bluuebunny/crossref_metadata_2025 huggingface dataset:
Preoperative topical antimicrobial decolonization in head and neck surgery
Authors: Shuman Andrew G. , Shuman Emily K. , Hauff Samantha J. , Fernandes Laura L. , Light Emily , Chenoweth Carol E. , Bradford Carol R.
Published: August 2012

Objectives/Hypothesis:

Surgical site infections (SSIs) are an important cause of morbidity and mortality after head and neck surgery. Our primary objective was to determine the efficacy of preoperative topical antimicrobial decolonization before head and neck surgery.

Study Design:

Prospective, randomized controlled trial.

Methods:

This study was conducted among 84 patients presenting for head and neck surgery requiring admission to an academic medical center. Preoperative cultures were performed to identify Staphylococcus aureus carriers. Patients were randomized to preoperative topical antimicrobial decolonization with a 5‐day regimen of chlorhexidine skin rinses and intranasal mupirocin coupled with standard perioperative systemic antimicrobial prophylaxis, versus standard prophylaxis alone. The main outcome was the incidence of SSIs.

Results:

Despite a trend suggesting a decrease in SSIs with perioperative topical antimicrobial decolonization (24% vs. 10%), there was no significant difference (odds ratio, 0.34; 95% confidence interval, 0.10–1.18; P = .079). Patients with a higher American Society of Anesthesiologists score (3 vs. 1; P = .02), with more operative blood loss (P = .05), and who required operative takeback (P = .04) had a higher rate of SSIs; there was a trend suggesting a higher rate of SSIs among patients undergoing clean‐contaminated surgery compared to clean cases (P = .08) and among those having received prior radiation (P = .07) or chemotherapy (P = .06).

Conclusions:

Preoperative antimicrobial decolonization did not significantly decrease the incidence of SSIs after head and neck surgery, but might be considered for high‐risk groups despite the lack of conclusive evidence confirming efficacy. Risk factors for SSIs after head and neck surgery are identified for the first time in a prospective study. Laryngoscope, 2012
Evaluation of adult pott's puffy tumor: Our five cases and 27 literature cases
Authors: Akiyama Kosuke , Karaki Masayuki , Mori Nozomu
Published: August 2012

Objectives/Hypothesis:

Pott's puffy tumor (PPT) is defined as one or more subperiosteal abscesses of the frontal bone based on osteomyelitis. PPT is observed predominantly in the adolescent age group and rarely in adults. Some parameters affecting prognosis and an appropriate surgical approach for antecedent frontal sinusitis have not been elucidated due to the rarity of patients with adult PPT.

Study Design:

Retrospective patient record and literature study.

Methods:

Five patients from our cohort and 27 patients identified in a literature search formed the study group.

Results:

The incidence rate of intracranial complications was lower than in previous reports at 29.0%. There was no correlation between the incidence rate of intracranial complications and each patient's parameters. It was indicated that the department first consulted by the patients was possibly related to the initial diagnosis and the incidence rate of intracranial complications.

Conclusions:

Although the incidence rate of major complications is lower than in children and later than in earlier published adult cases, patients are still at high risk of serious intracranial complications. Early diagnosis and adequate treatment may contribute to reducing the incidence rate. Laryngoscope, 2012
Hunsaker mon‐jet tube ventilation: A 15‐year experience
Authors: Hu Amanda , Weissbrod Philip A. , Maronian Nicole C. , Hsia Jennifer , Davies Joanna M. , Sivarajan Gouri K. , Hillel Allen D.
Published: August 2012

Objective/Hypothesis:

The Hunsaker Mon‐Jet tube (HMJT) (Xomed, Jacksonville, FL) has been used effectively for subglottic ventilation. We previously reported a series of 552 patients over a 10‐year period with no major complications. This is a continuation of that series with an additional 5 years of cases.

Study Design:

Retrospective consecutive case series.

Methods:

Patients who were ventilated with the HMJT for microlaryngeal surgery at the University of Washington Medical Center over a 15‐year period (1995–2010) were identified from the Voice Disorders database. Charts were reviewed for demographic data, laryngeal diagnosis, and anesthetic parameters. Main outcome measure was the rate of complications.

Results:

Fifty‐seven complications occurred in 49 cases out of 839 cases (5.8% complication rate). In descending order, the complications were hypoxia (SpO2 <90%, n = 30, 3.6%), hypercarbia (end tidal CO2 of >60 mm Hg, n = 17, 2.0%), airway obstruction (n = 4, 0.5%), barotrauma (n = 2, 0.2%), seeding of blood into trachea (n = 2, 0.2%), submucosal injection of air (n = 1, 0.1%), and mucosal damage (n = 1, 0.1%). Factors associated with complications included high body mass index (P = .04), American Society of Anesthesiology class III or IV (P = .01), history of heart disease (P = .02), history of previous laryngeal surgery (P = .02), longer duration of case (P = .006), and laser use (P = .005).

