bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinico-Laboratory Profile and Immediate Outcomes of Hyperbilirubinemic Babies Admitted in Kanti Children Hospital
Authors: Nepal Deepeshwara , Banstola Dinesh , Khakal Ajaya Kumar , Mishra Udbhabhat , Maheseth Chandeshawar
Published: December 2009

Introduction: Jaundice is an important problem in the neonatal period especially in the first week of life. Our objective of the study is to find out the immediate outcome of hyperbilirubinemic babies admitted in Kanti Children Hospital. Methodology: This is a retrospective study and carried out in tertiary care paediatric hospital. Results: Altogether 73 babies were enrolled in the study. Male babies outnumbered the female (72.6% vs. 27.4%).Only 2.4% babies were near-term. LBW babies constitute 19.2% of the study population.86.3% of babies also have clinical sepses as defined by WHO criteria. Almost half of the babies have mild hyperbilirubinemia (15-19.9 mg/dl). Most of the babies (94.5%) improved and the mortality was 5.5%. Conclusion: Healthy term babies with a serum bilirubin <17mg/dl should not be admitted for routinely as they do not need phototherapy. Phototherapy is effective in most of the time, but exchange transfusion should also be carried out when phototherapy fails. Causes of hyperbilirubinemia should be searched extensively especially to rule out haemolysis. Key words: hyperbilirubinemia, kernicterus, neonates, phototherapy DOI: 10.3126/jnps.v30i1.2457 Journal of Nepal Paediatric Society Vol.30(1) 2010 31-36
Lennox Gastaut Syndrome: A Case Report
Authors: Shrestha Merina , Shrestha Laxman , Shrestha Prakash Sundar
Published: December 2009

Lennox-Gastaut syndrome (LGS) is a severe form of childhood epilepsy that is defined by generalized multiple type seizures, slowness of intellectual growth, and a specific EEG disturbance. Children affected might previously have infantile spasms or underlying brain disorder but etiology can be idiopathic. LGS seizures are often treatment resistant and the long term prognosis is poor. Key words: epilepsy, intellectual growth DOI: 10.3126/jnps.v30i1.2461Journal of Nepal Paediatric Society Vol.30(1) 2010 50-52
Bubble-CPAP in Neonatal Unit of TUTH
Authors: Shrestha Merina , Basnet Sudha , Shrestha Prakash Sundar
Published: December 2009

Introduction: Nasal Continuous Positive Airway Pressure (CPAP) in newborn babies with respiratory distress reduces requirement for mechanical ventilation thereby decreasing referral to higher centre. In our neonatal unit prior to the use of this intervention, morbidity and mortality associated with respiratory distress was significant which has decreased after we started CPAP in Kartik 2065 (October 2008) including a decrease in referrals to higher centre for ventilator support.The objective of this study was to evaluate the outcome of bubbling CPAP in newborn babies who had respiratory distress. Methods: Observational study done in neonatal unit of TUTH over a period of 3 months i.e from Kartik to Poush 2065 B.S (mid of October to mid of January,2008) Results: 127 neonates were admitted, of whom 15 babies with respiratory distress (11.8% of total admissions) received CPAP. 11 babies improved, while 4 babies died. Among those attending follow up (8 babies) none had any features of chronic lung disease. Conclusion: In resource poor settings where level II neonatal care is already exists; CPAP can be easily applied for newborn babies with respiratory distress with promising results and it helps to decrease neonatal morbidity and mortality. Key words: CPAP, neonatal mortality, respitatory Distress. DOI: 10.3126/jnps.v30i1.2465 Journal of Nepal Paediatric Society Vol.30(1) 2010 64-68
Path Guidance Information in Advance of Work Zones at Urban Freeway Interchanges
Authors: Finley Melisa D. , Ullman Gerald L. , Nelson Alicia A.
Published: December 2009

Work activities at complex urban freeway interchanges often result in modified lane assignments and the temporary misalignment of existing overhead guide signs with the travel lanes. Researchers conducted a driving simulator study to determine whether the location and accuracy of driver lane changes made before major freeway-to-freeway interchanges were affected by temporarily misaligned permanent guide signing, temporary guide signing, and route shield pavement markings. The results of this study verify that when the lane assignment arrows on existing overhead guide signs are covered and the signs are temporarily misaligned with the travel lanes, drivers are not clear about which lane they need to be in to reach their destination; thus they wait to make a lane change until they are closer to the exit ramp gore area. Additional path guidance information presented to drivers before the interchange can be beneficial. The results of the study also indicate that smaller temporary lane assignment signs, route shield pavement markings upstream of the interchange, or both encourage drivers to make their lane change further upstream of the exit ramp gore area. Either of these devices or a combination should be used to provide drivers with additional path guidance information in work zones in which the existing overhead guide signs are temporarily misaligned with the travel lanes and the lane assignment arrows are covered.
Comparison of Driver Behavior at Highway–Railroad Crossings in Two Cities
Authors: Khattak Aemal J.
Published: December 2009

