bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication and Investigation of a Micro-Progressive Die Set for Microforming of Sheet Metals
Authors: Nehme Christopher R. , Sagar Amrit , Messner William C. , James Thomas P.
Published: April 2016

Progressive microforming is an attractive option for manufacturing high aspect-ratio micro-parts out of sheet metal. It is a highly economical alternative to both MEMS processing and micro-machining due to the ability to produce near-net shape parts through parallel forming processes. Current limitations in the field include precise alignment of microforming tools and an understanding of forces encountered when scaling down traditional forming processes. A five stage micro-progressive aluminum die set consisting of four shearing stages and one bending stage was fabricated by micro-machining. The die set was designed to produce right angle micro-brackets from 25 um thick annealed copper foil, with a measured average grain size of 47 um. Die clearances were set at 3 um along shearing edges and 38 um along the bending edge, corresponding to 12% and 152% material thickness, respectively. The produced micro-brackets are intended to be used as electrical connectors and consist of a nominally 280 um by 260 um tab extending vertically from a 780 um by 260 um base. In order to implement and investigate the progressive microforming process, a novel micro-press system was constructed which allows for precision alignment of the die set and workpiece. Using a prepared workpiece, forces at the first stage of the die set were measured and compared to analytical predictions based on models from the literature.
Phased Array Ultrasonic Technique Parametric Evaluation for Composite Materials
Authors: Taheri Hossein , Ladd Katrina M. , Delfanian Fereidoon , Du Jikai
Published: April 2016

A series of ultrasonic elements arranged in a phased array transducer can provide the capability to activate each element separately but in a programmed sequence. This will help the acoustic signal to be generated at desired focusing distances and anticipated angles for specific materials and structures. In case of composite material inspection, this characteristic of the phased array method can improve the undesirable effects of the high attenuation and anisotropic structure of composite materials on response signals. In this study different phased array probes and wedges which are commercially available were evaluated for their response signals’ characteristics. First, the capability and resolution of bulk wave generation were studied for each set of probe and wedge, and the response signals were compared to that of the conventional single element ultrasonic transducers for different thicknesses composite plates. Then the resolution of the response signals and their sensitivity to defect size were evaluated and compared to the single element transducers as well. Next, each phased array probe and wedge set was used to generate plate waves in aluminum plates based on plate wave propagation theory, probe and wedge physical properties and the definition of delay law. Results show a general improvement in response signals’ strength and resolution for phased array method in comparison to the single element transducers. Also some plate wave modes could be generated with optimized signal generation parameters in phased array system.
Stretchable Impedance Spectroscopy Sensor for Mammalian Cells Impedance Measurements
Authors: Zhang Xudong , Petrissans Remi , Li Fang , Voiculescu Ioana
Published: April 2016

In this paper, an impedance spectroscopy biosensor fabricated on a stretchable substrate has been investigated. A thin stretchable membrane integrated with an impedance biosensor tolerated cyclic strain without cracking. The electric cell-substrate impedance spectroscopy (ECIS) technique has been used to monitor the impedance of the membrane of bovine aortic endothelial cells (BAEC). Integrating mechanical stretching and ECIS sensing onto a single platform requires biocompatible, highly flexible, and reversibly stretchable (elastic) materials for device fabrication. In addition, the interfacial impedance of electrode material to electrolyte should be small to improve the sensitivity of the impedance measurements. In this research, the biocompatible and stretchable membrane was fabricated from polydimethylsiloxane (PDMS), and the ECIS sensor was fabricated on pre-stretched PDMS membrane using sputtering microfabrication and pattern-transferring processes. The stretchable membrane, integrated with the ECIS sensor, can be used to simulate the dynamic environment of organisms and enable the analysis of the cell activity in vitro.
System Identification Using Neural Nets for Dynamic Modeling of a Surface Marine Vehicle
Authors: Xiros Nikolaos I. , Loghis Eleftherios K.
Published: April 2016

The scale model of a surface marine vehicle with electric propulsion by a dc motor and waterjet is built. A mathematical model capable to adequately describe the motion of the vehicle under a variety of conditions is developed by fusing basic principles with data series obtained through a series of field experiments. The aim is to minimize the number and cost of sensors needed in this end, without unacceptably compromising accuracy, by employing knowledge of vehicle dynamics in order to form a customized gray-box modeling approach. A set of nonlinear differential equations, used to depict the behavior of the marine vehicle at hand are derived. This dynamic model will form the basis for applying physicomimetic approaches to control and navigation of a standalone or swarm of similar vehicles. In the physicomimetic controller synthesis approach, the control problem is tackled by the concept of virtual forces acting on the vehicle and in result generating motion patterns that are desired in a certain application, e.g. avoid obstacles and collisions. To achieve physicomimetic control one needs to effectively cancel the actual dynamics or physics to which a vehicle’s motion complies with and then impose the desired dynamics through virtual forces. In the present work, as first step, a series of open loop experiments allow us developing the actual dynamics of vehicle motion.
Modeling of Near-Field Concentrated Solar Thermophotovoltaic Microsystem
Authors: Elzouka Mahmoud , Kulsreshath Mukesh , Ndao Sidy
Published: April 2016

