bluuebunny/crossref_metadata_2025 huggingface dataset:
Bone marrow transplant options and preferences in a sickle cell anemia cohort on chronic transfusions
Authors: Hansbury Eileen N. , Schultz William H. , Ware Russell E. , Aygun Banu
Published: August 2011

Background

Bone marrow transplantation (BMT) using human leukocyte antigen (HLA)‐matched sibling donors can be curative for children with sickle cell anemia (SCA). However, minimal data exist regarding availability of HLA‐identical matched siblings for transplant‐eligible children, and family interest in pursuing transplantation.

Methods

We retrospectively analyzed a pediatric SCA cohort receiving chronic transfusions between July 2004 and January 2011. Data were analyzed regarding the number of full siblings and half‐siblings, availability, and family interest in HLA testing the full siblings, and interest in proceeding with HLA‐matched transplantation.

Results

Among 113 patients, 46 (41%) had at least 1 full sibling and 40 (35%) had an unaffected full sibling who could serve as a BMT donor. The families of 23 of these patients (58%) agreed to HLA‐type sibling, 8 of whom (35%) were matched. Transfusion indications for families agreeing to HLA typing included stroke (46%) abnormal TCD (29%), acute chest syndrome (21%), and other CNS reasons (4%). Common reasons to decline HLA typing or transplantation included fear of the process, toxicities of the procedure, and comfort with current quality of life on transfusions. Only 8 of 113 (7%) were eligible for matched BMT, and only 3 (3%) underwent HLA‐matched transplantation. Two unmatched children received haploidentical transplantation.

Conclusions

Most families of children with SCA on chronic transfusions choose to proceed with HLA typing. However, when a matched sibling was identified, most families declined to proceed with matched‐sibling transplantation. Discussing BMT as a treatment option, offering HLA typing and identifying barriers may improve acceptance of this treatment modality. Pediatr Blood Cancer 2012; 58: 611–615. © 2011 Wiley Periodicals, Inc.
EPR spectroscopic and computational characterization of the 2‐dehydro‐m‐xylylene and 4‐dehydro‐m‐xylylene triradicals
Authors: Neuhaus Patrik , Winkler Michael , Sander Wolfram
Published: August 2011

The isomeric 2‐dehydro‐ and 4‐dehydro‐1,3‐benzoquinodimethanes, 18 and 19, were generated by irradiation of the corresponding triiodo compounds in cryogenic argon matrices and characterized by electron paramagnetic resonance spectroscopy. In agreement with multireference computations, both systems possess quartet ground states, whereas in the isomeric 5‐dehydro‐m‐xylylene 20 the 2B2 doublet state lies energetically below the 4B2 state, so that no characteristic quartet signals could be observed for this triradical under similar experimental conditions. The best estimates for the adiabatic doublet–quartet energy splittings (CAS(7,7)‐AQCC/cc‐pVTZ//CAS(9,9)‐RS2c/cc‐pVTZ) of 18–20 are 10.4, 7.7, and −1.3 kcal/mol, respectively. The measured zero‐field splitting parameters of 18 and 19 are discussed in terms of the contributions of carbenoid resonance structures (spin polarization of the π‐system) to the resonance hybrid of the title triradicals. Copyright © 2011 John Wiley & Sons, Ltd.
Value of three‐dimensional power Doppler to predict clinical and histological response to neoadjuvant chemotherapy in locally advanced cervical carcinoma
Authors: Qin J. , Cheng X. , Chen X. , Zhang X. , Lu W. , Xie X.
Published: August 2011

Objective

Platinum‐based neoadjuvant chemotherapy followed by radical hysterectomy is an alternative therapeutic strategy for locally advanced cervical carcinoma but variables used to predict chemotherapy response are not well defined. We investigated the potential of three‐dimensional (3D) power Doppler in predicting response to neoadjuvant chemotherapy.

Methods

We enrolled 61 eligible patients with locally advanced cervical carcinoma who underwent neoadjuvant chemotherapy followed by surgery or radiation. Before the initial chemotherapy, we measured 3D power Doppler vascular indices, including vascularization index (VI), flow index (FI) and vascularization flow index (VFI), of the whole cervical carcinoma. We also measured two‐dimensional (2D) hemodynamic parameters, such as resistance index and pulsatility index, at three random spots inside the tumor. The associations of all parameters with clinical and histological responses to chemotherapy were evaluated through univariable and multiple logistic regression analysis.

Results

The clinical and histological response rates to chemotherapy were 70.5% and 70.7%, respectively. Univariable logistic regression analysis showed that VI, FI and VFI were significantly higher in clinical responders than in non‐responders (P < 0.05), and that FI was significantly higher in histological responders (P = 0.012). Multiple logistic regression analysis showed that FI was the only significant factor associated with both clinical and histological responses. The best FI cut‐off values were 35.3 and 37.3 for clinical response and histological response, respectively (with sensitivity 86.0% and 73.2%, and specificity 72.2% and 64.7%). Interestingly, none of the 2D hemodynamic parameters was significantly correlated with either response.

