bluuebunny/crossref_metadata_2025 huggingface dataset:
Identifying and Categorizing Opportunities for Design for Sustainable User Behavior
Authors: Withanage Chathura , Ashok Rahul , Hölttä-Otto Katja , Otto Kevin
Published: January 2015

The constantly growing world population and depleting natural resources make promoting sustainable behavior of paramount importance. Household energy is a significant percent of global energy consumption. While there has been significant work in improving energy awareness, there remains opportunity in designing systems that help direct users toward more sustainable behavior. This is particularly true since user behavior, as influenced by attitudes, beliefs and preferences, is a main driver of the household energy consumption. In this paper, a method is presented to identify and categorize design for sustainable behavior opportunities as failure modes on unnecessary overconsumption. We do this by comparing actual behavior against the minimum necessary to complete the task. Any deviation from the energy minimum is a failure mode opportunity. We clarify when opportunities are suitable for design for sustainable behavior, and when opportunities require stronger intervention of product or process redesign. To do this, user behavior was analyzed in a living laboratory format. Subjects were asked to perform a simple daily cooking activity in two phases; first in their routine manner and subsequently by trying to reduce energy consumption. In addition to recorded data on energy consumed, the users were interviewed on each user activity to understand which activities people were aware of means to reduce energy and in which they were not. The overall results show that all participants were able to reduce their energy consumption significantly when asked to do so, but these energy reducing behaviors were often ignored and not part of their daily routine. Based on this analysis, we identify opportunities where improving energy awareness is the issue, and other opportunities where more difficult sustainable design of the product or the process is needed since users are already aware but choose not to bother with reducing consumption.
Optimal Dual-Mode Hybrid Electric Vehicle Powertrain Architecture Design for a Variety of Loading Scenarios
Authors: Bayrak Alparslan Emrah , Ren Yi , Papalambros Panos Y.
Published: January 2015

A hybrid-electric vehicle powertrain architecture consists of single or multiple driving modes, i.e., connection arrangements among engine, motors and vehicle output shaft that determine distribution of power. While most architecture development work to date has focused primarily on passenger cars, interest has been growing in exploring architectures for special-purpose vehicles such as vans or trucks for civilian and military applications, whose weights or payloads can vary significantly during operations. Previous findings show that the optimal architecture can be sensitive to vehicle weight. In this paper we investigate architecture design under a distribution of vehicle weights, using a simulation-based design optimization strategy with nested supervisory optimal control and accounting for powertrain complexity. Results show that an architecture under a single load has significant differences and lower fuel efficiency than an architecture designed to work under a variety of loading scenarios.
Collective Dynamics of Arrays of Micro Cantilevers Interacting Through Fringing Electrostatic Fields
Authors: Krylov Slava , Lulinsky Stella , Ilic Bojan R. , Schneider Inbar
Published: January 2015

We investigate the collective nonlinear behavior of an array of micro cantilevers interacting by fringing electrostatic fields and fabricated of silicon on insulator (SOI) wafer. The interaction is due to the mechanical coupling originated in the flexibility of the anchor and of the electrostatic coupling through voltage-dependent electrostatic force. In the framework of the reduced order model based on the Galerkin decomposition the array is considered as an assembly of single degree of freedom oscillators. The mechanical coupling matrix is extracted using the full scale finite element analysis of the array while the electrostatic force is approximated by a fit build using the three-dimensional numerical simulation. We show numerically and experimentally that large amplitude collective vibrations of the array can be achieved using parametric excitation while the dynamic properties of the array can be efficiently tuned by the applied voltage.
FEM Analysis of Bone-Ligaments-Tooth Models for Biomechanical Simulation of Individual Orthodontic Devices
Authors: Savignano Roberto , Barone Sandro , Paoli Alessandro , Razionale Armando V.
Published: January 2015

In the last decades, research in the orthodontic field has focused on the development of more comfortable and aesthetic appliances such as thermoformed aligners. Aligners have been used in orthodontics since the mid 20-century. Nonetheless, there is still not enough knowledge about how they interact with teeth. This paper is focused on the development of a Finite Element Method (FEM) model to be used in the optimization process of geometrical attributes of removable aligners. The presented method integrates Cone Beam Computed Tomography (CBCT) data and optical data in order to obtain a customized model of the dental structures, which include both crown and root shapes. The digital simulation has been focused on analyzing the behavior of three upper frontal teeth. Moreover, the analyses have been carried out by using different aligners’ thicknesses with the support of composite structures polymerized on teeth surfaces while simulating a 2 degrees rotation of an upper central incisor.
Dynamics of an Imperfect Microbeam Considering its Exact Shape
Authors: Bataineh Ahmad M. , Younis Mohammad I.
Published: January 2015

We study the static and dynamic behavior of electrically actuated micromachined arches. First, we conduct experiments on micromachined polysilicon beams by driving them electrically and varying their amplitude and frequency of voltage loads. The results reveal several interesting nonlinear phenomena of jumps, hysteresis, and softening behaviors. Next, we conduct analytical and theoretical investigation to understand the experiments. First, we solve the Eigen value problem analytically. We study the effect of the initial rise on the natural frequency and mode shapes, and use a Galerkin-based procedure to derive a reduced order model, which is then used to solve both the static and dynamic responses.

