bluuebunny/crossref_metadata_2025 huggingface dataset:
Distinct Roles of Candida albicans Drug Resistance Transcription Factors
TAC1
,
MRR1
, and
UPC2
in Virulence
Authors: Lohberger Andrea , Coste Alix T. , Sanglard Dominique
Published: November 2013

Azoles are widely used in antifungal therapy in medicine. Resistance to azoles can occur in
Candida albicans
principally by overexpression of multidrug transporter gene
CDR1
,
CDR2
, or
MDR1
or by overexpression of
ERG11
, which encodes the azole target. The expression of these genes is controlled by the transcription factors (TFs)
TAC1
(involved in the control of
CDR1
and
CDR2
),
MRR1
(involved in the control of
MDR1
), and
UPC2
(involved in the control of
ERG11
). Several gain-of-function (GOF) mutations are present in hyperactive alleles of these TFs, resulting in the overexpression of target genes. While these mutations are beneficial to
C. albicans
survival in the presence of the antifungal drugs, their effects could potentially alter the fitness and virulence of
C. albicans
in the absence of the selective drug pressure. In this work, the effect of GOF mutations on
C. albicans
virulence was addressed in a systemic model of intravenous infection by mouse survival and kidney fungal burden assays. We engineered a set of strains with identical genetic backgrounds in which hyperactive alleles were reintroduced in one or two copies at their genomic loci. The results obtained showed that neither
TAC1
nor
MRR1
GOF mutations had a significant effect on
C. albicans
virulence. In contrast, the presence of two hyperactive
UPC2
alleles in
C. albicans
resulted in a significant decrease in virulence, correlating with diminished kidney colonization compared to that by the wild type. In agreement with the effect on virulence, the decreased fitness of an isolate with
UPC2
hyperactive alleles was observed in competition experiments with the wild type
in vivo
but not
in vitro
. Interestingly,
UPC2
hyperactivity delayed filamentation of
C. albicans
after phagocytosis by murine macrophages, which may at least partially explain the virulence defects. Combining the
UPC2
GOF mutation with another hyperactive TF did not compensate for the negative effect of
UPC2
on virulence. In conclusion, among the major TFs involved in azole resistance, only
UPC2
had a negative impact on virulence and fitness, which may therefore have consequences for the epidemiology of antifungal resistance.
Renal failure: unusual clinical presentation of an isolated intrarenal hydatid cyst
Authors: Nadeem Mehwash , Biyabani Syed Raziuddin , Pervez Shahid
Published: November 2013

Cystic echinococcosis or hydatid disease is a zoonotic parasitic infection caused by larval stage of cestodeEchinococcusspp. Humans are an accidental intermediate host and present with the involvement of different organs, the liver being the most common while kidney is the rarest site. Here, authors are reporting a case of a 55-year-old woman who presented with renal failure and was found to have a right-sided intrarenal hydatid cyst, diagnosed and treated with nephroscopy without sacrificing the kidney. She had an uneventful postoperative course and her renal function improved dramatically. She is now on oral albendazole therapy and doing well on follow-up. To the best of our knowledge, renal failure has never been reported in the literature as clinical manifestation of intrarenal hydatid cyst in adult population.
The association of cycling with all-cause, cardiovascular and cancer mortality: findings from the population-based EPIC-Norfolk cohort
Authors: Sahlqvist Shannon , Goodman Anna , Simmons Rebecca K , Khaw Kay-Tee , Cavill Nick , Foster Charlie , Luben Robert , Wareham Nicholas J , Ogilvie David
Published: November 2013

Objectives

To investigate associations between modest levels of total and domain-specific (commuting, other utility, recreational) cycling and mortality from all causes, cardiovascular disease and cancer.

Design

Population-based cohort study (European Prospective Investigation into Cancer and Nutrition study-Norfolk).

Setting

Participants were recruited from general practices in the east of England and attended health examinations between 1993 and 1997 and again between 1998 and 2000. At the first health assessment, participants reported their average weekly duration of cycling for all purposes using a simple measure of physical activity. At the second health assessment, participants reported a more detailed breakdown of their weekly cycling behaviour using the EPAQ2 physical activity questionnaire.

Participants

Adults aged 40–79 years at the first health assessment.

Primary outcome measure

All participants were followed for mortality (all-cause, cardiovascular and cancer) until March 2011.

Results

There were 22 450 participants with complete data at the first health assessment, of whom 4398 died during follow-up; and 13 346 participants with complete data at the second health assessment, of whom 1670 died during follow-up. Preliminary analyses using exposure data from the first health assessment showed that cycling for at least 60 min/week in total was associated with a 9% reduced risk of all-cause mortality (adjusted HR 0.91, 95% CI 0.84 to 0.99). Using the more precise measures of cycling available from the second health assessment, all types of cycling were associated with greater total moderate-to-vigorous physical activity; however, there was little evidence of an association between overall or domain-specific cycling and mortality.

