bluuebunny/crossref_metadata_2025_split huggingface dataset:
Current Situation of Design Criteria for Intervertebral Disc Prosthesis
Authors: Vargas-Alcaraz Epifanio , Espinosa-Bautista Adrián , López-Parra Marcelo 
Published: April 2014

This paper presents the literature review on the design criteria for intervertebral disc prosthesis. The design criteria relate to the design features that intervertebral prosthesis must accomplish (i.e. fixation to bones, spine mobility, energy absorption and etcetera). The need to improve the performance has led to changes in the features which reflect in the current design criteria.
Currently, the disc prosthesis technology is experiencing a generational change. The first generation was thoroughly studied while the second generation is in the clinical tests stage. During the time the first generation prostheses were applied in patients there was not a clear trend in the clinical results which produced a lack of trust and reliability in the performance of the disc prosthesis. The changes in the design features of one generation compared to the next generation are based in the deepening in the knowledge of the problem and the results obtained with the first generation prostheses.
Some design criteria were identified for the first generation. These criteria were not completely characterized since there was not enough information to be used by the designer. This lack of characterization of most design criteria produced many different versions without a clear focus which help to define the basic design features of disc prostheses. This document presents the necessary information to thoroughly characterize the design criteria outlining the missing information for the design criteria found. An analysis is done of the design criteria in the second generation of prosthesis.
Finally if the information contained in the design criteria is enough, the clinical results would be better focused to achieve a more repeatable, reproducible and reliable process for a total disc intervertebral prosthesis replacement as now is considered the vertebral fusion, this is a gold standard.
Pressure Drop and Heat Transfer Characteristics of Pin Fin Enhanced Microgaps in Single Phase Microfluidic Cooling
Authors: Wan Zhimin , Joshi Yogendra K. 
Published: April 2014

Three dimensional (3D) stacking of semiconductor chips is an emerging technology which promises improved electrical performance including improved bandwidth, reduced wire interconnection lengths, and reduced signal delay. However, due to the higher power density per unit volume of the stacking, it poses great challenge for thermal management. Inter-tier microfluidic cooling with microgaps with surface area enhancements such as pin fins can potentially achieve superior thermal performance. As such, the hydraulic and thermal characteristics of this configuration over parametric ranges of practical interest are important. Conventional correlations developed in the literature for macropin fins show large errors for dense arrays of micropins.
In this work, the hydraulic and thermal characteristics of a microgap with pin fin were investigated for a large range of Reynolds number (Re) based on pin fin diameter (Dp) by numerical modeling. The effects of the pin fin dimensions including diameter, transversal spacing, longitudinal spacing, height and Re on the friction factor (f) and colburn j factor were studied. Correlations of the f and j for dense arrays of micro pins are developed based on parametric runs over 22< Re <357, pin fin diameter of 100 μm, pitch/ diameter ratios of 1.5 ∼ 2.25, and height/ diameter ratios of 1.5 ∼ 2.25. The validity of the correlations is confirmed by experiments. Lastly, a parametric optimization was done and the thermal resistance of the microgap with 150 W heat generation is reduced by 28.5% with the optimized dimensions for a given pumping power compared to an un-optimized pin fin configuration.
Tire-Terrain Normal and Longitudinal Dynamics and Slip Power Losses of an Unmanned Ground Vehicle
Authors: Salama Mostafa , Vantsevich Vladimir V. 
Published: April 2014