Conclusions:

Although subglottic ventilation via an HMJT is a safe alternative to traditional endotracheal intubation in an appropriately selected population, practitioners should remain vigilant about the known complications. Laryngoscope, 2012
Ossicular fusion and cholesteatoma in auriculo‐condylar syndrome: In vivo evidence of arrest of embryogenesis
Authors: Propst Evan J. , Ngan Bo Y. , Mount Richard J. , Martin‐Munoz Daniel , Blaser Susan , Harrison Robert V. , Cushing Sharon L. , Papsin Blake C.
Published: August 2012

Auriculo‐condylar syndrome (ACS) is a rare condition affecting first branchial arch structures. The types of hearing loss and temporal bone findings in ACS have not been reported. We describe a 14‐year‐old male with constricted pinnae, mandibular dysostosis, glossoptosis, a high‐arched palate, hearing loss, and cholesteatoma. Computed tomography imaging demonstrated malleoincudal joint ankylosis. The fused malleoincudal complex was removed during mastoidectomy for cholesteatoma. Electron microscopy and histopathology of the joint suggested the fusion was congenital. This is the first report of ossicular fusion and cholesteatoma in ACS and the most detailed in vivo evidence of disruption of embryogenesis during malleoincudal joint formation. Laryngoscope, 2012
How long is long enough to follow up children after cholesteatoma surgery? A 29‐year study
Authors: Kuo Chin‐Lung , Shiao An‐Suey , Liao Wen‐Huei , Ho Ching‐Yin , Lien Chiang‐Feng
Published: August 2012

Objectives/Hypothesis:

To identify an association between follow‐up period and cholesteatoma recidivism.

Study Design:

Retrospective review.

Methods:

From 1982 to 2011, we retrospectively screened a consecutive series of children (≤18 years) with acquired cholesteatomas after primary surgery. The cumulative recidivism rates were calculated using standard calculation methods and Kaplan‐Meier survival analysis.

Results:

A total of 73 operations were performed on 71 patients. The mean age was 10.7 years, and the mean follow‐up period was 15.4 years. The number of censored cases increased with the follow‐up time. Sixty‐four (88%) operations had a follow‐up period of 5 years or longer, and 41 (56%) operations 15 years or longer. Cholesteatoma recidivism was observed in seven ears (five recurrent and two residual diseases). The mean detection time was 10.4 years (range 1.9–17.2 years). Five of the seven ears (71.4%) with recidivism were detected more than 10 years after surgery. The recidivism rate increased with the follow‐up time. However, the rates at 5, 10, 15, 20, and 25 years as calculated by the standard calculation method (1.4%, 2.7%, 8.2%, 9.5% and 9.5%, respectively) were underestimated compared with that by Kaplan‐Meier analysis (1.4%, 3.1%, 11.6%, 14.4% and 14.4%, respectively).

Conclusions:

The Kaplan‐Meier survival analysis method should be used when discussing recidivism rates, because the number of censored cases inevitably increases with observation time. Due to the late occurrence of recidivism and because the recidivism rate increases as time goes on, children should be periodically followed up for as long as possible. Laryngoscope, 2012
Congruences and ideals on Peirce algebras: a heterogeneous/homogeneous point of view
Authors: Pinto Sandra Marques , Oliveira‐Martins M. Teresa
Published: August 2012

For a Peirce algebra \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}${\mathcal P}$\end{document}, lattices \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathrm{Cong}\mathcal {P}$\end{document} of all heterogenous Peirce congruences and \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathrm{Ide}\mathcal {P}$\end{document} of all heterogenous Peirce ideals are presented. The notions of kernel of a Peirce congruence and the congruence induced by a Peirce ideal are introduced to describe an isomorphism between \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathrm{Cong}\mathcal {P}$\end{document} and \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathrm{Ide}\mathcal {P}$\end{document}. This isomorphism leads us to conclude that the class of the Peirce algebras is ideal determined. Opposed to Boolean modules case, each part of a Peirce ideal I = (I1, I2) determines the other one. A similar result is valid to Peirce congruences. A characterization of the simple Peirce algebras is presented coinciding to that given by Brink, Britz and Schmidt in a homogeneous approach.
On the constructive notion of closure maps
Authors: Ardeshir Mohammad , Ramezanian Rasoul
Published: August 2012

Let A be a subset of the constructive real line. What are the necessary and sufficient conditions for the set A such that A is continuously separated from other reals, i.e., there exists a continuous function f with f−1(0) = A? In this paper, we study the notions of closed sets and closure maps in constructive reverse mathematics.
On proofs of the incompleteness theorems based on Berry's paradox by Vopěnka, Chaitin, and Boolos
Authors: Kikuchi Makoto , Kurahashi Taishi , Sakai Hiroshi
Published: August 2012

By formalizing Berry's paradox, Vopěnka, Chaitin, Boolos and others proved the incompleteness theorems without using the diagonal argument. In this paper, we shall examine these proofs closely and show their relationships. Firstly, we shall show that we can use the diagonal argument for proofs of the incompleteness theorems based on Berry's paradox. Then, we shall show that an extension of Boolos' proof can be considered as a special case of Chaitin's proof by defining a suitable Kolmogorov complexity. We shall show also that Vopěnka's proof can be reformulated in arithmetic by using the arithmetized completeness theorem.
Impact of Filler Functionalisation on the Crystallinity, Thermal Stability and Mechanical Properties of Thermoplastic Elastomer/Carbon Nanotube Nanocomposites
Authors: Prado Luís Antônio Sanchez de Almeida , Kopyniecka Agata , Chandrasekaran Swetha , Broza Georg , Roslaniec Zbigniew , Schulte Karl
Published: August 2012

In the present work, the functionalisation of oxidised SWCNTs and MWCNTs is studied. The functionalised fillers are characterised by Raman spectroscopy and TGA. The functionalised fillers are dispersed in a PBT‐PTMO thermoplastic elastomer matrix via in situ polymerisation. The functionalisation causes a fine filler dispersion right at beginning of nanocomposite manufacturing. The fillers act as nucleating agents for crystallisation and evidences for a grafting from PBT at the surface of the functionalised nanotubes are found. An outstanding reinforcement effect by the functionalised CNTs is confirmed by tensile tests.

