bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathophysiology of myocardial reperfusion injury: preconditioning, postconditioning, and translational aspects of protective measures
Authors: Sanada Shoji , Komuro Issei , Kitakaze Masafumi
Published: August 2011

Heart diseases due to myocardial ischemia, such as myocardial infarction or ischemic heart failure, are major causes of death in developed countries, and their number is unfortunately still growing. Preliminary exploration into the pathophysiology of ischemia-reperfusion injury, together with the accumulation of clinical evidence, led to the discovery of ischemic preconditioning, which has been the main hypothesis for over three decades for how ischemia-reperfusion injury can be attenuated. The subcellular pathophysiological mechanism of ischemia-reperfusion injury and preconditioning-induced cardioprotection is not well understood, but extensive research into components, including autacoids, ion channels, receptors, subcellular signaling cascades, and mitochondrial modulators, as well as strategies for modulating these components, has made evolutional progress. Owing to the accumulation of both basic and clinical evidence, the idea of ischemic postconditioning with a cardioprotective potential has been discovered and established, making it possible to apply this knowledge in the clinical setting after ischemia-reperfusion insult. Another a great outcome has been the launch of translational studies that apply basic findings for manipulating ischemia-reperfusion injury into practical clinical treatments against ischemic heart diseases. In this review, we discuss the current findings regarding the fundamental pathophysiological mechanisms of ischemia-reperfusion injury, the associated protective mechanisms of ischemic pre- and postconditioning, and the potential seeds for molecular, pharmacological, or mechanical treatments against ischemia-reperfusion injury, as well as subsequent adverse outcomes by modulation of subcellular signaling mechanisms (especially mitochondrial function). We also review emerging translational clinical trials and the subsistent clinical comorbidities that need to be overcome to make these trials applicable in clinical medicine.
A-kinase anchoring proteins: scaffolding proteins in the heart
Authors: Diviani Dario , Dodge-Kafka Kimberly L. , Li Jinliang , Kapiloff Michael S.
Published: August 2011

The pleiotropic cyclic nucleotide cAMP is the primary second messenger responsible for autonomic regulation of cardiac inotropy, chronotropy, and lusitropy. Under conditions of prolonged catecholaminergic stimulation, cAMP also contributes to the induction of both cardiac myocyte hypertrophy and apoptosis. The formation of localized, multiprotein complexes that contain different combinations of cAMP effectors and regulatory enzymes provides the architectural infrastructure for the specialization of the cAMP signaling network. Scaffolds that bind protein kinase A are called “A-kinase anchoring proteins” (AKAPs). In this review, we discuss recent advances in our understanding of how PKA is compartmentalized within the cardiac myocyte by AKAPs and how AKAP complexes modulate cardiac function in both health and disease.
Lower limb-localized vascular phenomena explain initial orthostatic hypotension upon standing from squat
Authors: Tschakovsky Michael E. , Matusiak Kristine , Vipond Catherine , McVicar Lisa
Published: August 2011

The cause(s) of initial orthostatic hypotension (transient fall in blood pressure within 15 s upon active rising) have not been established. We tested the hypothesis that this hypotension is due to local vascular phenomena in contracting leg muscles from the brief effort of standing up. Seventeen young healthy subjects (2 male and 15 female, 22.5 ± 1.0 years) performed an active rise from resting squat after a 10-s squat, a 1-min squat, or a 5-min squat. Beat-by-beat arterial blood pressure, cardiac output, heart rate, and stroke volume (Finometer finger photoplethysmography) and right common femoral artery blood flow (Doppler and Echo ultrasound) were recorded. Data are means ± SE. Quiet standing before squat represented baseline. Peak increases in lower limb and total vascular conductance (ml·min−1·mmHg−1) upon standing were not different within squat conditions (10-s squat, 50.0 ± 12.4 vs. 44.3 ± 5.0; 1-min squat, 54.7 ± 9.2 vs. 50.5 ± 4.5; 5-min squat, 67.4 ± 13.7 vs. 58.8 ± 3.9; all P > 0.574). Mean arterial blood pressure (in mmHg) fell to a nadir well below standing baseline in all conditions despite increases in cardiac output. The hypotension predicted by the increase in leg vascular conductance accounted for this hypotension [observed vs. predicted (in mmHg): 10-s squat, −17.1 ± 2.1 vs. −18.3 ± 5.5; 1-min squat, −22.0 ± 3.8 vs. −25.3 ± 4.9; 5-min squat, −28.3 ± 4.0 vs. −29.2 ± 6.7]. We conclude that rapid contraction induced dilation in leg muscles with the effort of standing, along with a minor potential contribution of elevated lower limb arterio-venous pressure gradient, outstrips compensatory cardiac output responses and is the cause of initial orthostatic hypotension upon standing from squat.
Cx37 deletion enhances vascular growth and facilitates ischemic limb recovery
Authors: Fang Jennifer S. , Angelov Stoyan N. , Simon Alexander M. , Burt Janis M.
Published: August 2011

