheretherketone (CFR/PEEK) with a surface hydroxyapatite (HA) coating, the bone‐implant interfacial shear strength of HA‐coated CFR/PEEK after osseointegration is unclear. We examined the interfacial shear strength of HA‐coated CFR/PEEK implants after in vivo implantation in a rabbit femur‐implant pull‐out test model. HA coating was performed by a newly developed method. Uncoated CFR/PEEK, HA‐coated blasted titanium alloy, and uncoated blasted titanium alloy were used as control implants. The implants were inserted into drilled femoral cortex, and pull‐out tests were conducted after 6 and 12 weeks of implantation to determine maximum interfacial shear strength. The HA‐coated CFR/PEEK (15.7 ± 4.5 MPa) and HA‐coated titanium alloy (14.1 ± 6.0 MPa) exhibited significantly larger interfacial shear strengths than the uncoated CFR/PEEK (7.7 ± 1.8 MPa) and the uncoated titanium alloy (7.8 ± 2.1 MPa) at 6 weeks. At 12 weeks, only the uncoated CFR/PEEK (8.3 ± 3.0 MPa) exhibited a significantly smaller interfacial shear strength, as compared to the HA‐coated CFR/PEEK (17.4 ± 3.6 MPa), HA‐coated titanium alloy (14.2 ± 4.8 MPa), and uncoated titanium alloy (15.0 ± 2.6 MPa). Surface analysis of the removed implants revealed detachment of the HA layer in both the HA‐coated CFR/PEEK and titanium alloy implants. The proposed novel HA coating method of CFR/PEEK significantly increased interfacial shear strength between bone and CFR/PEEK. The achieved interfacial shear strength of the HA‐coated CFR/PEEK implant is of the same level as that of grit‐blasted titanium alloy with HA. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1618–1625, 2012
Characteristics and consumption patterns of Australian organic consumers
Authors: Oates Liza , Cohen Marc , Braun Lesley
Published: April 2012

BACKGROUND: Increasingly, Australians are choosing to consume organically produced food, but only a small percentage consume organic food exclusively, and there is little information in the scientific literature that describes their actual level of intake. In order to provide a more meaningful description of Australian organic consumers the ‘Organic Consumption Survey’ and ‘Organic Food Intake Survey’ were conducted online in 2010. The aims were to provide information about the characteristics of regular organic consumers and quantify levels of organic consumption.

RESULTS: The majority of participants (n = 318) were female (80.3%), 25–55 years old (80.3%), living in urban areas (61.2%), born in Australia (68.9%) and were in a healthy weight range (55.5%). Organic fruit and vegetables had the highest uptake by organic consumers and meat products the lowest. The majority of participants consumed at least 65% organic food in their diet, including 35% certified organic food.

CONCLUSION: A better understanding of organic consumers may help to serve the long‐term interests of the organic industry and other stakeholders of food marketing. Clearer definitions of organic consumers may also inform research evaluating the purported health benefits of organic foods. Copyright © 2012 Society of Chemical Industry
Adrenocortical carcinoma: Past, present, and future
Authors: LaFemina Jennifer , Brennan Murray F.
Published: April 2012

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy. Due to its rarity, heterogeneity, and a lack of a comprehensive understanding of the pathogenesis, little progress has been made in treatment and outcomes. The current review explores the past, present, and future of the understanding and treatment of this disease process. J. Surg. Oncol. 2012; 106:586–594. © 2012 Wiley Periodicals, Inc.
Atmospheric dynamics and elevated ozone concentrations in the northern Adriatic
Authors: Prtenjak Maja Telišman , Jeričević Amela , Klaić Zvjezdana Bencetić , Alebić‐Juretić Ana , Bulić Ivana Herceg
Published: April 2012

The influence of mesoscale flow on the elevated O3concentrations recorded during 13–19 August 2000 in the coastal town of Rijeka (45.33°N, 14.45°E) has been examined. Although high levels of ozone concentration are often observed there, this episode was unique due to hourly afternoon concentrations persistently higher than 180 µg m−3and nocturnal levels above 100 µg m−3. To study this episode, available meteorological and ozone measurements were analysed, along with supplemental numerical simulations and trajectories. The measurements revealed favourable atmospheric conditions for the production of ozone, i.e., high air temperatures associated with (1) the exchange of two dominant (although relatively weak) large‐scale flows: southwesterlyversusnortheasterly bora winds, and (2) local thermal circulation. The bora wind was relatively weak and short lasting. Although the bora transported the polluted air mass away along the western Adriatic coast, the southwesterly flow returned ozone‐rich air toward the Alps, thus contributing to the overall pollution over the northern Adriatic Sea. Models revealed the superposition of the southwesterly wind and local, thermally induced winds that caused the regional transport of ozone toward the Alps and the eastern Adriatic coast. However, while the regional transport of ozone from the northern Adriatic was found to enhance somewhat the ozone concentrations in Rijeka at the end of period studied, its surrounding local emission sources, uniform local thermal circulation systems, and recirculation of pollutants were crucial factors in the formation of the large daytime and night time ozone levels observed in Rijeka.
The rotational advancement of medial plantar flap for coverage of foot defect: A case report
Authors: Beidas Omar E. , Tan Benny K. , Petersen J. Dayne
Published: April 2012