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Poly(2‐oxazoline)s as Polymer Therapeutics
Authors: Luxenhofer Robert , Han Yingchao , Schulz Anita , Tong Jing , He Zhijian , Kabanov Alexander V. , Jordan Rainer
Published: August 2012

Poly(2‐oxazoline)s (POx) are currently discussed as an upcoming polymer platform for biomaterials design and especially for polymer therapeutics. POx meet specific requirements needed for the development of next‐generation polymer therapeutics such as biocompatibility, high modulation of solubility, variation of size, architecture as well as chemical functionality. Although in the early 1990s first and promising POx‐based systems were presented, the field lay dormant for almost two decades. Only very recently, POx‐based polymer therapeutics came back into the focus of very intensive research. In this review, we give an overview on the chemistry and physicochemical properties of POx and summarize the research of POx–protein conjugates, POx–drug conjugates, POx‐based polyplexes and POx micelles for drug delivery.
Rad59 regulates association of Rad52 with DNA double‐strand breaks
Authors: Pannunzio Nicholas R. , Manthey Glenn M. , Liddell Lauren C. , Fu Becky Xu Hua , Roberts Cai M. , Bailis Adam M.
Published: August 2012

Homologous recombination among repetitive sequences is an important mode of DNA repair in eukaryotes following acute radiation exposure. We have developed an assay in Saccharomyces cerevisiae that models how multiple DNA double‐strand breaks form chromosomal translocations by a nonconservative homologous recombination mechanism, single‐strand annealing, and identified the Rad52 paralog, Rad59, as an important factor. We show through genetic and molecular analyses that Rad59 possesses distinct Rad52‐dependent and ‐independent functions, and that Rad59 plays a critical role in the localization of Rad52 to double‐strand breaks. Our analysis further suggests that Rad52 and Rad59 act in multiple, sequential processes that determine genome structure following acute exposure to DNA damaging agents.
Clinicopathological study in progressive supranuclear palsy with pedunculopontine stimulation
Authors: Hazrati Lili‐Naz , Wong Janice C. , Hamani Clement , Lozano Andres M. , Poon Yu‐Yan , Dostrovsky Jonathan O. , Hutchison William D. , Zadikoff Cindy , Moro Elena
Published: August 2012

Background:

Pedunculopontine nucleus (PPN) DBS has emerged as a potential intervention for patients with gait and balance disorders. However, targeting this nucleus can be challenging. We report on the first neuropathological analyses after PPN‐DBS surgery in advanced progressive supranuclear palsy (PSP).

Methods:

Two patients with PSP underwent unilateral PPN‐DBS surgery and were clinically followed to autopsy. Both patients underwent postmortem neuropathological analysis, including choline acetyltransferase immunohistochemistry, to ascertain PPN boundaries and electrode location.

Results:

Both patients experienced partial improvement in some motor and nonmotor domains postintervention, but died shortly of other complications. Postmortem neuropathological analysis of each patient confirmed the electrode in a region of cholinergic neuronal loss corresponding to the PPN.

Conclusions:

We provide histopathological evidence for the validity of our stereotactic approach to target the PPN and correlate electrode location with clinical outcomes. © 2012 Movement Disorder Society
1H NMR analysis of O‐methyl‐inositol isomers: a joint experimental and theoretical study
Authors: De Almeida Mauro V. , Couri Mara Rubia C. , De Assis João Vitor , Anconi Cleber P. A. , Dos Santos Hélio F. , De Almeida Wagner B.
Published: August 2012

Density functional theory (DFT) calculations of 1H NMR chemical shifts for l‐quebrachitol isomers were performed using the B3LYP functional employing the 6‐31G(d,p) and 6‐311 + G(2d,p) basis sets. The effect of the solvent on the B3LYP‐calculated NMR spectrum was accounted for using the polarizable continuum model. Comparison is made with experimental 1H NMR spectroscopic data, which shed light on the average uncertainty present in DFT calculations of chemical shifts and showed that the best match between experimental and theoretical B3LYP 1H NMR profiles is a good strategy to assign the molecular structure present in the sample handled in the experimental measurements. Among four plausible O‐methyl‐inositol isomers, the l‐quebrachitol 2a structure was unambiguously assigned based only on the comparative analysis of experimental and theoretical 1H NMR chemical shift data. The B3LYP infrared (IR) spectrum was also calculated for the four isomers and compared with the experimental data, with analysis of the theoretical IR profiles corroborating assignment of the 2a structure. Therefore, it is confirmed in this study that a combined experimental/DFT spectroscopic investigation is a powerful tool in structural/conformational analysis studies. Copyright © 2012 John Wiley & Sons, Ltd.
A novel electrodiagnostic assessment of the laryngeal closure reflex
Authors: Carey Bridget , Sulica Lucian , Wu Anita , Branski Ryan
Published: August 2012