This paper attempts to answer two questions pertaining to highway–railroad grade crossing (HRGC) safety. First, does unsafe driver behavior differ at HRGCs located in two cities? Second, is there a difference in drivers’ response to the same safety treatment at two HRGCs? The two HRGCs investigated are in Waverly and Fremont, Nebraska. Unsafe behaviors investigated at both locations were passing around closing or closed gates and making U-turns while waiting for trains to pass. The safety treatment used at the HRGCs was a barrier installed along the street center leading up to the gates that made it difficult for drivers to engage in unsafe maneuvers. Analysis of the collected data showed that drivers in Waverly engaged in more frequent gate passing compared with drivers in Fremont. Conversely, drivers in Fremont more frequently made U-turns at HRGCs. Installation of the barrier reduced gate passing and U-turns at both locations; the percentage of reductions in gate passing and U-turns at the two locations were comparable. Based on the results, the conclusions are that drivers’ unsafe behavior at HRGCs is location-dependent, but the order of magnitude of drivers’ response to the same safety treatment at different locations is quite similar.
Derivation of Van Aerde Traffic Stream Model from Tandem-Queuing Theory
Authors: Wu Ning , Rakha Hesham
Published: December 2009

The relationship between the traffic stream flow, speed, and density can be described with a fundamental diagram. With a reasonable fundamental diagram, the maximum flow rate of motorways and the corresponding traffic quality can be estimated more accurately. According to different theories such as the car-following theory, queuing theory, or theory of fluid dynamics, different models for the fundamental diagram can be established. From queuing theory, several models can be found. However, the existing queuing models consider a roadway cross section as a stand-alone queuing counter, and thus the interaction between consecutive vehicles cannot be considered sufficiently. This paper presents a new model treating a road stretch as a series of many queuing counters. The new model yields a single-regime fundamental diagram that fully corresponds to the well-known Van Aerde model. In the Van Aerde model, the model parameters can be easily measured and calibrated using loop detector data. The application and calibration of the model are demonstrated with sample data sets and compared with other state-of-the-art traffic stream models. The results demonstrate the superiority of this model in capturing traffic stream behavior.
Analysis of the Breakdown Process on Congested Freeways
Authors: Habib-Mattar Caroline , Polus Abishai , Cohen Moshe A.
Published: December 2009

The aim of the study is to model the flow breakdown phenomenon on congested freeways. Because of the importance of the breakdown phenomenon, the present research focuses on analyzing, understanding, and modeling heavy-flow breakdowns when no apparent bottlenecks exist. It is hypothesized that breakdowns are caused by internal microscopic flow oscillations and the transition from dense flow to unstable flow on freeways. A new density-versus-time model was developed to describe this phenomenon. The model shows the density behavior over time, which increases sharply toward the peak period and then decreases and increases again toward the breakdown. This new revelation is described by a combination of an exponential model, a logistic model, and a weighting function. This density–time relationship is calibrated by using data collected from a congested freeway at 1-min intervals. The beginning of the unstable flow is defined as the drop in speed below 60 km/h; it is shown that breakdown is defined as a process that starts at the local minimum of the new model and ends at the beginning of the unstable flow. It was found that the model well describes the behavior of density over time, from the increase in density through the breakdown process and into the rapid density-fluctuation phase of the unstable flow.
A Study of Phase Transitions on Multilane Roads in the Framework of Three-Phase Traffic Theory
Authors: Kerner Boris S. , Klenov Sergey L.
Published: December 2009

A numerical study of phase transitions in traffic flow on multilane roads in the framework of three-phase traffic theory is presented. It was found that when vehicle merging became easier at a bottleneck, wide moving jams emerged more frequently in synchronized flow upstream of the bottleneck. Depending on the traffic phase and lane-changing probability, lane changing was responsible for qualitatively opposite effects, such as congested traffic dissolution or, in contrast, the emergence of nuclei for traffic breakdown and moving jam emergence. It was found that at a sequence of closely located adjacent bottlenecks, phase transitions between different road lanes resulted in nonregular spatiotemporal traffic dynamics.
Implementing Travel Time Reliability for Evaluation of Congestion Relief Schemes on Expressways
Authors: Mehran Babak , Nakamura Hideki
Published: December 2009

Preevaluation of the impacts of congestion relief schemes on travel time reliability is significant for road authorities. However, most existing approaches to estimating travel time reliability rely mainly on empirical data and are therefore not of help for evaluating improvement schemes before implementation. A methodology is presented to estimate travel time reliability on the basis of modeling travel time variations as a function of demand, capacity, weather conditions, and road accidents. For a subject expressway segment, patterns of demand and capacity were generated for each 5-min interval during a year by using the Monte Carlo simulation technique, and accidents were generated randomly according to traffic conditions. A whole year analysis was performed by comparing demand and available capacity for each scenario; shock wave analysis was used to estimate the queue length at each time interval. Travel times were estimated from refined speed–flow relationships. The buffer time index was estimated as a measure of travel time reliability and compared with observed values from empirical data. After validation, the methodology was applied to assess the impact on travel time reliability of opening the hard shoulder to traffic. Opening the hard shoulder to traffic during the peak periods was found to ameliorate travel time reliability significantly and mitigate congestion levels, which could result in up to a 26% cut in the number of accidents occurring.
Driver Behavior at Freeway-Ramp Merging Areas
Authors: Kondyli Alexandra , Elefteriadou Lily
Published: December 2009