Studies of the tire-terrain interaction have mostly been completed on vehicles with steered wheels, but not much work has been done regarding skid-steered Unmanned Ground Vehicles (UGV). This paper introduces a mathematical model of normal and longitudinal dynamics of a UGV with four skid-steered pneumatic tire wheels. Unlike the common approach, in which two wheels at each side are treated as one wheel (i.e., having the same rotational speeds), all four wheels in this study are independently driven. Thus the interaction of each tire with deformable terrain is introduced as holonomic constraints.
The stress-strain characteristics for tire-soil interaction are analyzed based on modern Terramechanics methods and then further used to determine the circumferential wheel forces of the four tires. Contributions of three components of each tire circumferential force to tire slippages are modeled and analyzed when the tire normal loads vary during vehicle straight-line motion. The considered tire-soil characteristics are mathematically reduced to a form that allows condensing the computational time for on-line computing tire-terrain characteristics. Additionally, rolling resistance of the tires is analyzed and incorporated in the UGV dynamic equations.
Moreover, the paper describes the physics of slip power losses in the tire-soil interaction of the four tires and applies it to small skid-steered UGV. This study also formulates an optimization problem of the minimization of the power losses in the tire-soil interactions due to the tire slippage.
Floating Type Ocean Wave Power Station (Wells Type Runner Work Submerged in Seawater)
Authors: Okamoto Shun , Eshima Toru , Kanemoto Toshiaki , Umekage Toshihiko 
Published: April 2014

The authors have invented the unique ocean wave power station, which is composed of the floating type platform with a pair of floats lining up at the interval of one wave pitch and the counter-rotating type wave power unit boarding on the middle position of the platform. Such profiles may make the flow velocity at the runner twice faster than that of the traditional fixed type (OWC). The counter-rotating type wave power unit is composed of the tandem runners submerged in the seawater and the peculiar generator with double rotational armatures. The tandem runners counter-rotate in keeping each rotational direction constant, even at the oscillating flow, where the relative rotational speed is also twice faster than that in the single runner/armature type. It can be expected to make the runner size larger, namely the output higher because the torques are counter balanced in the unit and never act on the platform.
At preliminary research, the single stage Wells type runner was boarded on the above platform, while the behavior of the platform and the performance of the power unit were investigated experimentally. The runner works fruitfully in response to the oscillating platform.
Softness Measurement Technics of Human Skin by Indentation Devices Imitating Palpation
Authors: Sakuma Atsushi 
Published: April 2014

The characteristics of human skin are easily changed by the states of the body because it is very sensitive to environmental transformation. And the development of the condition measurement technology of human skin is very important for improvement in QOL because it reflects body condition. Then, various devices for the condition measurement of human skin had been developed but there was no technique which can evaluate the skin by objective parameter easily.
In this paper, spherical indentation testing is studied to evaluate the dimension and rigidity of thin soft-tissues like human skin. Here, the Hertz contact theory is functionally expanded to evaluate indentations for the thin tissues. In the expansions, the technique used for evaluating the thickness of finite specimens is first explained by analyzing the experimental results of indentations. Then, the Young’s modulus of the tissue with finite thickness is theoretically derived by defining an equivalent indentation strain for the analysis of the indentation process. The expansions are examined to evaluate its reliability by applying them to measure Young’s modulus of some thin materials. Furthermore, this technology is applied to the elasticity investigation of the human skin. Especially, the measurement results of elasticity characteristics of the skin of human face are shown as the first report. The influences of sex and ultraviolet rays and so on are discussed to reveal the mechanics of human skin in this report. Moreover, it is discussed about the validity of the device which measures the elasticity of the skin of human face.
Hole-Pattern Seals Performance Optimization Using Computational Fluid Dynamics and Design of Experiment Techniques
Authors: Untaroiu Alexandrina , Liu Cheng , Migliorini Patrick J. , Wood Houston G. , Untaroiu Costin D. 
Published: April 2014