Introduction: We describe a novel, clinically applicable conduction study of the laryngeal nerves. Methods: Seventeen normal volunteer subjects were included. Activation of the sensory territory of the superior laryngeal nerve was performed by administration of low level brief electrical stimuli. The laryngeal closure reflex (LCR) evoked by this stimulus was recorded by needle electrodes. Mean minimal latencies were calculated for each response, and proposed values for the upper limit of normal were determined. Results: Uniform, consistent early ipsilateral responses and late bilateral responses, which exhibit greater variation in latency and morphology, were recorded. Significant side‐to‐side differences in latencies were observed, consistent with the length discrepancy between right and left recurrent laryngeal nerves. Conclusions: This technique yields clear, quantifiable data regarding neurologic integrity of laryngeal function, heretofore unobtainable in the clinical setting. This study may yield clinically relevant information regarding severity and prognosis in patients with laryngeal neuropathic injury. Muscle Nerve 47:432‐436, 2013
Ulnar nerve lesion at the wrist related to pisotriquetral joint arthropathy
Authors: Seror Paul , Vuillemin Valérie
Published: August 2012

Introduction: Ulnar nerve lesions at the wrist (UNLW) are always difficult to localize clinically and sometimes electrophysiologically. Finding conduction block when studying ulnar motor nerve conduction (CB) across the wrist is sometimes the only way to demonstrate that the ulnar deep motor branch (UDMB) is entrapped. Methods: An elderly woman who had bilateral carpal tunnel syndrome (CTS) and thumb osteoarthritis for many years experienced worsening of left hand impairment recently. Results: Electrodiagnostic and ultrasound examinations revealed an acute and severe UDMB lesion related to pisotriquetral joint effusion. The patient received a local injection of a corticosteroid that provided rapid recovery. Conclusions: The diagnosis of UDMB lesion is especially difficult when CTS coexists, but CTS may allow for early diagnosis, if CB at the wrist is not overlooked. Chondrocalcinosis was responsible for the systemic inflammation, the CTS, the pisotriquetral joint effusion, and the UDBM compression, which has not been reported previously. Muscle Nerve, 2013
Assessing Post‐traumatic Time Interval in Human Dry Bone
Authors: de Boer H. H. , van der Merwe A. E. , Hammer S. , Steyn M. , Maat G. J. R.
Published: August 2012

The post‐traumatic status of antemortem fractures in human dry bone remains is currently defined as being either ‘healing’ or ‘healed’. However, detailed ‘dating’ of the related post‐traumatic time interval would be desirable, since it would aid in assessing individual medical status and care at the time of death. Within forensic pathology practice, fresh tissue healing phases are routinely used as an intrinsic parameter for the length of the post‐traumatic time interval. Unfortunately, the direct application of such a method is hampered when applied to dry bone skeletal material.

This study explores the possibility of applying a fracture dating system, drawn forth from the traditional forensic pathology method, on dry bone remains. More specifically, the aim is to establish the extent to which various histomorphological features indicative of specific time intervals of healing are consistently detectable. Human dry bones with fractures and amputations in various phases of healing were studied.

Results show that the complementary use of radiological and histological investigation techniques improves the differentiation between various healing phases and thus allow for a more detailed dating of lesions. For future use, healing features that have proven to be consistently detectable and their related post traumatic time intervals are listed. The system aids in demarcating a considerably more ‘narrow’ post‐traumatic time interval than usual. Copyright © 2012 John Wiley & Sons, Ltd.
Robust estimation of interconnected systems subject to sensor nonlinearities
Authors: Mahmoud Magdi S. , AL‐Sunni Fouad M.
Published: August 2012

An efficient robust LMI‐based scheme is developed for decentralized state‐estimation of linear interconnected systems with static nonlinear interconnections and subjected to sensor nonlinearities. The interconnections satisfy quadratic constraints with manipulated parameters and the sensor nonlinearities are modeled as sector nonlinearities. The design procedure utilizes a general linear estimator structure and consists of two steps: the first giving a block‐diagonal Lyapunov matrix together with the robustness degree and the second determining the filter parameters. A numerical example is provided to illustrate the applicability of the method. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis, polymerization, and thermal properties of benzoxazine based on bisphenol‐S and allylamine
Authors: Liu Yanfang , Wang Man , Zhang Haili , Zhao Shasha , Run Mingtao
Published: August 2012

A bifunctional benzoxazine monomer, 6,6′‐bis(3‐allyl‐3,4‐dihydro‐2H‐benzo[e][1,3]oxazinyl) sulfone (BS‐ala), was synthesized from bisphenol‐S, allylamine and formaldehyde via a solution method. The chemical structure of BS‐ala was confirmed by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and elemental analysis. The polymerization behavior of BS‐ala was investigated by FTIR, solid‐state 13C NMR, and differential scanning calorimetry (DSC). The oxazine ring opening polymerization is prior to the addition polymerization of allyl group, and the exothermic peaks corresponding to the two reactions appear partially overlapped in the DSC curve. The storage modulus of the resultant polybenzoxazine at 25°C is about 3.9 GPa, and the glass transition temperature is 254°C. The 5% and 10% weight loss temperatures of the polybenzoxazine are about 335°C and 361°C in both air and nitrogen, respectively. The char yield is about 58% at 800°C in nitrogen, whereas almost no residue is remained at 700°C in air. Copyright © 2012 John Wiley & Sons, Ltd.
Iron overload signature in chrysotile‐induced malignant mesothelioma
Authors: Jiang Li , Akatsuka Shinya , Nagai Hirotaka , Chew Shan‐Hwu , Ohara Hiroki , Okazaki Yasumasa , Yamashita Yoriko , Yoshikawa Yutaka , Yasui Hiroyuki , Ikuta Katsuya , Sasaki Katsunori , Kohgo Yutaka , Hirano Seishiro , Shinohara Yasushi , Kohyama Norihiko , Takahashi Takashi , Toyokuni Shinya
Published: August 2012