Modeling of a near-field concentrated solar thermophotovoltaic (STPV) microsystem is carried out to investigate the use of STPV-based solid-state energy conversion as a high power density MEMS power generator. Near-field radiation can be realized between two closely separated surfaces (i.e. order of radiation wavelength), resulting in the enhancement of the heat radiation flux orders of magnitudes higher than the blackbody limit, consequently increasing cell output power density. The Near-field STPV model consists of an absorber/emitter model used to estimate the net power absorbed from solar irradiance, a near-field radiation transfer model to evaluate the power tunneled from the emitter to the PV cell at different separation distances, and a PV cell model to determine the photocurrent generated due to thermal radiation absorbed. Results reveal that decreasing separation distance between the emitter and the PV cell increases the absorber/emitter thermal efficiency, increases conversion efficiency, and the power density (×100 far-field). The results also predict increase in cooling power requirement as the separation distance is decreased, which may be a limiting design parameter for near-field STPV microsystems. Based on the model, an overall conversion efficiency of 17% at a separation distance of 10 nm and emitter temperature of 2000 K with solar concentration 6000 sun can be reached; this corresponds to an output power density of 9×105 W/m2.
Shear and Longitudinal Acoustic Communication and Power Transfer Through Plates Using Acoustic Wedges
Authors: Litman R. B. , Wilt K. R. , Scarton H. A. , Saulnier G. J.
Published: April 2016

Techniques for wireless acoustic communication and energy transfer along steel plates and piping to avoid physical penetrations and wire feed-throughs are presented. Longitudinal and shear acoustic waves (polarized in the direction of the plate/pipe wall thickness) transmitted into steel plates using steel wedges are analyzed using finite-element analysis. Propagation of steady-state waves at frequencies of 1 MHz in steel plates using triangular steel wedges with varying wave launch angles were used, where the steel plate was bounded by cement on one side and engine oil on the other. Successful simulation was achieved at large axial distance from the transmitting wedge with reception into a second reversed wedge, which is applicable for both power and data transmissions. At a distance of 0.41 m the energy transfer efficiency was seen to increase with increasing launch angle to 0.1 % for shear waves and 0.03 % for longitudinal waves when operating with an 80 degree wedge.
Theoretical and Experimental Studies of Love Mode Surface Acoustic Wave Sensors for Cellular Sensing
Authors: Li Fang , Qin Lifeng , Wang Qing-Ming
Published: April 2016

Cell-based biosensors have the capacity to respond to a wide range of analytes in a physiologically relevant manner. By employing living cells as sensors, bioanalytes can be screened without requiring apriori knowledge of the analyte’s chemistry. The ability to operate and screen for unknown analytes provides benefits in numerous applications, including pharmacology, cell biology, toxicology, and environmental monitoring. Recent studies have demonstrated that acoustic wave devices are capable of quantitatively probing the behaviors of cells attaching to sensor surface. Among various types of acoustic devices, Love mode sensor has many advantages in liquid environment. However, up to now, the use of Love mode devices as cell-based sensors is limited, including theoretical and experimental studies. In this study, we developed a theoretical model for cell-based Love mode sensors. The devices were designed, fabricated and utilized for cell adhesion monitoring.
Detection of Anomalous Sodium Chloride Concentrations in Perspiration Using Microsensors
Authors: Gaibor David , Goulamaly Mehdi , Jariwala Nilu , Piontkowski Mark , Zenouzi Mansour , Sirokman Gergely , Khabari Ali
Published: April 2016

It is common knowledge that an early diagnosis of a disease improves the treatment provided to a patient. With the advent of nanotechnology, engineers and scientists are beginning to utilize these nanoscale capabilities in the hope of - early disease detection. Viral, bacterial infections and other chronic diseases seem to alter the concentrations of some compounds present in sweat [1,2]. This project attempts to detect some of these diseases by measuring the variation in salinity of sweat that differs from the commonly accepted level [2]. By creating a low-cost, reusable and portable microsensor, it can then apply the same principles to construct a nanosensor to yield even more accurate results. The electrical signals obtained by the sensor produce data that translates into diagnostic medical results for sweat-related illnesses such as cystic fibrosis [3]. For a deeper and thorough understanding of all aspects of the sensor, multiple concepts for measuring sweat using electrical signals were considered. Ultimately, the concept chosen to measure varying sweat concentrations was through a capacitor. Multiple capacitor designs were simulated to determine the best way of maximizing performance. After the sensors were constructed, they were tested using various concentrations of sodium chloride (NaCl), from 0.1 grams per liter to 5 grams per liter, dissolved in distilled water to mimic the effect of authentic human sweat [4]. The designed sensor is successfully able to determine the likelihood of a person having cystic fibrosis using a sweat sample as their sweat sodium chloride concentration will correspond to an electrical signal obtained throughout the testing process.
Light Weight Optimization Design for a Connection Frame Considering Thermal-Structural Coupling Deformation
Authors: Zhang Lufan , Long Zhili , Cai Jiandong , Fang Jiwen
Published: April 2016