Conclusions

Cycling, in particular for utility purposes, was associated with greater moderate-to-vigorous and total physical activity. While this study provides tentative evidence that modest levels of cycling may reduce the risk of mortality, further research is required to confirm how much cycling is sufficient to induce health benefits.
Percutaneous sclerotherapy with ethanolamine oleate for venous malformations of the head and neck
Authors: Alexander Matthew David , McTaggart Ryan A , Choudhri Omar A , Marcellus Mary L , Do Huy M
Published: November 2013

Introduction

Venous malformations frequently occur in the head and neck, and they can require treatment for a variety of reasons. Among multiple therapeutic approaches employed, percutaneous sclerotherapy has become one of the most commonly used treatments, with numerous sclerosants successfully utilized. Ethanolamine oleate has approval from the Food and Drug Administration for sclerosis of esophageal varices, and is used by some practitioners for the treatment of venous malformations. This study reports single center results of percutaneous sclerotherapy with ethanolamine oleate to treat venous malformations of the head and neck.

Materials and methods

Prospectively maintained procedural records were retrospectively reviewed to identify all patients with venous malformations who underwent percutaneous sclerotherapy. The Mulliken and Glowacki classification was used to diagnose venous malformations. Medical records and images were reviewed to record demographic information, lesion characteristics, treatment sessions, and clinical and imaging response. Quantitative volumetric analysis was conducted to augment commonly used poorly reproducible subjective outcome measures. Response was assessed after each session and completion of all percutaneous treatment. A χ2analysis was performed to evaluate the effects of the above described characteristics on outcomes.

Results

52 interventions were performed for lesions in 26 patients. No complications occurred following any procedures. Response to individual sessions was categorized as excellent following two (3.8%) sessions, good following 45 (86.5%), and fair following four (7.7%) session. No sessions resulted in poor responses. Final results were excellent in two patients (7.7%), good in 22 (84.6%), and fair in two (7.7%). Average lesion volume reduction was 39% following each session, and 61% after treatment completion. Periorbital lesions were significantly less likely than lesions located elsewhere to have good or excellent outcomes. No other lesion or demographic features affected outcomes.

Conclusions

Percutaneous sclerotherapy with ethanolamine oleate appears to be safe and effective for the treatment of venous malformations and should be considered when treating these complex lesions. The efficacy of this agent appears to match or exceed that of other sclerosants used for such treatment, and further investigation in prospective controlled research is warranted.
Evolving gonococcal antimicrobial resistance: research priorities and implications for management
Authors: Hook Edward W , Van Der Pol Barbara
Published: November 2013

The combination of continually increasing minimum inhibitory concentration values, and outright resistance to the currently available treatments forNeisseria gonorrhoeae,and the paucity of new drugs in the developmental pipeline raises questions that require concentrated research attention at both the microbiologic and programme levels. Here, we describe the need for research related to the mechanisms of resistance, strategies to reduce or prevent the development of resistance and the need for optimal surveillance using local, national and global data.
Berberine Reduces Rat Intestinal Tight Junction Injury Induced by Ischemia–Reperfusion Associated with the Suppression of Inducible Nitric Oxide Synthesis
Authors: Gu Lili , Li Ning , Yu Wenkui , Gong Jianfeng , Li Qiurong , Zhu Weiming , Li Jieshou
Published: November 2013

Berberine (BBR) has been shown to attenuate the deleterious effects of ischemia/reperfusion (I/R) injury in the brain. We evaluated the effects of BBR on intestinal tight junction (TJ) changes during mesenteric I/R. I/R was induced in rats by the occlusion of the superior mesenteric artery and reperfusion. The rats were randomized into four groups: control, BBR, I/R, and I/R + BBR. Intestinal permeability was determined by the lactulose/mannitol test. The ileum and colon were harvested to assess mucosal injury and inducible nitric oxide synthase activity. The TJ ultrastructure was studied by transmission electron microscopy. The expressions and locations of the TJ proteins, occludin and ZO-1, in the epithelium were investigated by immunofluorescence microscopy. We also used Western blot analysis to detect the distribution of TJ proteins in lipid raft fractions. Our results suggest that I/R-induced intestinal TJ dysfunction can be improved by BBR, thereby demonstrating the therapeutic potential of BBR for intestinal I/R.
Neuroprotective Effects of Lycium chinense Miller Against Rotenone-Induced Neurotoxicity in PC12 Cells
Authors: Im A-Rang , Kim Young-Hwa , Uddin Md Romij , Chae Sungwook , Lee Hye Won , Kim Yeong Shik , Lee Mi Young
Published: November 2013

Rotenone, an inhibitor of mitochondrial complex I, has been widely regarded as a neurotoxin because it induces a Parkinson's disease-like syndrome. The fruit and root bark of Lycium chinense Miller have been used as traditional medicines in Asia to treat neurodegenerative diseases. In this study, we examined the neuroprotective effects of Lycium chinense Miller extracts in rotenone-treated PC12 cells. Treatment with rotenone reduced PC12 cell viability and cellular ATP levels. Conversely, caspase 3/7 activity, the ratio of Bax:Bcl-2 expression levels, mitochondrial superoxide level, and intracellular calcium (Ca2+) concentration were elevated. Pretreatment with Lycium chinense Miller extracts significantly increased cell viability and ATP levels. Additionally, they attenuated caspase activation, mitochondrial membrane depolarization and mitochondrial superoxide production. Moreover, confocal microscopy showed that the mitochondrial staining pattern was restored from that of extracts treated cells and that the increase in intracellular Ca 2+ level was blunted by treatment with the extracts. Our results suggest that Lycium chinense Miller extracts may have the possible beneficial effects in Parkinson's disease by attenuating rotenone induced toxicity.
Effects of Tetramethylpyrazine on Microglia Activation in Spinal Cord Compression Injury of Mice
Authors: Shin Jung-Won , Moon Ja-Young , Seong Ju-Won , Song Sang-Hoon , Cheong Young-Jin , Kang Chulhun , Sohn Nak-Won
Published: November 2013