This case describes the use of the medial plantar artery flap used to cover a lateral foot wound in a 19‐year‐old male with a history of spina bifida. The original operative plan was for coverage with a medial plantar flap based distally on retrograde flow through the lateral plantar artery; however, this had to be revised intraoperatively as his vascular anatomy was not adequate to support a flap of this type. Thus, advancement with rotation modification of the conventional medial plantar flap was performed with good results. At 2‐month follow‐up, the patient's flap had fully healed, he returned to full weight‐bearing status, and he had gross sensation in the sole of his foot. This case illustrates the use of the well‐described medial plantar flap by rotating and advancing the flap for reconstruction of defects of the foot. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Multilayer reconstructions for defects overlying the Achilles tendon with the lateral‐arm flap: Long‐term follow‐up of 16 cases
Authors: Smit Jeroen M. , Darcy Catharine M. , Audolfsson Thorir , Hartman Ed H.M. , Acosta Rafael
Published: April 2012

Defects of the Achilles tendon and the overlying soft tissue are challenging to reconstruct. The lateral‐arm flap has our preference in this region as it provides thin pliable skin, in addition, the fascia and tendon can be included in the flap as well. The aim of this report is to share the experience the authors gained with this type of reconstruction. The authors report the largest series in the published reports today. Patients and methods: A retrospective review was performed of all patients treated between January 2000 and January 2009 with a lateral‐arm flap for a soft‐tissue defect overlying the Achilles tendon. Results: In the reviewed period, 16 soft‐tissue defects overlying the Achilles tendon were reconstructed, with a mean follow‐up of 63 months. In three cases, tendon was included into the flap and in two, a sensory nerve was coapted. Fifteen cases (94%) were successful, one failed. In seven cases, a secondary procedure was necessary for thinning of the flap. Conclusion: The lateral‐arm flap is a good and safe option for the reconstruction of defects overlying the Achilles tendon. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
The MG‐QOL15 Japanese version: Validation and associations with clinical factors
Authors: Masuda Masayuki , Utsugisawa Kimiaki , Suzuki Shigeaki , Nagane Yuriko , Kabasawa Chiaki , Suzuki Yasushi , Shimizu Yuko , Utsumi Hiroya , Fujihara Kazuo , Uchiyama Shinichiro , Suzuki Norihiro
Published: April 2012

Introduction:

Our study aim was to produce a Japanese translation of the 15‐item Myasthenia Gravis Quality‐of‐Life Scale (MG‐QOL15), assess its reliability and validity, and examine clinical factors affecting self‐perceived QOL in MG.

Methods:

We evaluated 327 consecutive patients with MG seen at six neurological centers. All patients completed the Japanese version of the MG‐QOL15 (MG‐QOL15‐J), the Beck Depression Inventory—second edition (BDI‐II), and a generic health‐related QOL questionnaire, the SF‐36. Disease severity was determined according to the Myasthenia Gravis Foundation of America (MGFA) quantitative MG score and the MG composite.

Results:

The MG‐QOL15‐J exhibited adequate internal reliability, test–retest repeatability, and concurrent validity with SF‐36, disease severity, and known‐patient groups categorized by MGFA post‐intervention status. Multivariate analysis revealed severity, dose of oral corticosteroids, and BDI‐II as independent factors negatively affecting QOL.

Conclusion:

The MG‐QOL15‐J is anticipated to be a valuable clinical measure of QOL in Japanese patients with MG. Muscle Nerve 46: 166–173, 2012
High frequency sacral root nerve block allows bladder voiding
Authors: Boger Adam S. , Bhadra Narendra , Gustafson Kenneth J.
Published: April 2012

Aims

Dyssynergic reflexive external urethral sphincter (EUS) activity following spinal cord injury can prevent bladder voiding, resulting in significant medical complications. Irreversible sphincterotomies or neurotomies can prevent EUS activation and allow bladder voiding, but may cause incontinence or loss of sacral reflexes. We investigated whether kilohertz frequency (KF) electrical conduction block of the sacral roots could prevent EUS activation and allow bladder voiding.

Methods

The S2 sacral nerve roots were stimulated bilaterally to generate bladder pressure in six cats. One S1 nerve root was stimulated proximally (20 Hz biphasic pulse trains) to evoke EUS pressure, simulating worst‐case dyssynergic EUS reflexes. KF waveforms (12.5 kHz biphasic square wave) applied to an electrode implanted distally on the S1 nerve root blocked nerve conduction, preventing the increase in EUS pressure and allowing voiding.

Results

Applying KF waveforms increased bladder voiding in single, limited‐duration trials from 3 ± 6% to 59 ± 12%. Voiding could be increased to 82 ± 9% of the initial bladder volume by repeating or increasing the duration of the trials.