Driver behavior is an important factor affecting traffic operations, and it accounts to a large extent for the observed variability in roadway performance. Researchers have developed various driver behavior–related models for operational analysis and simulation applications. These models consider drivers’ choices related to gap identification and selection, lane changing, and so on. However, the literature related to drivers’ thinking processes and support for the assumptions used in existing models is scarce. This study conducted three focus groups to investigate drivers’ intended actions along a freeway-ramp merging segment. Several scenarios were discussed in which participants indicated their thinking process and likely actions while merging or traversing a merging segment. The study considers noncongested and congested traffic conditions. It also correlates the drivers’ responses to their individual characteristics.
New Calibration Methodology for Microscopic Traffic Simulation Using Enhanced Simultaneous Perturbation Stochastic Approximation Approach
Authors: Lee Jung-Beom , Ozbay Kaan
Published: December 2009

Traffic simulation models can represent real-world conditions such as delays, travel times, queues, and flows. However, accurate evaluation of these traffic conditions depends on the selection of model parameters and the calibration methodology. Most previous calibration studies have focused on minimizing the sum of the differences between the observed data and simulation output during a certain time period on a typical day. However, to capture a realistic distribution of all possible traffic conditions, a more general calibration methodology that can be used with any traffic condition is required. This paper proposes a new calibration methodology–-the Bayesian sampling approach in conjunction with the application of the simultaneous perturbation stochastic approximation (SPSA) optimization method [enhanced SPSA (E-SPSA)]–-that enables the modeler to enhance calibration by considering statistical data distribution. Instead of calibrating with input data for certain time periods, calibration is performed with data obtained from a complete input distribution. Mean square variation (MSV) was used to evaluate the accuracy of the proposed E-SPSA calibration approach. On the basis of the MSV of flows, the MSV value of the E-SPSA methodology was found to be 0.940, which was greater than the variation of speed obtained from SPSA-only (0.897) or from a variation approach (0.888). Thus, this proposed methodology not only makes it possible to overcome some of the limitations of previous calibration approaches, but also improves the results of simulation model calibration by accurately capturing a wide range of real-world conditions. Future work will focus on testing the proposed calibration methodology using more extensive data sets and models developed using simulation tools other than PARAMICS.
How Parameters of Microscopic Traffic Flow Models Relate to Traffic Dynamics in Simulation
Authors: Punzo Vincenzo , Ciuffo Biagio
Published: December 2009

Several methodological issues in setting up a calibration process for traffic microsimulation models are still unresolved. The influence of individual parameters of microscopic models on simulated traffic dynamics is also far from clear. To address those issues, the paper sets up a methodology based on the sensitivity analysis of traffic flow models (the one used here is AIMSUN). Sensitivity analysis was performed by means of a series of 30 analyses of variance. These were designed to evaluate the effect of parameters on the variance of the simulated outputs and to draw a general inference about ( a) the proper interval for the aggregation of measurements, ( b) the proper measure of performance (e.g., traffic counts versus speeds), ( c) the proper traffic measurement locations, and ( d) the subset of parameters to calibrate. The analysis allowed quantification of the effect of the single parameters on different traffic phases. For example, it was possible to quantify the extent of the influence of the parameter reaction time on simulated outputs in locations in which free flow, rather than congested conditions, occurs. The great differences between parameters in affecting the different traffic phases suggested that parameters are likely to be calibrated independently, that is, using data from different locations. The first evidence of the possibility of breaking the calibration problem into two subproblems is given. This entails great benefits in regard to computational time, given the exponential computational complexity of the calibration problem.
Molecular mechanisms of microvascular failure in central nervous system injury—synergistic roles of NKCC1 and SUR1/TRPM4
Authors: Simard J. Marc , Kahle Kristopher T. , Gerzanich Volodymyr
Published: December 2009

Microvascular failure largely underlies the damaging secondary events that accompany traumatic brain injury (TBI). Changes in capillary permeability result in the extravasation of extracellular fluid, inflammatory cells, and blood, thereby producing cerebral edema, inflammation, and progressive secondary hemorrhage (PSH). Recent work in rat models of TBI and stroke have implicated 2 ion transport proteins expressed in brain endothelial cells as critical mediators of edema formation: the constitutively expressed Na+-K+-2Cl– cotransporter, NKCC1, and the trauma/ischemia-induced SUR1-regulated NCCa-ATP (SUR1/TRPM4) channel. Whereas NKCC1 function requires adenosine 5′-triphosphate (ATP), activation of SUR1/TRPM4 occurs only after ATP depletion. This opposite dependence on intracellular ATP levels implies that one or the other mechanism will activate/deactivate as ATP concentrations rise and fall during periods of ischemia/reperfusion, resulting in continuous edema formation regardless of cellular energy status. Moreover, with critical ATP depletion, sustained opening of SUR1/TRPM4 channels results in the oncotic death of endothelial cells, leading to capillary fragmentation and PSH. Bumetanide and glibenclamide are 2 well-characterized, safe, FDA-approved drugs that inhibit NKCC1 and the SUR1/TRPM4 channel, respectively. When used alone, these drugs have provided documented beneficial effects in animal models of TBI- and ischemiaassociated cerebral edema and PSH. Given the mechanistic and temporal differences by which NKCC1 and the SUR1/TRPM4 channel contribute to the pathophysiological mechanisms of these events, combination therapy with bumetanide and glibenclamide may yield critical synergy in preventing injury-associated capillary failure.
Factors influencing the risk of local recurrence after resection of a single brain metastasis
Authors: Patel Akash J. , Suki Dima , Hatiboglu Mustafa Aziz , Abouassi Hiba , Shi Weiming , Wildrick David M. , Lang Frederick F. , Sawaya Raymond
Published: December 2009

Object

Local recurrence (LR) of a resected brain metastasis occurs in up to 46% of patients. Postoperative whole-brain radiation therapy (WBRT) reduces that incidence. To isolate factors associated with the risk of LR after resection, the authors only studied patients who did not receive adjuvant radiotherapy.