Conclusion

FI is a potential marker for predicting both clinical and histological responses to chemotherapy in patients with locally advanced cervical carcinoma. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Protection against Nippostrongylus brasiliensis infection in mice is independent of GM‐CSF
Authors: Shim Doris S C , Schilter Heidi C , Knott Michelle L , Almeida Ranni A , Short Robert P , Mackay Charles R , Dent Lindsay A , Sewell William A
Published: August 2011

Granulocyte macrophage‐colony stimulating factor (GM‐CSF) is a cytokine with the capacity to promote inflammation in a wide variety of infectious and inflammatory diseases. These conditions include allergic airway inflammation, which is driven by T‐helper 2 (Th2) cells. Because of the importance of Th2 cells in parasite infections, we have investigated the role of GM‐CSF in mice infected with the nematode Nippostrongylus brasiliensis. The effect of primary and secondary infection was investigated in mice lacking functional genes for GM‐CSF (CSF2 genes) (ΔGM‐CSF mice), and in mice lacking the cytokine receptor common β chain (Δβ mice), the latter being unable to signal in response to GM‐CSF and interleukin (IL)‐5. ΔGM‐CSF mice showed no significant defect in parasite immunity, measured by larval numbers in the lungs, worm numbers in the intestine or egg numbers in the faeces, in either primary or secondary infection. By contrast, the Δβ mice showed increased parasite burden, with higher numbers of lung larvae after secondary infection and higher numbers of intestinal worms and faecal eggs after both primary and secondary infection. Unexpectedly, there were increased numbers of circulating eosinophils in the ΔGM‐CSF mice, associated with significantly reduced larval numbers in the lungs. These results indicate that GM‐CSF is redundant in protection against N. brasiliensis infection, and that the increased susceptibility of Δβ mice to infection is likely to be attributed to the lack of IL‐5 signalling in these mice. The results suggest that clinical use of agents that neutralise GM‐CSF may not be associated with increased risk of parasite infection.
Remarkable patterns of surface water ordering around polarized buckminsterfullerene
Authors: Chopra Gaurav , Levitt Michael
Published: August 2011

Accurate description of water structure affects simulation of protein folding, substrate binding, macromolecular recognition, and complex formation. We study the hydration of buckminsterfullerene, the smallest hydrophobic nanosphere, by molecular dynamics simulations using a state-of-the-art quantum mechanical polarizable force field (QMPFF3), derived from quantum mechanical data at the MP2/aug-cc-pVTZ(-hp) level augmented by CCSD(T). QMPFF3 calculation of the hydrophobic effect is compared to that obtained with empirical force fields. Using a novel and highly sensitive method, we see polarization increases ordered water structure so that the imprint of the hydrophobic surface atoms on the surrounding waters is stronger and extends to long-range. We see less water order for empirical force fields. The greater order seen with QMPFF3 will affect biological processes through a stronger hydrophobic effect.
Treatment experiences of children and adolescents with attention‐deficit/hyperactivity disorder
Authors: Leggett Catherine , Hotham Elizabeth
Published: August 2011

Aim:  To gain insight into the treatment experiences of children and adolescents diagnosed with attention‐deficit/hyperactivity disorder (ADHD).

Methods:  Convenience sampling was used to recruit eligible parents and carers at paediatric clinics of the Children's, Youth and Women's Health Service to participate in an interview to discuss experiences, using a semi‐structured questionnaire.

Results:  Thirty‐five interviews were conducted. Twenty‐five subjects had trialled an average of 1.5 interventions prior to receiving an ADHD diagnosis, namely, dietary modifications (46%), behavioural therapy (24%), learning assistance (8%) and natural remedies (8%). Following an ADHD diagnosis, 25 subjects tried an average of 2.8 interventions, most commonly behavioural therapies (48%), expressive therapies (48%) and fish oil (36%). All subjects started psychostimulant medication after receiving an ADHD diagnosis. Despite 52% of parents expressing initial reluctance towards psychostimulants, 97% reported positive experiences with use in terms of schooling, social interaction and family life. Of those being treated with psychostimulants, 22 (73%) were concurrently using other treatments at the time of interview.

Conclusions:  Few patients use psychostimulant medication in isolation, with the majority of parents using multiple approaches to manage their child's behaviour. Parents tried a variety of therapies before commencing psychostimulant medication, often because of fears regarding psychostimulant safety. Parents were generally happy with the results gained; however adolescents interviewed were less convinced of the benefits of psychostimulants.
Positional Accuracy of TIGER 2000 and 2009 Road Networks
Authors: Zandbergen Paul A. , Ignizio Drew A. , Lenzer Kathryn E.
Published: August 2011

The Topologically Integrated Geographic Encoding and Referencing (TIGER) data are an essential part of the US Census and represent a critical element in the nation's spatial data infrastructure. TIGER data for the year 2000, however, are of limited positional accuracy and were deemed of insufficient quality to support the 2010 Census. In response the US Census Bureau embarked on the MAF/TIGER Accuracy Improvement Project (MTAIP) in an effort to improve the positional accuracy of the database, modernize the data processing environment and improve cooperation with partner agencies. Improved TIGER data were released for the entire US just before the 2010 Census. The current study characterizes the positional accuracy of the TIGER 2009 data compared with the TIGER 2000 data based on selected road intersections. Three US counties were identified as study areas and in each county 100 urban and 100 rural sample locations were selected. Features in the TIGER 2000 and 2009 data were compared with reference locations derived from high resolution natural color orthoimagery. Results indicate that TIGER 2009 data are much improved in terms of positional accuracy compared with the TIGER 2000 data, by at least one order of magnitude across urban and rural areas in all three counties for most accuracy metrics. TIGER 2009 is consistently more accurate in urban areas compared with rural areas, by a factor of at least two for most accuracy metrics. Despite the substantial improvement in positional accuracy, large positional errors of greater than 10 m are relatively common in the TIGER 2009 data, in most cases representing remnant segments of minor roads from older versions of the TIGER data. As a result, based on the US Census Bureau's suggested accuracy metric, the TIGER 2009 data meet the accuracy expectation of 7.6 m for two of the three urban areas but for none of the three rural areas. The suggested metric is based on the National Standard for Spatial Data Accuracy (NSSDA) protocol and was found to be very sensitive to the presence of a small number of very large errors. This presents challenges during attempts to characterize the accuracy of TIGER data or other spatial data using this protocol.
Protective effects of a magnesium magnetic isotope (Mg25)‐exchanging nanoparticle (25MgPMC16) on mitochondrial functional disorders in esmolol‐induced cardiac arrest in rats
Authors: Adeli S. , Zarrindast M. R. , Niknahad H. , Sarkar S. , Bidgoli S. A. , Korani M. , Ghasemzadeh P. , Rezayat S. M.
Published: August 2011