We use two symmetric modes in the reduced order model to have accurate and converged results. We use long time integration to solve the nonlinear ordinary differential equations, and then modify our model using effective length to match experimental results.

To further improve the matching with the experimental data, we curve-fit the exact profile of the microbeam to match the experimentally measured profile and use it in the reduced-order model to generate frequency-response curves.

Finally, we use another numerical technique, the shooting technique, to solve the nonlinear ordinary differential equations. By using shooting and the curve fitted function, we found that we get good agreement with the experimental data.
Design of a Low Energy, Self Contained Subsea Burrowing Robot Based on Localized Fluidization Exhibited by Atlantic Razor Clams
Authors: Dorsch Daniel S. , Winter Amos G.
Published: January 2015

The Atlantic razor clam (Ensis directus) burrows by contracting its valves, fluidizing the surrounding soil and reducing burrowing drag. Moving through a fluidized, rather than static, soil requires energy that scales linearly with depth, rather than depth squared. In addition to providing an advantage for the animal, localized fluidization may provide significant value to engineering applications such as vehicle anchoring and underwater pipe installation. This paper presents the design of a self-actuated, radially expanding burrowing mechanism that utilizes E. directus’ burrowing methods. The device is sized to be a platform for an anchoring system for autonomous underwater vehicles. Scaling relationships presented allow for design of burrowing systems of different sizes for a variety of applications. The minimum contraction time for a given device size governs how quickly the device must move. Contraction displacement necessary to achieve fluidization is presented. The maximum force for a given size mechanism is also calculated, and allows for sizing actuators for different systems. This paper presents the design of a system that will allow testing of these parameters in a laboratory setting. These relationships provide the optimal sizing and power needs for various size subsea borrowing systems.
Dynamic Impact Measurements on Crossings, in Free Floating and In-Situ Conditions
Authors: Boogaard M. A. , Schwab A. L. , Li Z.
Published: January 2015

As vibration based condition monitoring requires a good understanding of the dynamic behaviour of the structure, a good model is needed. At the TU Delft a train borne monitoring system is being developed which currently focusses on crossings. Crossings are prone to very fast degradation due to impact loading. In this paper a finite element model of a free floating frog is presented and validated up to a 100 Hz using dynamic impact measurements. The mode shapes of the free floating frog are then also compared to some preliminary results from an in-situ test. This comparison shows that the in-situ frequencies can be up to twice the free floating frequency.
An Inverted Straight Line Mechanism for Augmenting Joint Range of Motion in a Humanoid Robot
Authors: Knabe Coleman , Lee Bryce , Hong Dennis
Published: January 2015

Many robotic joints powered by linear actuators suffer from a loss of torque towards the limits of the range of motion. This paper presents the design of a fully backdriveable, force controllable rotary actuator package employed on the Tactical Hazardous Operations Robot (THOR). The assembly pairs a ball screw-driven linear Series Elastic Actuator (SEA) with a planar straight line mechanism. The mechanism is a novel inversion of a Hoeken’s four-bar linkage, using the ball screw as a linear input to actuate the rotary joint. Link length ratios of the straight line mechanism have been chosen to optimize constant angular velocity, resulting in a nearly constant mechanical advantage and peak torque of 115 [Nm] throughout the 150° range of motion. Robust force control is accomplished through means of a lookup table, which is accurate to within ±0.62% of the nominal torque profile for any load case.
On the Stability of Continuous-Time Systems With Stochastic Delay: Applications to Gene Regulatory Circuits
Authors: Sadeghpour Mehdi , Orosz Gábor
Published: January 2015

In this paper the dynamics and stability of a linear system with stochastic delay are investigated. We assume that the delay may take finitely many different values and its dynamics are modeled by a continuous-time Markov chain. Semi-discretization is used to derive the dynamics of the second moment which leads to necessary and sufficient stability conditions for the trivial solution. We apply these results to investigate the stability of the steady state of an auto-regulatory gene-protein network. We demonstrate that stochastic delay may stabilize the system when the corresponding deterministic system with average delay is unstable.
Micro-Robotic Actuation Units Based on Thin-Film Piezoelectric and High-Aspect Ratio Polymer Structures
Authors: Shin Minchul , Choi Jongsoo , Rudy Ryan Q. , Kao Christopher , Pulskamp Jeffrey S. , Polcawich Ronald G. , Oldham Kenn R.
Published: January 2015

A fabrication procedure is presented for creating microactuation elements that link piezoelectric thin-films with high-aspect ratio parylene microstructures. Resulting actuators permit relatively large rotational motions for low voltage operation, while maintaining large weight-bearing capacity. Actuator fabrication is performed on a silicon wafer though a combination of metal and thin-film lead-zirconate-titanate (PZT) deposition and patterning, parylene refill of high-aspect ratio trenches, and dry release of moving parts from the silicon substrate. Static and dynamic responses of various test structures are measured, to estimate material properties of the integrated PZT-polymer structures, for use in future actuator modeling and optimization.
Topology Optimization for Design of Origami-Based Active Mechanisms
Authors: Fuchi Kazuko , Buskohl Philip R. , Joo James J. , Reich Gregory W. , Vaia Richard A.
Published: January 2015