The unique contributions of connexin (Cx)37 and Cx40, gap junction-forming proteins that are coexpressed in vascular endothelium, to the recovery of tissues from ischemic injury are unknown. We recently reported that Cx37-deficient (Cx37−/−) animals recovered ischemic hindlimb function more quickly and to a greater extent than wild-type (WT) or Cx40−/− animals, suggesting that Cx37 limits recovery in the WT animal. Here, we tested the hypothesis that enhanced angiogenesis, arteriogenesis, and vasculogenesis contribute to improved postischemic hindlimb recovery in Cx37−/− animals. Ischemia was induced unilaterally in the hindlimbs of WT or Cx37−/− mice (isoflurane anesthesia). Postsurgical limb appearance, use, and perfusion were documented during recovery, and the number (and size) of large and small vessels was determined. Native collateral number, predominantly established during embryonic development (vasculogenesis), was also determined in the pial circulation. Both microvascular density in the gastrocnemius of the ischemic limb (an angiogenic field) and the number and tortuosity of larger vessels in the gracilis vasculature (an arteriogenic field) were increased in Cx37−/− animals compared with WT animals. Cx37−/− mice also had an increased (vs. WT) number of collateral vessels in the pial circulation. These findings suggest that in Cx37−/− animals, improved recovery of the ischemic hindlimb involves enhanced vasculogenesis, resulting in increased numbers of collaterals in the hindlimb (and pial circulations) and more extensive collateral remodeling and angiogenesis. These results are consistent with Cx37 exerting a growth-suppressive effect in the vasculature that limits embryonic vasculogenesis as well as arteriogenic and angiogenic responses to ischemic injury in the adult animal.
Nitric oxide synthase 3 deficiency limits adverse ventricular remodeling after pressure overload in insulin resistance
Authors: Kurtz Baptiste , Thibault Helene B. , Raher Michael J. , Popovich John R. , Cawley Sharon , Atochin Dmitriy N. , Hayton Sarah , Shakartzi Hannah R. , Huang Paul L. , Bloch Kenneth D. , Buys Emmanuel , Scherrer-Crosbie Marielle
Published: August 2011

Insulin resistance (IR) and systemic hypertension are independently associated with heart failure. We reported previously that nitric oxide synthase 3 (NOS3) has a beneficial effect on left ventricular (LV) remodeling and function after pressure-overload in mice. The aim of our study was to investigate the interaction of IR and NOS3 in pressure-overload-induced LV remodeling and dysfunction. Wild-type (WT) and NOS3-deficient (NOS3−/−) mice were fed either a standard diet (SD) or a high-fat diet (HFD) to induce IR. After 9 days of diet, mice underwent transverse aortic constriction (TAC). LV structure and function were assessed serially using echocardiography. Cardiomyocytes were isolated, and levels of oxidative stress were evaluated using 2′,7′-dichlorodihydrofluorescein diacetate. Cardiac mitochondria were isolated, and mitochondrial respiration and ATP production were measured. TAC induced LV remodeling and dysfunction in all mice. The TAC-induced decrease in LV function was greater in SD-fed NOS3−/−mice than in SD-fed WT mice. In contrast, HFD-fed NOS3−/−developed less LV remodeling and dysfunction and had better survival than did HFD-fed WT mice. Seven days after TAC, oxidative stress levels were lower in cardiomyocytes from HFD-fed NOS3−/−than in those from HFD-fed WT. Nω-nitro-l-arginine methyl ester and mitochondrial inhibitors (rotenone and 2-thenoyltrifluoroacetone) decreased oxidative stress levels in cardiomyocytes from HFD-fed WT mice. Mitochondrial respiration was altered in NOS3−/−mice but did not worsen after HFD and TAC. In contrast with its protective role in SD, NOS3 increases LV adverse remodeling after pressure overload in HFD-fed, insulin resistant mice. Interactions between NOS3 and mitochondria may be responsible for increased oxidative stress levels in HFD-fed WT mice hearts.
Fixed Point Theorems for Nonlinear Contractions in Menger Spaces
Authors: Ume Jeong Sheok
Published: August 2011

The main purpose of this paper is to introduce a new class of Ćirić‐type
contraction and to present some fixed point theorems for this mapping as well as
for Caristi‐type contraction. Several examples are given to show that our results
are proper extension of many known results.
Extra-Abdominal Fibromatosis (Desmoid Tumor): A Rare Tumor of the Lower Extremity Arising from the Popliteal Fossa
Authors: Ali Kaygin Mehmet , Dag Ozgur , Erkut Bilgehan , Ates Azman , Kayaoglu Refik Cetin , Kadioglu Hakan
Published: August 2011

Aggressive fibromatosis is a rare soft tissue tumor. Although it lacks metastatic potential, it can grow aggressively in a locally infiltrating pattern. The tumors frequently recur after surgical excision, which remains the treatment of choice. Optional combinations of radiotherapy and/or chemotherapy have been used postoperatively for recurrent disease and/or inoperable cases. A palpable mass was detected in the popliteal fossa of the right lower extremity in a 48-year-old man. Magnetic resonance imaging showed a contrast-enhancing noncalcified lesion initially felt to represent a vascular tumor. An invasive mass adherent to the surrounding tissue was visualized intraoperatively and extensively debulked. The patient's postoperative course was uneventful. Histologic examination of the surgical specimen was consistent with an extra-abdominal desmoid tumor. After appropriate recognition, wide local excision may be the most appropriate treatment for fibromatosis of the extremity. However, the rarity of this tumor and the difficulty inherent in distinguishing it from similar-appearing tumors are necessitating histologic confirmation of the diagnosis.
Bevacizumab and Weekly Docetaxel in Patients with Metastatic Castrate-Resistant Prostate Cancer Previously Exposed to Docetaxel
Authors: Francini Filippo , Pascucci Alessandra , Francini Edoardo , Bargagli Gianluca , Conca Raffaele , Licchetta Antonella , Roviello Giandomenico , Martellucci Ignazio , Chiriacò Giorgio , Miano Salvatora Tindara , Marzocca Giuseppe , Manganelli Antonio , Ponchietti Roberto , Savelli Vinno , Petrioli Roberto
Published: August 2011