Methods

The authors reviewed data from 570 cases involving patients who had undergone resection of a previously untreated single brain metastasis at The University of Texas M. D. Anderson Cancer Center between 1993 and 2006 without receiving postoperative WBRT. All tumors were measured preoperatively on MR images. The resection method (en bloc resection [EBR] or piecemeal resection [PMR]) was noted at the time of surgery. Predictors of LR were assessed using the Cox proportional hazards model.

Results

The median patient age was 58 years, 55% were male, and 88% had a Karnofsky Performance Scale Score ≥ 80. The most common primary cancers were those of the lung (28%), skin (melanoma, 21%), kidney (19%), and breast (11%). Piecemeal resection was performed in 201 patients (35%) and EBR in 369 (65%). Local recurrence developed in 84 patients (15%). The histological type of the primary cancer did not significantly predict LR; however, 7 of 22 patients with sarcoma developed LR (p = 0.16). The authors identified 2 variables that increased the risk of LR. Undergoing PMR carried a significantly higher LR risk than EBR (crude hazard ratio [HR] 1.7, 95% CI 1.1–2.6, p = 0.03). Tumors exceeding the median volume (9.7 cm3) had a significantly higher LR risk than those that were < 9.7 cm3 (crude HR 1.7; 95% CI 1.1–2.6; p = 0.02). In the multivariate analysis, small tumors removed by EBR had a significantly lower LR risk.

Conclusions

The LR risk of a single brain metastasis is influenced by biological factors (such as tumor volume) and treatments (such as the resection method). Early administration of postoperative WBRT may be particularly warranted when such negative tumor-related prognostic factors are noted or when treatment-related ones such as PMR are unavoidable.
Performance and training standards for endovascular ischemic stroke treatment
Authors: Meyers Philip M. , Schumacher H. Christian , Alexander Michael J. , Derdeyn Colin P. , Furlan Anthony J. , Higashida Randall T. , Moran Christopher J. , Tarr Robert W. , Heck Donald V. , Hirsch Joshua A. , Jensen Mary E. , Linfante Italo , McDougall Cameron G. , Nesbit Gary M. , Rasmussen Peter A. , Tomsick Thomas A. , Wechsler Lawrence R. , Wilson John A. , Zaidat Osama O.
Published: December 2009

Stroke is the third leading cause of death in the USA, Canada, Europe, and Japan. According to the American Heart Association and the American Stroke Association, there are now 750,000 new strokes that occur each year, resulting in 200,000 deaths, or 1 of every 16 deaths, per year in the USA alone. Endovascular therapy for patients with acute ischemic stroke is an area of intense investigation. The American Stroke Association has given a qualified endorsement of intraarterial thrombolysis in selected patients. Intraarterial thrombolysis has been studied in two randomized trials and numerous case series. Although two devices have been granted FDA approval with an indication for mechanical stroke thrombectomy, none of these thrombectomy devices has demonstrated efficacy for the improvement of patient outcomes. The purpose of the present document is to define what constitutes adequate training to perform neuroendovascular procedures in patients with acute ischemic stroke and what performance standards should be adopted to assess outcomes. These guidelines have been written and approved by multiple neuroscience societies which historically have been directly involved in the medical, surgical and endovascular care of patients with acute stroke. The participating member organizations of the Neurovascular Coalition involved in the writing and endorsement of this document are the Society of NeuroInterventional Surgery, the American Academy of Neurology, the American Association of Neurological Surgeons/Congress of Neurological Surgeons Cerebrovascular Section, and the Society of Vascular & Interventional Neurology.
Biocultural Diversity in the Southern Amazon
Authors: Heckenberger Michael
Published: December 2009

Recent studies in Amazonia historical ecology have revealed substantial diversity and dynamic change in coupled natural human systems. In the southern Amazon, several headwater basins show evidence of substantial pre-Columbian landscape modification, particularly in areas historically dominated by speakers of the Arawak language family. The headwater basin of the Xingu River, the easternmost of these areas occupied by Arawak-speaking peoples, has revealed such a complex built environment. This discussion examines settlement pattern and land-use, which have implications for understanding the dynamics of natural-human systems in the Upper Xingu basin and other areas across the transitional forests of the southern Amazon.
Contributions of the C-Terminal Helix to the Structural Stability of a Hyperthermophilic Fe-Superoxide Dismutase (TcSOD)
Authors: Wang Sha , Yan Yong-Bin , Dong Zhi-Yang
Published: December 2009