Connection frame, as a key module in macro-micro motion platform, is employed to realize a high acceleration, high speed and ultra-precision positioning motion. In the paper, six working conditions of connection frame are obtained by analyzing its driving processes. The maximum deformation in the different working conditions is calculated by the mechanical analysis which affects ultra-precision positioning. Moreover, the maximum deformation of thermal-structural coupling analysis increases the influence on the positioning. Under the same situation, the change trends of deformation and stress distribution of connection mechanism can be obtained by changing the surface loads. The maximum deformation and stress increase with the loads. However, for ever-increasing market demand, it is not adequate to only consider high acceleration under accuracy requirement. The higher acceleration is needed by light weight of connection frame. Therefore, an optimization model is built and studied, which takes the weight of connection frame as objective and takes the thermal deformation as constraint. Connection frame structure model can be calculated in ANSYS and the optimal solution can be obtained by genetic algorithm (GA) in MATLAB. With MATLAB and ANSYS optimization, the rate of convergence has been improved by 3%. Design variables for optimal solution are obtained. The weight and the maximum thermal-structural coupling displacement have been improved by 24.3% and 27.3% respectively. The first six order vibration modes of connection frame are obtained by the finite element method. And the simulation data can be verified by experiment. At last, an optimization connection frame structure considering thermal-structure coupling deformation is obtained.
Simulation and Experiment of a MEMS Omnidirectional Inertial Switch
Authors: Cao Y. , Wang J. , Xi Z. W. , Nie W. R. , Wang X. J. , Ouyang Q.
Published: April 2016

A MEMS omnidirectional inertial switch was designed and fabricated based on non-silicon surface micromachining technology. The switch consists of mass-spring system, flexible radial electrodes and axial electrode. It has omnidirectional sensitivities in a half sphere. The modal analysis of the switch was performed. The system stiffness of the mass-spring system and the response displacement of the mass in all directions under the applied shock acceleration of 450g was obtained by using the FE method, as a result, the switch has good omnidirectional performance and small distributed threshold acceleration. The fabricated switches were tested by a shock test device. The results show that the threshold acceleration of the switches is within the range of 270g to 450g. As an acceleration exceeding the threshold value acting along the X-axis or Z-axis, the switch can be reliably closed and have a long contact time.
Removal of Multi-Walled Carbon Nanotubes From Contaminated Surfaces With Microscale Topological Features
Authors: Karimi Zahra , Su Paul , Haghpanah Babak , Doerr William W. , Gritzo Louis A. , Hassan Syed , Vaziri Ashkan
Published: April 2016

Experiments were performed to examine the ability of surfactants to remove multi-walled carbon nanotubes (MWCNTs) from silicon wafers with nano and micro scaled features. Well-defined microscale topological features on silicon wafers were induced using photo lithography and plasma etching. The etching time was varied to create variation in topological features with the size and height of ∼ 8±1 μm, and ∼2±1 μm, respectively. MWCNTs in the form of pristine liquid solution were deposited on the surface of silicon wafers using the spin coating process. During cleaning, the contaminated surfaces were first sprayed with one of the two surfactants, sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS), or water. MWCNTs were wiped off using a wiping mechanism. The area density of the MWCNTs was quantified prior to and after their removal using scanning electron microscopy (SEM) and post-image processing. The results show decreasing removal efficiency for all the surfactants as the topological features on the wafers deepen through increasing the etching time. Surfactants show better decontamination efficiency compared with water.
Influence of Process Parameters on the Mechanical Response of Various Layers Processed Using Direct Metal Laser Sintering (DMLS)
Authors: Ahmed S. , Doak H. , Mian A. , Srinivasan R.
Published: April 2016

During the DMLS process, sintering of the top layer creates melting and heat affected zone in previously sintered layers. In this paper, we will examine the effects of any given process parameter, such as laser power and laser scanning speed, on the mechanical properties and microstructural morphology within the processed layers.
Anisotropic Behavior of Single Grain Cu6Sn5 Intermetallic
Authors: Choudhury Soud Farhan , Ladani Leila
Published: April 2016