Exposure to asbestos is a risk for malignant mesothelioma (MM) in humans. Among the commercially used types of asbestos (chrysotile, crocidolite, and amosite), the carcinogenicity of chrysotile is not fully appreciated. Here, we show that all three asbestos types similarly induced MM in the rat peritoneal cavity and that chrysotile caused the earliest mesothelioma development with a high fraction of sarcomatoid histology. The pathogenesis of chrysotile‐induced mesothelial carcinogenesis was closely associated with iron overload: repeated administration of an iron chelator, nitrilotriacetic acid, which promotes the Fenton reaction, significantly reduced the period required for carcinogenesis; massive iron deposition was found in the peritoneal organs with high serum ferritin; and homozygous deletion of the CDKN2A/2B/ARF tumour suppressor genes, the most frequent genomic alteration in human MM and in iron‐induced rodent carcinogenesis, was observed in 92.6% of the cases studied with array‐based comparative genomic hybridization. The induced rat MM cells revealed high expression of mesoderm‐specific transcription factors, Dlx5 and Hand1, and showed an iron regulatory profile of active iron uptake and utilization. These data indicate that chrysotile is a strong carcinogen when exposed to mesothelia, acting through the induction of local iron overload. Therefore, an intervention to remove local excess iron might be a strategy to prevent MM after asbestos exposure. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Morphological, mechanical, and thermal characterization of biopolymer composites based on polylactide and nanographite platelets
Authors: Narimissa Esmaeil , Gupta Rahul K. , Choi Hyoung J. , Kao Nhol , Jollands Margaret
Published: August 2012

This work focuses on development and optimization of polylactide (PLA) and nanographite platelets (NGP) based composites to display possible superior mechanical and improved thermal stability. Melt blending and dry mixing methods of fabrication were employed at temperature of 180°C. Different Loading fractions of NGP were incorporated into polymer matrix. Morphological evaluation techniques such as XRD and TEM were applied to determine the degree of dispersion of NGPs into PLA matrix. Mechanical properties were evaluated and correlated to structural morphologies of PLA/NGP composites. Thermal properties of composites were studied to examine possible changes inTg,Tc,Tm, and percentage crystallinity of these composites. The effect of mixing was also explored through double extrusion of some samples. It was concluded that composites containing 3 wt% NGP showed optimum mechanical performance without any significant changes in the thermal characteristics. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Optimization‐driven design of dies for profile extrusion: Parameterization, strategy, and performance
Authors: Ettinger H.J. , Pittman J.F.T. , Sienz J.
Published: August 2012

A computational design optimization environment is developed, handling, for the first time, streamline dies used for profiles in unplasticized polyvinyl chloride (uPVC) having multiple complex features, as well as simpler designs. Die cavity cross sections are described by planar contours, such as the cutting paths for wire electrical discharge machining of the plates from which streamline profile dies are constructed. Contours are parameterized using key points, and by joining the contours with ruled surfaces, the three‐dimensional geometry can be reconstructed. For the optimization a developed flow analysis on each die cross section is used with the avoid‐cross‐flow strategy. Cross sections are partitioned and the die is balanced to obtain the required flow rate through each. A robust and efficient parallel decoupled optimization strategy is developed. In application to a uPVC window profile, five cross sections were optimized. The number of design variables on each ranged from 2 to 46, and the cross section optimizations converged within one to seven cycles. Compared with the work of an experienced designer making manual changes to the computer‐aided design model, guided by computational fluid dynamics analyses, the design quality was comparable or better and computational demands similar; however, the time required from the designer was reduced seven times. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Preparation and characterization of novel ultra‐high molecular weight polyethylene composite fibers filled with nanosilica particles
Authors: Yeh Jen‐Taut , Wang Chuen‐Kai , Yeh Alice , Huang Lu‐Kai , Wang Wen‐Hung , Hsieh Kuo‐Huang , Huang Chi‐Yuan , Chen Kan‐Nan
Published: August 2012