Secondary mechanisms, including inflammation and microglia activation, serve as targets for the development and application of pharmacological strategies in the management of spinal cord injury (SCI). Tetramethylpyrazine (TMP), an active ingredient of Ligusticum wallichii (chuanxiong), has shown anti-inflammatory and neuroprotective effects against SCI. However, it remains uncertain whether the inflammation-suppressive effects of TMP play a modulatory role over microglia activation in SCI. The present study investigated the effects of TMP on microglia activation and pro-inflammatory cytokines in spinal cord compression injury in mice. For a real-time PCR measurement of pro-inflammatory cytokines, SCI was induced in mice by the clip compression method (30 g force, 1 min) and TMP (15 or 30 mg/kg, i.p.) was administered once, 30 minutes before the SCI induction. For immunohistochemistry, TMP (30 mg/kg, i.p.) treatment was given three times during the first 48 hours after the SCI. 30 mg/kg of TMP treatment reduced the up-regulation of TNF-α, IL-1β and COX-2 mRNA in the spinal tissue at four hours after the SCI induction. TMP also significantly attenuated microglia activation and neutrophil infiltration at 48 hours after the SCI induction. In addition, iNOS expression in the spinal tissue was attenuated with TMP treatment. These results suggest that TMP plays a modulatory role in microglia activation and may protect the spinal cord from or potentially delay secondary spinal cord injury.
Influence of Six Medicinal Herbs on Collagenase-Induced Osteoarthritis in Rats
Authors: Nirmal Pallavi , Koppikar Soumya , Bhondave Prashant , Narkhede Aarti , Nagarkar Bhagyashri , Kulkarni Vinayak , Wagh Narendrakumar , Kulkarni Omkar , Harsulkar Abhay , Jagtap Suresh
Published: November 2013

Medicinal herbs have been effectively used for their anti-inflammatory activity, but their exact role has not yet been documented in scientific literature for the management of Osteoarthritis (OA). Since Sida cordifolia L., Piper longum L., Zingiber officinale Rosc., Ricinus communis L., Vitex negundo L. and Tribulus terrestris L. have been widely used in traditional medicine for their anti-inflammatory activity, to evaluate anti-osteoarthritic activity of these herbs, we used a collagenase type II-induced osteoarthritis (CIOA) rat model. Arthritis was induced in wistar rats by intra-articular injection of collagenase type II. Powders of herbs were given orally for 20 days as a suspension in water (270 mg/kg b. wt.). The effects of the treatment in the rats were monitored by physiological parameters like body weight, knee diameter, paw retraction, paw volume, glycosaminoglycan (GAG) release, radiography and histopathology of knee joint. Selected herbs have significantly prevented body weight loss and knee swelling compared to arthritic control (CIOA). All test groups, including indomethacin (standard drug, 3 mg/kg), significantly reduced paw volume compared to CIOA. GAG release in the serum was significantly lowered in herb treated groups compared to indomethacin. The anterior posterior radiographs of S. cordifolia and P. longum treated groups showed a protective effect against OA. Histopathology revealed protection in the structure of the articular cartilage and in chondrocyte pathology as well as reduced clefting. Treatment with herbs has shown chondroid matrix within normal limits. From the results, we observed that S. cordifolia and P. longum possess potent anti-osteoarthritic activity.
Interaction of Rhubarb and Methotrexate in Rats: In Vivo and Ex Vivo Approaches
Authors: Shia Chi-Sheng , Juang Shin-Hun , Tsai Shang-Yuan , Lee Chao Pei-Dawn , Hou Yu-Chi
Published: November 2013

Rhubarb, the rhizome of Rheum palmatum L. (RP), is a popular herb used in Chinese medicine prescriptions. RP contains a variety of polyphenolic anthraquinones, such as aloe-emodin, rhein, emodin and chrysophanol. Our previous study found that the anthraquinones in RP existed predominantly as glucuronides/sulfates in the bloodstream, which were putative substrates of MRPs. Methotrexate (MTX) is a widely used immunosuppressant and anticancer agent, but it has a narrow therapeutic index. The transcellular transport of MTX is mediated by multidrug resistance associated proteins (MRPs). This study investigated the effects of coadministration of RP on MTX pharmacokinetics in rats. The possible involvement of MRP 2 was verified by using cell models and various typical MRP 2 substrates. The results showed that coadministration of 0.5 mg/kg of RP significantly increased the AUC 0-t and MRT of MTX by 307% and 364%, and 1.0 g/kg of RP significantly increased the AUC 0-t and MRT of MTX by 602% and 419%, respectively. Cell line studies indicated that the activity of MRP 2 was inhibited by the metabolites of RP and rhein. In conclusion, concomitant administration of RP markedly increased the systemic exposure of MTX via inhibiting MRP 2-mediated excretion.
DIRAC POINTS, TOPOLOGICAL EDGE MODES AND NONRECIPROCAL TRANSMISSION IN ONE-DIMENSIONAL METAMATERIAL-BASED COUPLED-CAVITY ARRAYS
Authors: YANNOPAPAS VASSILIOS
Published: November 2013