Origami structures morph between 2D and 3D conformations along predetermined fold lines that efficiently program the form of the structure and show potential for many engineering applications. However, the enormity of the design space and the complex relationship between origami-based geometries and engineering metrics place a severe limitation on design strategies based on intuition. The presented work proposes a systematic design method using topology optimization to distribute foldline properties within a reference crease pattern, adding or removing folds through optimization, for a mechanism design. Following the work of Schenk and Guest, foldable structures are modeled as pin-joint truss structures with additional constraints on fold, or dihedral, angles. The performance of a designed origami mechanism is evaluated in 3D by applying prescribed forces and finding displacements at set locations. The integration of the concept of origami in mechanism design thus allows for the description of designs in 2D and performance in 3D. Numerical examples indicate that origami mechanisms with desired deformations can be obtained using the proposed method. A constraint on the number of foldlines is used to simplify a design.
Fatigue Test for Thick Wire Bonds
Authors: Dagdelen Turker , El-Rayes Karim , Park Sangtak , Khater Mahmoud , Saritas Resul , Abdel-Rahman Eihab , Yavuz Mustafa
Published: January 2015

Thick bonding wires used in power modules experience a wide range of temperature and mechanical load cycling conditions. This leads to cracks at the wire heel due to fatigue. In this study, a new type of thick wire bonds, Aluminum coated copper, was subjected to fatigue test to investigate its durability. Unlike traditional thermal cycling, this test involves applying a pattern of repetitive prescribed displacements to a wire foot while fatigue failure is detected via a Wheatstone bridge. The aim is to compare different wire materials to the number-of-cycles-to-failure, thereby quantifying the reliability and life time of thick wire bond.
Topology Optimization With Unknown-but-Bounded Load Uncertainty
Authors: Zhao Xike , Song Wei , Gea Hae Chang , Xu Limei
Published: January 2015

In this paper, convex modeling based topology optimization with load uncertainty is presented. The load uncertainty is described using the non-probabilistic based unknown-but-bounded convex model, and the strain energy based topology optimization problem under uncertain loads is formulated. Unlike the conventional deterministic topology optimization problem, the maximum possible strain energy under uncertain loads is selected as the new objective in order to achieve a safe solution. Instead of obtaining approximated solutions as used before, an exact solution procedure is presented. The problem is first formulated as a single level optimization problem, and then rewritten as a two-level optimization problem. The upper level optimization problem is solved as a deterministic topology optimization with the load which generated from the worst structure response in the lower level problem. The lower level optimization problem is to identify this worst structure response, and it is found equivalent to an inhomogeneous eigenvalue problem. Three different cases are discussed for accurately evaluating the global optima of the lower level optimization problem, while the corresponding sensitivities are derived individually. With the function value and sensitivity information ready, the upper level optimization problem can be solved through existing gradient based optimization algorithms. The effectiveness of the proposed convex modeling based topology optimization is demonstrated through different numerical examples.
Customizable Joint Mechanism for Knee Orthosis
Authors: Eschbach Matthew , Huber Martin , Ilies Horea , Kazerounian Kazem
Published: January 2015

Knee pain, muscle weakness, and their associated medical conditions cause a significant loss of mobility for a large and growing number of people. Accordingly, the need for effective, simple, and noninvasive methods for controlling these problems is becoming more apparent. To that end, we have designed a quasi-passive knee-orthosis that employs a “hybrid joint mechanism” as a central component. This joint combines a four-bar linkage with a compliant mechanism to follow natural knee motion. A poorly fitted knee orthosis can detrimentally affect its effectiveness due to the large variability in the patient-specific knee motion. Our design can be optimized to fit a given user, based on both motion capture data and their particular condition, which leads to several potential advantages over standardized hinges. In this paper, we will explore the design and individualization process of the joint mechanism as well as the background covering various design decisions.
High Reconfigurable Robotic Gripper for Flexible Assembly
Authors: Canali C. , Cannella F. , Chen F. , Hauptman T. , Sofia G. , Caldwell D. G. , Eytan A. A.
Published: January 2015

This paper describes a general purpose gripper to be used into industrial manufacturing application. The gripper has been developed in the context of the AUTORECON project. It is based on a 2 degrees of freedom finger that is able to adapt itself to objects of various shape, size, material and weight. Thanks to its highly reconfigurable and adaptive capabilities, the gripper described here is an attempt to create a gripper suitable in industrial application to assemble compounds of several different workpieces using only one robot. The high dexterity and the wide range of possible uses of the gripper described here intends to explore a new approach to the design of industrial grippers to be used in factory automation. Moreover, the adaptive capabilities of this gripper make it suitable to grasp workpieces with complicated geometry or highly irregular shape, as it has been proved in performed automotive test rig described here.
Powering Pacemakers With a Nonlinear Hybrid Rotary-Translational Energy Harvester
Authors: Kuch Benjamin , Karami M. Amin
Published: January 2015

An application of a nonlinear Hybrid Rotary-Translational (HRT) generator is presented. An HRT generator differs from traditional energy harvesting devices in that it has the ability to harvest multi-axis base excitation. The device consists of a pendulum-like system whose rotations are caused by the base excitations. The swinging pendulum is coupled to a direct current micro generator to generate electricity.