Conclusions

Sacral nerve block can prevent EUS activation and allow complete bladder voiding, potentially eliminating the need for a neurotomy. Eliminating neurotomy requirements could increase patient acceptance of bladder voiding neuroprostheses, increasing patient quality of life and reducing the cost of patient care. Neurourol. Urodynam. 31:677–682, 2012. © 2012 Wiley Periodicals, Inc.
A cognitive accountability mechanism for penalizing misbehaving ECN‐based TCP stacks
Authors: Latré Steven , de Meerssche Wim Van , Deschrijver Dirk , Papadimitriou Dimitri , Dhaene Tom , Turck Filip De
Published: April 2012

The introduction of high‐bandwidth demanding services such as multimedia services has resulted in important changes on how services in the Internet are accessed and what quality‐of‐experience requirements (i.e. limited amount of packet loss, fairness between connections) are expected to ensure a smooth service delivery. In the current congestion control mechanisms, misbehaving Transmission Control Protocol (TCP) stacks can easily achieve an unfair advantage over the other connections by not responding to Explicit Congestion Notification (ECN) warnings, sent by the active queue management (AQM) system when congestion in the network is imminent. In this article, we present an accountability mechanism that holds connections accountable for their actions through the detection and penalization of misbehaving TCP stacks with the goal of restoring the fairness in the network. The mechanism is specifically targeted at deployment in multimedia access networks as these environments are most prone to fairness issues due to misbehaving TCP stacks (i.e. long‐lived connections and a moderate connection pool size). We argue that a cognitive approach is best suited to cope with the dynamicity of the environment and therefore present a cognitive detection algorithm that combines machine learning algorithms to classify connections into well‐behaving and misbehaving profiles. This is in turn used by a differentiated AQM mechanism that provides a different treatment for the well‐behaving and misbehaving profiles. The performance of the cognitive accountability mechanism has been characterized both in terms of the accuracy of the cognitive detection algorithm and the overall impact of the mechanism on network fairness. Copyright © 2012 John Wiley & Sons, Ltd.
A quadratically convergent inexact SQP method for optimal control of differential algebraic equations
Authors: Houska Boris , Diehl Moritz
Published: April 2012

In this paper, we present an inexact sequential quadratic programming method in the context of a direct multiple shooting approach for differential algebraic equations. For the case that a numerical integration routine is used to compute the states of a relaxed differential algebraic equation, the computation of sensitivities, with respect to a large number of algebraic states, can become very expensive. To overcome this limitation, the inexact sequential quadratic programming method that we propose in this paper requires neither the computation of any sensitivity direction of the differential state trajectory, with respect to the algebraic states, nor the consistent initialization of the differential algebraic equation. We prove the locally quadratic convergence of the proposed method. Finally, we demonstrate the numerical performance of the method by optimizing a distillation column with 82 differential and 122 algebraic states. Copyright © 2012 John Wiley & Sons, Ltd.
Thermal properties and moisture absorption of nanofillers‐filled epoxy composite thin film for electronic application
Authors: Voo Richard , Mariatti M. , Sim L. C.
Published: April 2012

This current study aimed to enhance the thermal conductivity of thin film composites without compromising other polymer qualities. The effect of adding high thermal conductivity nanoparticles on the thermal properties and moisture absorption of thin film epoxy composites was investigated. Three types of fillers in nanosize with high thermal conductivity properties, boron nitride (BN), synthetic diamond (SD), and silicon nitride (Si3N4) were studied. SN was later used as an abbreviation for Si3N4. The contents of fillers varied between 0 and 2 vol.%. An epoxy nanocomposite solution filled with high thermal conductivity fillers was spun at 1500–2000 rpm to produce thin film 40–60 µm thick. The effects of the fillers on thermal properties and moisture absorption were studied. The addition of 2 vol.% SD produced the largest improvement with 78% increment in thermal conductivity compared with the unfilled epoxy. SD‐filled epoxy thin film also showed good thermal stability with the lowest coefficients of thermal expansion, 19 and 124 ppm, before and afterTg, respectively, which are much lower compared with SN‐filled and BN‐filled epoxy thin film composites. However the SD‐filled epoxy film has its drawback as it absorbs more moisture compared with BN‐filled and SN‐filled epoxy film. Copyright © 2012 John Wiley & Sons, Ltd.
ALK+ anaplastic large cell lymphoma exhibits phosphatidylinositol‐3 kinase/akt activity with retained but inactivated PTEN—A report from the Children's Oncology Group
Authors: Thakral Charu , Hutchison Robert E. , Shrimpton Antony , Barrett Donna , Laver Joseph , Link Michael , Halleran Devin R. , Hudson Sandra
Published: April 2012

Background

ALK+ anaplastic large cell lymphoma (ALCL) is usually a disease of young patients. We investigated phosphatidylinositol‐3 kinase (PI3K)/Akt pathway‐associated factors in pediatric cases and cell lines.

Procedure

Patient materials consisted of tissue slides of ALK+/CD30+ ALCL from 33 patients treated on Pediatric Oncology Group protocols (9219, n = 8 and 9315, n = 25). Slides were examined by immunohistochemistry for phospho(p)‐Akt and PTEN, the primary feedback regulator of the pathway, as well as for p27kip1 and stathmin‐1. ALCL cell lines SUDHL‐1 and Karpas‐299 were examined for ALK, pALK, pAkt, p27/Kip1, PTEN, pPTEN, CD30, pSTAT3, and pSTAT5; ALK inhibition was performed using compound PF‐2341066 and PTEN genes were sequenced.

Results

A majority of patients expressed pAkt, PTEN, and stathmin, with p27kip1 levels less than controls. Cell lines showed expression of ALK, pALK, pSTAT3, pSTAT5, CD30, pAkt, PTEN, and pPTEN, with p27 slightly less than positive controls, and germline PTEN DNA. There was evidence of phosphorylated PTEN (pPTEN) associated with inhibited function. Pharmacologic inhibition of activated ALK diminished pSTAT3, pSTAT5, and CD30 expression but not pAkt or pPTEN in cultured cell lines.