Ultrahigh molecular weight polyethylene (UHMWPE)/nanosilica (F2Sy) and UHMWPE/modified nanosilica (F2Smx‐y) as‐prepared fibers were prepared by spinning of F2Sy and F2Smx‐y gel solutions, respectively. Modified nanosilica particles were prepared by grafting maleic anhydride grafted polyethylenes onto nanosilica particles. The achievable draw ratios (Dra) of F2Sy and F2Smx‐y as‐prepared fibers approached a maximal value as the original and modified nanosilica contents reached corresponding optimum values; the maximal Dra value obtained for F2Smx‐y as‐prepared fiber specimens was significantly higher than that of the F2Sy as‐prepared fiber specimens prepared at the optimum nanosilica content. The melting temperature and evaluated lamellar thickness values of F2Sy and F2Smx‐y as‐prepared fiber series specimens decrease, but crystallinity values increase significantly, as their original and modified nanosilica contents respectively increase. Similar to the achievable drawing properties of the as‐prepared fibers, the orientation factor, tensile strength (σf) and initial modulus (E) values of both drawn F2Sy and F2Smx‐y fiber series specimens with a fixed draw ratio reach a maximal value as the original and/or modified nanosilica contents approach the optimum values; the σf and E values of the drawn F2Smx‐y fiber specimens are significantly higher than those of the corresponding drawn F2Sy fiber specimens prepared at the same draw ratios and nanosilica contents but without being modified. To understand the interesting ultradrawing, thermal, orientation and tensile properties of F2Sy and F2Smx‐y fiber specimens, Fourier transform infrared, specific surface area and transmission electron microscopy analyses of the original and modified nanosilica were performed in this study. © 2012 Society of Chemical Industry
Synthesis and properties of a novel hyperbranched polyphosphoramidate using an A2 + CB2 approach
Authors: Liu Yuhong , Yan Ni , Li Feng , Chen Ping
Published: August 2012

The synthesis of hyperbranched polyphosphoramidate (HPPAE) has been successfully achieved via a facial A2 + CB2 approach. First, an AB2 type intermediate is generated by the reaction between the phosphorus chloride group of ethyldichlorophosphate and the secondary amine group of diethanolamine. Second, the above intermediate can further self‐condense to produce the hyperbranched polymer. The molecular weight and the structural characterization of HPPAE were checked by gel permeation chromatography and Fourier transform infrared and NMR (13C and 31P) spectroscopy. The degradation study of HPPAE indicated that phosphate and phosphoramide bonds between the branch points are responsible for its complete hydrolysis in an aqueous phosphate buffer (pH 7.4) after 6 days. In addition, HPPAE presents a strong fluorescence peak at 450 nm, exhibiting the potential to track drug transport and distribution in real time. © 2012 Society of Chemical Industry
Geometric Evolution of Polygonal Terrain Networks in the Canadian High Arctic: Evidence of Increasing Regularity over Time
Authors: Haltigin Timothy W. , Pollard Wayne H. , Dutilleul Pierre , Osinski Gordon R.
Published: August 2012

Polygon networks are usually described qualitatively as becoming more regular through time, but such a concept has yet to be demonstrated numerically. The aim of this study is to address this question quantitatively in order to determine if polygonal terrain networks actually become more regular as they develop. Spatial point pattern analysis (SPPA), which can quantify overall network geometries based on the randomness or regularity exhibited by the spatial arrangement of polygon‐bounding trough intersections, was used at three ice‐wedge polygon sites in the Canadian High Arctic. SPPA was applied in two ways: (i) on the present‐day networks observed in the field; and (ii) on historical arrangements derived by distinguishing primary from secondary troughs. In all cases, the polygonal networks had undergone a statistically significant regularisation over the course of their development. Although the method was applied only to terrestrial ice‐wedge polygons, such an approach may also be useful for interpreting the evolution of Antarctic sublimation polygons and geometrically similar polygonal networks on Mars. Copyright © 2012 John Wiley & Sons, Ltd. and Her Majesty the Queen in Right of Canada.
The CCPS chemical reactivity evaluation tool
Authors: Mark Davis Edward , Silva Dan , Murphy John
Published: August 2012

Incidents involving uncontrolled chemical reactions continue to result in injuries, fatalities, and economic loss and harm in industry. These incidents are often the result of not identifying or understanding the chemical reactivity hazards involved in storage, mixing, or processing operations. The chemical reactivity evaluation tool (RMT) and the Help Guide that accompanies it can be used as an aid in identifying and evaluating chemical reactivity hazards so that they may be effectively avoided or controlled. This paper will describe the RMT and demonstrate its use in identifying reactivity hazards in chemical storage, handling, and processing operations. The RMT and Help Guide are available as a free download from AIChE (www.aiche.org) and search “RMR.” © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012
Imidacloprid as a contact arrestant for larvae of the European chafer, Amphimallon majale
Authors: Zhu Gengping , Petersen Matthew J , Liu Guoqing , Peck Daniel C
Published: August 2012

BACKGROUND: Manipulative studies of the behavioral response of soil‐dwelling insects to insecticides and other antagonists are stymied by the difficulties of observing and interpreting interactions played out below ground. Six experiments were carried out using X‐ray radiography to quantify the movement of the European chafer, Amphimallon majale (Razoumowsky), larvae in response to imidacloprid and how this was affected by host plant cues and cold temperature.

RESULTS: The movement of third instars was arrested in imidacloprid‐treated soil at ≥ 0.6 ppm concentration. At ≥ 0.8 ppm, the arrestant effect of imidacloprid was stronger than the attraction cue posed by germinating grass seed. There was a less disruptive effect on dispersal distance in vertical versus lateral panels. In vertical panels, there was a less disruptive effect on downward movement under a cold temperature treatment that simulated overwintering conditions.