Background. The aim of this paper was to evaluate the activity and tolerability of docetaxel (D) and bevacizumab (Bev) in patients with metastatic castrate-resistant prostate cancer (CRPC) previously exposed to D.Methods. Treatment consisted of D 30 mg/m2i.v. for four consecutive weekly administrations followed by a 2-week rest interval, in addition to Bev 5 mg/kg i.v. every 2 weeks.Results. Forty-three patients were enrolled: a PSA response was observed in 27 patients (62.7%, 95% CI: 0.41 to 0.91), and a palliative response was achieved in 31 patients (72.1%, 95%CI: 0.48 to 1.02). After a median followup of 11.3 months, only five patients had died. The regimen was generally well tolerated.Conclusion. Weekly D + biweekly Bev seems to be an effective and well-tolerated treatment option for patients with metastatic CRPC previously exposed to D-based chemotherapy.
Primary Pulmonary Epithelioid Hemangioendothelioma: A Rare Cause of PET-Negative Pulmonary Nodules
Authors: Cazzuffi Riccardo , Calia Nunzio , Ravenna Franco , Pasquini Claudio , Saturni Sara , Cavallesco Giorgio Narciso , Quarantotto Francesco , Rinaldi Rosa , Cogo Annaluisa , Caramori Gaetano , Papi Alberto
Published: August 2011

We report here a case of primary pulmonary epithelioid hemangioendothelioma diagnosed in a 67-year-old Caucasian man, presenting with exertion dyspnoea, dry cough, and multiple bilateral pulmonary nodules revealed by computed tomography. At the 18F-fluorodeoxyglucose positron emission tomography, these nodules were negative. The histopathological diagnosis was made on a pulmonary wedge resection (performed during video-thoracoscopic surgery).
Designing a Long Acting Erythropoietin by Fusing Three Carboxyl-Terminal Peptides of Human Chorionic GonadotropinβSubunit to theN-Terminal andC-Terminal Coding Sequence
Authors: Fares Fuad , Havron Avri , Fima Eyal
Published: August 2011

A new analog of EPO was designed by fusing one and two CTPs to theN-terminal andC-terminal ends of EPO (EPO-(CTP)3), respectively. This analog was expressed and secreted efficiently in CHO cells. Thein vitrotest shows that the activity of EPO-(CTP)3in TFI-1 cell proliferation assay is similar to that of EPO-WT and commercial rHEPO. However,in vivostudies indicated that treatment once a week with EPO-(CTP)3(15 μg/kg) dramatically increased (~8 folds) haematocrit as it was compared to rHuEPO. Moreover, it was found that EPO-(CTP)3is more effective than rHuEPO and Aranesp in increasing reticulocyte number in mice blood. The detected circulatory half-lives of rHuEPO, Aranesp, and EPO-(CTP)3following IV injection of 20 IU were 4.4, 10.8, and 13.1 h, respectively. These data established the rational for using this chimera as a long-acting EPO analog in clinics. The therapeutic efficacy of EPO-CTP analog needs to be established in higher animals and in human clinical trials.
Imaging and Documenting Gammarideans
Authors: Haug Carolin , Mayer Gerd , Kutschera Verena , Waloszek Dieter , Maas Andreas , Haug Joachim T.
Published: August 2011

We give an overview of available techniques for imaging and documenting applied to gammarideans and discuss their advantages and disadvantages. Although recent techniques, such as confocal laser scanning microscopy (cLSM), focused ion beam scanning electron microscopy (FIB SEM), or computed microtomography (μCT), provide new possibilities to detect and document structures, these high-tech devices are expensive, and access to them is often limited. Alternatively, there are many possibilities to enhance the capabilities of established techniques such as macrophotography and light microscopy. We discuss improvements of the illumination with polarized light and the possibilities of utilizing the autofluorescence of animals such as the gammarideans. In addition, we present software-based enhancing tools such as image fusion and image stitching.
Discovery of Diagnosis Pattern of Coronary Heart Disease with Qi Deficiency Syndrome by the T‐Test‐Based Adaboost Algorithm
Authors: Zhao Huihui , Chen Jianxin , Hou Na , Zhang Peng , Wang Yong , Han Jing , Hou Qin , Qi Qige , Wang Wei
Published: August 2011

Coronary heart disease (CHD) is still the leading cause of death for adults worldwide. Traditional Chinese medicine (TCM) has a history of 1000 years fighting against the disease and provides a complementary and alternative treatment to it. Syndrome is the core of TCM diagnosis and it is traditionally diagnosed based on macroscopic symptoms as well as tongue and pulse recognitions of patients. Establishment of the diagnosis method in the microcosmic level is an urgent and major problem in TCM. The aim of this study was to establish characteristic diagnosis pattern for CHD with Qi deficiency syndrome (QDS). Thirty‐four biological parameters were detected in 52 patients having unstable angina (UA) with or without QDS. Then, we presented a novel data mining method, t‐test‐based Adaboost algorithm, to establish highest prediction accuracy with the least number of biological parameters for UA with QDS. We gained a pattern composed of five biological parameters that distinguishes UA with QDS patients from non‐QDS patients. The diagnosis accuracy of the patterns could reach 84.5% based on a 3‐fold cross validation technique. Moreover, we included 85 UA cases collected from hospitals located in the north and south of China to further verify the association between the pattern and QDS. The classification accuracy is 83.5%, which keeps consistent with the accuracy obtained by the cross‐validation technique. The association between a symptom and the five biological parameters was established by the data mining method and it reached an accuracy of ~80%. These results showed that the t‐test‐based Adaboost algorithm might be a powerful technique for diagnosing syndrome in TCM in the context of CHD.
The Effect of Intermittent Signal on the Performance of Code Tracking Loop in GNSS Receivers
Authors: Chang Chung-Liang
Published: August 2011