We show that topological frequency band structures emerge in one-dimensional (1D) electromagnetic (EM) lattices of metamaterial components without the application of an external magnetic field. Such lattices can be cavity arrays coupled with metamaterial elements which generate alternate positive and negative-phase hopping strengths. The topological nature of the band structure manifests itself by the occurrence of Dirac points in the band structure, by the emergence of edge modes in finite arrays as well as by a nonreciprocal scattering spectrum. Specific EM designs for demonstrating the above phenomena are discussed.
OPTICAL RESONATOR ANALOG OF A PHOTONIC TOPOLOGICAL INSULATOR: A FINITE-DIFFERENCE TIME-DOMAIN STUDY
Authors: LIANG G. Q. , CHONG Y. D.
Published: November 2013

A periodic lattice of optical ring resonators can act as a photonic topological insulator, with the role of spin played by the direction of propagation of light within each ring. Using finite-difference time-domain (FDTD) simulations, we compute the projected band diagram of the system and its transmission spectrum, and demonstrate the existence of the topological edge states. The FDTD results are in good agreement with the predictions of transfer matrix theory.
WEAK LIMITS FOR QUANTUM WALKS ON THE HALF-LINE
Authors: LIU CHAOBIN , PETULANTE NELSON
Published: November 2013

For a discrete two-state quantum walk (QW) on the half-line with a general condition at the boundary, we formulate and prove a weak limit theorem describing the terminal behavior of its transition probabilities. In this context, localization is possible even for a walk predicated on the assumption of homogeneity. For the Hadamard walk on the half-line, the weak limit is shown to be independent of the initial coin state and to exhibit no localization.
An Experimental Method for the Active Learning of Greedy Algorithms
Authors: Velázquez-Iturbide J. Ángel
Published: November 2013

Greedy algorithms constitute an apparently simple algorithm design technique, but its learning goals are not simple to achieve. We present a didactic method aimed at promoting active learning of greedy algorithms. The method is focused on the concept of selection function, and is based on explicit learning goals. It mainly consists of an experimental method and the interactive system, GreedEx, that supports it. We also present our experience of five years using the didactic method and the evaluations we conducted to refine it, which are of two kinds: usability evaluations of GreedEx and analysis of students’ reports. Usability evaluations revealed a number of opportunities of improvement for GreedEx, and the analysis of students’ reports showed a number of misconceptions. We made use of these findings in several ways, mainly: improving GreedEx, elaborating lecture notes that address students’ misconceptions, and adapting the class and lab sessions and materials. As a consequence of these actions, our didactic method currently satisfies its initial goals. The article has two main contributions. First, the didactic method itself can be valuable for computer science educators in their teaching of algorithms. Secondly, the refinement process we have carried out, which was a multifaceted, medium-term action research, can be of interest to researchers of technology-supported computing education, since it illustrates how the didactic method was integrated into our educational practice.
The effect of puberty on fat oxidation rates during exercise in overweight and normal-weight girls
Authors: Chu L. , Riddell M. C. , Schneiderman J. E. , McCrindle B. W. , Hamilton J. K.
Published: November 2013

Excess weight is often associated with insulin resistance (IR) and may disrupt fat oxidation during exercise. This effect is further modified by puberty. While studies have shown that maximal fat oxidation rates (FOR) during exercise decrease with puberty in normal-weight (NW) and overweight (OW) boys, the effect of puberty in NW and OW girls is unclear. Thirty-three NW and OW girls ages 8–18 yr old completed a peak aerobic capacity test on a cycle ergometer. FOR were calculated during progressive submaximal exercise. Body composition and Tanner stage were determined. For each participant, a best-fit polynomial curve was constructed using fat oxidation vs. exercise intensity to estimate max FOR. In a subset of the girls, IR derived from an oral glucose tolerance test ( n = 20), and leptin and adiponectin levels ( n = 11) were assessed in relation to FOR. NW pre-early pubertal girls had higher max FOR [6.9 ± 1.4 mg·kg fat free mass (FFM)−1·min−1] than NW mid-late pubertal girls (2.2 ± 0.9 mg·kg FFM−1·min−1) ( P = 0.002), OW pre-early pubertal girls (3.8 ± 2.1 mg·kg FFM−1·min−1), and OW mid-late pubertal girls (3.3 ± 0.9 mg·kg FFM−1·min−1) ( P < 0.05). Bivariable analyses showed positive associations between FOR with homeostatic model assessment of IR ( P = 0.001), leptin ( P < 0.001), and leptin-to-adiponectin ratio ( P = 0.001), independent of percent body fat. Max FOR decreased in NW girls during mid-late puberty; however, this decrease associated with puberty was blunted in OW girls due to lower FOR in pre-early puberty. The presence of IR due to obesity potentially masks the effect of puberty on FOR during exercise in girls.
Tourist Behavior Pattern Mining Model Based on Context
Authors: Liu Dong-sheng , Fan Shu-jiang
Published: November 2013

Personalized travel experience and service of tourist has been a hot topic research in the tourism service supply chain. In this paper, we take the context into consideration and propose an analyzed method to the tourist based on the context: firstly, we analyze the context which influences the tourist behavior patterns, select the main context factors, and construct the tourist behavior pattern model based on it; then, we calculate the interest degree of the tourist behavior pattern and mine out the rules with high interest degree with the association rule algorithm; we can make some recommendations to the tourist with better personalized travelling experience and services. At last, we make an experiment to show the feasibility and effectiveness of our method.
External Electric Field-Assisted Laser Percussion Drilling for Highly Reflective Metals
Authors: Ho Chao-Ching , Tseng Guan-Ru , Chang Yuan-Jen , Hsu Jin-Chen , Kuo Chia-Lung
Published: November 2013