The considered application is the energy harvesting from heartbeat induced vibrations. The motivation behind studying the effectiveness of this application comes from battery hindrance. The use of relatively large batteries to power pacemakers presents many medical problems, including increasing the size of the device to accommodate the battery causing surgery complications as well as needing periodic battery replacement. An energy harvesting device can eliminate the need for such a battery, relying instead on the power generated by the beating heart.

The nonlinearity of the device allows constant power to be generated across a wider range of frequencies (heartbeats per minute). The contractions of the heart are considered to be the base excitations of the device, causing the pendulum to swing. To validate and then optimize the design of the HRT system, the behavior and the power generation of the system will be studied under different parameters: size of generator, mass and length of pendulum components as well as frequency of heart beats (beats per minute). This presents an interesting design problem whose goal is to find the best HRT parameters that would result in generating the sufficient amounts of power required by pacemakers.

A method in approximating the nonlinear dynamics of the electro-mechanical energy harvesting system is also presented. By studying the analytical solutions to the nonlinear electromechanical system under a sine wave excitation, we can gain insight into the problem. The extent of this paper will only cover the analytical solution to the vertically excited pendulum. Perturbation methods, specifically the multiple scales method will be employed to study the effects of forcing amplitude and frequency on the system behavior and the energy harvesting system.
Performance of Reduced Order Models of Moving Heat Source Deposition Problems for Efficient Inverse Analysis
Authors: Michopoulos John G. , Dennis Brian , Komninelli Foteini , Iliopoulos Athanasios , Akbariyeh Ashkan
Published: January 2015

In order to reduce the demanding computational requirements for the numerical solution of problems involving heat transfer problems of moving heat source deposition, we present an approach utilizing reduced order models based on proper orthogonal decomposition and associated Galerkin projection. We subsequently describe the finite element implementation of solution methodology for both the full order and the reduced order models, as well as the respective computational implementation details. Using this methodology, we performed a sensitivity analysis for a problem of a moving heat source to investigate the performance characteristics of the relevant reduced order model size and present the efficiency of the approach. We demonstrated the efficiency of the reduced models for performing inverse analysis.
Evaluating the Bottom-Up Method for Functional Decomposition in Product Dissection Tasks
Authors: Booth Joran W. , Bhasin Abihnav K. , Reid Tahira , Ramani Karthik
Published: January 2015

The purpose of this study is to continue to explore which function identification methods work best for specific design tasks. Prior literature describes the top-down and bottom-up approaches as equivalent methods for functional decomposition. Building on our prior work, this study tests the bottom-up method against the top-down and enumeration methods. We used a 3-factor within-subject study (n=136). While most of our diagram-oriented metrics were not statistically different, we found statistical support that: 1.) students reported that the dissection activity was more useful when using bottom-up, and 2.) that student engineers committed many more syntax errors when using the bottom-up method (by listing parts instead of functions). We believe that both these results are due to the increased focus on individual parts. We do not know if an increased attention to the parts would increase novelty or fixation, and recommend future studies to find out.
Analytical Periodic Motions of a Parametric Oscillator With Quadratic Nonlinearity
Authors: Luo Albert C. J. , Yu Bo
Published: January 2015

In this paper, the analytical solutions of periodic motions in a parametric oscillator are presented by the finite Fourier series expansion, and the stability and bifurcation analysis of periodic motions are performed. Numerical illustrations of periodic motions are presented through phase trajectories and analytical spectrum.
Design of a Wearable Scissored-Pair Control Moment Gyroscope (SP-CMG) for Human Balance Assist
Authors: Chiu Jimmy , Goswami Ambarish
Published: January 2015

Our research examines the feasibility of usign a wearable scissored-pair control moment gyroscope (CMG) for human balance assist. The CMG is a momentum exchange device consisting of a fast spinning flywheel mounted on a gimbal. The gimbal motion changes the direction of the flywheel rotation axis, which generates a reactionless torque. A scissored-pair CMG has the additional advantage of isolating the output torque to a single axis, where off-axis torques are canceled out. A properly designed CMG device worn as a backpack can apply a torque in the sagittal plane of the human trunk. This can help in restoring postural balance and in fall mitigation.

This paper describes the complete design process of a scissored-pair CMG device with constraints on size, mass and dynamic properties for human wearability. A prototype of this device is built, utilizing a novel dual-flywheel design; it weighs about 8kg and is able to generate over 20Nm of torque. A custom hardware is built specifically for verifying the torque output of the device. To our knowledge this is the only device that generates the range of reactionless torque given its weight and size.
Folding Rigid Origami With Closure Constraints
Authors: Xi Zhonghua , Lien Jyh-Ming
Published: January 2015

Rigid origami is a class of origami whose entire surface remains rigid during folding except at crease lines. Rigid origami finds applications in manufacturing and packaging, such as map folding and solar panel packing. Advances in material science and robotics engineering also enable the realization of self-folding rigid origami and have fueled the interests in computational origami, in particular the issues of foldability, i.e., finding folding steps from a flat sheet of crease patterns to desired folded state. For example, recent computational methods allow rapid simulation of folding process of certain rigid origamis. However, these methods can fail even when the input crease pattern is extremely simple. This paper attempts to address this problem by modeling rigid origami as a kinematic system with closure constraints and solve the foldability problem through a randomized method. Our experimental results show that the proposed method successfully fold several types of rigid origamis that the existing methods fail to fold.
Untethered Microrobots Actuated With Focused Permanent Magnet Field
Authors: Torres Nahum A. , Ruggeri Serena , Popa Dan O.
Published: January 2015