This paper analyzes the code tracking performance in the presence of signal blanking in Global Navigation Satellite System (GNSS). The blanking effect is usually caused by buildings that obscure the signal in either a periodic or random manner. In some cases, ideal blanking is used to remove random or periodic interference. Nevertheless, the effect of temporary discontinuity of signal often leads to the tracking and position error. To analyze this problem, three types of blanking model are considered: no blanking, periodic blanking, and random blanking of the signals input into the code tracking loop. The mean time to lose lock (MTLL) is to assess the performance of code tracking system under signal blanking. Finally, the effect of steady-state tracking errors on the performance of tracking loop resulting from blanking environment is also discussed.
The Tonsils Revisited: Review of the Anatomical Localization and Histological Characteristics of the Tonsils of Domestic and Laboratory Animals
Authors: Casteleyn Christophe , Breugelmans Sofie , Simoens Paul , Van den Broeck Wim
Published: August 2011

This paper gives an overview of the anatomical localization and histological characteristics of the tonsils that are present in ten conventional domestic animal species, including the sheep, goat, ox, pig, horse, dog, cat, rabbit, rat, and pigeon. Anatomical macrographs and histological images of the tonsils are shown. Six tonsils can be present in domestic animals, that is, the lingual, palatine, paraepiglottic, pharyngeal, and tubal tonsils and the tonsil of the soft palate. Only in the sheep and goat, all six tonsils are present. Proper tonsils are absent in the rat, and pigeon. In the rabbit, only the palatine tonsils can be noticed, whereas the pig does not present palatine tonsils. The paraepiglottic tonsils lack in the ox, horse, and dog. In addition, the dog and cat are devoid of the tubal tonsil and the tonsil of the soft palate.
Drag Reduction of Bacterial Cellulose Suspensions
Authors: Ogata Satoshi , Numakawa Tetsuya , Kubo Takuya
Published: August 2011

Drag reduction due to bacterial cellulose suspensions with small environmental loading was investigated. Experiments were carried out by measuring the pressure drop in pipe flow. It was found that bacterial cellulose suspensions give rise to drag reduction in the turbulent flow range. We observed a maximum drag reduction ratio of 11% and found that it increased with the concentration of the bacterial cellulose suspension. However, the drag reduction effect decreased in the presence of mechanical shear.
Vertical Gate RF SOI LIGBT for SPICs with Significantly Improved Latch-Up Immunity
Authors: Zhang Haipeng , Qi Ruisheng , Zhang Liang , Su Buchun , Wang Dejun
Published: August 2011

Based on the previous achievements in improving latch-up immunity of SOI LIGBT, process simulation on our proposed VG RF SOI NLIGBT was carried out with TCAD to provide a virtually fabricated device structure. Then, an approximate latching current model was derived according to the condition of minimum regenerative feedback couple between the parasitic dual-transistors. The model indicates that its latching current is a few orders higher than those before. Further verification through device simulation was done with TCAD, which proved that its weak snapback voltage in the off state is about 0.5–2.75 times higher than those breakdown voltages reported before, its breakdown voltage in the off state is about 19 V higher than its weak snapback voltage, and its latching current density in the on state is about 2-3 orders of magnitude higher than those reported before at room temperature due to hole current bypass through P+ contact in P-well region. Therefore, it is characterized by significantly improved latch-up immunity.
A Discrete-Time Decoupled Current Control Scheme Applied to VSC-Based Three-Phase Three-Line Systems
Authors: Wang Hui , Li Qingmin , Wang Guangzhu , Tan Xingguo
Published: August 2011

Accurate current control of the voltage source converters (VSCs) is one of the key research subjects in modern power electronics. To achieve a preferable solution to current coupling effect in the VSC-based three-phase three-line system, a discrete-time decoupled current control strategy is proposed in the paper. With integration of the α-β transform and two independent current controllers, the proposed methodology can effectively implement decoupled control of the three-phase currents, which can thereby eliminate the impact from the neutral-point voltage especially under asymmetrical loading conditions. Control performance under digital realization was characterized with extensive tests on a shunt active power filter (SAPF) platform. Both the simulative and experimental results have demonstrated that the SAPF could function well and thereby verified the feasibility and effectiveness of the proposed current control methodology.
Modeling of Self‐Vibratory Drilling Head‐Spindle System for Predictions of Bearings Lifespan
Authors: Forestier F. , Gagnol V. , Ray P. , Paris H.
Published: August 2011