A main goal of non-contacting mechanical seals is to provide minimal leakage during operation. This may be achieved by specifying a small clearance between the mating faces that is just enough to avoid rubbing contact while allowing some tolerable leakage. The amount of leakage flow is reduced through the acceleration and deceleration of the fluid through a tortuous path, so the sealing performance depends on the geometric characteristics of the leakage path.
This study focuses on annular hole-pattern seals, which are non-contacting mechanical seals commonly used in high pressure compressors. A Design of Experiments (DOE) approach is used to investigate the effects of various geometric variables on the leakage rate of a hole-pattern seal during normal operating conditions. The design space, defined by the ranges of hole diameter, hole depth, axial space between holes and number of holes in circumferential direction, is discretized using the simple random sampling method. Then, steady-state Computational Fluid Dynamics (CFD) simulations are performed at each design point to evaluate seal performance. To better understand the sensitivity of the hole-pattern seal leakage rate with respect to design variables selected, response surfaces are built through its values at design points using quadratic polynomial fitting. The results show that the optimal solution had a better leakage control ability over the base model design. It is believed that the results of this study will assist in improving the design of annular hole-pattern seals.
Towards Thermal Characterization of Pico-Liter Volumes Using the 3Omega Method
Authors: Roy Shilpi , Kodama Takashi , Lingamneni Srilakshmi , Panzer Matthew A. , Asheghi Mehdi , Goodson Kenneth E. 
Published: April 2014

The continued efforts in the biological community to optimize methodologies such as PCR and to characterize biological reactions and processes are motivating reductions in sample volume. There is a growing need for the detection of thermal phenomena in these small volumes, such as the heat released by recombination and the effective conductivities and capacities in extremely small fluidic regions. While past work has focused largely on heat transport in essentially bulk fluid volumes, there is a need to scale these techniques to the much smaller volumes of interest for biological and biomedical research.”
This work applies the 3ω measurement technique to μL volumes by using heaters with dimensions of 200–700μm in lengths and 2–5μm in widths. We investigate fluid samples of DI water, silicone oil, and a salt buffer solution to experimentally determine their temperature-dependent thermal properties from 25°C to 80°C. Validation is achieved through comparison of these values of thermal conductivity κ and volumetric heat capacity Cν to literature. The work also demonstrates the device capability to conduct temperature-dependent measurements down to pL droplet volumes by conducting a volume analysis given the dimensions of heaters used, independent of droplet boundary conditions. Sensitivity and uncertainty analyses based on these heater dimensions and surrounding material stack show the detection capabilities of these heaters, as they are optimally designed to maximize signal while accommodating the size restrictions of small volume droplets.
Analysis of Friction in Bi-Dimensional Pipe Flow Using Non Conventional Constitutive Models
Authors: Catania Giuseppe , Sorrentino Silvio 
Published: April 2014

The design of hydraulic transmission lines for control and actuation requires accurate knowledge of their dynamic response: some standard techniques are known to obtain a consistent dynamic model of a fluid line, including the contribution of inertia, compressibility and friction.
In this paper an efficient procedure is developed for simulating the dynamic response in both the frequency and time domains, focusing the attention on the modal analysis of a discretized model of a fluid line. A bi-dimensional approach is adopted, modeling the laminar flow frequency-dependent friction by means of non-integer order differential laws, which may improve the accuracy of the simulated responses in comparison with more traditional Newtonian models.
Anti-Infective Activities of Lactobacillus Strains in the Human Intestinal Microbiota: from Probiotics to Gastrointestinal Anti-Infectious Biotherapeutic Agents
Authors: Liévin-Le Moal Vanessa , Servin Alain L. 
Published: April 2014