Intermetallic (IMC) layers (Cu6Sn5 and Cu3Sn) are an essential component of a solder joint for good metallurgical bonding. However, the mechanical and physical properties of IMC layers differ significantly from the solder and substrate, and excessive IMC layers can lower the reliability of solder joints due to their brittle nature. Moreover, continuous miniaturization of packages and joints has increased the volume fraction of IMCs to a point where smaller joints could be completely composed of IMCs. Further miniaturization of joints may result in statistical grain size effects. One of the most common types of IMCs in microelectronic joints is Cu6Sn5, which is formed in a variety of bonding materials with different compositions of Sn, Cu, and Ag. Due to its large percentage of volume in solder joint; to predict the reliability of micro solder joints, it is necessary to characterize single crystal Cu6Sn5 IMC completely. This study reports the information on grain growth orientation and elastic-plastic properties such as young’s modulus, hardness, yield strength and strain hardening exponent of single grain of Cu6Sn5 in Sn-3.5Ag/Cu solder alloy system. IMCs materials were grown using reflow process using an experiment in which the time and temperature of reflow process was varied. Electron backscatter diffraction (EBSD) analysis was conducted after the reflow to measure the grain size and determine the preferred grain orientation. It was found that the growth orientation is in the orientation of the c-axis. Nanoindentation was carried out in 4 individual grains with different crystallographic orientation along normal to the growth axis to determine the elastic properties of Cu6Sn5 single crystal. Plastic properties were predicted using the nanoindentation results and Dao reverse analysis model. The results indicate that the hardness for Cu6Sn5 grains with different orientation along normal to growth axis is statistically indistinguishable. Lower elastic modulus was observed for a grain with [010] direction parallel to the loading direction. Yield strength of a grain with (001) plane parallel to the loading direction was slightly lower than other grain orientations. Overall, the experimental results obtained were found to be within the range shown in the literature.
Coupled FSI Simulations of the Interaction of a Flexible Hydrofoil With Large Scale Unsteady Flows
Authors: Lee Abe H. , Campbell Robert L. , Craven Brent A. , Hambric Stephen A.
Published: April 2016

Fluid-structure interaction (FSI) effects must be considered when flexible structures are subjected to unsteady flows. Large-scale unsteady flows can excite structural vibrations significantly and cause the fluid flow to be altered by the large amplitude vibrations. In this work, an in-house finite-element structural code FEANL is tightly coupled with the open-source computational-fluid dynamics (CFD) library package OpenFOAM to simulate the interaction of a backward-skewed, flexible hydrofoil with vortical flow structures shed from a large upstream rigid cylinder in the Penn State-ARL 12” water tunnel. To simulate the turbulent flow at a moderate computational cost, hybrid LES-RANS approaches, i.e. Delayed-Detached-Eddy-Simulation (DDES) and k–ω SST-SAS, are used. The hybrid approaches have been widely employed to simulate massively-separated flows at moderately high Reynolds numbers. Both of the turbulence models are used for a coarse mesh CFD-only case (no FSI effects by assuming a rigid structure) to test their capabilities, and the results of the two models are compared. DDES is chosen to simulate a fine mesh CFD-only case to conduct a mesh convergence study, and it is then used for final FSI simulations. The purpose of this work is focused on obtaining computational results; detailed comparisons against experimental data will be made in future work.
Pseudomonas aeruginosa AlgU Contributes to Posttranscriptional Activity by Increasing
rsmA
Expression in a
mucA22
Strain
Authors: Stacey Sean D. , Pritchett Christopher L.
Published: April 2016

Pseudomonas aeruginosa
thrives in multiple environments and is capable of causing life-threatening infections in immunocompromised patients. RsmA is a posttranscriptional regulator that controls virulence factor production and biofilm formation. In this study, we investigated the expression and activity of
rsmA
and the protein that it encodes, RsmA, in
P. aeruginosa
mucA
mutant strains, which are common in chronic infections. We determined that AlgU regulates a previously unknown
rsmA
promoter in
P. aeruginosa
. Western blot analysis confirmed that AlgU controls
rsmA
expression in both a laboratory strain and a clinical isolate. RNase protection assays confirmed the presence of two
rsmA
transcripts and suggest that RpoS and AlgU regulate
rsmA
expression. Due to the increased amounts of RsmA in
mucA
mutant strains, a translational leader fusion of the RsmA target,
tssA1
, was constructed and tested in
mucA
,
algU
,
retS
,
gacA
, and
rsmA
mutant backgrounds to examine posttranscriptional activity. From these studies, we determined that RsmA is active in
mucA22
mutants, suggesting a role for RsmA in
mucA
mutant strains. Taken together, we have demonstrated that AlgU controls
rsmA
transcription and is responsible for RsmA activity in
mucA
mutant strains. We propose that RsmA is active in
P. aeruginosa
mucA
mutant strains and that RsmA also plays a role in chronic infections.

IMPORTANCE
P. aeruginosa
causes severe infections in immunocompromised patients. The posttranscriptional regulator RsmA is known to control virulence and biofilm formation. We identify a new
rsmA
promoter and determine that AlgU is important in the control of
rsmA
expression. Mutant
mucA
strains that are considered mucoid were used to confirm increased
rsmA
expression from the AlgU promoter. We demonstrate, for the first time, that there is RsmA activity in mucoid
P. aeruginosa
strains. Our work suggests that RsmA may play a role during chronic infections as well as acute infections.
Spore Peptidoglycan
Authors: Popham David L. , Bernhards Casey B.
Published: April 2016