1 In cardiac surgery, agents are needed to produce temporary cardiac arrest (cardioplegia). One of these agents is esmolol (ESM) which is a short‐acting selective beta‐1 adrenergic receptor antagonist and its overdose causes diastolic ventricular arrest.

2 The 25MgPMC16 (porphyrin adducts of cyclohexil fullerene‐C60) is known as a nanoparticle which has a cardioprotective effect when the heart is subjected to stressful conditions.

3 In this study, we aimed to confirm the deleterious effects of ESM overdose on cardiac mitochondria and identify any protective effects of 25MgPMC16 in male Wistar rats. Esmolol 100 mg kg−1 (LD50 = 71 mg kg−1) was injected intravenously (i.v.) into tail vein to induce cardiac arrest. This dose was obtained from an ESM dose–response curve which induces at least 80% arrest in rats.

4 25MgPMC16 at three different doses (45, 90 and 224 mg kg−1) was injected i.v. as pretreatment, eight hours before ESM injection. 25MgCl2 or 24MgPMC16 were used as controls. Following cardiac arrest, the heart was removed and the mitochondria extracted. Mitochondrial viability and the adenosine 5′‐diphosphate sodium salt hydrate/Adenosine 5′‐triphosphate disodium salt hydrate (ADP/ATP) ratio were measured as biomarkers of mitochondrial function.

5 Results indicate that 25MgPMC16 caused a significant increase in mitochondrial viability and decrease in ADP/ATP ratio. No significant changes were seen with 24MgPMC16 or 25MgCl2. It is concluded that cardiac arrest induced by ESM overdose leads to a significant decrease in mitochondrial viability and their ATP levels, whereas pretreatment by 25MgPMC16 can protect mitochondria by increasing ATP level through liberation of Mg into cells and the improvement of hypoxia.
The Endothelium Modulates the Arterial Wall Mechanical Response to Intra‐Aortic Balloon Counterpulsation: In Vivo Studies
Authors: Bia Daniel , Cabrera‐Fischer Edmundo I. , Zócalo Yanina , Armentano Ricardo L.
Published: August 2011

Intra‐aortic balloon pump (IABP) benefits could depend on variations in the cardiovascular biomechanical properties associated with blood flow‐induced endothelium‐dependent changes. However, if IABP results in changes in the peripheral artery biomechanics and if the endothelium plays a role in these potential changes remains unknown. The aim of this study is to characterize acute IABP effects on peripheral artery biomechanics in control and acute heart failure (AHF) states and the role of the endothelium in IABP effects on peripheral artery biomechanics. Pressure and diameter were recorded in sheep (n= 7) iliac arteries (IAs), before and during 1:2 IABP, during four states: (i) control with intact IA; (ii) AHF with intact IA; (iii) control with de‐endothelialized (DE) (mechanical rubbing) IA; and (iv) AHF with DE IA. Arterial distensibility, elastic modulus, and conduit function (CF) (1/characteristic impedance) were calculated. The results of this study include: (i) during control conditions, IABP resulted in intact IA dilatation, stiffness reduction, and CF increase; (ii) AHF induction determined a reduction in intact IA diameter and CF, and a stiffness increase. These changes reverted during IABP; (iii) the increase in IA stiffness observed after DE remained unchanged during IABP; (iv) in DE IA, AHF did not result in diameter or stiffness changes; and (v) IABP during AHF did not associate changes in diameter or stiffness in the DE IA. In conclusion, during control and AHF states, IABP results in IA dilatation and stiffness reduction. The integrity of the endothelial layer would be critical for the IABP‐associated changes in IA biomechanics.
Narratives of Sexual Consent and Coercion: Forced Prostitution Trials in Progressive-Era New York City
Authors: Donovan Brian , Barnes-Brus Tori
Published: August 2011

This article analyzes testimony about forced prostitution voiced in New York City's Court of General Sessions from 1908 to 1915. During these years, the problem of coercive prostitution—commonly called “white slavery”—received an unprecedented amount of attention from journalists, politicians, and antivice activists. Drawing from verbatim transcripts of compulsory-prostitution trials, our research examines the relationship between cultural narratives and courtroom storytelling. We show how the white slavery narrative in popular culture oriented prosecutors, defense attorneys, judges, and jurors in prostitution trials. Extending the account of social control in the sociological literature on antivice activism, our analysis shows that the prosecution of forced prostitution was not simply a top-down exercise of juridical power. Using insights from conversation analysis and cultural history, an examination of compulsory-prostitution cases reveals a quadripartite storytelling process where judges and jurors—with different orientations to the white slavery narrative—played a constitutive role in how the defense and prosecution argued their cases.
Acid Test
Authors: Wong Wei
Published: August 2011