Hyperthermophilic superoxide dismutases (SODs) are of particular interest due to their potential industrial importance and scientific merit in studying the molecular mechanisms of protein folding and stability. Compared to the mesophilic SODs, the hyperthermostable Fe-SODs (TcSOD and ApSOD) have an extended C-terminal helix, which forms an additional ion-pairing network. In this research, the role of the extended C-terminus in the structural stability of TcSOD was studied by investigating the properties of two deletion mutants. The results indicated that the ion-pairing network at the C-terminus had limited contributions to the stability of TcSOD against heat- and GdnHClinduced inactivation. The intactness of the C-terminal helix had dissimilar impact on the two stages of TcSOD unfolding induced by guanidinium chloride. The mutations slightly decreased the Gibbs free energy of the dissociation of the tetrameric enzymes, while greatly affected the stability of the molten globule-like intermediate. These results suggested that the additional ion-pairing network mainly enhanced the structural stability of TcSOD by stabilizing the monomers.
Antioxidant Activity of a Red Lentil Extract and Its Fractions
Authors: Amarowicz Ryszard , Estrella Isabell , Hernández Teresa , Dueñas Montserrat , Troszyńska Agnieszka , Kosińska Agnieszka , Pegg Ronald  B.
Published: December 2009

Phenolic compounds were extracted from red lentil seeds using 80% (v/v) aqueous acetone. The crude extract was applied to a Sephadex LH-20 column. Fraction 1, consisting of sugars and low-molecular-weight phenolics, was eluted from the column by ethanol. Fraction 2, consisting of tannins, was obtained using acetone-water (1:1; v/v) as the mobile phase. Phenolic compounds present in the crude extract and its fractions demonstrated antioxidant and antiradical activities as revealed from studies using a β-carotene-linoleate model system, the total antioxidant activity (TAA) method, the DPPH radical-scavenging activity assay, and a reducing power evaluation. Results of these assays showed the highest values when tannins (fraction 2) were tested. For instance, the TAA of the tannin fraction was 5.85 μmol Trolox® eq./mg, whereas the crude extract and fraction 1 showed 0.68 and 0.33 μmol Trolox® eq./mg, respectively. The content of total phenolics in fraction 2 was the highest (290 mg/g); the tannin content, determined using the vanillin method and expressed as absorbance units at 500 nm per 1 g, was 129. There were 24 compounds identified in the crude extract using an HPLC-ESI-MS method: quercetin diglycoside, catechin, digallate procyanidin, and p-hydroxybenzoic were the dominant phenolics in the extract.
1-(6-Ethoxy-6-oxohexyl)-4-methylquinolinium Iodide
Authors: Winstead Angela , Oyaghire Stanley
Published: December 2009

The N-ethoxycarbonylhexyl quaternary salt of lepidine has been synthesized in one step in 56% yield. 1H and 13C NMR data are reported.
Preparation and Hydrogen Absorption/Desorption of Nanoporous Palladium Thin Films
Authors: Li Wen-Chung , Balk Thomas John
Published: December 2009

Nanoporous Pd (np-Pd) was prepared by co-sputtering Pd-Ni alloy films onto Si substrates, followed by chemical dealloying with sulfuric acid. X-ray diffractometry and chemical analysis were used to track the extent of dealloying. The np-Pd structure was changed from particle-like to sponge-like by diluting the sulfuric acid etchant. Using suitable precursor alloy composition and dealloying conditions, np-Pd films were prepared with uniform and open sponge-like structures, with interconnected ligaments and no cracks, yielding a large amount of surface area for reactions with hydrogen. Np-Pd films exhibited shorter response time for hydrogen absorption/desorption than dense Pd films, showing promise for hydrogen sensing.
A Novel Fabrication Method for Functionally Graded Materials under Centrifugal Force: The Centrifugal Mixed-Powder Method
Authors: Watanabe Yoshimi , Inaguma Yoshifumi , Sato Hisashi , Miura-Fujiwara Eri
Published: December 2009

One of the fabrication methods for functionally graded materials (FGMs) is a centrifugal solid-particle method, which is an application of the centrifugal casting technique. However, it is the difficult to fabricate FGMs containing nano-particles by the centrifugal solid-particle method. Recently, we proposed a novel fabrication method, which we have named the centrifugal mixed-powder method, by which we can obtain FGMs containing nano-particles. Using this processing method, Cu-based FGMs containing SiC particles and Al-based FGMs containing TiO2 nano-particles on their surfaces have been fabricated. In this article, the microstructure and mechanical property of Cu/SiC and Al/TiO2 FGMs, fabricated by the centrifugal mixed-powder method are reviewed.
Feasibility of Using Multilayer Platelets as Toughening Agents
Authors: Chin Yuan-Liang , Tuan Wei-Hsing
Published: December 2009

It is known that the toughness of brittle ceramics can be improved significantly with the addition of hard platelets. In the present study, platelet-shape multilayer ceramic laminates are utilized as a toughening agent for alumina ceramics. They are prepared by laminating the BaTiO3-based ceramic tapes. Although the elastic modulus of the BaTiO3-based platelets is lower than that of the alumina matrix, and the platelets are also reactive to alumina at elevated temperatures, the weak platelets are found to exhibit the ability to deflect major matrix cracks by forming a large number of microcrack branches within the platelets, thus achieving the desired toughening effect.
Nanoporous Carbide-Derived Carbon Material-Based Linear Actuators
Authors: Torop Janno , Arulepp Mati , Leis Jaan , Punning Andres , Johanson Urmas , Palmre Viljar , Aabloo Alvo
Published: December 2009