Conclusion

We conclude that the PI3K/Akt pathway is activated in many, though not all, pediatric ALK+ ALCL. Our data suggest that activation of this pathway involves post‐translational regulation of PTEN. Pharmacologic inhibition of activated ALK does not reduce modest levels of activated Akt as it does with the more abundant levels of activated STAT3 or STAT5. Future therapy of ALCL might, in selected patients, best combine agents inhibiting PI3K/Akt with those targeting ALK. Pediatr Blood Cancer 2012;59:440–447. © 2012 Wiley Periodicals, Inc.
X‐ray scattering study on the damage in fibers used in soft body armor after folding
Authors: Kobayashi H. , McDonough W.G. , Dunkers J.P. , Wight S.A. , Lee H.J. , Kim J.H. , Forster A.L. , Rice K.D. , Holmes G.A.
Published: April 2012

The goals of the research effort described in this article are to develop a framework to evaluate improvements in next‐generation fibers used in soft body armor and to anticipate long‐term performance and potential fiber deterioration. This effort to date has included the effect of folding on the fibers and exploring the interaction between the specific fiber strain energy and their sound velocity. Previous work in this lab noted a severe drop‐off of tensile strength and strain‐to‐failure in poly(p‐phenylene benzobisoxazole) (PBO) fibers when subjected to repeated folding. Subsequent work on poly(p‐phenylene terephthalamide) (PPTA) fibers showed at most a slight drop‐off in these mechanical properties. Results from wide angle X‐ray diffraction indicated that both PPTA and PBO fibers showed no significant changes in the d‐spacing and the apparent crystal size. However, with small angle X‐ray scattering, it was found that the void and fibril sizes within PBO fibers may decrease after folding. Environmental scanning electron microscopy showed no damage to the fiber surfaces upon folding, and confocal microscopy revealed extensive internal damage to the PBO fibers that tracks well with the SAXS and mechanical testing results. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
QF‐PCR: application, overview and review of the literature
Authors: Mann Kathy , Ogilvie Caroline Mackie
Published: April 2012

Quantitative fluorescent polymerase chain reaction has been in diagnostic use in the UK for over 10 years and has proved to be a cost‐effective, robust and accurate rapid prenatal test for common aneuploidies. Specific advantages include detection of triploidy, mosaicism and maternal cell contamination. Its application at our centre is described, with developments including stand‐alone testing and improvements in strategies for the preparation and testing of chorionic villus biopsies. © 2012 John Wiley & Sons, Ltd.
Genetic counselling and ethical issues with chromosome microarray analysis in prenatal testing
Authors: McGillivray George , Rosenfeld Jill A , McKinlay Gardner R. J. , Gillam Lynn H.
Published: April 2012

Molecular karyotyping using chromosome microarray analysis (CMA) detects more pathogenic chromosomal anomalies than classical karyotyping, making CMA likely to become a first tier test for prenatal diagnosis. Detecting copy number variants of uncertain clinical significance raises ethical considerations. We consider the risk of harm to a woman or her fetus following the detection of a copy number variant of uncertain significance, whether it is ethically justifiable to withhold any test result information from a woman, what constitutes an ‘informed choice’ when women are offered CMA in pregnancy and whether clinicians are morally responsible for ‘unnecessary’ termination of pregnancy. Although we are cognisant of the distress associated with uncertain prenatal results, we argue in favour of the autonomy of women and their right to information from genome‐wide CMA in order to make informed choices about their pregnancies. We propose that information material to a woman's decision‐making process, including uncertain information, should not be withheld, and that it would be paternalistic for clinicians to try to take responsibility for women's decisions to terminate pregnancies. Non‐directive pre‐test and post‐test genetic counselling is central to the delivery of these ethical objectives. © 2012 John Wiley & Sons, Ltd.
Prenatal chromosomal microarray analysis in a diagnostic laboratory; experience with >1000 cases and review of the literature
Authors: Breman Amy , Pursley Amber N. , Hixson Patricia , Bi Weimin , Ward Patricia , Bacino Carlos A. , Shaw Chad , Lupski James R. , Beaudet Arthur , Patel Ankita , Cheung Sau W. , Van den Veyver Ignatia
Published: April 2012

Objective

To evaluate the results of prenatal chromosomal microarray analysis (CMA) on >1000 fetal samples referred for testing at our institution and to compare these data to published reports.

Methods

High resolution CMA was offered to women undergoing amniocentesis or chorionic villus sampling. Parental samples were obtained concurrently to exclude maternal cell contamination and assist interpretation of copy number variations.

Results

Clinically significant copy number variations were observed in 85/1115 cases (7.6%) overall, and in 45/1075 cases (4.2 %) if 40 abnormal cases with known chromosome abnormalities or familial genomic imbalances were excluded. Eighteen of the 1115 cases had variants of unclear clinical significance (1.6%). Indications yielding the most clinically significant findings were abnormal karyotype/fluorescence in situ hybridization (26/61, 42.6%), family history of chromosomal abnormality (13/137, 9.5%), abnormal ultrasound (38/410, 9.3%), abnormal serum screening (2/37, 5.4%) and advanced maternal age (5/394, 1.3%). Of 1075 cases having no previously known cytogenetic abnormality or family history, 18 (1.7%) had clinically significant genomic changes undetectable by conventional prenatal chromosome analysis.