Survival signaling downstream of a neurotrophin receptor requires a ligand that can bind stably under acidic conditions.
Automatically assessing the ABCs
Authors: Black Matthew P. , Kazemzadeh Abe , Tepperman Joseph , Narayanan Shrikanth S.
Published: August 2011

Automatic literacy assessment is an area of research that has shown significant progress in recent years. Technology can be used to automatically administer reading tasks and analyze and interpret children's reading skills. It has the potential to transform the classroom dynamic by providing useful information to teachers in a repeatable, consistent, and affordable way. While most previous research has focused on automatically assessing children reading words and sentences, assessments of children's earlier foundational skills is needed. We address this problem in this research by automatically verifying preliterate children's pronunciations of English letter-names and the sounds each letter represents (“letter-sounds”). The children analyzed in this study were from a diverse bilingual background and were recorded in actual kindergarten to second grade classrooms. We first manually verified (accept/reject) the letter-name and letter-sound utterances, which serve as the ground-truth in this study. Next, we investigated four automatic verification methods that were based on automatic speech recognition techniques. We attained percent agreement with human evaluations of 90% and 85% for the letter-name and letter-sound tasks, respectively. Humans agree between themselves an average of 95% of the time for both tasks. We discuss the various confounding factors for this assessment task, such as background noise and the presence of disfluencies, that impact automatic verification performance.
Duality Property for Positive Weak Dunford‐Pettis Operators
Authors: Aqzzouz Belmesnaoui , Bouras Khalid , Moussa Mohammed
Published: August 2011

We prove that an operator is weak Dunford‐Pettis if its adjoint is one but the converse is false in general, and we give some necessary and sufficient conditions under which each positive weak Dunford‐Pettis operator has an adjoint which is weak Dunford‐Pettis.
In vitro Study on Hepatitis B Virus Infecting Human Choriocarcinoma JEG3 Cells and Its Mechanism
Authors: Ding Yang , Ma Li , Wang Xin-zhu , Zhang Jian , Zhao Gui-zhen , Wang Zhao-quan , Dou Xiao-guang
Published: August 2011

Aim: To build a hepatitis B virus (HBV)-infected human trophoblast cell model in vitro and determine the mechanism of intrauterine HBV infection. Methods: Serum from hepatitis B-infected patients containing HBV DNA >109 was drawn, subsequently inoculated into human trophoblast cells in vitro (JEG3) and passage-cultured. The supernatants and intracellular HBV viral load of inoculated cells were tested by real-time PCR, and HBV DNA was determined by Southern blot. Results: From inoculation of the 1st passage JEG3 cells, the supernatant viral load of the 1st passage was seen increasing over time, which peaked at 120 h, whereas the HBV viral load was seen decreasing gradually in subsequent passages, and tested negative after the 6th passage. In addition, infected cells of HBV DNA were tested by Southern blot, and showed continual expression in the subsequent cell passages 1–5 while passage 6 was negative. HBsAg was tested as positive from different passages 1–5, and its concentration was also seen decreasing with each subsequent passage cultured until the 6th passage when it tested negative. Conclusion: HBV could infect human trophoblast cells (JEG3) in vitro, and it showed continual expression in subsequent cell passages 1–5.
Gene expression profiling of human whole blood samples with the Illumina WG-DASL assay
Authors: Winn Mary E , Shaw Marian , April Craig , Klotzle Brandy , Fan Jian-Bing , Murray Sarah S , Schork Nicholas J
Published: August 2011

Background

Microarray-based gene expression analysis of peripheral whole blood is a common strategy in the development of clinically relevant biomarker panels for a variety of human diseases. However, the results of such an analysis are often plagued by decreased sensitivity and reliability due to the effects of relatively high levels of globin mRNA in whole blood. Globin reduction assays have been shown to overcome such effects, but they require large amounts of total RNA and may induce distinct gene expression profiles. The Illumina whole genome DASL assay can detect gene expression levels using partially degraded RNA samples and has the potential to detect rare transcripts present in highly heterogeneous whole blood samples without the need for globin reduction. We assessed the utility of the whole genome DASL assay in an analysis of peripheral whole blood gene expression profiles.

Results

We find that gene expression detection is significantly increased with the use of whole genome DASL compared to the standard IVT-based direct hybridization. Additionally, globin-probe negative whole genome DASL did not exhibit significant improvements over globin-probe positive whole genome DASL. Globin reduction further increases the detection sensitivity and reliability of both whole genome DASL and IVT-based direct hybridization with little effect on raw intensity correlations. Raw intensity correlations between total RNA and globin reduced RNA were 0.955 for IVT-based direct hybridization and 0.979 for whole genome DASL.

Conclusions

Overall, the detection sensitivity of the whole genome DASL assay is higher than the IVT-based direct hybridization assay, with or without globin reduction, and should be considered in conjunction with globin reduction methods for future blood-based gene expression studies.
Functional neural correlates of reduced physiological falls risk
Authors: Nagamatsu Lindsay S , Hsu Chun Liang , Handy Todd C , Liu-Ambrose Teresa
Published: August 2011

Background

It is currently unclear whether the function of brain regions associated with executive cognitive processing are independently associated with reduced physiological falls risk. If these are related, it would suggest that the development of interventions targeted at improving executive neurocognitive function would be an effective new approach for reducing physiological falls risk in seniors.