Devices using electroactive polymer-supported carbon material can be exploited as alternatives to conventional electromechanical actuators in applications where electromechanical actuators have some serious deficiencies. One of the numerous examples is precise microactuators. In this paper, we show for first time the dilatometric effect in nanocomposite material actuators containing carbide-derived carbon (CDC) and polytetrafluoroetylene polymer (PTFE). Transducers based on high surface area carbide-derived carbon electrode materials are suitable for short range displacement applications, because of the proportional actuation response to the charge inserted, and high Coulombic efficiency due to the EDL capacitance. The material is capable of developing stresses in the range of tens of N cm-2. The area of an actuator can be dozens of cm2, which means that forces above 100 N are achievable. The actuation mechanism is based on the interactions between the high-surface carbon and the ions of the electrolyte. Electrochemical evaluations of the four different actuators with linear (longitudinal) action response are described. The actuator electrodes were made from two types of nanoporous TiC-derived carbons with surface area (SA) of 1150 m2 g-1 and 1470 m2 g-1, respectively. Two kinds of electrolytes were used in actuators: 1.0 M tetraethylammonium tetrafluoroborate (TEABF4) solution in propylene carbonate and pure ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf). It was found that CDC based actuators exhibit a linear movement of about 1% in the voltage range of 0.8 V to 3.0 V at DC. The actuators with EMITf electrolyte had about 70% larger movement compared to the specimen with TEABF4 electrolyte.
Terpenyl-Purines from the Sea
Authors: Gordaliza Marina
Published: December 2009

Agelasines, asmarines and related compounds are natural products with a hybrid terpene-purine structure isolated from numerous genera of sponges (Agela sp., Raspailia sp.). Some agelasine analogs and related structures have displayed high general toxicity towards protozoa, and have exhibited broad-spectrum antimicrobial activity against a variety of species, including Mycobacterium tuberculosis, and also an important cytotoxic activity against several cancer cell lines, including multidrug-resistant ones. Of particular interest in this context are the asmarines (tetrahydro[1,4]diazepino[1,2,3-g,h]purines), which have shown potent antiproliferative activity against several types of human cancer cell lines. This review summarizes the sources of isolation, chemistry and bioactivity of marine alkylpurines and their bioactive derivatives.
New Conjugated Benzothiazole-N-oxides: Synthesis and Biological Activity
Authors: Gajdoš Peter , Magdolen Peter , Zahradník Pavol , Foltínová Pavlína
Published: December 2009

Eleven new 2-styrylbenzothiazole-N-oxides have been prepared by aldol – type condensation reactions between 2-methylbenzothiazole–N-oxide and para-substituted benzaldehydes. Compounds with cyclic amino substituents showed typical push-pull molecule properties. Four compounds were tested against various bacterial strains as well as the protozoan Euglena gracilis as model microorganisms. Unlike previously prepared analogous benzothiazolium salts, only weak activity was recorded.
Upgrading SELEX Technology by Using Lambda Exonuclease Digestion for Single-Stranded DNA Generation
Authors: Avci-Adali Meltem , Paul Angel , Wilhelm Nadj , Ziemer Gerhard , Wendel Hans Peter
Published: December 2009

The generation of single-stranded DNA (ssDNA) molecules plays a key role in the SELEX (Systematic Evolution of Ligands by EXponential enrichment) combinatorial chemistry process and numerous molecular biology techniques and applications, such as DNA sequencing, single-nucleotide polymorphism (SNP) analysis, DNA chips, DNA single-strand conformation polymorphism (SSCP) analysis and many other techniques. The purity and yield of ssDNA can affect the success of each application. This study compares the two ssDNA production methods, the strand separation by streptavidin-coated magnetic beads and alkaline denaturation and the lambda exonuclease digestion, in regard to the purity of generated ssDNA and the efficiency. Here, we demonstrate the considerable benefits of ssDNA production by lambda exonuclease digestion for in vitro selection of DNA aptamers. We believe that the generation of ssDNA aptamers using this method will greatly improve the success rate of SELEX experiments concerning the recovery of target-specific aptamers.
Synthesis and in Vitro Cytotoxic Activity of Compounds with Pro-Apoptotic Potential
Authors: Apicela Soares Gisell , Barbosa de Oliveira Renata , Fernandes de Andrade Saulo , Alves Ricardo José , Leomar Zani Carlos , De Souza-Fagundes Elaine Maria
Published: December 2009

In our search for new anticancer therapies, some compounds synthesized in our lab were selected and their potential cytotoxic activity was evaluated in vitro against two cancer cells lines including a solid tumor (UACC-62, melanoma) and a human lymphoma (JURKAT). Compounds showing cytotoxic activity were subjected to an apoptosis assay. Two compounds showed promising results.
Synergistic Chondroprotective Effect of α-Tocopherol, Ascorbic Acid, and Selenium as well as Glucosamine and Chondroitin on Oxidant Induced Cell Death and Inhibition of Matrix Metalloproteinase-3—Studies in Cultured Chondrocytes
Authors: Graeser Anne-Christi , Giller Katri , Wiegand Heike , Barella Luca , Boesch Saadatmandi Christine , Rimbach Gerald
Published: December 2009