In this study, an external electric field was employed during the laser percussion drilling on highly reflective materials. The laser-produced plasma was sputtered substantially, and the charged ions in the plasma plume were drawn by the electrodes. Different configurations of plate electrodes were proposed and investigated in this work to provide a simple, low-cost method that allows expelling the laser-induced plasma during the percussion drilling process. The electric field resulted from the potential that was applied across the two electrodes. This electrical perturbation produced a uniform electric field when the laser-generated plasma was created in the plane plate-charged capacitor. The electric field with different electrode configurations applied to the charged particles that are carrying the electrons was also simulated in this work. All processing work was performed in air under standard atmospheric conditions and in the absence of assisting process gas. The depth of the holes drilled when various types of electrode configurations were used was measured, and the results were used to evaluate the percussion drilling rate. Results show that vaporized debris is expelled by the applied electric field; hence, in optimal configuration the penetration depth can be increased by up to 91.1%.
Effect of Exercise on Metabolic Syndrome Variables in Breast Cancer Survivors
Authors: Thomas Gwendolyn A. , Alvarez-Reeves Marty , Lu Lingeng , Yu Herbert , Irwin Melinda L.
Published: November 2013

Objective. Breast cancer survivors are highly sedentary, overweight, or obese, which puts them at increased risk for comorbid chronic disease. We examined the prevalence of, and changes in, metabolic syndrome following 6 months of an aerobic exercise versus usual care intervention in a sample of sedentary postmenopausal breast cancer survivors.Design and Methods. 65 participants were randomized to an aerobic exercise intervention (EX) (n=35) mean BMI 30.8 (±5.9) kg/m2or usual care (UC) (n=30) mean BMI 29.4 (±7.4) kg/m2. Metabolic syndrome prevalence was determined, as well as change in criteria and overall metabolic syndrome.Results. At baseline, 55.4% of total women met the criteria for metabolic syndrome. There was no statistically significant change in metabolic syndrome when comparing EX and UC. However, adhering to the exercise intervention (at least 120 mins/week of exercise) resulted in a significant (P=.009) decrease in metabolic syndromez-score from baseline to 6 months (-0.76±0.36) when compared to those who did not adhere (0.80±0.42).Conclusions. Due to a higher prevalence of metabolic syndrome in breast cancer survivors, lifestyle interventions are needed to prevent chronic diseases associated with obesity. Increasing exercise adherence is a necessary target for further research in obese breast cancer survivors.
Comparison of Structural Properties between Monopile and Tripod Offshore Wind-Turbine Support Structures
Authors: Chen Da , Huang Kai , Bretel Valentin , Hou Lijun
Published: November 2013

Offshore wind power provides a new kind of green energy. This paper presents a comparison study on the structural properties of monopile and tripod wind-turbine support structures, which are used extensively in offshore wind farms. Both structures have the same upper tower, but different lower structures, one with a monopile and the other with a tripod. Static, fatigue, and modal analyses indicate that both the tripod and monopile structures are feasible in the field, but that the tripod structure is superior to the monopile structure. Static analysis reveals that the location of maximum stress in the monopile structure is different from that in the tripod structure, and that the tripod structure shows higher stiffness and greater stress-control capacity than the monopile structure. Fatigue analysis indicates that the tripod structure has a longer lifetime than the monopile structure. Modal analysis indicates that the two structures exhibit large differences in their natural frequencies. Unlike the monopile structure, the third and first modes both have a substantial influence on the dynamic response of the tripod structure.
Novel Optical Fiber Dynamic Light Scattering Measurement System for Nanometer Particle Size
Authors: Chen Zhemin , Hu Pengbing , Meng Qingqiang , Dong Xinyong
Published: November 2013

We present a novel optical fiber dynamic light scattering measurement system for nanometer particle size. A multimode fiber probe is used to highly efficiently couple and deliver laser light, while a single-mode fiber probe is used to only receive single scattering light. This design not only improves the measuring ability of the system but also provides flexibility in choosing scattering angle for measurement. By using this system, four kinds of polystyrene nanoparticles are evaluated. Experimentation shows the measured sizes of the nanoparticles are well consistent with the nominal ones, verifying the feasibility of the system.
Influence of Removable Devices' Heterouse on the Propagation of Malware
Authors: Han Xie , Li Yi-Hong , Feng Li-Ping , Song Li-Peng
Published: November 2013

The effects of removable devices’ heterouse in different areas on the propagation of malware spreading via removable devices remain unclear. As a result, in this paper, we present a model incorporating the heterogeneous use of removable devices, obtained by dividing the using rate into local area’s rate, neighbour area’s rate and global area’s rate, and then getting the final rate by multiplying the corresponding area ratio. The model’s equilibria and their stability conditions are obtained mathematically and verified by deterministic and stochastic simulations. Simulation results also indicate that the heterogeneity in using rate significantly changes the prospective propagation course of malware. Additionally, the thresholds of removable devices’ using rate in neighbour area are given, which can guide us in designing effective countermalware method.
Analysis of the Degradation of MOSFETs in Switching Mode Power Supply by Characterizing Source Oscillator Signals
Authors: Zheng Xueyan , Wu Lifeng , Guan Yong , Li Xiaojuan
Published: November 2013