Conclusion

Current experience confirms that the detection rate of CMA for prenatal chromosomal abnormalities surpasses that of conventional karyotype analysis and continues to improve with higher resolution arrays, while maintaining a low frequency of results of unclear clinical significance. © 2012 John Wiley & Sons, Ltd.
Integration of microarray technology into prenatal diagnosis: counselling issues generated during the NICHD clinical trial
Authors: Wapner Ronald J. , Driscoll Deborah A. , Simpson Joe Leigh
Published: April 2012

Cytogenetic microarray analysis (CMA) in prenatal testing detects chromosome abnormalities and new genetic syndromes that would be missed by conventional cytogenetics and has the potential to significantly enhance prenatal genetic evaluation. A large Eunice Kennedy Shriver National Institute Of Child Health and Human Development (NICHD)‐sponsored multicentered trial to assess the role of CMA as a primary prenatal diagnostic tool has been completed, and results will soon be available. Integration of this technology into clinical care will require thoughtful changes in patient counseling. Here, we examine four cases, all ascertained in the NICHD prenatal microarray study, to illustrate the challenges and subtleties of genetic counseling required with prenatal CMA testing. Although the specifics of each case are distinct, the underlying genetic principles of uncertainty, variable expressivity, and lack of precise genotype–phenotype correlation are well known and already part of prenatal counseling. Counselor and practitioner education will need to include both the science of interpreting array findings as well as development of improved approaches to uncertainty. A team approach to interpretation will need to be developed, as will standardized guidelines by professional organizations and laboratories. Of equal import is additional research into patient attitudes and desires, and a better understanding of the full phenotypic spectrum of copy number variants discoveredin utero. © 2012 John Wiley & Sons, Ltd.
A new approach for the preparation of hydrophilic poly(L‐lactide) porous scaffold for tissue engineering by using lamellar single crystals
Authors: Bakry Ahmed , Martinelli Andrea , Bizzarri Mariano , Cucina Alessandra , D'Ilario Lucio , Francolini Iolanda , Piozzi Antonella , Proietti Sara
Published: April 2012

The aim of the present work was to study the possibility of building a porous scaffold for tissue engineering with a new bottom‐up approach, obtained by assembling two‐dimensional‐micro, one‐dimensional‐nano sized poly(L‐lactide) lamellar single crystals. This choice was dictated by the fact that polymer single crystals have structural and morphological features which can be exploited for chemical surface modifications to give a system characterized by a high specific active surface area. Indeed, the outermost amorphous regions can undergo functionalization reactions easily, whereas the inner, relatively inaccessible and inert crystalline core ensures morphological and mechanical stability. The assembling method employed to give the porous structures is based on a mould pressing, salt leaching technique and was found to be facile and versatile. In the first part of this paper we report the experimental results obtained to find the best conditions to achieve a suitable frame in terms of morphology, porosity and mechanical properties. In the second part of the paper, we describe the biological tests performed by using mouse fibroblasts seeded onto scaffolds prepared from pristine and surface hydrolysed lamellae. The results show that the samples obtained are suitable for sustaining cells which can proliferate and reach the inner pores of the scaffold containing hydrolysed single crystals much better than those prepared from pristine lamellae. Copyright © 2012 Society of Chemical Industry
Synthesis and in vitro biological evaluation as antitumour drug carriers of folate‐targeted N‐isopropylacrylamide‐based nanohydrogels
Authors: Blanco María Dolores , Benito Marta , Olmo Rosa , Teijón César , Pérez Elena , Katime Issa , Teijón José M
Published: April 2012

Copolymeric nanohydrogels based on N‐isopropylacrylamide, N‐(pyridin‐4‐ylmethyl)acrylamide and tert‐butyl‐2‐acrylamidoethyl carbamate, synthesized by microemulsion polymerization, were characterized using Fourier transform infrared spectroscopy and their size (38–52 nm) determined using quasielastic light scattering. Folic acid was covalently attached to the nanohydrogels (1.40 ± 0.07 mmol g−1). Tamoxifen (6.7 ± 0.2–7.3 ± 1.2 µg TMX mg−1 nanohydrogel), a hydrophobic anticancer drug, and 5‐fluorouracil (7.7 ± 0.7–10.14 ± 1.75 µg 5‐FU mg−1 nanohydrogel), a hydrophilic anticancer drug, were loaded into the nanohydrogels. Maximum in vitro TMX release (77–84% of loaded drug) depended on interactions of the drug with hydrophobic clusters of the nanogels; however, no nanogel/5‐FU interactions allowed total release of the loaded drug. The cytotoxicity of unloaded nanohydrogels in MCF7, T47D and HeLa cells was low. Cell uptake of nanogels without bound folic acid took place in the three cell types by unspecific internalization in a time‐dependent process. Cell uptake increased for folic acid‐targeted nanohydrogels in T47D and HeLa cells, which have folate receptors. The administration of 10 and 30 µmol L−1 TMX by TMX‐loaded nanogels and 10 µmol L−1 5‐FU by 5‐FU‐loaded nanogels was effective on the three cell types, and the best results were obtained for folic acid‐targeted nanohydrogels. Copyright © 2012 Society of Chemical Industry
Synthesis of pentablock and multibranched copolymers bearing poly(ethylene glycol), hyperbranched polyglycidol, and poly(L‐lactide) with biocompatibility for controlled drug release
Authors: Wang Jing , Kim Min Hee , Kang Dong Eun , Suh Hongsuk , Kim Il
Published: April 2012