Overproduction of reactive oxygen species and impaired antioxidant defence accompanied by chronic inflammatory processes may impair joint health. Pro-inflammatory cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α) stimulate the expression of metalloproteinases which degrade the extracellular matrix. Little is known regarding the potential synergistic effects of natural compounds such as α-tocopherol (α-toc), ascorbic acid (AA) and selenium (Se) on oxidant induced cell death. Furthermore studies regarding the metalloproteinase-3 inhibitory activity of glucosamine sulfate (GS) and chondroitin sulfate (CS) are scarce. Therefore we have studied the effect of α-toc (0.1–2.5 µmol/L), AA (10–50 µmol/L) and Se (1–50 nmol/L) on t-butyl hydroperoxide (t-BHP, 100–500 µmol/L)-induced cell death in SW1353 chondrocytes. Furthermore we have determined the effect of GS and CS alone (100–500 µmol/L each) and in combination on MMP3 mRNA levels and MMP3 secretion in IL-1β stimulated chondrocytes. A combination of α-toc, AA, and Se was more potent in counteracting t-BHP-induced cytotoxicity as compared to the single compounds. Similarly a combination of CS and GS was more effective in inhibiting MMP3 gene expression and secretion than the single components. The inhibition of MMP3 secretion due to GS plus CS was accompanied by a decrease in TNF-α production. Combining natural compounds such as α-toc, AA, and Se as well as GS and CS seems to be a promising strategy to combat oxidative stress and cytokine induced matrix degradation in chondrocytes.
Enaminones in Heterocyclic Synthesis: A Novel Route to Tetrahydropyrimidines, Dihydropyridines, Triacylbenzenes and Naphthofurans under Microwave Irradiation
Authors: Al-Mousawi Saleh Mohammed , El-Apasery Morsy Ahmed , Elnagdi Mohamed H.
Published: December 2009

Condensation of phthalimidoacetone (1) with DMFDMA (N,N-Dimethylformamide dimethyl acetal) has afforded enaminone 2. Refluxing 2 with equimolecular amounts of benzaldehyde and urea in acetic acid afforded a mixture of tetrahydropyrimidine 5 and the dihydropyridine 6. Compound 2 undergoes self-condensation on heating in acetic acid or under microwave irradiation in presence of acidic zeolite to give 1,3,5-triacylbenzene 9. Reacting enaminone 11a with naphthoquinone 15 afforded the naphthofuran 18. The possible formation of the aldehyde 19 was excluded based on an HMQC experiment, which revealed that the carbonyl carbon is not linked to any hydrogen.
Soft Fruit Traceability in Food Matrices using Real-Time PCR
Authors: Palmieri Luisa , Bozza Elisa , Giongo Lara
Published: December 2009

Food product authentication provides a means of monitoring and identifying products for consumer protection and regulatory compliance. There is a scarcity of analytical methods for confirming the identity of fruit pulp in products containing Soft Fruit. In the present work we have developed a very sensible qualitative and quantitative method to determine the presence of berry DNAs in different food matrices. To our knowledge, this is the first study that shows the applicability, to Soft Fruit traceability, of melting curve analysis and multiplexed fluorescent probes, in a Real-Time PCR platform. This methodology aims to protect the consumer from label misrepresentation.
Insulin and Insulin-Sensitizing Drugs in Neurodegeneration: Mitochondria as Therapeutic Targets
Authors: Cardoso Susana , Santos Renato , Correia Sonia , Carvalho Cristina , Zhu Xiongwei , Lee Hyoung-Gon , Casadesus Gemma , Smith Mark  A. , Perry George , Moreira Paula  I.
Published: December 2009

Insulin, besides its glucose lowering effects, is involved in the modulation of lifespan, aging and memory and learning processes. As the population ages, neurodegenerative disorders become epidemic and a connection between insulin signaling dysregulation, cognitive decline and dementia has been established. Mitochondria are intracellular organelles that despite playing a critical role in cellular metabolism are also one of the major sources of reactive oxygen species. Mitochondrial dysfunction, oxidative stress and neuroinflammation, hallmarks of neurodegeneration, can result from impaired insulin signaling. Insulin-sensitizing drugs such as the thiazolidinediones are a new class of synthetic compounds that potentiate insulin action in the target tissues and act as specific agonists of the peroxisome proliferator-activated receptor gamma (PPAR-γ). Recently, several PPAR agonists have been proposed as novel and possible therapeutic agents for neurodegenerative disorders. Indeed, the literature shows that these agents are able to protect against mitochondrial dysfunction, oxidative damage, inflammation and apoptosis. This review discusses the role of mitochondria and insulin signaling in normal brain function and in neurodegeneration. Furthermore, the potential protective role of insulin and insulin sensitizers in Alzheimer´s, Parkinson´s and Huntington´s diseases and amyotrophic lateral sclerosis will be also discussed.
Potential of MODIS EVI in Identifying Hurricane Disturbance to Coastal Vegetation in the Northern Gulf of Mexico
Authors: Wang Fugui , D’Sa Eurico J.
Published: December 2009