Bacterial endospores possess multiple integument layers, one of which is the cortex peptidoglycan wall. The cortex is essential for the maintenance of spore core dehydration and dormancy and contains structural modifications that differentiate it from vegetative cell peptidoglycan and determine its fate during spore germination. Following the engulfment stage of sporulation, the cortex is synthesized within the intermembrane space surrounding the forespore. Proteins responsible for cortex synthesis are produced in both the forespore and mother cell compartments. While some of these proteins also contribute to vegetative cell wall synthesis, others are sporulation specific. In order for the bacterial endospore to germinate and resume metabolism, the cortex peptidoglycan must first be degraded through the action of germination-specific lytic enzymes. These enzymes are present, yet inactive, in the dormant spore and recognize the muramic-δ-lactam modification present in the cortex. Germination-specific lytic enzymes across
Bacillaceae
and
Clostridiaceae
share this specificity determinant, which ensures that the spore cortex is hydrolyzed while the vegetative cell wall remains unharmed.
Bacillus
species tend to possess two redundant enzymes, SleB and CwlJ, capable of sufficient cortex degradation, while the clostridia have only one, SleC. Additional enzymes are often present that cannot initiate the cortex degradation process, but which can increase the rate of release of small fragments into the medium. Between the two families, the enzymes also differ in the enzymatic activities they possess and the mechanisms acting to restrict their activation until germination has been initiated.
Clostridium perfringens
Sporulation and Sporulation-Associated Toxin Production
Authors: Li Jihong , Paredes-Sabja Daniel , Sarker Mahfuzur R. , McClane Bruce A.
Published: April 2016

The ability of
Clostridium perfringens
to form spores plays a key role during the transmission of this Gram-positive bacterium to cause disease. Of particular note, the spores produced by food poisoning strains are often exceptionally resistant to food environment stresses such as heat, cold, and preservatives, which likely facilitates their survival in temperature-abused foods. The exceptional resistance properties of spores made by most type A food poisoning strains and some type C foodborne disease strains involve their production of a variant small acid-soluble protein-4 that binds more tightly to spore DNA than to the small acid-soluble protein-4 made by most other
C. perfringens
strains. Sporulation and germination by
C. perfringens
and
Bacillus
spp. share both similarities and differences. Finally, sporulation is essential for production of
C. perfringens
enterotoxin, which is responsible for the symptoms of
C. perfringens
type A food poisoning, the second most common bacterial foodborne disease in the United States. During this foodborne disease,
C. perfringens
is ingested with food and then, by using sporulation-specific alternate sigma factors, this bacterium sporulates and produces the enterotoxin in the intestines.
Single-eye trial of a topical carbonic anhydrase inhibitor versus intravitreal bevacizumab for the treatment of taxane drug-induced cystoid macula oedema
Authors: Hassall Mark M , Andrew Nicholas Howard
Published: April 2016

Taxanes are a class of microtubule stabilising agents used to treat a wide range of malignancies. Taxane drug-induced cystoid macula oedema (TDICMO) is a known but rare complication of therapy. First reported with Docetaxel in 2003 and Paclitaxel in 2007, there are currently less than 20 cases of TDICMO in the literature. Although most cases resolve following taxane cessation, several authors have tried using carbonic anhydrase inhibitors or intravitreal bevacizumab to accelerate resolution or when taxane therapy cannot be discontinued. We report the first published case of TDICMO treated with a single-eye trial of topical dorzolamide versus intravitreal bevacizumab.
Severe transaminitis in a paediatric patient with systemic lupus erythaematosus and a discussion of the literature
Authors: Sarda Garima , Harvey Rohini
Published: April 2016

A 15-year-old African-American girl with known systemic lupus erythaematosus (SLE) presented to the emergency room with fever, abdominal distension, pain and vomiting. She was found to have severe transaminitis on laboratory examination, which prompted further work up including imaging and liver biopsy. Although complete diagnostic criteria were not met, histology was suggestive of autoimmune hepatitis (AIH). She was treated with steroids and azathioprine with good response and resolution of liver function tests. Availability of the literature discussing patients of any age with SLE and AIH is minimal, and consists mostly of small case series and some case reports. The juvenile literature on SLE and AIH occurring in the same patient is even scarcer and should be further studied at a multicentre level.
Pyomyositis in a patient with systemic lupus erythaematosus and a review of the literature
Authors: Meesiri Somchai
Published: April 2016

Pyomyositis (PM) is a common masquerading disease that is frequently misdiagnosed. A concurrent state of immunodeficiency is observed in up to 75% of tropical PM cases. PM in systemic lupus erythaematosus (SLE) is a relatively rare disease. I report a case of PM that was caused byKlebsiella pneumoniaein a patient with SLE who presented with leg pain, fever and a lupus flare-up. The patient was correctly diagnosed using a CT scan. Immediate surgical drainage was performed, and empirical antibiotics were administered. The patient was discharged while in a recovering condition. The clinical features, the results of radiographic investigations and the management of PM in SLE are synopsised in this article to underscore the importance of considering this relatively rare disease during differential diagnosis in patients with SLE with muscle pain with or without fever. I also emphasise the need to exclude mycobacterial infection in patients with SLE with PM.
An economic analysis of resting versus nonresting perennial pastures during the critical acclimation period
Authors: Fryza Stefanie , Carlberg Jared G. , Khakbazan Mohammad , Robins Clayton D. , Block Hushton C. , Scott Shannon L. , Huang John , Durunna Obioha N.
Published: April 2016