SUMMARYA vast and diverse array of microbial species displaying great phylogenic, genomic, and metabolic diversity have colonized the gastrointestinal tract. Resident microbes play a beneficial role by regulating the intestinal immune system, stimulating the maturation of host tissues, and playing a variety of roles in nutrition and in host resistance to gastric and enteric bacterial pathogens. The mechanisms by which the resident microbial species combat gastrointestinal pathogens are complex and include competitive metabolic interactions and the production of antimicrobial molecules. The human intestinal microbiota is a source from whichLactobacillusprobiotic strains have often been isolated. Only six probioticLactobacillusstrains isolated from human intestinal microbiota, i.e.,L. rhamnosusGG,L. caseiShirota YIT9029,L. caseiDN-114 001,L. johnsoniiNCC 533,L. acidophilusLB, andL. reuteriDSM 17938, have been well characterized with regard to their potential antimicrobial effects against the major gastric and enteric bacterial pathogens and rotavirus. In this review, we describe the current knowledge concerning the experimental antibacterial activities, including antibiotic-like and cell-regulating activities, and therapeutic effects demonstrated in well-conducted, placebo-controlled, randomized clinical trials of these probioticLactobacillusstrains. What is known about the antimicrobial activities supported by the molecules secreted by such probioticLactobacillusstrains suggests that they constitute a promising new source for the development of innovative anti-infectious agents that act luminally and intracellularly in the gastrointestinal tract.
Genital Chlamydia trachomatis: Understanding the Roles of Innate and Adaptive Immunity in Vaccine Research
Authors: Vasilevsky Sam , Greub Gilbert , Nardelli-Haefliger Denise , Baud David 
Published: April 2014

SUMMARYChlamydia trachomatisis the leading cause of bacterial sexually transmitted disease worldwide, and despite significant advances in chlamydial research, a prophylactic vaccine has yet to be developed. This Gram-negative obligate intracellular bacterium, which often causes asymptomatic infection, may cause pelvic inflammatory disease (PID), ectopic pregnancies, scarring of the fallopian tubes, miscarriage, and infertility when left untreated. In the genital tract,Chlamydia trachomatisinfects primarily epithelial cells and requires Th1 immunity for optimal clearance. This review first focuses on the immune cells important in a chlamydial infection. Second, we summarize the research and challenges associated with developing a chlamydial vaccine that elicits a protective Th1-mediated immune response without inducing adverse immunopathologies.
RIG-I Detects mRNA of Intracellular Salmonella enterica Serovar Typhimurium during Bacterial Infection
Authors: Schmolke Mirco , Patel Jenish R. , de Castro Elisa , Sánchez-Aparicio Maria T. , Uccellini Melissa B. , Miller Jennifer C. , Manicassamy Balaji , Satoh Takashi , Kawai Taro , Akira Shizuo , Merad Miriam , García-Sastre Adolfo 
Published: April 2014

ABSTRACT

The cytoplasmic helicase RIG-I is an established sensor for viral 5′-triphosphorylated RNA species. Recently, RIG-I was also implicated in the detection of intracellular bacteria. However, little is known about the host cell specificity of this process and the bacterial pathogen-associated molecular pattern (PAMP) that activates RIG-I. Here we show that RNA of
Salmonella enterica
serovar Typhimurium activates production of beta interferon in a RIG-I-dependent fashion only in nonphagocytic cells. In phagocytic cells, RIG-I is obsolete for detection of
Salmonella
infection. We further demonstrate that
Salmonella
mRNA reaches the cytoplasm during infection and is thus accessible for RIG-I. The results from next-generation sequencing analysis of RIG-I-associated RNA suggest that coding bacterial mRNAs represent the activating PAMP.

IMPORTANCE
S. Typhimurium
is a major food-borne pathogen. After fecal-oral transmission, it can infect epithelial cells in the gut as well as immune cells (mainly macrophages, dendritic cells, and M cells). The innate host immune system relies on a growing number of sensors that detect pathogen-associated molecular patterns (PAMPs) to launch a first broad-spectrum response to invading pathogens. Successful detection of a given pathogen depends on colocalization of host sensors and PAMPs as well as potential countermeasures of the pathogen during infection. RIG-I-like helicases were mainly associated with detection of RNA viruses. Our work shows that S. Typhimurium is detected by RIG-I during infection specifically in nonimmune cells.
Discovering Functions of Unannotated Genes from a Transcriptome Survey of Wild Fungal Isolates
Authors: Ellison Christopher E. , Kowbel David , Glass N. Louise , Taylor John W. , Brem Rachel B. 
Published: April 2014