Methods

We performed a secondary analysis of 73 community-dwelling senior women aged 65 to 75 years old who participated in a 12-month randomized controlled trial of resistance training. Functional MRI data were acquired while participants performed a modified Eriksen Flanker Task - a task of selective attention and conflict resolution. Brain volumes were obtained using MRI. Falls risk was assessed using the Physiological Profile Assessment (PPA).

Results

After accounting for baseline age, experimental group, baseline PPA score, and total baseline white matter brain volume, baseline activation in the left frontal orbital cortex extending towards the insula was negatively associated with reduced physiological falls risk over the 12-month period. In contrast, baseline activation in the paracingulate gyrus extending towards the anterior cingulate gyrus was positively associated with reduced physiological falls risk.

Conclusions

Baseline activation levels of brain regions underlying response inhibition and selective attention were independently associated with reduced physiological falls risk. This suggests that falls prevention strategies may be facilitated by incorporating intervention components - such as aerobic exercise - that are specifically designed to induce neurocognitive plasticity.

Trial Registration

ClinicalTrials.gov Identifier: NCT00426881
Concept of Information as a Bridge between Mind and Brain
Authors: Schroeder Marcin J.
Published: August 2011

The article is focused on the special role of the concept of information understood in terms of the one-many categorical opposition in building a bridge between mind and brain. This particular choice of the definition of information allows unification of the main two manifestations of information implicitly present in literature, the selective and the structural. It is shown that the concept of information formulated this way together with the concept of information integration can be used to explain the unity of conscious experience, and furthermore to resolve several fundamental problems such as understanding the experiential aspect of consciousness without getting into homunculus fallacy, defending free will from mechanistic determinism, and explaining symbolic representation and aesthetical experience. The dual character of selective and structural manifestations opens the way between the orthodox information scientific description of the brain in terms of the former, and description of mind in terms of the latter.
An Object-Based Classification Approach for Mapping Migrant Housing in the Mega-Urban Area of the Pearl River Delta (China)
Authors: D'Oleire-Oltmanns Sebastian , Coenradie Bodo , Kleinschmit Birgit
Published: August 2011

Urban areas develop on formal and informal levels. Informal development is often highly dynamic, leading to a lag of spatial information about urban structure types. In this work, an object-based remote sensing approach will be presented to map the migrant housing urban structure type in the Pearl River Delta, China. SPOT5 data were utilized for the classification (auxiliary data, particularly up-to-date cadastral data, were not available). A hierarchically structured classification process was used to create (spectral) independence from single satellite scenes and to arrive at a transferrable classification process. Using the presented classification approach, an overall classification accuracy of migrant housing of 68.0% is attained.
Single Versus Bi-Directional (Reversal) Gear Tooth Bending Stress and Life (S-N) Evaluation
Authors: Chen Joe
Published: August 2011

The significant gear fatigue bending life variation between the single directional versus bi-directional loading had been observed over the decades, but very limit information has been revealed. To gain the comprehend understanding of this subject for practical usages, the author thus first tried to apply the conventional popular fatigue theories to evaluate the difference, but in vein. This report is to describe the course of assessment and also propose a new method to minimize the discrepancy between the theoretical and test results.
The Design of RODS Software on the Basis of Transmission Machinery Robust Optimal Designing System
Authors: Zhang Hui Xia , Lu Xin Chun , Lu Long
Published: August 2011

On the basis of theory research and transmission machinery robust optimal designing system, a new software RODS for structural parameters optimal design is developed with C programming language, by which the complex calculation is fulfilled with computer automatically. This software is easy to understand, and it also can fulfill the optimal design of gear pump structural parameters quickly and efficiently.
Study on Ultrasonic Lapping System of Spiral Bevel Gear
Authors: Yang Jian Jun , Wei Bing Yang , Deng Xiao Zhong , Fang Zong De
Published: August 2011

Based on non-smooth impact theory, the dynamic model of spiral bevel gear is constructed by considering of input shaft angle excitation. The Maximal Lyapunov Exponents (MLEs) curves for backlash 0.10mm and 0.14mm caused by exciting amplitude are given. The simulation results indicate that gear backlash, excited amplitude and retard torque have influence on the dynamics behavior of spiral bevel gear system. The experiments show that the vibration noise is deduced after ultrasonic gear lapping.
Quantitative Evaluation of Aero Spiral Bevel Gear Meshing Quality
Authors: Jiang Ping , Liu Guang Lei , Zhang Rui Ting , Wang Chong Qing
Published: August 2011

In order to precisely control the meshing performance of spiral bevel gear pair, this paper represents a quantitative evaluation method using transmission error curve and tooth face contact trace. The design, using local synthesis method, obtains the manufacturing parameters of gear pair and forms the tooth face of spiral bevel gear. This paper accomplishes the quantitative evaluation by the following methods: using tooth contact analysis (TCA) to obtain actual transmission error curve and tooth face contact trace; quantitatively evaluating the transmission error curve by comparing the web values of actual and preset theoretical transmission error curves; quantitatively evaluating the tooth face contact trace by comparing the requirements (such as in shape, size and position) defined for spiral bevel gear tooth face contact trace and the corresponding parameters of an externally-connected rectangle, which surrounds the tooth face contact trace and is used to describe tooth face contact trace. This paper conducts a meshing performance analysis and quantitative evaluation of an aero spiral bevel gear pair. The result shows that, the actual and preset theoretical transmission error curves are basically in coincidence and the tooth face contact trace meets the requirements. This quantitative evaluation method lays a foundation for analyzing the relationship between transmission error curve and tooth face contact trace and for analyzing the installation error sensitivity.
Design and Analysis for High-Speed Gear Coupling
Authors: Lei Xue Mei , Ge Yu Zhu , Zhang Yue Chun , Liu Ping
Published: August 2011