Switching Mode Power Supply (SMPS) has been widely applied in aeronautics, nuclear power, high-speed railways, and other areas related to national strategy and security. The degradation of MOSFET occupies a dominant position in the key factors affecting the reliability of SMPS. MOSFETs are used as low-voltage switches to regulate the DC voltage in SMPS. The studies have shown that die-attach degradation leads to an increase in on-state resistance due to its dependence on junction temperature. On-state resistance is the key indicator of the health of MOSFETs. In this paper, an online real-time method is presented for predicting the degradation of MOSFETs. First, the relationship between an oscillator signal of source and on-state resistance is introduced. Because oscillator signals change when they age, a feature is proposed to capture these changes and use them as indicators of the state of health of MOSFETs. A platform for testing characterizations is then established to monitor oscillator signals of source. Changes in oscillator signal measurement were observed with aged on-state resistance as a result of die-attach degradation. The experimental results demonstrate that the method is efficient. This study will enable a method to predict the failure of MOSFETs to be developed.
The Effective Use of the Piston Effect, Natural Cold Sources, and Energy Saving in Beijing Subways
Authors: Li Zhenzhen , Chen Chao , Pan Song , Yan Le , Li Kang
Published: November 2013

With the development of the subway, the energy consumption of subway ventilation and air-conditioning systems is increasing rapidly. To solve this problem, this paper describes the environment of a subway station in Beijing subway line no. 2 from July to September, 2011, and uses numerical methods to quantitatively analyze and evaluate the contributions of the subway piston effect and natural outdoor cold sources to energy saving in the air-conditioning system and improvement of the subway environment. The results show that the piston effect can be used for ventilation in each area of the subway station. During summer, part of the subway air-conditioning season, a natural cold source can introduce a cold capacity of 5,100 GJ to the subway station.
Cylinder Position Servo Control Based on Fuzzy PID
Authors: Cai Shibo , Wu Shunlei , Bao Guanjun
Published: November 2013

The arbitrary position control of cylinder has always been the hard challenge in pneumatic system. We try to develop a cylinder position servo control method by combining fuzzy PID with the theoretical model of the proportional valve-controlled cylinder system. The pressure differential equation of cylinder, pressure-flow equation of proportional valve, and moment equilibrium equation of cylinder are established. And the mathematical models of the cylinder driving system are linearized. Then fuzzy PID control algorithm is designed for the cylinder position control, including the detail analysis of fuzzy variables and domain, fuzzy logic rules, and defuzzification. The stability of the proposed fuzzy PID controller is theoretically proved according to the small gain theorem. Experiments for targets position of 250 mm, 300 mm, and 350 mm were done and the results showed that the absolute error of the position control is less than 0.25 mm. And comparative experiment between fuzzy PID and classical PID verified the advantage of the proposed algorithm.
Dynamic Shear Characteristic and Fracture Feature of Inconel 690 Alloy under Different High Strain Rates and Temperatures
Authors: Chen Tao-Hsing , Tsai Chih-Kai , Fang Te-Hua
Published: November 2013

The high strain shear rate behaviour of Inconel 690 alloy was investigated by using the split Hopkinson torsional bar. The shear strain rates were tested at 900 s−1, 1900 s−1, and 2600 s−1and at temperatures of −100°C, 25°C, and 300°C, respectively. It was found that the dynamic shear behaviour of Inconel 690 alloy was sensitive to strain rate and temperature. The fracture shear strain increased with increasing strain rate and temperature. In addition, the strain rate sensitivity was increased with increasing strain and strain rate but decreased with increasing temperature. Finally, the fracture surfaces were found to contain dimple-like features, and the dimple density increased with increasing strain rate and temperature.
Modeling of Stenotic Coronary Artery and Implications of Plaque Morphology on Blood Flow
Authors: Moreno Carlos , Bhaganagar Kiran
Published: November 2013

A diseased coronary artery has been modeled to study the implications of plaque morphology on the fluid dynamics. In our previous study, we have successfully classified the coronary plaques of 42 patients who underwent intravascular ultrasound (IVUS) into four-types (Type I, Type II, Type III, and Type IV) based on the plaque morphology. In this study, we demonstrate that, for the same degree of stenosis (height of the plaques), hemodynamics parameters are strongly dependent on the plaque shape. This study is the first one to clearly demonstrate that in addition to wall shear stress, presence of turbulence and location of transition from laminar to turbulence state are additional hemodynamics parameters to identify plaques vulnerable to rupture.
Existence of Positive Periodic Solutions for a Class of Higher-Dimension Functional Differential Equations with Impulses
Authors: Suping Zhang , Wei Jiang
Published: November 2013

By employing the Krasnoselskii fixed point theorem, we establish some criteria for the existence of positive periodic solutions of a class ofn-dimension periodic functional differential equations with impulses, which improve the results of the literature.
Efficient CUDA Polynomial Preconditioned Conjugate Gradient Solver for Finite Element Computation of Elasticity Problems
Authors: Zhang Jianfei , Zhang Lei
Published: November 2013