A series of multibranched pentablock copolymer (mBr5BlC), poly(L‐lactide)‐b‐HBP‐b‐poly(ethylene glycol)‐b‐HBP‐b‐poly(L‐lactide) (HBP = hyperbranched polyglycidol), has been synthesized by ring‐opening multibranching polymerization of glycidol using bifunctional poly(ethylene glycol) [PEG; molecular weight (MW) = 1000] as an initiator, followed by ring‐opening polymerization (ROP) of L‐lactide in the presence of stannous octoate. The ROP of different amounts of L‐lactide on HBP‐b‐PEG‐b‐HBP [MW = 2550; polydispersity index (PDI) = 1.08] yielded a series of the targeted mBr5BlCs of the MW range of 4360–15,300 with narrow PDI. All the mBr5BlCs have been well demonstrated to be in possession of good biocompatibility as biomaterials for various applications in biological medicine areas. The mBr5BlCs with tunable MW exhibited promising controllability in self‐assembly into spherical micellar structures with an average diameter range of 59–140 nm, which have no acute and intrinsic cytotoxicity against normal cells and provide a convenient strategy for drug loading. The anticancer drug doxorubicin was demonstrated to have a good affinity with the copolymer system, and its controlled release was performed in various pHs. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Electro‐osmotic flow in nanochannels with voltage‐controlled polyelectrolyte brushes: Dependence on grafting density and normal electric field
Authors: Cao Qianqian , Zuo Chuncheng , Li Lujuan , Zhang Yinhe , Yan Guang
Published: April 2012

Molecular dynamics simulations were performed for electro‐osmotic flow (EOF) confined in a polyelectrolyte‐grafted nanochannel under variable grafting density and normal electric field. With decreasing the value of the normal electric field, the brush undergoes a collapse transition, and the ion distribution is changed significantly. The brush thickness increases on increasing the grafting density at positive and weak negative electric fields, whereas a reduced brush thickness is observed at strong negative electric field. Our results further reveal that the flow velocity is not only dependent on conformational transition of the brush but also related to the cation and anion distributions. At low grafting density, the EOF is almost completely quenched at high electric field strength due to strong surface friction between ions and walls. For the case of very dense grafting, the flow velocity is influenced weakly within the brush when varying the grafting density. Additionally, a bidirectional flow occurs at an intermediate electric field. The investigation on fluid flux indicates that the fluid flux is insensitive to the grafting density, when the normal electric field is removed. For nonzero normal electric fields, a significant change in the fluid flux is observed at low grafting densities. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Specific Heat Capacity, Thermal Behavior, and Thermal Hazard of 2,4‐Dinitroanisole
Authors: Xing Xiaoling , Zhao Fengqi , Ma Shunnian , Xu Kangzhen , Xiao Libai , Gao Hongxu , An Ting , Hu Rongzu
Published: April 2012

The thermal hazard of 2,4‐dinitroanisole (2,4‐DNAN) was evaluated by microcalorimetry methods. The specific heat capacity, melting enthalpy, and the solidification heat of 2,4‐DNAN were determined with a Micro‐DSCIII calorimeter. The thermal decomposition behavior of 2,4‐DNAN at four different heating rates was studied by using a C‐500 type calvet microcalorimeter. The kinetic and thermodynamic parameters were obtained from the analysis of the heat flow data. The critical temperature of thermal explosion (Tb) and the initial decomposition temperature (Tp0) were determined to distinctly evaluate the thermal hazard of 2,4‐DNAN.
The Role of Aluminum in the Detonation and Post‐Detonation Expansion of Selected Cast HMX‐Based Explosives
Authors: Manner Virginia W. , Pemberton Steven J. , Gunderson Jake A. , Herrera Tommy J. , Lloyd Joseph M. , Salazar Patrick J. , Rae Philip , Tappan Bryce C.
Published: April 2012

In order to improve understanding of how aluminum contributes in non‐ideal explosive mixtures, cast‐cured formulations have been analyzed in a series of cylinder tests and plate‐pushing experiments. This study describes the contribution of 15 % aluminum (median size of 3.2 μm) vs. lithium fluoride (an inert substitute for aluminum; <5 μm) in cast‐cured HMX formulations in different temporal regimes. Small cylinder tests were performed to analyze the detonation and wall velocities (1–20 μs) for these formulations. Near‐field blast effects of 58 mm diameter spherical charges were measured at 152 mm and 254 mm using steel plate acceleration. Pressure measurements at 1.52 m gave information about free‐field pressure at several milliseconds. While the observed detonation velocities for all formulations were within uncertainty, significantly higher cylinder wall velocities, plate velocities, and pressures were observed for the aluminum formulations at ≥2 μs. Additionally, hydrocode calculations were performed to determine how non‐ideal behavior affected the plate test results. Collectively, this work gives a clearer picture of how aluminum contributes to detonation on timescales from 1 μs to about 2 ms, and how the post‐detonation energy release contributes to wall velocities and blast effects. The experiments indicate that significant aluminum reactions occur after the CJ plane, and continue to contribute to expansion at late times.
Structure and dynamics in solution of the stop codon decoding N‐terminal domain of the human polypeptide chain release factor eRF1
Authors: Polshakov Vladimir I. , Eliseev Boris D. , Birdsall Berry , Frolova Ludmila Yu.
Published: April 2012