This paper investigates the actuation of untethered microrobots with a focused magnetic field generated by a permanent magnet wand. The microrobots are chrome-steel spheres or Neodynium cubes with a size of 250 μm, which perform desired planar motions directed by the movement of the wand. We propose and evaluate novel methods to enhance the focused magnetic field of the wand by sharpening its tip, increase microrobot velocities via novel mechanical amplifiers, and reduce environmental forces via inexpensive anti-friction coatings. We document results of automated operation and teleoperated control of the microrobot during competition at the Mobile Microrobotics Challenge (MMC) held in 2013. Experimental results from the mobility and microassembly challenge indicate an excellent degree of precision motion control over the robot, at a price of a slightly lower maximum speed when compared to conventional electromagnetic actuation.
A New Virtual Coiling Method and its Use in Evaluation of Combining Coiling and Flow-Diversion Treatment in a Patient-Specific Aneurysm
Authors: Damiano Robert , Xiang Jianping , Levy Elad , Meng Hui
Published: January 2015

A new realistic finite element method (FEM) based endovascular coil deployment technique was developed to explore the hemodynamic modifications of coiling in addition to flow diverter (FD) treatment. A patient-specific internal carotid artery aneurysm was used as a test case, and a single flow diverter was deployed using a previously developed method [1], along with several coils using the new method. Results showed fluctuations in hemodynamic parameters at low packing densities (1–3 coils) which are unexpected. At high packing density however (6 coils), results were consistent with expectations. These results suggest that adding coils at low packing densities to FD treatment may not cause significant additional flow reduction into the aneurysm sac, but may provide a scaffold for aneurysmal thrombus formation.
Silicon nitride, a high potential dielectric for 600 V integrated RC-snubber applications
Authors: Krach Florian , Schwarzmann Holger , Bauer Anton J. , Erlbacher Tobias , Frey Lothar
Published: January 2015

Monolithically integrated RC-snubbers were realized by metal-insulator-semiconductor capacitors on a silicon substrate also serving as a series resistor. These devices provide a promising alternative to passive surface-mounted device components that are commonly used for snubber applications in power electronic circuits. The surface area of the substrate was enlarged with circular trench structures to increase the integration level of the capacitor, and a silicon nitride layer with a thickness of 1.05 μm was deposited on top of a 20 nm-thin silicon oxide layer as a potential dielectric for applications up to 600 V. With the trench geometry, a capacitance per surface area of 0.6 nF/mm2 was achieved, which is more than ten times the capacitance of a planar device using the same dielectric layers. However, combining the thick silicon nitride layer with the trench geometry caused an excessive wafer bow of nearly 800 μm, so deposition and structuring of a surface passivation layer, such as polyimide, was not feasible. Therefore, inert oil had to be used as a surface passivation for high voltage measurements. The silicon nitride dielectric exhibits a leakage current density lower than 0.3 nA/mm2 at the requested 600 V operating voltage, while dielectric breakdown of the devices is observed at 1050 V. A low deviation in capacitance and series resistance across the wafer and a high yield regarding the high voltage stability is achieved because of the good quality and homogeneity of the silicon nitride dielectric layer.
Science Signaling
Podcast: 13 January 2015
Authors: Haura Eric B. , Smith Matthew A. , VanHook Annalisa M.
Published: January 2015

A new assay could improve identification of tumors that are likely to respond to therapies that inhibit epidermal growth factor receptor (EGFR) signaling.
Hydrazidase, a Novel Amidase Signature Enzyme That Hydrolyzes Acylhydrazides
Authors: Oinuma Ken-Ichi , Takuwa Atsushi , Taniyama Kosuke , Doi Yuki , Takaya Naoki
Published: January 2015

The degradation mechanisms of natural and artificial hydrazides have been elucidated. Here we screened and isolated bacteria that utilize the acylhydrazide 4-hydroxybenzoic acid 1-phenylethylidene hydrazide (HBPH) from soils. Physiological and phylogenetic studies identified one bacterium as
Microbacterium
sp. strain HM58-2, from which we purified intracellular hydrazidase, cloned its gene, and prepared recombinant hydrazidase using an
Escherichia coli
expression system. The
Microbacterium
sp. HM58-2 hydrazidase is a 631-amino-acid monomer that was 31% identical to indoleacetamide hydrolase isolated from
Bradyrhizobium japonicum
. Phylogenetic studies indicated that the
Microbacterium
sp. HM58-2 hydrazidase constitutes a novel hydrazidase group among amidase signature proteins that are distributed within proteobacteria, actinobacteria, and firmicutes. The hydrazidase stoichiometrically hydrolyzed the acylhydrazide residue of HBPH to the corresponding acid and hydrazine derivative. Steady-state kinetics showed that the enzyme hydrolyzes structurally related 4-hydrozybenzamide to hydroxybenzoic acid at a lower rate than HBPH, indicating that the hydrazidase prefers hydrazide to amide. The hydrazidase contains the catalytic Ser-Ser-Lys motif that is conserved among members of the amidase signature family; it shares a catalytic mechanism with amidases, according to mutagenesis findings, and another hydrazidase-specific mechanism must exist that compensates for the absence of the catalytic Ser residue. The finding that an environmental bacterium produces hydrazidase implies the existence of a novel bacterial mechanism of hydrazide degradation that impacts its ecological role.
VSL#3 induces and maintains short-term clinical response in patients with active microscopic colitis: a two-phase randomised clinical trial
Authors: Rohatgi Sarika , Ahuja Vineet , Makharia Govind K , Rai Tarun , Das Prasenjit , Dattagupta Siddharth , Mishra Veena , Garg Sushil Kumar
Published: January 2015