Economic evaluations were carried out on stochastically simulated production systems using data from a grazing systems’ trial, which evaluated the impact of resting (i.e., grazing cessation) alfalfa (Medicago sativa L.) – bromegrass (Bromus riparius Rehm. ‘Fleet’) and grass-only (G) pastures during the critical prefrost period on beef cattle (Bos taurus) productivity. Grazing systems were compared on the basis of calculated net present value of returns analysis. Lower production costs through reduced fertilization requirements resulted in alfalfa–grass (AG) preference over G pastures, while returns from increased calf sale weights resulted in nonrested systems being preferred over rested systems. However, low presence of alfalfa in the AG pastures likely limited the potential for resting pastures to improve production through increased alfalfa persistence. This evaluation found nonrested grazing of AG pastures to be preferred over other treatments on the basis of increased returns and reduced risk.
Feeding steers hay with extruded flaxseed together or sequentially has a profound effect on erythrocyte trans 11-18:1 (vaccenic acid)
Authors: Vahmani P. , Rolland D.C. , McAllister T.A. , Block H.C. , Proctor S.D. , Guan L.L. , Prieto N. , Aalhus J.L. , Dugan M.E.R.
Published: April 2016

Extruded flaxseed and ground hay [25% and 75%; dry matter (DM) basis] were fed in a total mixed ration (TMR) or sequentially (non-TMR) to three pens of eight crossbred steers per diet. At 112 d, erythrocytes from non-TMR steers had 65% more vaccenic acid (trans 11-18:1) than TMR steers (P < 0.05).
Chikusetsu saponin V attenuates H2O2-induced oxidative stress in human neuroblastoma SH-SY5Y cells through Sirt1/PGC-1α/Mn-SOD signaling pathways
Authors: Wan Jingzhi , Deng Lili , Zhang Changcheng , Yuan Qin , Liu Jing , Dun Yaoyan , Zhou Zhiyong , Zhao Haixia , Liu Chaoqi , Yuan Ding , Wang Ting
Published: April 2016

Oxidative stress plays a vital role in the pathogenesis of neurodegenerative diseases. Chikusetsu saponin V (CsV), the most abundant member of saponins from Panax japonicus (SPJ), has attracted increasing attention for its potential to treat neurodegenerative diseases. However, the mechanisms are unclear. Our study intended to investigate the antioxidative effects of CsV in human neuroblastoma SH-SY5Y cells. Our data showed that CsV attenuated H2O2-induced cytotoxicity, inhibited ROS accumulation, increased the activities of superoxide dismutase (SOD) and GSH, and increased mitochondrial membrane potential dose-dependently. Further exploration of the mechanisms showed that CsV exhibited these effects through increasing the activation of oxidative-stress-associated factors including Sirt1, PGC-1α, and Mn-SOD. Moreover, CsV inhibited H2O2-induced down-regulation of Bcl-2 and up-regulation of Bax in a dose-dependent manner and, thus, increased the ratio of Bcl-2/Bax. In conclusion, our study demonstrated that CsV exhibited neuroprotective effects possibly through Sirt1/PGC-1α/Mn-SOD signaling pathways.
Recent developments in the tidal deformability of spinning compact objects
Authors: Pani Paolo , Gualtieri Leonardo , Maselli Andrea , Ferrari Valeria
Published: April 2016

We review recent work on the theory of tidal deformability and the tidal Love numbers of a slowly spinning compact object within general relativity. Angular momentum introduces couplings between distortions of different parity and new classes of spin-induced, tidal Love numbers emerge. Due to spin-tidal effects, a rotating object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second-order in the spin. The tidal Love numbers depend strongly on the object’s internal structure. All tidal Love numbers of a Kerr black hole (BH) were proved to be exactly zero to first-order in the spin and also to second-order in the spin, at least in the axisymmetric case. For a binary system close to the merger, various components of the tidal field become relevant. Preliminary results suggest that spin-tidal couplings can introduce important corrections to the gravitational waveforms of spinning neutron star (NS) binaries approaching the merger.
Improvement of electrocatalytic effect in voltammetric sensors based on phthalocyanines
Authors: Rodríguez-Méndez María L. , Medina-Plaza Cristina , García-Hernández Celia , Rodríguez Silvia , García-Cabezón Cristina , Paniagua David , Rodríguez-Pérez Miguel A. , de Saja José A.
Published: April 2016