Based on the analysis of application, this paper explains and enriches the design criteria of high-speed gear coupling. New design idea and method of calculating the geometry and parameters are provided respectively according to structure. The strength, lubrication and stability of high-speed gear coupling are simply analyzed.
The Research on General Modeling Methods of the Complicated Transmission Based on Hypergraph Theory
Authors: Xiang Chang Le , Zhang Ying Ying , Liu Hui , Cui Meng
Published: August 2011

In order to be adapt to the increasingly large complex transmission modeling, this paper propose methods of building generalized modeling through applying hypergraph theory to the complex fixed axis transmission, the planetary gear transmission and the integrated transmission. The author established conversion rules between the real transmission to hypergraph, and found feasibility algorithm for relay route auto search. Hypergraph theory can be further used to realize automatic generation of general dynamics model.
Study of Bearing Modelling in the Helicopter Gearbox
Authors: Zamponi Laurent , Mermoz Emmanuel , Linares Jean Marc
Published: August 2011

In trying to incessantly reduce gearboxes weight, designers can negatively impact the service reliability, particularly in the aeronautic industry, where a weight reduction is often linked with stiffness decrease. Looking for weight savings, gearbox casings are classically made of magnesium or aluminium alloy. In addition, helicopter gearbox design is included the integration of several functions within the same part (like the shafts which gather one or more gears, splines and integrated bearings raceways). These particularities in the design are requiring some specific methodologies for Power Transmission bearing modelling. In this paper, a comparison between tests and simulations results of the aforementioned gearboxes is presented. The first section of the article focuses on the helicopter gearbox description and associated finite elements modelling. Then, the second section provides a comparison between the experimental observations with the results of both FEM simulation and classical analytical simulation. This comparison demonstrates the interest of using FEM simulation to analyze gearboxes behaviour.
Original Research on Logarithmic Spiral Bevel Gear
Authors: Yan Hong Bo , Li Qiang , Wei Zi Liang , Wu Shu Qin
Published: August 2011

In this article, logarithmic spiral curve is successfully applied to bevel gear transmission and used as dentiform line of helicoid bevel gear. Put forward a novel logarithmic spiral bevel gear drive. Because spiral angle on each point of logarithmic spiral curve is constant, the problem of variational spiral angle is solved faultlessly. Analyze the basic characteristics of logarithmic spiral curve and demonstrates the condition of the logarithmic spiral curve used as pitch curve. Put forward the new kind of transmission form of logarithmic spiral bevel gear and it makes up the deficiency in current bevel gear transmission area.
A Fuzzy Logic Based Rocket Launch Tube’s DFMEA
Authors: Pornpibunsompop Tosapolporn , Charoenpon Attapon , Pankaew Ekaratch
Published: August 2011

DFMEA is a significantly efficient tool to systematically evaluate risk in early stage of product design and development but some of knowledge and information are uncertain and imprecise. This research focuses on fuzzy logic approach to diminish weaknesses and applies to launch tube’s DFMEA. The methodology started from determine membership function of severity, occurrence, and detection and provide fuzzy rule base to arranged category of risk. Afterwards, center average index was selected as defuzzifier for risk value representation. Consequently, the prioritization based on risk value was done and chosen the first five risk value of potential failure modes to analyze causes then recommended appropriate actions. After application of fuzzy logic approach, the most vital potential failure mode is damaged launch tube due to detention force which is rated as first and second priority depending on potential cause or mechanism. The third priority is launch tube distortion. The mechanical load calculation and proper material selection are the recommended actions for overcoming those potential failure modes.
Mechanical Strain for 0.16 µm nMOSFET on 30 µm Si-Substrate
Authors: Kao H. L. , Ke J. Y. , Chen M. T. , Lee Y. C. , Yeh C. S. , Shih S. P.
Published: August 2011

This paper reports the successful substrate transfer based on standard IC processing to an alternative substrate e.g. plastic. The device on ultra-thin Si substrate using grinding backside Si and thermo-compression bonding process is proposed. Acceptable electrical performances are achieved means that the substrate transfer process is controlled well. The DC characteristics of nMOSFETs as a function of orientations and device sizes under mechanical strain are also reported. Good performance and reliability of nMOSFETs under mechanical strain is obtained. The results suggest the feasibility of substrate transfer in achieving well-performance nMOSFETs for 3D integration or SiP technologies.
Effect of Amount of Cutting Fluid on Surface Finish of Turned Parts
Authors: Islam M.N.
Published: August 2011

This paper presents the experimental and analytical results of the effect that the amount of cutting fluid has on the surface finish of turned parts. The experiments were planned using Taguchi’s orthogonal array methodology. A three-level, four-parameter orthogonal array (L81) was selected for designing the experiments. The selected four input parameters are cutting speed, feed rate, depth of cut, and amount of cutting fluid. Mild steel AISI 1030 was chosen as the work material. A total of 81 experimental runs were conducted, and the surface roughness parameter arithmetic average was measured offline using a surface finish analyzer. Subsequently, the results were analyzed applying three methods—traditional analysis, Pareto ANOVA, and the Taguchi method. The results indicate that the amount of cutting fluid has a negligible effect on surface finish. However, the interaction between the two major contributors—cutting speed and feed rate—is influenced noticeably by the amount of cutting fluid.
Study on Improved Tabu Search Algorithm for Min-Max Vehicle Routing Problem
Authors: Ren Chun Yu
Published: August 2011