The machining of deep holes is limited due to inadequate chip evacuation, which induces tool breakage. To limit this drawback, retreat cycles and lubrication are used. An alternative response to the evacuation problem is based on high‐speed vibratory drilling. A specific tool holder induces axial self‐maintained vibration of the drill, which enables the chips to be split. The chips are thus of a small size and can be evacuated. To anticipate the potential risk of decreased spindle lifespan associated with these vibrations, a model of the behavior of the system (spindle—self‐vibrating drilling head—tool) is elaborated. In order to assess the dynamic behavior of the system, this study develops a rotor‐based finite element model, integrated with the modelling of component interfaces. The current results indicate that the simulations are consistent with the experimental measurements. The influence of spindle speed and feed rate on bearing lifespan is highlighted.
Platelet Function in Patients with Diabetes Mellitus: From a Theoretical to a Practical Perspective
Authors: Kakouros Nicholaos , Rade Jeffrey J. , Kourliouros Antonios , Resar Jon R.
Published: August 2011

Patients with diabetes mellitus have an increased prevalence of vascular disease. Pathologic thrombosis associated with atherosclerotic plaque rupture is a major cause of morbidity and mortality. Platelets are intimately involved in the initiation and propagation of thrombosis. Evidence suggests that platelets from patients with type 2 diabetes have increased reactivity and baseline activation compared to healthy controls. We review the pathophysiology of platelet hyperreactivity in DM patients and its implications in clinical practice, with particular focus on acute coronary syndromes, percutaneous coronary intervention, and novel antiplatelet agents.
Assessment of a Neural-Network-Based Optimization Tool: A Low Specific-Speed Impeller Application
Authors: Checcucci Matteo , Sazzini Federica , Marconcini Michele , Arnone Andrea , Coneri Mario , De Franco Luigi , Toselli Matteo
Published: August 2011

This work provides a detailed description of the fluid dynamic design of a low specific-speed industrial pump centrifugal impeller. The main goal is to guarantee a certain value of the specific-speed number at the design flow rate, while satisfying geometrical constraints and industrial feasibility. The design procedure relies on a modern optimization technique such as an Artificial-Neural-Network-based approach (ANN). The impeller geometry is parameterized in order to allow geometrical variations over a large design space. The computational framework suitable for pump optimization is based on a fully viscous three-dimensional numerical solver, used for the impeller analysis. The performance prediction of the pump has been obtained by coupling the CFD analysis with a 1D correlation tool, which accounts for the losses due to the other components not included in the CFD domain. Due to both manufacturing and geometrical constraints, two different optimized impellers with 3 and 5 blades have been developed, with the performance required in terms of efficiency and suction capability. The predicted performance of both configurations were compared with the measured head and efficiency characteristics.
Blocking Epidermal Growth Factor Receptor Signaling in HTR-8/SVneo First Trimester Trophoblast Cells Results in Dephosphorylation of PKBα/AKT and Induces Apoptosis
Authors: Bolnick J. , Albitar L. , Laidler L. L. , Abdullah R. , Leslie K. K.
Published: August 2011

We identified a major peptide signaling target of EGF/EGFR pathway and explored the consequences of blocking or activating this pathway in the first trimester extravillous trophoblast cells, HTR-8/SVneo. A global analysis of protein phosphorylation was undertaken using novel technology (Kinexus Kinetworks) that utilizes SDS-polyacrylamide minigel electrophoresis and multi-lane immunoblotting to permit specific and semiquantitative detection of multiple phosphoproteins. Forty-seven protein phosphorylation sites were queried, and the results reported based on relative phosphorylation at each site. EGF- and Iressa-(gefitinib, ZD1839, an inhibitor of EGFR) treated HTR-8/SVneo cells were subjected to immunoblotting and flow cytometry to confirm the phosphoprotein screen and to assess the effects of EGF versus Iressa on cell cycle and apoptosis. EGFR mediates the phosphorylation of important signaling proteins, including PKBα/AKT. This pathway is likely to be central to EGFR-mediated trophoblast survival. Furthermore, EGF treatment induces proliferation and inhibits apoptosis, while Iressa induces apoptosis.
Aging Behaviour of Al-Mg-Si Alloys Subjected to Severe Plastic Deformation by ECAP and Cold Asymmetric Rolling
Authors: Farè S. , Lecis N. , Vedani M.
Published: August 2011

A study was carried out on aging behaviour of a 6082 alloy processed by two different severe plastic deformation techniques: ECAP and asymmetric rolling. Both techniques were able to generate an ultrafine-grained structure in samples processed at room temperature. It was stated that severe straining promotes marked changes in the postdeformation aging kinetics. The peaks of β′′/β′ transition phases were anticipated and of progressively reduced intensity over the coarse grained alloy. A further peak accounting for onset of recrystallization also appeared in the most severely deformed samples. Full consistency in peak shape and position was found when comparing materials processed by ECAP and asymmetric rolling.
Isothermal aging treatments performed at 180°C revealed that in the severely deformed samples, aging became so fast that the hardness curves continuously decreased due to overwhelming effects of structure restoration. On the contrary, aging at 130°C offers good opportunities for fully exploiting the precipitate hardening effects in the ultrafine-grained alloy.
Improving SERS Detection of Bacillus thuringiensis Using Silver Nanoparticles Reduced with Hydroxylamine and with Citrate Capped Borohydride
Authors: Félix-Rivera Hilsamar , González Roxannie , Rodríguez Gabriela Del Mar , Primera-Pedrozo Oliva M. , Ríos-Velázquez Carlos , Hernández-Rivera Samuel P.
Published: August 2011