Background

The probiotic mixture VSL#3 has proven efficacious in inflammatory bowel diseases and irritable bowel syndrome; however, its efficacy in microscopic colitis (MC) is being investigated.

Objective

To evaluate the safety and efficacy of a multistrain probiotic, VSL#3, in inducing clinical remission and achieving clinical response, as compared with mesalamine, in patients with active MC.

Methods

A randomised, open labelled study comparing the efficacy of 900 billion colony-forming units/day of VSL#3 (group (Gp) A) or 1.6 g of mesalamine/day (Gp B) for 8 weeks in 30 patients with MC was conducted. After a washout period of 2 weeks, Gp B received 8 weeks of VSL#3 and Gp A was off medication for the next 8 weeks. The primary end points were clinical remission and clinical response at 8 weeks.

Results

Of 30 patients, 15 were randomised in each arm. 11 patients in Gp A and 13 patients in Gp B completed 8 weeks of treatment. 5 (46%) of 11 patients in Gp A and 1 (8%) of 13 patients in Gp B attained clinical remission (p=0.022). Clinical response was seen in Gp A, as evidenced by a lower stool weight (377.6±104.5 g) as compared with Gp B (507±168.2 g; p=0.03). VSL#3 was effective in maintaining clinical response up to 10 weeks, even after discontinuation of therapy. Secondary end points like stool parameters, histology and well-being improved in both treatment groups.

Conclusions

The probiotic VSL#3 was found to offer the benefit of inducing as well as maintaining short-term clinical response in patients with active MC.

Trial registration number

The clinical trial is registered with CLINICAL TRIAL REGISTRY INDIA;http://ctri.nic.in, CTRI No. “CTRI/2008/091/000086” (registered on: 23/06/2008).
Documentation and treatment of hypertension: quality of care and missed opportunities in a family medicine resident clinic
Authors: So Phillip , Lin Steven Y
Published: January 2015

Background

In the USA, uncontrolled hypertension contributes to 1000 deaths a day. However, little is known about the quality of hypertension management in family medicine resident clinics.

Objectives

To examine rates of documentation and treatment of elevated blood pressure, and to identify missed opportunities to address hypertension.

Study design A cross-sectional chart review of 1011 adult patient visits between 2 January and 4 February 2013 was performed in a resident-run federally qualified health centre. For patients with elevated blood pressure at time of visit, we noted whether or not the residents had documented a diagnosis or discussion of hypertension and the presence or absence of a treatment plan. We compared these rates with those from a national sample of primary care physicians.

Results

262/1011 (26%) of adult patients had elevated blood pressure at time of visit. Of those, 115/262 (44%) had documentation and a plan for treatment, 79/262 (30%) had documentation but no plan, and 68/262 (26%) had neither documentation nor plan. Nationally, 45% of patients are diagnosed and treated compared with 44% of study visits with documentation and treatment.

Conclusions

Fewer than half of visits of patients with elevated blood pressure resulted in both documentation and a treatment plan. Nevertheless, these rates are comparable to national providers. Elevated blood pressure was more likely to be missed during acute visits and in patients with less elevated blood pressure.
Republished: Mucinous tumours of appendix and ovary: an overview and evaluation of current practice
Authors: Rouzbahman Marjan , Chetty Runjan
Published: January 2015

Mucinous lesions of the appendix and ovary are commonly encountered in routine practice. There are several published classification schemes for appendiceal mucinous neoplasms with resultant inconsistent use of terms and clinical doubt. While nomenclature is more settled with regards to ovarian mucinous neoplasms, the difficulty here lies with distinguishing primary from secondary mucinous tumours. This review highlights the terminology and nomenclature for appendiceal mucinous tumours, the relationship with ovarian mucinous neoplasms and pseudomyxoma peritonei, and the features that assist in separating primary from secondary ovarian mucinous tumours.
Cyclic neutropenia in a basset hound
Authors: Köster Liza , Harper Cindy , Goddard Amelia
Published: January 2015

A six‐month‐old male basset hound was referred for intermittent malaise and pyrexia that repeated every 10–11 days. Sequential blood counts and bone marrow aspirates demonstrated severe neutropenia and increased myeloid precursor cells in the bone marrow from day 2 of each cycle. By day 5, the bone marrow had predominantly mature neutrophils and band cells, and by day 10 the myeloid precursors had decreased with a myeloid:erythroid of 0.4:1. During the same period, the blood neutrophils had rebounded to normal counts by day 5 and were declining by days 9 and 10. The monocytes and platelets were oscillating in an opposite phase to the neutrophils. The age of onset, regular cycle length, oscillations of neutrophil, platelet and monocyte counts and characteristic bone marrow cytology were diagnostic for cyclic neutropenia. This syndrome has never before been described in any breed other than the grey collie. The grey collie gene mutation was not found in this dog. However, based on the clinical signs and haematological and bone marrow results, it can be deduced that cyclic neutropenia may develop as a result of other mutations in neutrophil elastase expression.
Laboratory device to characterize electrokinetic geocomposites for fluid fine tailings dewatering
Authors: Bourgès-Gastaud Sébastien , Stoltz Guillaume , Dolez Patricia , Blond Éric , Touze-Foltz Nathalie
Published: January 2015