CONCLUSION: Larvae of A. majale do not remotely detect imidacloprid in the soil; they neither evade contact, nor are repelled after contact. Imidacloprid thereby acts as a contact arrestant to disrupt grub movement. This finding might help to explain the synergistic effect of imidacloprid in combination with other biological agents for white grub control, and its effects on grub overwintering behavior. © 2012 Society of Chemical Industry
Electrical properties of lateral p–n junction diodes fabricated by selective growth of n+ diamond
Authors: Hoshino Yuto , Kato Hiromitsu , Makino Toshiharu , Ogura Masahiko , Iwasaki Takayuki , Hatano Mutsuko , Yamasaki Satoshi
Published: August 2012

We fabricated diamond lateral p–n junction diodes by selective growth of n+‐type diamond and evaluated their structural and electrical properties. The phosphorus‐doped n+ diamond was selectively grown by microwave chemical vapor deposition at the side of a boron‐doped p‐type layer to form lateral p–n junction diodes. No distinct defects are observed at the interface of the p–n junction diode by cross‐sectional transmission electron microscopy, implying the good homoepitaxial growth of the n‐type diamond. Electron beam induced‐current measurements directly confirmed the existence of the depletion layer in p–n junction diode. The electrical properties of the lateral p–n junction diodes were investigated at room temperature to 773 K. The devices show normal diode characteristics at all temperatures. A very low leakage current <10−14 A in the reverse bias was obtained at room temperature, resulting in a high rectification ratio of 108. Although the rectification ratio decreases with increasing temperature, it possesses 106 even at 573 K. A breakdown voltage was examined to be more than 100 V.
Computational simulation of the p‐n doped silicon quantum dot
Authors: Chen Jiangchao , Schmitz Andrew , Kilin Dmitri S.
Published: August 2012

Elongated crystalline silicon quantum dot (QD) codoped with aluminum and phosphorous together has been modeled with a formula of Si36Al1P1H42. The calculations of electronic structure are done by VASP software in the basis of plane waves, and valent electrons are treated explicitly while core electrons are described with pseudopotentials. Compared with undoped model, Si38H42, the results show the features in the electronic structure of the codoped QD of lowest unoccupied molecular orbital and highest occupied molecular orbital contributed by dopants, and transitions between those bands make contributions to many properties different from undoped model. The role of thermal motion of ions was also explored at (i) high and (ii) ambient temperatures. (i) At high temperature, the thermal motion of ions leads to the break of crystal structure. (ii) At ambient temperatures, the motion of ions facilitates the nonadiabatic couplings between electronic states. The relevant electronic dynamics also calculated with computed nonadiabatic couplings. This simulation predicts the charge transfer across p‐n junction on atomistic scale. © 2012 Wiley Periodicals, Inc.
Novel theoretical studies of the dehydrogenation of LiBH2NH3
Authors: Wang Kun , Zhang Jian‐Guo , Man Tian‐Tian , Wu Man , Zhang Shao‐Wen , Zhang Tong‐Lai , Yang Li
Published: August 2012

It is believed that the dehydrogenation of LiNH2BH3 (LAB) proceeds through a combination of the decomposition of the LiBH2NH3 (LBA) and LAB isomers. The dehydrogenation of LBA, an isomer of LAB, is discussed in this article. It is demonstrated that the loss of H2 from LBA takes place in a two‐step reaction. Studies of the dehydrogenation process were performed using Møller–Plesset second‐order perturbation theory with a 6‐311++G(3df,2pd) basis set. The intrinsic reaction coordinate was calculated to determine the minimum energy paths. Finally, the rate constants were obtained using the transition‐state theory (TST), TST/Eckart, canonical variational transition‐state theory (CVT), CVT/small‐curvature tunneling correction, and CVT/zero‐curvature tunneling correction methods from 200 to 2500 K. This is the first report on a different dehydrogenation mechanism for an alkali‐metal amidoborane, and the energy barrier of LBA is much lower than that of the traditionally studied LAB. © 2012 Wiley Periodicals, Inc.
Current‐density functional study of the HeH+ molecular ion under a strong ultrashort magnetic field
Authors: Vikas
Published: August 2012

The HeH+ molecular ion under an ultrashort magnetic field on the order of 109 G is investigated through quantum fluid dynamics and a current‐density functional theory (CDFT) based approach, employing a vector exchange–correlation (XC) potential which depends on the electronic charge‐density as well as on the current‐density. The behavior of the exchange and correlation energies of the HeH+ ion is analyzed and compared with those obtained using an approach based on the time‐dependent density functional theory (TD‐DFT) under similar computational constraints but employing a scalar XC potential dependent only on the electronic charge‐density. The CDFT‐based approach yields exchange and correlation energies as well as TD electronic charge‐densities drastically different from those obtained using the TD‐DFT‐based approach particularly, at typical TD magnetic field strengths. This is attributed to the nonadiabatic effects induced by the vector XC potential of the CDFT in the oscillating charge‐density of the HeH+ ion, which are further explained in the terminology of quantum fluid dynamics. The vector XC potential of the CDFT‐based approach is observed to augment the magnetic interactions in the H2 molecule and in the He ion, whereas it opposes the magnetic interactions in the HeH+ ion particularly, at the intermediate magnetic field strengths. © 2012 Wiley Periodicals, Inc.
Density functional theory study of Aun (n = 1–5) clusters supported on montmorillonite
Authors: Briones‐Jurado Claudia , de la Mora Pablo , Agacino‐Valdés Esther
Published: August 2012