The development of techniques that could be useful in fields other than biological warfare agents countermeasures such as medical diagnostics, industrial microbiology, and environmental applications have become a very important subject of research. Raman spectroscopy can be used in near field or at long distances from the sample to obtain fingerprinting information of chemical composition of microorganisms. In this research, biochemical components of the cell wall and endospores of Bacillus thuringiensis (Bt) were identified by surface‐enhanced Raman scattering (SERS) spectroscopy using silver (Ag) nanoparticles (NPs) reduced by hydroxylamine and borohydride capped with sodium citrate. Activation of “hot spots”, aggregation and surface charge modification of the NPs, was studied and optimized to obtain signal enhancements from Bt by SERS. Slight aggregation of the NPs as well as surface charge modification to a more acidic ambient was induced using small‐size borohydride‐reduced NPs in the form of metallic suspensions aimed at increasing the Ag NP‐Bt interactions. Hydroxylamine‐reduced NPs required slight aggregation and no pH modifications in order to obtain high spectral quality results in bringing out SERS signatures of Bt.
Two-Lane Traffic Flow Simulation Model via Cellular Automaton
Authors: Rawat Kamini , Katiyar Vinod Kumar , Gupta Pratibha
Published: August 2011

Road traffic microsimulations based on the individual motion of all the involved vehicles are now recognized as an important tool to describe, understand, and manage road traffic. Cellular automata (CA) are very efficient way to implement vehicle motion. CA is a methodology that uses a discrete space to represent the state of each element of a domain, and this state can be changed according to a transition rule. The well-known cellular automaton Nasch model with modified cell size and variable acceleration rate is extended to two-lane cellular automaton model for traffic flow. A set of state rules is applied to provide lane-changing maneuvers. S-t-s rule given in the BJH model which describes the behavior of jammed vehicle is implemented in the present model and effect of variability in traffic flow on lane-changing behavior is studied. Flow rate between the single-lane road and two-lane road where vehicles change the lane in order to avoid the collision is also compared under the influence of s-t-s rule and braking rule. Using results of numerical simulations, we analyzed the fundamental diagram of traffic flow and show that s-t-s probability has more effect than braking probability on lane-changing maneuver.
Circulating and Disseminated Tumor Cells in the Management of Advanced Prostate Cancer
Authors: Kruck Stephan , Gakis Georgios , Stenzl Arnulf
Published: August 2011

Management of prostate cancer is recognized as one of the most important medical problems. Latest findings concerning the role of circulating (CTC) and disseminated tumor cells (DTC) have provided new insights into the biology of metastasis with important implications for the clinical management of prostate cancer patients. Most of the established methods of circulating/disseminated tumor cell enrichment use density-gradient centrifugation and immunomagnetic procedures. Reverse transcriptase polymerase chain reaction is another used detection technique. Novel methods, the CTC-chip and the epithelial immunospot assay already showed promising results. For localized and metastatic prostate cancer, significant correlations between spreading tumor cells and well-established indicators of disease activity have been demonstrated. Careful randomized prospective trials will be required to justify the routine use of CTCs/DTCs for therapy decision making.
In Situ Synthesis of Poly(methyl methacrylate)/SiO2 Hybrid Nanocomposites via “Grafting Onto” Strategy Based on UV Irradiation in the Presence of Iron Aqueous Solution
Authors: Zhang Hong , Li Chao , Guo Jinshan , Zang Limin , Luo Jiahe
Published: August 2011

Poly(methyl methacrylate)/SiO2 (PMMA/SiO2) hybrid composites were prepared via “grafting onto” strategy based on UV irradiation in the presence of iron aqueous solution. Two steps were used to graft polymethyl methacrylate (PMMA) onto the surface of nanosilica, anchoring 3‐(methacryloxy) propyl trimethoxysilane (MPTS) onto the surface of nanosilica to modify it with double bonds, and then grafting PMMA onto the surface of nanosilica with FeCl3 as photoinitiator. The products were characterized by FT‐IR, TGA, TEM, DLS, and XPS. The results showed that it is easy to graft PMMA onto the surface of nanosilica under UV irradiation, and the hybrid particles are monodisperse and have core‐shell structure with nanosilica as the core and PMMA layers as the shell. Furthermore, the products initiated by FeCl3 have higher monomer conversion, percent grafting, and better monodispersion compared with the products initiated by traditional photoinitiator such as 2‐hydroxy‐4‐(2‐hydroxyethoxy)‐2‐methyl‐propiophenone (Irgacure 2959).
Community Structure of Leaf-Litter Ants in a Neotropical Dry Forest: A Biogeographic Approach to Explain Betadiversity
Authors: Silvestre Rogério , Demétrio Manoel F. , Delabie Jacques H. C.
Published: August 2011

This paper describes habitat and geographic correlates of ant diversity in Serra da Bodoquena, a poorly surveyed region of central-western Brazil. We discuss leaf-litter ant diversity on a regional scale, with emphasis on the contribution of each of the processes that form the evolutionary basis of contemporary beta diversity. The diversity of leaf-litter ants was assessed from a series of 262 Winkler samples conducted in two microbasins within a deciduous forest domain. A total of 170 litter-dwelling ant species in 45 genera and 11 subfamilies was identified. The data showed that the study areas exhibited different arrangements of ant fauna, with a high turnover in species composition between sites, indicating high beta diversity. Our analysis suggests that the biogeographic history of this tropical dry forest in the centre of South America could explain ant assemblage structure more than competitive dominance. The co-occurrence analysis showed that species co-occur less often than expected by chance in only two of the localities, suggesting that, for most of the species, co-occurrences are random. The assessment of the structure of the diversity of litter-dwelling ants is the first step in understanding the beta diversity patterns in this region of great biogeographic importance.
Existence of Subharmonic Solutions for a Class of Second‐Order p‐Laplacian Systems with Impulsive Effects
Authors: Gong Wen-Zhen , Zhang Qiongfen , Tang X. H.
Published: August 2011