Graphics processing unit (GPU) has obtained great success in scientific computations for its tremendous computational horsepower and very high memory bandwidth. This paper discusses the efficient way to implement polynomial preconditioned conjugate gradient solver for the finite element computation of elasticity on NVIDIA GPUs using compute unified device architecture (CUDA). Sliced block ELLPACK (SBELL) format is introduced to store sparse matrix arising from finite element discretization of elasticity with fewer padding zeros than traditional ELLPACK-based formats. Polynomial preconditioning methods have been investigated both in convergence and running time. From the overall performance, the least-squares (L-S) polynomial method is chosen as a preconditioner in PCG solver to finite element equations derived from elasticity for its best results on different example meshes. In the PCG solver, mixed precision algorithm is used not only to reduce the overall computational, storage requirements and bandwidth but to make full use of the capacity of the GPU devices. With SBELL format and mixed precision algorithm, the GPU-based L-S preconditioned CG can get a speedup of about 7–9 to CPU-implementation.
Fourteen Limit Cycles in a Seven-Degree Nilpotent System
Authors: Huang Wentao , Chen Ting , Gu Tianlong
Published: November 2013

Center conditions and the bifurcation of limit cycles for a seven-degree polynomial differential system in which the origin is a nilpotent critical point are studied. Using the computer algebra system Mathematica, the first 14 quasi-Lyapunov constants of the origin are obtained, and then the conditions for the origin to be a center and the 14th-order fine focus are derived, respectively. Finally, we prove that the system has 14 limit cycles bifurcated from the origin under a small perturbation. As far as we know, this is the first example of a seven-degree system with 14 limit cycles bifurcated from a nilpotent critical point.
The Protective Role of Resveratrol against Arsenic Trioxide-Induced Cardiotoxicity
Authors: Zhang Weiqian , Guo Changming , Gao Ruifeng , Ge Ming , Zhu Yanzhu , Zhang Zhigang
Published: November 2013

Arsenic trioxide (As2O3) shows substantial anticancer activity in patients with acute promyelocytic leukemia (APL). Unfortunately, limiting the application of this effective agent to APL patients is severe cardiotoxicity. Resveratrol, the natural food-derived polyphenolic compound, is well known for its antioxidant properties and protects the cardiovascular system. But the potential role of resveratrol against As2O3in heart via nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) is unclear. The present study evaluated the effects of pretreatment with resveratrol and As2O3on oxidative stress and cardiac dysfunction in rat. In the present study, resveratrol decreased As2O3-induced reactive oxygen species generation, oxidative DNA damage, and pathological alterations. In addition, cardiac dysfunction parameters, intracellular calcium and arsenic accumulation, glutathione redox ratio, and cAMP deficiency levels were observed in As2O3-treated rats; these changes were attenuated by resveratrol. Furthermore, resveratrol significantly prohibited the downregulation of both Nrf2 and HO-1 gene expressions that were downregulated by As2O3, whereas resveratrol did not alter As2O3-induced nitric oxide formation. Thus, the protective role of resveratrol against As2O3-induced cardiotoxicity is implemented by the maintenance of redox homeostasis (Nrf2-HO-1 pathway) and facilitating arsenic efflux. Our findings suggest coadministration with resveratrol, and As2O3might provide a novel therapeutic strategy for APL.
Gelucire BasedIn SituGelling Emulsions: A Potential Carrier for Sustained Stomach Specific Delivery of Gastric Irritant Drugs
Authors: Saxena Ashwin , Mishra Arun K. , Verma Navneet , Bhattacharya Shiv S. , Ghosh Amitava , Verma Anurag , Pandit Jayanta K.
Published: November 2013

Non steroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed medications to the geriatric patients for the treatment of arthritis and other painful disorders. The major side effects of NSAIDs are related to their effects on the stomach and bowels. The present study concerns assessment of the potential of liquidin situgelling emulsion formulations (emulgels) as patient compliant stomach specific sustained release carrier for the delivery of highly gastric irritant drug, Piroxicam. Emulgels were prepared, without using any emulgent, by mixing different concentrations of molten Gelucire 39/01 with low viscosity sodium alginate solution prepared in deionized water at 50°C. CaCO3was used as buoyancy imparting as well as crosslinking agent. Emulgels so prepared were homogenous, physically stable, and rapidly formed into buoyant gelled mass when exposed to simulated gastric fluid (SGF, pH 1.2). Drug release studies carried out in SGF revealed significant retardation (P<0.05) of Piroxicam release from emulgels compared to conventionalin situgelling formulations prepared without Gelucire 39/01. Pharmacodynamic studies carried out inalbino ratsrevealed significantly increased analgesic/anti-inflammatory response fromin situemulgels compared to conventionalin situgelling formulations. Further,in vivotoxicity studies carried out inalbino ratsrevealed no signs of gastric ulceration upon prolonged dosing.
A Polynomial Preconditioned Global CMRH Method for Linear Systems with Multiple Right-Hand Sides
Authors: Zhang Ke , Gu Chuanqing
Published: November 2013

The restarted global CMRH method (Gl-CMRH(m)) (Heyouni, 2001) is an attractive method for linear systems with multiple right-hand sides. However, Gl-CMRH(m) may converge slowly or even stagnate due to a limited Krylov subspace. To ameliorate this drawback, a polynomial preconditioned variant of Gl-CMRH(m) is presented. We give a theoretical result for the square case that assures that the number of restarts can be reduced with increasing values of the polynomial degree. Numerical experiments from real applications are used to validate the effectiveness of the proposed method.
External Fractional-Order Gradient Vector Perona-Malik Diffusion for Sinogram Restoration of Low-Dosed X-Ray Computed Tomography
Authors: Hu Shaoxiang
Published: November 2013