The high‐resolution NMR structure of the N‐domain of human eRF1, responsible for stop codon recognition, has been determined in solution. The overall fold of the protein is the same as that found in the crystal structure. However, the structures of several loops, including those participating in stop codon decoding, are different. Analysis of the NMR relaxation data reveals that most of the regions with the highest structural discrepancy between the solution and solid states undergo internal motions on the ps–ns and ms time scales. The NMR data show that the N‐domain of human eRF1 exists in two conformational states. The distribution of the residues having the largest chemical shift differences between the two forms indicates that helices α2 and α3, with the NIKS loop between them, can switch their orientation relative to the β‐core of the protein. Such structural plasticity may be essential for stop codon recognition by human eRF1.
Brane tilings and reflexive polygons
Authors: Hanany A. , Seong R.‐K.
Published: April 2012

Reflexive polygons have attracted great interest both in mathematics and in physics. This paper discusses a new aspect of the existing study in the context of quiver gauge theories. These theories are 4d supersymmetric worldvolume theories of D3 branes with toric Calabi‐Yau moduli spaces that are conveniently described with brane tilings. We find all 30 theories corresponding to the 16 reflexive polygons, some of the theories being toric (Seiberg) dual to each other. The mesonic generators of the moduli spaces are identified through the Hilbert series. It is shown that the lattice of generators is the dual reflexive polygon of the toric diagram. Thus, the duality forms pairs of quiver gauge theories with the lattice of generators being the toric diagram of the dual and vice versa.
DC‐SCRIPT: AR and VDR regulator lost upon transformation of prostate epithelial cells
Authors: Ansems Marleen , Karthaus Nina , Hontelez Saartje , Aalders Tilly , Looman Maaike W. , Verhaegh Gerald W. , Schalken Jack A. , Adema Gosse J.
Published: April 2012

BACKGROUND

Nuclear receptors (NR), including the Androgen Receptor (AR) and the Vitamin D Receptor (VDR), play an important role in prostate cancer etiology. We recently found that DC‐SCRIPT is a prognostic marker in breast cancer and a unique NR coregulator differentially regulating different classes of NRs. Here we investigated the importance of DC‐SCRIPT in prostate cancer.

METHODS

DC‐SCRIPT mRNA expression was measured by qPCR. Immunohistochemistry was used to detect DC‐SCRIPT protein expression. The functional effects of DC‐SCRIPT on the transcriptional activity of AR and VDR were assessed by luciferase reporter assays and qPCR assays on well‐known AR and VDR target genes.

RESULTS

DC‐SCRIPT mRNA was higher in normal than in corresponding malignant prostate tissue but could not be related to disease stage. DC‐SCRIPT protein was found in morphologically normal prostate glands and in infiltrating immune cells. Strikingly, DC‐SCRIPT protein expression was absent in malignant prostate epithelial tissue and prostate carcinoma cell lines. DC‐SCRIPT protein expression appears to be lost prior to the basal cell marker HMW cytokeratin used in prostate carcinoma diagnostics. In addition, our data demonstrated that DC‐SCRIPT repressed transcription mediated by wild‐type and mutated AR while enhancing VDR mediated transcription. In addition, transient expression of DC‐SCRIPT expression in prostate carcinoma cells strongly repressed cell growth.

CONCLUSIONS

DC‐SCRIPT is a key regulator of nuclear receptors AR and VDR that play an opposite role in prostate cancer etiology and loss of DC‐SCRIPT may be involved in the onset of prostate cancer. Prostate 72:1708–1717, 2012. © 2012 Wiley Periodicals, Inc.
A dual indicator set to help farms achieve more sustainable crop protection
Authors: Wustenberghs Hilde , Delcour Ilse , D'Haene Karoline , Lauwers Ludwig , Marchand Fleur , Steurbaut Walter , Spanoghe Pieter
Published: April 2012

BACKGROUND: Farmers are being called to use plant protection products (PPPs) more consciously and adopt more sustainable crop protection strategies. Indicators will help farmers to monitor their progress towards sustainability and will support their learning process. Talking the indicators through in farmers' discussion groups and the resulting peer encouragement will foster knowledge acquirement and can lead to changes in attitudes, norms, perception and behaviour.

RESULTS: Using a participatory approach, a conceptual framework for on‐farm sustainable crop protection practices was created. The same participatory approach was used to design a dual indicator set, which pairs a pesticide impact assessment system (PIAS) with a farm inquiry. The PIAS measures the risk for human health and the environment exerted by chemical crop protection. The inquiry reveals the farmers' response to this risk, both in terms of the actions they take and their knowledge, awareness and attitude.