By using minimax methods in critical point theory, a new existence theorem of infinitely many periodic solutions is obtained for a class of second‐order p‐Laplacian systems with impulsive effects. Our result generalizes many known works in the literature.
Phospholipase A2 Mediates Apolipoprotein-Independent Uptake of Chylomicron Remnant-Like Particles by Human Macrophages
Authors: Napolitano Mariarosaria , Kruth Howard S. , Bravo Elena
Published: August 2011

Apolipoprotein E-receptor-mediated pathways are the main routes by which macrophages take up chylomicron remnants, but uptake may also be mediated by receptor-independent routes. To investigate these mechanisms, triacylglycerol (TG) accumulation induced by apolipoprotein-free chylomicron remnant-like particles (CRLPw/o) in human monocyte-derived macrophages was evaluated. Macrophage TG content increased about 5-fold after incubation with CRLPw/o, and this effect was not reduced by the inhibition of phagocytosis, macropinocytosis, apolipoprotein E function, or proteoglycan bridging. The role of lipases, including lipoprotein lipase, cholesteryl ester hydrolase, and secretory (sPLA2) and cytosolic phospholipase A2, was studied using [3H]TG-labelled CRLPw/o. Total cell radioactivity after incubation with [3H]TG CRLPw/o was reduced by 15–30% by inhibitors of lipoprotein lipase and cholesteryl ester hydrolase and by about 45% by inhibitors of sPLA2 and cytosolic PLA2. These results suggest that macrophage lipolytic enzymes mediate the internalization of postprandial TG-rich lipoproteins and that sPLA2and cytosolic PLA2, play a more important role than extracellular lipoprotein lipase-mediated TG hydrolysis.
Dietary Conjugated Linoleic Acid and Hepatic Steatosis: Species-Specific Effects on Liver and Adipose Lipid Metabolism and Gene Expression
Authors: Vyas Diwakar , Kadegowda Anil Kumar G. , Erdman Richard A.
Published: August 2011

Objective. To summarize the recent studies on effect of conjugated linoleic acid (CLA) on hepatic steatosis and hepatic and adipose lipid metabolism highlighting the potential regulatory mechanisms.Methods. Sixty-four published experiments were summarized in whichtrans-10,cis-12 CLA was fed either alone or in combination with other CLA isomers to mice, rats, hamsters, and humans were compared.Summary and Conclusions. Dietarytrans-10,cis-12 CLA induces a severe hepatic steatosis in mice with a more muted response in other species. Regardless of species, when hepatic steatosis was present, a concurrent decrease in body adiposity was observed, suggesting that hepatic lipid accumulation is a result of uptake of mobilized fatty acids (FA) from adipose tissue and the liver's inability to sufficiently increase FA oxidation and export of synthesized triglycerides. The potential role of liver FA composition, insulin secretion and sensitivity, adipokine, and inflammatory responses are discussed as potential mechanisms behind CLA-induced hepatic steatosis.
An Investigation Into the Social Context of Low-Income, Urban Black and Latina Women
Authors: Shelton Rachel C. , Goldman Roberta E. , Emmons Karen M. , Sorensen Glorian , Allen Jennifer D.
Published: August 2011

Understanding factors that promote or prevent adherence to recommended health behaviors is essential for developing effective health programs, particularly among lower income populations who carry a disproportionate burden of disease. We conducted in-depth qualitative interviews ( n = 64) with low-income Black and Latina women who shared the experience of requiring diagnostic follow-up after having a screening mammography with abnormal findings. We found that in addition to holding negative and fatalistic cancer-related beliefs, the social context of these women was largely defined by multiple challenges and major life stressors, factors that may interfere with their ability to attain health. Factors commonly mentioned included competing health issues, economic hardship, demanding caretaking responsibilities and relationships, insurance-related challenges, distrust of health care providers, and inflexible work policies. Black women also reported discrimination and medical mistrust, whereas Latinas experienced difficulties associated with immigration and social isolation. These results suggest that effective health interventions not only address change among individuals but must also change health care systems and social policies in order to reduce health disparities.
Field investigations into the adhesion recovery in leaf-contaminated wheel–rail contacts with locomotive sanders
Authors: Arias-Cuevas O , Li Z
Published: August 2011