Frequent hurricane landfalls along the northern Gulf of Mexico, in addition to causing immediate damage to vegetation, also have long term effects on coastal ecosystem structure and function. This study investigated the utility of using time series enhanced vegetation index (EVI) imagery composited in MODIS product MOD13Q1 for assessing hurricane damage to vegetation and its recovery. Vegetation in four US coastal states disturbed by five hurricanes between 2002 and 2008 were explored by change imagery derived from pre- and post-hurricane EVI data. Interpretation of the EVI changes within months and between years distinguished a clear disturbance pattern caused by Hurricanes Katrina and Rita in 2005, and a recovering trend of the vegetation between 2005 and 2008, particularly within the 100 km coastal zone. However, for Hurricanes Gustav, Ike, and Lili, the disturbance pattern which varied by the change imagery were not noticeable in some images due to lighter vegetation damage. The EVI pre- and post-hurricane differences between two adjacent years and around one month after hurricane disturbance provided the most likely damage area and patterns. The study also revealed that as hurricanes damaged vegetation in some coastal areas, strong precipitation associated with these storms may benefit growth of vegetation in other areas. Overall, the study illustrated that the MODIS product could be employed to detect severe hurricane damage to vegetation, monitor vegetation recovery dynamics, and assess benefits of hurricanes to vegetation.
Toward 100 Mega-Frames per Second: Design of an Ultimate Ultra-High-Speed Image Sensor
Authors: Vu Truong Son Dao , Goji Etoh Takeharu , Tanaka Masatoshi , Hoang Dung Nguyen , Le Cuong Vo , Takehara Kohsei , Akino Toshiro , Nishi Kenji , Aoki Hitoshi , Nakai Junichi
Published: December 2009

Our experiencein the design of an ultra-high speed image sensor targeting the theoretical maximum frame rate is summarized. The imager is the backside illuminated in situ storage image sensor (BSI ISIS). It is confirmed that the critical factor limiting the highest frame rate is the signal electron transit time from the generation layer at the back side of each pixel to the input gate to the in situ storage area on the front side. The theoretical maximum frame rate is estimated at 100 Mega-frames per second (Mfps) by transient simulation study. The sensor has a spatial resolution of 140,800 pixels with 126 linear storage elements installed in each pixel. The very high sensitivity is ensured by application of backside illumination technology and cooling. The ultra-high frame rate is achieved by the in situ storage image sensor (ISIS) structure on the front side. In this paper, we summarize technologies developed to achieve the theoretical maximum frame rate, including: (1) a special p-well design by triple injections to generate a smooth electric field backside towards the collection gate on the front side, resulting in much shorter electron transit time; (2) design technique to reduce RC delay by employing an extra metal layer exclusively to electrodes responsible for ultra-high speed image capturing; (3) a CCD specific complementary on-chip inductance minimization technique with a couple of stacked differential bus lines.
Electronic Nose for Quality Control of Colombian Coffee through the Detection of Defects in “Cup Tests”
Authors: Rodríguez Juan , Durán Cristhian , Reyes Adriana
Published: December 2009

Electronic noses (ENs), are used for many applications, but we must emphasize the importance of their application to foodstuffs like coffee. This paper presents a research study about the analysis of Colombian coffee samples for the detection and classification of defects (i.e., using “Cup Tests”), which was conducted at the Almacafé quality control laboratory in Cúcuta, Colombia. The results obtained show that the application of an electronic nose called “A-NOSE”, may be used in the coffee industry for the cupping tests. The results show that e-nose technology can be a useful tool for quality control to evaluate the excellence of the Colombian coffee produced by National Federation of Coffee Growers.
A Focusing Method in the Calibration Process of Image Sensors Based on IOFBs
Authors: Fernández Pedro R. , Lázaro José L. , Gardel Alfredo , Cano Ángel E. , Bravo Ignacio
Published: December 2009

A focusing procedure in the calibration process of image sensors based on Incoherent Optical Fiber Bundles (IOFBs) is described using the information extracted from fibers. These procedures differ from any other currently known focusing method due to the non spatial in-out correspondence between fibers, which produces a natural codification of the image to transmit. Focus measuring is essential prior to carrying out calibration in order to guarantee accurate processing and decoding. Four algorithms have been developed to estimate the focus measure; two methods based on mean grey level, and the other two based on variance. In this paper, a few simple focus measures are defined and compared. Some experimental results referred to the focus measure and the accuracy of the developed methods are discussed in order to demonstrate its effectiveness.
A Cluster-Based Architecture to Structure the Topology of Parallel Wireless Sensor Networks
Authors: Lloret Jaime , Garcia Miguel , Bri Diana , Diaz Juan  R.
Published: December 2009

A wireless sensor network is a self-configuring network of mobile nodes connected by wireless links where the nodes have limited capacity and energy. In many cases, the application environment requires the design of an exclusive network topology for a particular case. Cluster-based network developments and proposals in existence have been designed to build a network for just one type of node, where all nodes can communicate with any other nodes in their coverage area. Let us suppose a set of clusters of sensor nodes where each cluster is formed by different types of nodes (e.g., they could be classified by the sensed parameter using different transmitting interfaces, by the node profile or by the type of device: laptops, PDAs, sensor etc.) and exclusive networks, as virtual networks, are needed with the same type of sensed data, or the same type of devices, or even the same type of profiles. In this paper, we propose an algorithm that is able to structure the topology of different wireless sensor networks to coexist in the same environment. It allows control and management of the topology of each network. The architecture operation and the protocol messages will be described. Measurements from a real test-bench will show that the designed protocol has low bandwidth consumption and also demonstrates the viability and the scalability of the proposed architecture. Our ccluster-based algorithm is compared with other algorithms reported in the literature in terms of architecture and protocol measurements.