Voltammetric sensors based on phthalocyanines have been used to detect a variety of compounds. In this paper, the state of the art of sensors prepared using classical techniques will be revised. Then, new strategies to improve the performance of the sensors will be described using as example sensors chemically modified with lutetium bisphthalocyanine (LuPc[Formula: see text] dedicated to the detection of phenols of interest in the food industry. Classical LuPc2carbon paste electrodes can detect phenols such as catechol, caffeic acid or pyrogallol with limits of detection in the range of 10[Formula: see text]–10[Formula: see text] M. The performance can be improved by using nanostructured Langmuir–Blodgett (LB) or Layer by Layer (LbL) films. The enhanced surface to volume ratio produce an increase in the sensitivity of the sensors. Limits of detection of 10[Formula: see text]–10[Formula: see text] M are attained, which are one order of magnitude lower than those obtained using conventional carbon paste electrodes. Moreover, these techniques can be used to co-immobilize two electrocatalytic materials in the same device. The limits of detection obtained in LB sensors combining LuPc2/AuNPs or LuPc2/CNT are further improved. Finally, the LB technique has been used to prepare biosensors where a phenol oxydase (such as tyrosinase or lacasse) is immobilized in a biomimetic environment that preserves the enzymatic activity. Moreover, LuPc2can be co-immobilized with the enzyme in a lipidic film formed by arachidic acid (AA). LuPc2can act as an electron mediator facilitating the electron transfer. These biomimetic sensors formed by LuPc2/AA/enzyme show Limits of detection of 10[Formula: see text] M and an enhanced selectivity.
Mass Spectrometry as a Preparative Tool for the Surface Science of Large Molecules
Authors: Rauschenbach Stephan , Ternes Markus , Harnau Ludger , Kern Klaus
Published: April 2016

Measuring and understanding the complexity that arises when nanostructures interact with their environment are one of the major current challenges of nanoscale science and technology. High-resolution microscopy methods such as scanning probe microscopy have the capacity to investigate nanoscale systems with ultimate precision, for which, however, atomic scale precise preparation methods of surface science are a necessity. Preparative mass spectrometry (pMS), defined as the controlled deposition of m/z filtered ion beams, with soft ionization sources links the world of large, biological molecules and surface science, enabling atomic scale chemical control of molecular deposition in ultrahigh vacuum (UHV). Here we explore the application of high-resolution scanning probe microscopy and spectroscopy to the characterization of structure and properties of large molecules. We introduce the fundamental principles of the combined experiments electrospray ion beam deposition and scanning tunneling microscopy. Examples for the deposition and investigation of single particles, for layer and film growth, and for the investigation of electronic properties of individual nonvolatile molecules show that state-of-the-art pMS technology provides a platform analog to thermal evaporation in conventional molecular beam epitaxy. Additionally, it offers additional, unique features due to the use of charged polyatomic particles. This new field is an enormous sandbox for novel molecular materials research and demands the development of advanced molecular ion beam technology.
Mechanics and Single-Molecule Interrogation of DNA Recombination
Authors: Bell Jason C. , Kowalczykowski Stephen C.
Published: April 2016

The repair of DNA by homologous recombination is an essential, efficient, and high-fidelity process that mends DNA lesions formed during cellular metabolism; these lesions include double-stranded DNA breaks, daughter-strand gaps, and DNA cross-links. Genetic defects in the homologous recombination pathway undermine genomic integrity and cause the accumulation of gross chromosomal abnormalities—including rearrangements, deletions, and aneuploidy—that contribute to cancer formation. Recombination proceeds through the formation of joint DNA molecules—homologously paired but metastable DNA intermediates that are processed by several alternative subpathways—making recombination a versatile and robust mechanism to repair damaged chromosomes. Modern biophysical methods make it possible to visualize, probe, and manipulate the individual molecules participating in the intermediate steps of recombination, revealing new details about the mechanics of genetic recombination. We review and discuss the individual stages of homologous recombination, focusing on common pathways in bacteria, yeast, and humans, and place particular emphasis on the molecular mechanisms illuminated by single-molecule methods.
New Vistas in Chemical Product and Process Design
Authors: Zhang Lei , Babi Deenesh K. , Gani Rafiqul
Published: April 2016

Design of chemicals-based products is broadly classified into those that are process centered and those that are product centered. In this article, the designs of both classes of products are reviewed from a process systems point of view; developments related to the design of the chemical product, its corresponding process, and its integration are highlighted. Although significant advances have been made in the development of systematic model-based techniques for process design (also for optimization, operation, and control), much work is needed to reach the same level for product design. Timeline diagrams illustrating key contributions in product design, process design, and integrated product-process design are presented. The search for novel, innovative, and sustainable solutions must be matched by consideration of issues related to the multidisciplinary nature of problems, the lack of data needed for model development, solution strategies that incorporate multiscale options, and reliability versus predictive power. The need for an integrated model-experiment-based design approach is discussed together with benefits of employing a systematic computer-aided framework with built-in design templates.
Statistical Methods in Integrative Genomics
Authors: Richardson Sylvia , Tseng George C. , Sun Wei
Published: April 2016

Statistical methods in integrative genomics aim to answer important biology questions by jointly analyzing multiple types of genomic data (vertical integration) or aggregating the same type of data across multiple studies (horizontal integration). In this article, we introduce different types of genomic data and data resources, and then we review statistical methods of integrative genomics with emphasis on the motivation and rationale of these methods. We conclude with some summary points and future research directions.
Discrete-Time Dynamical Maximum Power Tracking Control for a Vertical Axis Water Turbine with Retractable Blades
Authors: Mao Zhaoyong , Liu Qian , Cui Rongxin
Published: April 2016