Locomotives of railways worldwide have been using sand since 1838 to improve the wheel–rail adhesion during traction and braking operations. In more recent years, sanders have also been fitted to electrical and diesel multiple units in some railways to fight (often in combination with traction control or wheel slide protection systems) the low-adhesion conditions, especially encountered in autumn due to leaf contamination. In spite of the worldwide broad use of sand, different standards on sanding practice appear to be used by different railways, while there is a lack of fundamental understanding on the influence of sanding parameters, such as particle size distribution, feed rate, and number of sanding axles (among others), on the adhesion recovery, wear, and train detection. In order to gain a better understanding of these interrelationships, the authors have carried out laboratory investigations in recent years. As a continuation of that work, the influence of the sand particle size on the adhesion recovery in leaf-contaminated contacts is investigated in this article by means of traction tests of an electrical locomotive in a stabling yard. Three differently sized silica sands are used in the testing. In addition to the particle size investigations, the standard sand currently used in the Dutch railways is also tested to quantify its effectiveness against leaf contamination. Besides the immediate adhesion improvement upon sanding, the remaining friction level left for subsequent tractive wheel passages is also investigated for all sands tested. Furthermore, baseline tests (i.e. without application of sand) are also performed to obtain some quantitative insight into the impact of leaf contamination on the wheel–rail adhesion in the field.
On the classification of convex lattice polytopes
Authors: Liu Heling , Zong Chuanming
Published: August 2011

In 1980, Arnold studied the classification problem for convex lattice polygons of given area. Since then this problem and its high dimensional analogue have been studied by Bárány, Pach, Vershik and others. Bounds for the number of non-equivalent d-dimensional convex lattice polytopes of given volume have been achieved. In this paper we study Arnold's problem for centrally symmetric lattice polygons and the classification problem for convex lattice polytopes of given cardinality. In the plane we obtain analogues to the bounds of Arnold, Bárány and Pach in both cases. However, the number of non-equivalent d-dimensional convex lattice polytopes of w lattice points is infinite whenever w – 1 ≥ d ≥ 3, which may intuitively contradict to Bárány and Vershik's upper bound.
Studies on electro-oxidation of lignin and lignin model compounds. Part 2: N-Hydroxyphthalimide (NHPI)-mediated indirect electro-oxidation of non-phenolic lignin model compounds
Authors: Shiraishi Takumi , Takano Toshiyuki , Kamitakahara Hiroshi , Nakatsubo Fumiaki
Published: August 2011

The N-hydroxyphthalimide (NHPI)-mediated indirect electro-oxidation of non-phenolic lignin model compounds has been investigated for selective Cα-carbonylation of lignin. A cyclic voltammogram of NHPI in 0.1 M LiClO4/CH3CN with 2,6-lutidine interpreted that NHPI can act as a mediator in the indicated process in the range 0.5–0.8 V vs. Ag/Ag+. The corresponding Cα-carbonyl compounds was obtained in high yields (85–97%) in the case of the monomer 1-(4-ethoxy-3-methoxyphenyl) ethanol in 0.1 M LiClO4/CH3CN or 0.1 M LiClO4/(CH3CN/H2O=7/3) with a small amount of 2,6-lutidine at 0.7 V vs. Ag/Ag+. The processing of the dimeric lignin model compound (4-ethoxy-3-methoxyphenylglycerol-β-guaiacyl ether) also gave the corresponding Cα-carbonyl compound in high yield (88–92%). The reaction proceeds through hydrogen atom transfer in the NHPI-mediated electro-oxidation. On the other hand, the direct electro-oxidation and indirect electro-oxidation mediated by ABTS [2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate)] of the dimeric compound preferentially gave the corresponding Cα-Cβ cleavage product in low or moderate yields (5–40%). The conclusion is that NHPI is an excellent mediator for selective Cα-carbonylation of non-phenolic β-O-4 structures in lignin in electronic mediator system.
Selecting process parameter in injection molding via simulation optimization
Authors: Villarreal-Marroquín María G. , Mulyana Rachmat , Castro José M. , Cabrera-Ríos Mauricio
Published: August 2011

A simulation optimization method based on design of experiments and adaptive metamodeling techniques is applied in this work to set process parameters in injection molding. The proposed method is used first to select the best processing conditions to injection molding a disposable camera front plate in the presence of either a single performance measure or a composite function of a series of performance measures. Secondly, it is used to select the best injection gate configuration from three different injection scenarios, as well as the values of mold temperature and melt temperature for a real automotive part in order to minimize process variability. The optimization results are discussed in light of the performance of the simulation optimization method.
A multicriteria simulation optimization method for injection molding
Authors: Villarreal-Marroquín María G. , Cabrera-Ríos Mauricio , Castro José M.
Published: August 2011

Injection molding is the most important process for mass-producing plastic products. To help improve and facilitate the molding of plastic parts, advanced computer simulation tools have been developed. While modeling is complicated by itself, the difficulty of optimizing the injection molding process is that the performance measures involving the injection molding process usually show conflicting behaviors. Therefore, the best solution for one performance measure is usually not the best in some other performance measures. This paper introduces a simulation optimization method which considers multiple performance measures and is able to find a set of efficient solutions without having to evaluate a large number of simulations. The main components of the method are metamodeling, design of experiments, and data envelopment analysis. The method is illustrated and detailed here using a simple test example, and it is applied to a real injection molding case. The performance of the method using a different design of experiments is also discussed.
Characterization and classification of uranium ore concentrates (yellow cakes) using infrared spectrometry
Authors: Varga Zsolt , Öztürk Betül , Meppen Manuela , Mayer Klaus , Wallenius Maria , Apostolidis Christopf
Published: August 2011

In this work the applicability of Fourier-transform infrared spectrometry (FTIR) for nuclear forensic studies of uranium ore concentrates (UOC) are investigated. The technique was used for the identification of the type of uranium compound and various process-related impurities, which can give information on the production method of the material. The measured spectra were evaluated also by statistical means, using the soft independent modelling of class analogy (SIMCA) technique to reveal less apparent similarities between the measured UOC samples.