CONCLUSIONS: The dual indicator set allows for implementation in four tiers, each representing increased potential for monitoring and social learning. The indicator set can be adjusted on the basis of new findings, and the participatory approach can be extrapolated to other situations. Copyright © 2012 Society of Chemical Industry
Effects of cycloxaprid, a novel cis‐nitromethylene neonicotinoid insecticide, on the feeding behaviour of Sitobion avenae
Authors: Cui Li , Sun Lina , Yang Daibin , Yan Xiaojing , Yuan Huizhu
Published: April 2012

BACKGROUND: Cycloxaprid with cis‐configuration is a novel neonicotinoid insecticide, developed in China, that has good industrialisation prospects for its high activity against imidacloprid‐resistant pests. Studies were carried out to investigate the biological activity of cycloxaprid and its effect on the feeding behaviour of Sitobion avenae.

RESULTS: The results demonstrated that cycloxaprid had good contact and root‐systemic activity. The electrical penetration graph (EPG) revealed that cycloxaprid significantly increased the total time of non‐probing periods and greatly inhibited phloem ingestion of treated aphids because it significantly reduced the total time and the frequency of phloem ingestion. Furthermore, cycloxaprid can increase the phloem salivation of treated aphids by comparison with aphids treated with imdacloprid and distilled water. Consequently, a sublethal dose of cycloxaprid impaired aphid ingestion of phloem sap and thereby reduced the weight of aphids. On the other hand, EPG data showed that a sublethal dose of cycloxaprid had no significant effect on xylem sap ingestion, in contrast to imidacloprid.

CONCLUSION: All these tests indicated that cycloxaprid had both contact and root‐systemic activity, with sublethal effects resulting in reduction in Sitobion avenae phloem‐feeding behaviour and growth rate. Copyright © 2012 Society of Chemical Industry
Optical investigations of nonpolar homoepitaxial ZnO/(Zn,Mg)O quantum wells
Authors: Béaur L. , Bretagnon T. , Gil B. , Guillet T. , Brimont C. , Tainoff D. , Teisseire M. , Chauveau J.‐M.
Published: April 2012

We report growth of high quality ZnO/(Zn,Mg)O quantum wells, with 20% magnesium content, on M‐plane oriented ZnO substrates. The optical properties are studied by reflectance spectroscopy and continuous wave photoluminescence. The reflectance spectra reveal strong in‐plane optical anisotropies, as predicted by group theory. Signatures of confined excitons analogous to C‐exciton in bulk ZnO, are detected using light polarized along the c‐axis. Experiments performed in orthogonal polarization reveal confined states analogous to A and B bulk excitons. Envelope function calculations including excitonic interaction nicely match the experimental results. The weak Stokes‐shift between reflectance and photoluminescence spectra, and clear reflectance structures, are evidences of good interface morphologies. The independency of intensity of the photoluminescence with the temperature indicates the very small contributions of non‐radiative recombination channels in these samples (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prediction of boron–phosphorous nanographene‐like material
Authors: López‐Castillo Alejandro
Published: April 2012

In this work, nanographene based on Boron–Phosphorous is characterized theoretically by infrared, Raman spectroscopies, and other microscopic properties. Comparative studies among boron–phosphorous nanographene (BPNG), carbon one (CNG), and boron–nitrogen (BNNG) also suggest that it is experimentally possible to obtain the BPNG. There are several electronic similarities among BPNG, CNG, and BNNG. The studied ones have a circulene‐like structure with D6h and D3h symmetries for the carbon and boron compounds, respectively. The HOMO–LUMO gap obtained was compared with several sizes of those nanographenes. Compounds based on BP are expected to present intermediary properties in between the CNG and BNNG due to the electronegativity difference. The BPNG can be a promising material when used to obtain nanodevices, its gap is near the orange/VIS region. © 2012 Wiley Periodicals, Inc.
Some spin and spin‐free aspects of coulomb correlation in molecules
Authors: Luzanov A. V.
Published: April 2012

A spin component analysis of the cumulant (irreducible) density matrices is provided. In particular, the spin‐up spin‐down cumulant density matrix, π, is considered as the most general definition of the Coulomb‐hole density matrix. The local atomic cumulants produced from π, turn out to be the most important components of the atomic charge and spin correlators. These spin‐up spin‐down components, vanishing in the restricted Hartree–Fock model, reflect directly an effect of the Coulomb correlation on the generalized Wiberg bond order indices and Penney–Dirac bond orders. A spin‐free algorithm for computing spin correlators and related local spins is proposed. The algorithm is implemented numerically at full configuration interaction (FCI) and simple coupled‐cluster (CC) levels. The presented analysis is exemplified by some FCI and CC doubles computations on small hydrides and typical carbenes and cumulenes. © 2012 Wiley Periodicals, Inc.
Asymptotic enumeration of sparse 2‐connected graphs
Authors: Kemkes Graeme , Sato Cristiane M. , Wormald Nicholas
Published: April 2012

We determine an asymptotic formula for the number of labelled 2‐connected (simple) graphs on n vertices and m edges, provided that m ‐ n →∞ and m = O(nlog n) as n →∞. This is the entire range of m not covered by previous results. The proof involves determining properties of the core and kernel of random graphs with minimum degree at least 2. The case of 2‐edge‐connectedness is treated similarly. We also obtain formulae for the number of 2‐connected graphs with given degree sequence for most (“typical”) sequences. Our main result solves a problem of Wright from 1983. © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 2013