Existing fractional-order Perona-Malik Diffusion (FOPMD) algorithms are defined as fully spatial fractional-order derivatives (FSFODs). However, we argue that FSFOD is not the best way for diffusion since different parts of spatial derivative play different roles in Perona-Malik diffusion (PMD) and derivative orders should be decided according to their roles. Therefore, we adopt a novel fractional-order diffusion scheme, named external fractional-order gradient vector Perona-Malik diffusion (EFOGV-PMD), by only replacing integer-order derivatives of “external” gradient vector to their fractional-order counterparts while keeping integer-order derivatives of gradient vector for diffusion coefficients since the ability of edge indicator for 1-order derivative is demonstrated both in theory and applications. Here “external” indicates the spatial derivatives except for the derivatives used in diffusion coefficients. In order to demonstrate the power of the proposed scheme, some real sinograms of low-dosed computed tomography (LDCT) are used to compare the different performances. These schemes include PMD, regularized PMD (RPMD), and FOPMD. Experimental results show that the new scheme has good ability in edge preserving, is convergent quickly, has good stability for iteration number, and can avoid artifacts, dark resulting images, and speckle effect.
Magnetic Retraction of Bowel by Intraluminal Injectable Cyanoacrylate-Based Magnetic Glue
Authors: Wang Zhigang , Brown Andrew , André Pascal , Brown Stuart I. , Florence Gordon J. , Cuschieri Alfred
Published: November 2013

Magnetic retraction offers advantages over physical retraction by graspers because of reduced tissue trauma. The objectives of this study are to investigate a novel method of magnetisation of bowel segments by intraluminal injection of magnetic glue and to demonstrate the feasibility of magnetic retraction of bowel with sufficient force during minimal access surgery. Following an initial materials characterisation study, selected microparticles of stainless steel (SS410-μPs) were mixed with chosen cyanoacrylate glue (Loctite 4014). During intraluminal injection of the magnetic glue usingex vivoporcine colonic segments, a magnetic probe placed at the injected site ensured that the SS410-μPs aggregated during glue polymerisation to form an intraluminal mucosally adherent coagulum. The magnetised colonic segments were retracted by magnetic probes (5 and 10 mm) placed external to the bowel wall. A tensiometer was used to record the retraction force. With an injected volume of 2 mL in a particle concentration of 1 g/mL, this technique produced maximal magnetic retraction forces of 2.24 ± 0.23 N and 5.11 ± 0.34 N (), with use of 5 and 10 mm probes, respectively. The results indicate that the formation of an intraluminal coagulum based on SS410-μPs and Loctite 4014 produces sufficient magnetic retraction for bowel retraction.
Hopf Bifurcation Analysis for a Computer Virus Model with Two Delays
Authors: Zhang Zizhen , Yang Huizhong
Published: November 2013

This paper is concerned with a computer virus model with two delays. Its dynamics are studied in terms of local stability and Hopf bifurcation. Sufficient conditions for local stability of the positive equilibrium and existence of the local Hopf bifurcation are obtained by regarding the possible combinations of the two delays as a bifurcation parameter. Furthermore, explicit formulae for determining direction of the Hopf bifurcation and stability of the bifurcating periodic solutions are obtained by using the normal form method and center manifold theory. Finally, some numerical simulations are presented to support the theoretical results.
Reachability and Controllability of Fractional Singular Dynamical Systems with Control Delay
Authors: Zhang Hai , Cao Jinde , Jiang Wei
Published: November 2013

This paper is concerned with the reachability and controllability of fractional singular dynamical systems with control delay. The factors of such systems including the Caputo’s fractional derivative, control delay, and singular coefficient matrix are taken into account synchronously. The state structure of fractional singular dynamical systems with control delay is characterized by analysing the state response and reachable set. A set of sufficient and necessary conditions of controllability for such systems are established based on the algebraic approach. Moreover, an example is provided to illustrate the effectiveness and applicability of the proposed criteria.
Uncertainty Quantification and Bifurcation Analysis of an Airfoil with Multiple Nonlinearities
Authors: Liao Haitao
Published: November 2013

In order to calculate the limit cycle oscillations and bifurcations of nonlinear aeroelastic system, the problem of finding periodic solutions with maximum vibration amplitude is transformed into a nonlinear optimization problem. An algebraic system of equations obtained by the harmonic balance method and the stability condition derived from the Floquet theory are used to construct the general nonlinear equality and inequality constraints. The resulting constrained maximization problem is then solved by using the MultiStart algorithm. Finally, the proposed approach is validated, and the effects of structural parameter uncertainty on the limit cycle oscillations and bifurcations of an airfoil with multiple nonlinearities are studied. Numerical examples show that the coexistence of multiple nonlinearities may lead to low amplitude limit cycle oscillation.
Lagrangian Duality for Multiobjective Programming Problems in Lexicographic Order
Authors: Hu X. F. , Wang L. N.
Published: November 2013

This paper deals with a constraint multiobjective programming problem and its dual problem in the lexicographic order. We establish some duality theorems and present several existence results of a Lagrange multiplier and a lexicographic saddle point theorem. Meanwhile, we study the relations between the lexicographic saddle point and the lexicographic solution to a multiobjective programming problem.