The paper is focused on the Min-Max Vehicle Routing Problem. And solve this type of problems utilizing improved tabu search algorithm from the overall situation. According to the features of the problem, the essay centered the longest route to construct neighborhood structure. For the operation, 1-exchange and 2-opt* were applied, it can also fasten the speed of convergence, and boost the search efficiency. Finally, the good performance of this algorithm can be proved by experiment calculation and concrete examples.
Preparation of Nano Rice-Husk Ash and Effect on the Water-Resistance of Magnesium Oxychloride Composites
Authors: Xu Ke Jing , Xi Jin Tao , Guo Yan Qing
Published: August 2011

A new method to improve the water-resistance of magnesium oxychloride composites (MOCs), with the addition of nano rice-husk ash (RHA), was studied. The related properties of samples were characterized by scanning electron microscope (SEM) and Brunauer Emmett and Teller (BET). The phase composition of MOCs was determined by X-ray diffraction (XRD). The water-resistance of MOCs was estimated by calculating softening coefficients. The experiments show that the particles size of nano RHA prepared is about 50nm, and the SiO2content is 92.30 %; a suitable amount of nano RHA to MOCs obviously increases the water-resistance without reducing the bending strength of MOCs, and increases the softening coefficient from 0.29 to 0.78.
Self-Assembly Proton Exchange Membranes for Direct Methanol Fuel Cell with Size-Controlled Au Nanoparticles
Authors: Jin Ai Ping , Wan Zhao Hui , Lei Kai Chen
Published: August 2011

Charged Au nanoparticles with various diameters, from 2.7 nm to 10.3 nm, were synthesized by using various reducing agents. Then charged Au nanoparticles were self-assembled onto the NafionTM membrane surface as methanol barriers. It was found that the proton exchange membrane self-assembled with 3.9 nm Au particles had the lowest methanol crossover. The proton conductivity decreased with the increase of the particles size until the particles size was more than 6.2 nm and they had little influence on the membrane conductivity. All the self-assembled membranes have higher open circuit voltage (OCV) and performance than original Nafion212TM membrane. And the membranes self-assembled with 3.9 nm poly (diallymethylammonium chloride) (PDDA) modified Au (PDDA-Au) particles had the highest performance due to the reciprocal of the methanol permeation current density and membrane area resistance.
Conducting Polymer Functionalized Single-Walled Carbon Nanotubes: Synthesis, Morphological Characteristics and Thermal Stability
Authors: Niu Hong Mei
Published: August 2011

Nanocomposites of single-walled carbon nanotubes modified polypyrrole (PPy/SWNTs) were synthesized successfully by in situ oxidative polymerization method in the FeCl3·6H2O solution. The morphological structure, electrical conductivity and thermal stability of the nanocomposites were characterized by TEM, SEM, FTIR and TGA. The PPy/SWNTs were 50-100 nm in diameter of PPy coating uniformly on the surface of the SWNTs. FTIR spectra revealed the presence of covalently interaction between the PPy and the carbon nanotubes. The electrical conductivity of PPy/SWNTs composite and pure PPy were 93 and 8.0×10-3 S/cm, respectively. Meanwhile, the PPy/SWNTs composites possessed higher thermal stability (65.9 wt. % weight loss at 600 °C) compared to pure PPy (81.2 wt. % weight loss at 600°C), the content of SWNTs was 15.3 wt. %.
Carbon Nanotubes-Doped Glassy Carbon Ceramic Composite Electrode and its Electrocatalytic Reduction of Nitrite
Authors: Sun Dan Zi
Published: August 2011

A conductive glassy carbon ceramic composite electrode (GCCE) comprised of multi-walled carbon nanotubes (MWNTs) and glassy carbon microparticles in an organically modified silicate matrix was fabricated using a sol-gel method. The electrode thus prepared exhibits electrocatalytic behavior to the reduction of nitrite and facilitates the detection of nitrite at an applied potential of 0.0 V. A linear range from 2.5×10-5 to 3×10-3 M for the detection of sodium nitrite has been observed at the composite electrode with a sensitivity of 9.6 μA/mM and a detection limit of 9×10-6 M based on a signal-to-noise ratio of 3.
Characterization and Properties of Sol-Gel-Derived Polyurethane Acrylate/Silica Hybrid Materials
Authors: Yang Ze Hui , Wang Ji Hui , Ji Yun Dong , Yin Yan Zi
Published: August 2011

Novel organic –inorganic nanocomposite hybrid materials have been prepared by a sol-gel process. Tetraethoxysilane (TEOS) was used as inorganic source. Polyurethane acrylate (PUA) was the organic segment. 3-(trimethoxysilyl)propyl methacrylate (KH-570) was used as both a secondary inorganic source and a silane coupling agent to improve the compatibility of the organic and inorganic phases. X-ray diffraction indicates that silica was equally dispersed in polymer matrix. Furthermore, silica and polymer formed interpenetrating polymer network. Thermal property of the hybrid materials were checked by TGA study.
CdSe Quantum Dots Decorated by 3-Aminobenzeneboronic Acid as Fluorescence Probe for Glucose
Authors: Wang Shao Wei , Zhang Xia Ona , Yu Jing Hua
Published: August 2011