This paper addresses the power generation control system of a new drag-type Vertical Axis Turbine with several retractable blades. The returning blades can be entirely hidden in the drum, and negative torques can then be considerably reduced as the drum shields the blades. Thus, the power efficiency increases. Regarding the control, a Linear Quadratic Tracking (LQT) optimal control algorithm for Maximum Power Point Tracking (MPPT) is proposed to ensure that the wave energy conversion system can operate highly effectively under fluctuating conditions and that the tracking process accelerates over time. Two-dimensional Computational Fluid Dynamics (CFD) simulations are performed to obtain the maximum power points of the turbine’s output. To plot the tip speed ratio curve, the least squares method is employed. The efficacy of the steady and dynamic performance of the control strategy was verified using Matlab/Simulink software. These validation results show that the proposed system can compensate for power fluctuations and is effective in terms of power regulation.
The Friction of Saline Ice on Aluminium
Authors: Wallen-Russell Christopher , Lishman Ben
Published: April 2016

The friction of ice on other materials controls loading on offshore structures and vessels in the Arctic. However, ice friction is complicated, because ice in nature exists near to its melting point. Frictional heating can cause local softening and perhaps melting and lubrication, thus affecting the friction and creating a feedback loop. Ice friction is therefore likely to depend on sliding speed and sliding history, as well as bulk temperature. The roughness of the sliding materials may also affect the friction. Here we present results of a series of laboratory experiments, sliding saline ice on aluminium, and controlling for roughness and temperature. We find that the friction of saline ice on aluminiumμice-al=0.1typically, but that this value varies with sliding conditions. We propose physical models which explain the variations in sliding friction.
The Protective Effect of Beraprost Sodium on Diabetic Nephropathy by Inhibiting Inflammation and p38 MAPK Signaling Pathway in High-Fat Diet/Streptozotocin-Induced Diabetic Rats
Authors: Peng Li , Li Jie , Xu Yixing , Wang Yangtian , Du Hong , Shao Jiaqing , Liu Zhimin
Published: April 2016

Background. p38 mitogen-activated protein kinase (MAPK) plays a crucial role in regulating signaling pathways implicated in inflammatory processes leading to diabetic nephropathy (DN). This study aimed to examine p38 MAPK activation in DN and determine whether beraprost sodium (BPS) ameliorates DN by inhibiting inflammation and p38 MAPK signaling pathway in diabetic rats.Methods. Forty male Sprague Dawley (SD) rats were randomly divided into the normal control group, type 2 diabetic group, and BPS treatment group. At the end of the 8-week experiment, we measured renal pathological changes and the activation of the p38 MAPK signaling pathway and inflammation.Result. After BPS treatment, renal function, 24-hour urine protein, lipid profiles, and blood glucose level were improved significantly; meanwhile, inflammation and the expression of p38 MAPK signaling pathway in the diabetic kidney were attenuated.Conclusions. BPS significantly prevented type 2 diabetes induced kidney injury characterized by renal dysfunction and pathological changes. The protective mechanisms are complicated but may be mainly attributed to the inhibition of the p38 MAPK signaling pathway and inflammation in the diabetic kidney.
Tracking of Range and Azimuth for Continuous Imaging of Marine Target in Monopulse ISAR with Wideband Echoes
Authors: Xie Junhao , Zhou Wei , Zhou Gongjian , Yuan Yeshu , Li Shaobin
Published: April 2016

Real-time tracking of maneuvering targets is the prerequisite for continuous imaging of moving targets in inverse synthetic aperture radar (ISAR). In this paper, the range and azimuth tracking (RAT) method with wideband radar echoes is first presented for a mechanical scanning monopulse ISAR, which is regarded as the simplest phased array unit due to the two antenna feeds. To relieve the estimation fluctuation and poor robustness of the RAT method with a single snapshot, a modified range and azimuth tracking approach based on centroid algorithm (RATCA) with forgotten factor and multiple echoes is then proposed. The performances of different forgotten factors are investigated. Both theoretical analysis and experimental results demonstrate that RATCA is superior to RAT method. Particularly, when target echo is missing occasionally, RAT method fails while RATCA still keeps good performance. The potential of continuous imaging with shipborne ISAR is verified by experimental results. With minor modification, the method proposed in this paper can be potentially applied in the phased array radar.
Improving Indoor Localization Using Bluetooth Low Energy Beacons
Authors: Kriz Pavel , Maly Filip , Kozel Tomas
Published: April 2016

The paper describes basic principles of a radio-based indoor localization and focuses on the improvement of its results with the aid of a new Bluetooth Low Energy technology. The advantage of this technology lies in its support by contemporary mobile devices, especially by smartphones and tablets. We have implemented a distributed system for collecting radio fingerprints by mobile devices with the Android operating system. This system enables volunteers to create radio-maps and update them continuously. New Bluetooth Low Energy transmitters (Apple uses its “iBeacon” brand name for these devices) have been installed on the floor of the building in addition to existing WiFi access points. The localization of stationary objects based on WiFi, Bluetooth Low Energy, and their combination has been evaluated using the data measured during the experiment in the building. Several configurations of the transmitters’ arrangement, several ways of combination of the data from both technologies, and other parameters influencing the accuracy of the stationary localization have been tested.