The oil sands industry usually leads to the production of large quantities of mineral waste, such as fluid fine tailings (FFT), whose disposal is often challenging. Electrokinetic geocomposites (eGCPs) installed into the FFT disposal area may improve in situ dewatering, as eGCPs can drain water expulsed during FFT consolidation as well as impose a voltage across FFT to displace water by electro-osmosis. This paper presents a laboratory device specifically developed to evaluate eGCP performance for sludge dewatering. Based on the oedometer principle, the device aims at studying sludge consolidation as a function of boundary conditions (mechanical stress and (or) voltage), with drainage and electrical conduction ensured by two eGCPs positioned on both sides of the sludge layer. Preliminary results obtained with one particular eGCP are presented: the solids content was increased from 42% to 66%, which led to a significant improvement of the shear strength from nearly 0 kPa to a mean value of 40 kPa. The energy required for this experiment was 71 W·h (3.5 kW·h/(m3 of sludge)). The filtration performance remained satisfactory; the sludge particles were retained upstream of the filter, with clean water flowing through.
Effect of superthermal electrons on the characteristics of dust acoustic solitary waves in a magnetized hot dusty plasma with dust charge fluctuation
Authors: Shahmohammadi Nafise , Dorranian Davoud , Hakimipagouh Hossien
Published: January 2015

A nonlinear dust acoustic solitary wave (DASW) in a magnetized dusty plasma with superthermal electrons is studied analytically. In this model hot electrons are described by the kappa distribution function, but ions are taken to be Maxwellian and plasma pressure and dust-natural collisions have been taken into account. Using the reductive perturbation method the Zakharov–Kuznetsov equation is derived and effect of electrons’ hotness on the amplitude and width of soliton in dusty plasma is investigated. With decreasing energy of the hot electrons in the system, κ > 100, results coincide with the results of the dusty plasma system containing Maxwellian electrons. In this model anisotropy is caused by an external magnetic field while inhomogeneity is generated by ion density gradient in the plasma. The initial density decreases exponentially in the space along one direction. The amplitude of DASW is mainly affected by density inhomogenity rather than the electrons’ energy. With increasing energy of the system, the width of DASW increases significantly. Applying the effect of pressure in the model only rarefactive DASW may be generated in the dusty plasma.
Unconstrained canonical action for, and positive energy of, massive spin 2
Authors: Deser S.
Published: January 2015

Filling a much-needed gap, we exhibit the D = 4 Fierz–Pauli massive s = 2 action, and its — manifestly positive — energy, in terms of its 2s + 1 = 5 unconstrained helicity (2, 1, 0) excitations, after reducing and diagonalizing the troublesome helicity-zero sector.
Compound Danshen (Salvia miltiorrhiza) Dripping Pill for Coronary Heart Disease: An Overview of Systematic Reviews
Authors: Luo Jing , Song Weijiang , Yang Guoyan , Xu Hao , Chen Keji
Published: January 2015

Compound Danshen dripping pill (CDDP) is commonly used to treat coronary heart disease (CHD) in China. However, clinical practice has not been informed by evidence from relevant systematic reviews (SRs). This overview aims at summarizing evidence from SRs on CDDP for the treatment of CHD. We included SRs of randomized controlled trials (RCTs) on CDDP in treating CHD until March 2014 by searching the Cochrane Library, PubMed, EMBASE and four Chinese databases. Data were extracted according to a pre-designed form. We assessed the quality of SRs according to AMSTAR and graded the quality of evidence in the included SRs using the GRADE approach. All data analyses were descriptive. About 13 SRs involving a total of 34,071 participants with angina or acute myocardial infarction (AMI) were included. Few SRs assessed endpoints (5/13, 38.5%) and quality of life (QOL) (4/13, 30.8%). Most of the SRs suggested that CDDP had potential benefits for patients with CHD, such as improving symptoms and electrocardiogram (ECG) results, with few adverse reactions, while benefits in endpoints were unproved. Moreover, the overall quality of evidence in the SRs was poor, ranging from "very low" to "moderate", and most of the included SRs were of "low" (3/13, 23.1%) or "moderate" (9/13, 69.2%) quality with many serious flaws. Current SRs suggested potential benefits of CDDP for the treatment of CHD. However, high-quality evidence is warranted to support the application of CDDP in treating CHD.
Effect of In Vitro Transcorneal Approach of Aceclofenac Eye Drops through Excised Goat, Sheep, and Buffalo Corneas
Authors: Dave Vivek , Paliwal Sarvesh , Yadav Sachdev , Sharma Swapnil
Published: January 2015