A simple route to the production of high-quality CdSe quantum dots (QDs) is presented. The characterization of CdSe QDs was measured by Zetasizer Nano ZS, ultraviolet-visible spectoscopy and fluorospectrophotometer. The CdSe QDs were decorated by 3-Aminobenzeneboronic acid to obtain good fluorescent characteristic. Under the optimal conditions, the decreased normalized absorbance was linear to the concentration of glucose from 1.0×10−7 to 2.9×10−6 mol·L-1with a detection limit of 5.0´10-8mol·L-1. The relative standard deviation (RSD) for the determination of 1.0×10-7mol·L-1was 1.4 % by 11 replicate determination. In this paper, the fluorescent behavior of glucose with the decorated CdSe QDs was studied, and it is found that the system has a high sensitivity and selectivity for analysis of glucose.
Preparation of a Novel Poly-Silicic-Ferric Coagulant from Fly Ash Extract
Authors: Tan Juan , Yu Yan Zhen , Sun Yong
Published: August 2011

In this paper, a novel inorganic polymer coagulant was prepared by fly ash extract. The technology of preparing the poly-silicic-ferric coagulant by using fly ash extract and potassium ferrate has been designed. The influences of alkali concentration, temperature and heating time on the amount of silicon dissolution from fly ash were investigated. When temperature is 60°C, concentration of NaOH is 1.8mol / L and heating time responses to 38 hours, the content of silicon in the fly ash extract is better than that of the others. The effects of pH and Si/FeO42- mole ratio on morphology of the prepared coagulant were investigated by transmission electron microscopy (TEM). The results indicate that poly-silicic-ferric coagulant can be obtained when regulation of filtrate to pH about 1.4 with dilute sulfuric acid and Si/FeO42- mole ratio is about 3.5. At the same time, through the flocculation experiments of using the poly-silicic-ferric synthesized disposing of the model bentonite suspension, turbidity removal has been up to 90% more in the condition of low dosage.
Extraction Behavior of Scandium Cation in Ion Liquid Extraction System Using 1-Butyl-3-Methyl-Imidazolium Hexafluorophosphate and 2-Ethylhexyl Phosphonic Acid-2-Ethylhexyl Ester
Authors: Pan Zhong Wei , Li Guo Qing , Lin Liang Bao
Published: August 2011

The extraction behavior of scandium ion (Sc3+) was investigated using 1-butyl-3-methyl -imidazolium hexafluorophosphate ([Bmim]PF6­) ionic liquid as extraction solvent and 2-ethylhexyl phosphonic acid-2-ethylhexyl ester (P507, HA) as extractant. The extractablity of Sc3+ using [Bmim]PF6­ was less than 5% without P507. When the initial P507 concentration in IL phase was 0.2 mol/L, percentage extraction of 5×10-5 mol·L-1 Sc3+ exceeded 99%. The results showed that the extracted species in the Sc3+­-P507-[Bmim]PF6 system was neutral ScA3 and [Bmim]PF6 solvent could be used repeatedly.
Study on the Preparation and Mechanical Properties of Polystyrene/Y2O3 Composites
Authors: Dou Yan Li , Zhang Chun Ling , Sun Guoen , Xu Wen Hui
Published: August 2011

Rare earth yttria (Y2O3) reinforced polystyrene composites were prepared by melt blending process. Mechanical properties, wear resistance of the PS/Y2O3 composites were characterized in contrast to neat PS. The improvement of the mechanical properties and wear resistance was attributed to the reinforcing effect of Y2O3 powder. Well distribution of Y2O3 powder in the PS matrix and good interfacial bonding were achieved by pretreated of Y2O3 using titanate coupling and dispersant followed by calcinations process. Results indicated that both of the Y2O3 powder pretreatment process and melt blending process have significant effects on the composite properties. When the Y2O3 content were 2.8wt%, the modify effect to PS was optimal. When the Y2O3 calcined at 900°C was used, the impact of the composites were best, other performance improvements have also been good. When the Y2O3 content of 1.4wt%, the wear resistance of the composites were best.
The Magnetism of DNA Molecular Materials
Authors: Wang Yong Juan , Cheng Jie , Yue Xian Fang , Liu De Sheng
Published: August 2011

In this paper, the atomic magnetic moments and spin-splittings of the six-member ring N2C4 cluster with planar and folding configurations in DNA bases are studied, respectively. The results show that the surprising interplay between the molecular structure and their magnetic property. In the planar configuration, the cluster exhibits antiferromagnetism and ferromagnetism in the ground state and metastable state, respectively. In the folding configuration, it exhibits antiferromagnetism and ferrimagnetism in the ground state and metastable state, respectively.
High Temperature Electrochemical Synthesis of Tungsten Boride from Molten Salt
Authors: Cao Xiao Zhou , Wang Hui Ying , Meng Xi , Wang Chao , Yang He , Xue Xiang Xin
Published: August 2011

High temperature electrochemical synthesis of tungsten boride has been performed in KF-KCl melts with B2O3 and WO3 used as reactants at 1033K. The cathode product was investigated in the current density range 0.4A/cm2-0.6A/cm2 and characterized by means of XRD analyses and SEM. The results indicated that cathode product is mainly consist of W2B5 and WB4, the powders are fine (＜0.5um). Current density exert a great effect on the phase composition, particle size and morphology of the cathode product.