The adsorption and nucleation of gold clusters Aun (n = 1–5) on montmorillonite (MMT) is studied using the density functional theory. All the calculations were performed using the full‐potential linearized augmented‐plane‐wave method as implemented in the WIEN2k code. We constructed a MMT supercell of formula Si16Al6Mg2O40(OH)8 containing four unit cells and the first moments of the nucleation process were studied by adding the gold atoms one by one on the MMT. The results show that the interaction energies between the gold clusters and the MMT are negative indicating that the Aun–MMT complexes are stable. In the Aun–MMT systems (n = 3–5), two gold atoms maintain the coordination with basal oxygens and the AuO distance was about 2.0–2.3 Å. The AuAu average distance is 2.6 Å in the supported gold clusters. The formation of the second layer of gold atoms occurs upon the arrival of the third gold atom. We are reporting that the transition of 2D → 3D gold cluster structures is located from Au3 to Au4 on MMT. The total density of states of clusters Au, Au2, Au3, Au4, and Au5 on MMT allows us to affirm that (i) gold atoms are the main contributors to the states closest to the Fermi level and (ii) in Au4–MMT and Au5–MMT systems, the main contributors to the states closest to the Fermi level are the most external gold atoms, and therefore these atoms are probably the most susceptible to interact with adsorbates and the most active sites. Odd–even oscillations in the values of the energy gap and interaction energy were found: the odd‐numbered supported clusters, Au3 and Au5, have larger energy gaps and more negative interaction energies. © 2012 Wiley Periodicals, Inc.
On independent sets in hypergraphs
Authors: Kostochka Alexandr , Mubayi Dhruv , Verstraëte Jacques
Published: August 2012

The independence number of a hypergraph H is the size of a largest set of vertices containing no edge of H. In this paper, we prove that if Hn is an n‐vertex ‐uniform hypergraph in which every r‐element set is contained in at most d edges, where , then

urn:x-wiley::media:rsa20453:rsa20453-math-0004

where satisfies as . The value of cr improves and generalizes several earlier results that all use a theorem of Ajtai, Komlós, Pintz, Spencer and Szemerédi (J Comb Theory Ser A 32 (1982), 321–335). Our relatively short proof extends a method due to Shearer (Random Struct Algorithms 7 (1995), 269–271) and Alon (Random Struct Algorithms 9 (1996), 271–278). The above statement is close to best possible, in the sense that for each and all values of , there are infinitely many Hn such that

urn:x-wiley::media:rsa20453:rsa20453-math-0010

where depends only on r. In addition, for many values of d we show as , so the result is almost sharp for large r. We give an application to hypergraph Ramsey numbers involving independent neighborhoods.Copyright © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 44, 224‐239, 2014
Asymptotic normality of the size of the giant component in a random hypergraph
Authors: Bollobás Béla , Riordan Oliver
Published: August 2012

Recently, we adapted random walk arguments based on work of Nachmias and Peres, Martin‐Löf, Karp and Aldous to give a simple proof of the asymptotic normality of the size of the giant component in the random graph G(n,p) above the phase transition. Here we show that the same method applies to the analogous model of random k ‐uniform hypergraphs, establishing asymptotic normality throughout the (sparse) supercritical regime. Previously, asymptotic normality was known only towards the two ends of this regime. © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 2012
Two propensity score‐based strategies for a three‐decade observational study: investigating psychotropic medications and suicide risk
Authors: Leon Andrew C. , Demirtas Hakan , Li Chunshan , Hedeker Donald
Published: August 2012

The US Food and Drug Administration issued separate warnings for suicidality with antidepressants and antiepileptic drugs in the past 5 years. This study describes methods for examining the association of these agents with suicide attempts and suicide deaths in more broadly generalizable samples than examined by the US Food and Drug Administration. An observational study of mood disorders was examined that includes three decades of prospective assessments. Because of sample size differences, two distinct longitudinal implementations of the propensity adjustment are used in separate analyses of antidepressants and antiepileptic drugs. Propensity score quintile‐stratified safety analyses were used with the large antidepressant data set; whereas, propensity score matched safety analyses were used with the smaller antiepileptic drug data because stratification was not feasible. In each case, mixed‐effects survival models compared the safety of participants when receiving the respective class of medication to periods when they did not receive that medication. When participants were more severely ill, they were significantly more likely to receive either class of psychotropics. Propensity quintile‐stratified safety analyses found that risk of suicide attempts or suicides was significantly reduced when participants received antidepressants. In contrast, propensity score matched safety analyses found neither significant risk nor protection from suicidality among participants receiving antiepileptics. Copyright © 2012 John Wiley & Sons, Ltd.
Absolute risk regression for competing risks: interpretation, link functions, and prediction
Authors: Gerds Thomas A. , Scheike Thomas H. , Andersen Per K.
Published: August 2012

In survival analysis with competing risks, the transformation model allows different functions between the outcome and explanatory variables. However, the model's prediction accuracy and the interpretation of parameters may be sensitive to the choice of link function. We review the practical implications of different link functions for regression of the absolute risk (or cumulative incidence) of an event. Specifically, we consider models in which the regression coefficients β have the following interpretation: The probability of dying from cause D during the next t years changes with a factor exp(β) for a one unit change of the corresponding predictor variable, given fixed values for the other predictor variables. The models have a direct interpretation for the predictive ability of the risk factors. We propose some tools to justify the models in comparison with traditional approaches that combine a series of cause‐specific Cox regression models or use the Fine–Gray model. We illustrate the methods with the use of bone marrow transplant data. Copyright © 2012 John Wiley & Sons, Ltd.