The current study involves the evaluation of factors that influence the transcorneal permeation of aqueous drops of aceclofenac ophthalmic formulation through freshly excised goat, sheep, and buffalo corneas. Aceclofenac formulation with different concentrations 0.1–0.5% (w/v) and with different pH and different preservatives, was taken into account. The amount of drug permeated from different formulations was estimated using an Franz diffusion cell. A linear increase in drug permeation was observed with increase in pH (5.5 to 7.4). The apparent permeability coefficient was found to be maximum 15.01 ±  0.45 on goat cornea and maximum transport of aceclofenac was observed at physiological pH of tears (i.e., 7). The results advocate that aceclofenac 0.5% (w/v) ophthalmic solution (pH 7.0) containing BAK (0.01%) provides maximum in vitro ocular permeability through goat, sheep, and buffalo corneas.
Benzodiazepines and Z-Drug Use among HIV-Infected Patients in Taiwan: A 13-Year Nationwide Cohort Study
Authors: Wei Han-Ting , Chen Mu-Hong , Wong Wing-Wai , Chou Yuan-Hwa , Liou Ying-Jay , Su Tung-Ping , Chen Tzeng-Ji , Bai Ya-Mei
Published: January 2015

Introduction. Benzodiazepines (BZDs) and zolpidem, zopiclone, and zaleplon (Z-drugs) are commonly prescribed to HIV-infected patients. We hypothesized that frequent BZD and Z-drug use among these patients may be associated with psychiatric illnesses, particularly in long-term users.Methods. We included 1,081 patients with HIV between 1998 and 2011 from the Taiwan National Health Insurance Research Database and matched them according to age, sex, and comorbidity with uninfected controls to investigate the psychiatric diagnoses and prescriptions of BZDs and Z-drugs. Cumulative defined daily dose (cDDD) was assessed as the indicator of the duration of medication exposure. Patients exhibiting a cDDD exceeding 180 were defined as long-term users.Results. The patients with HIV had an increased risk of any use (odds ratio (OR): 8.70, 95% confidence interval (CI): 6.82–10.97) and long-term use (OR: 5.06, 95% CI: 3.63–7.04) of BZD and Z-drugs compared with those without HIV during the follow-up after demographic data and psychiatric comorbidities were adjusted.Conclusion. A large proportion of the HIV-infected patients received prescriptions of BZDs and Z-drugs. Mood disorders, insomnia, anxiety disorders, HIV infection, and substance use disorder were substantial predictors among the BZD and Z-drug users. These findings suggest that providing psychiatric services for HIV-infected patients is vital.
Neuroprotective Effect of Dexmedetomidine on Hyperoxia-Induced Toxicity in the Neonatal Rat Brain
Authors: Sifringer Marco , von Haefen Clarissa , Krain Maria , Paeschke Nadine , Bendix Ivo , Bührer Christoph , Spies Claudia D. , Endesfelder Stefanie
Published: January 2015

Dexmedetomidine is a highly selective agonist ofα2-receptors with sedative, anxiolytic, analgesic, and anesthetic properties. Neuroprotective effects of dexmedetomidine have been reported in various brain injury models. In the present study, we investigated the effects of dexmedetomidine on neurodegeneration, oxidative stress markers, and inflammation following the induction of hyperoxia in neonatal rats. Six-day-old Wistar rats received different concentrations of dexmedetomidine (1, 5, or 10 µg/kg bodyweight) and were exposed to 80% oxygen for 24 h. Sex-matched littermates kept in room air and injected with normal saline or dexmedetomidine served as controls. Dexmedetomidine pretreatment significantly reduced hyperoxia-induced neurodegeneration in different brain regions of the neonatal rat. In addition, dexmedetomidine restored the reduced/oxidized glutathione ratio and attenuated the levels of malondialdehyde, a marker of lipid peroxidation, after exposure to high oxygen concentration. Moreover, administration of dexmedetomidine induced downregulation of IL-1βon mRNA and protein level in the developing rat brain. Dexmedetomidine provides protections against toxic oxygen induced neonatal brain injury which is likely associated with oxidative stress signaling and inflammatory cytokines. Our results suggest that dexmedetomidine may have a therapeutic potential since oxygen administration to neonates is sometimes inevitable.
Comprehensive Analysis and Experimental Validation of an Improved Mathematical Modeling of Photovoltaic Array
Authors: Bal Satarupa , Anurag Anup , Nanda Mrutyunjaya , Sourav Suman
Published: January 2015

This paper proposes a simple, accurate, and easy to model approach for the simulation of photovoltaic (PV) array and also provides a comparative analysis of the same with two other widely used models. It is highly imperative that the maximum power point (MPP) is achieved effectively and thus a simple and robust mathematical model is necessary that poses less mathematical complexity as well as low data storage requirement, in which the maximum power point tracking (MPPT) algorithm can be realized in an effective way. Further, the resemblance of the P-V and I-V curves as obtained on the basis of experimental data should also be taken into account for theoretical validation. In addition, the study incorporates the root mean square deviation (RMSD) from the experimental data, the fill factor (FF), the efficiency of the model, and the time required for simulation. Two models have been used to investigate the I-V and P-V characteristics. Perturb and Observe method has been adopted for MPPT. The MPP tracking is realized using field programmable gate array (FPGA) to prove the effectiveness of the proposed approach. All the systems are modeled and simulated in MATLAB/Simulink environment.