ABSTRACTMost fungal genomes are poorly annotated, and many fungal traits of industrial and biomedical relevance are not well suited to classical genetic screens. Assigning genes to phenotypes on a genomic scale thus remains an urgent need in the field. We developed an approach to infer gene function from expression profiles of wild fungal isolates, and we applied our strategy to the filamentous fungusNeurospora crassa. Using transcriptome measurements in 70 strains from two well-defined clades of this microbe, we first identified 2,247 cases in which the expression of an unannotated gene rose and fell acrossN. crassastrains in parallel with the expression of well-characterized genes. We then used image analysis of hyphal morphologies, quantitative growth assays, and expression profiling to test the functions of four genes predicted from our population analyses. The results revealed two factors that influenced regulation of metabolism of nonpreferred carbon and nitrogen sources, a gene that governed hyphal architecture, and a gene that mediated amino acid starvation resistance. These findings validate the power of our population-transcriptomic approach for inference of novel gene function, and we suggest that this strategy will be of broad utility for genome-scale annotation in many fungal systems.IMPORTANCESome fungal species cause deadly infections in humans or crop plants, and other fungi are workhorses of industrial chemistry, including the production of biofuels. Advances in medical and industrial mycology require an understanding of the genes that control fungal traits. We developed a method to infer functions of uncharacterized genes by observing correlated expression of their mRNAs with those of known genes across wild fungal isolates. We applied this strategy to a filamentous fungus and predicted functions for thousands of unknown genes. In four cases, we experimentally validated the predictions from our method, discovering novel genes involved in the metabolism of nutrient sources relevant for biofuel production, as well as colony morphology and starvation resistance. Our strategy is straightforward, inexpensive, and applicable for predicting gene function in many fungal species.
Effect of aneurysm and ICA morphology on hemodynamics before and after flow diverter treatment
Authors: Larrabide Ignacio , Geers Arjan J , Morales Hernán G , Aguilar Martha L , Rüfenacht Daniel A 
Published: April 2014

BackgroundFlow diverter (FD) treatment aims to slow down blood flow inside the aneurysm and increase the average time that blood resides in the aneurysm.ObjectiveTo investigate the relationship between vessel and aneurysm morphology and their influence on the way in which braided FDs change intra-aneurysmal hemodynamics.Materials and methodsTwenty-three patient-specific intracranial aneurysm models at the supraclinoid segment of the internal carotid artery were studied. Vessel and aneurysm morphology was quantified and blood flow was modeled with computational fluid dynamics simulations. The relation between morphologic variables and the hemodynamic variables,WSS(wall shear stress) andtotime(ratio between the aneurysm volume and inflow at the aneurysm neck), was assessed statistically.ResultsIntra-aneurysmal flow was less dependent on the vessel than on aneurysm morphology. In summary, after treatment with a FD, a greater aneurysm flow reduction and redirection to the vessel main stream should be expected for (a) aneurysms located further away from the curvature peak, (b) aneurysms on the inner side of the bend, (c) aneurysms with no proximal stenosis, and (d) larger aneurysms.ConclusionsAlthough the change in intra-aneurysmal hemodynamics after FD treatment strongly depends on the morphology of the aneurysm, the hemodynamic effect of a FD is also linked to the parent vessel morphology and the position and orientation of the aneurysm with respect to it.
TWO FOR ONE: TIGHT APPROXIMATION OF 2D BIN PACKING
Authors: HARREN ROLF , JANSEN KLAUS , PRÄDEL LARS , SCHWARZ ULRICH M. , VAN STEE ROB 
Published: April 2014

In this paper, we study the two-dimensional geometrical bin packing problem (2DBP): given a list of rectangles, provide a packing of all these into the smallest possible number of unit bins without rotating the rectangles. Beyond its theoretical appeal, this problem has many practical applications, for example in print layout and VLSI chip design. We present a 2-approximate algorithm, which improves over the previous best known ratio of 3, matches the best results for the problem where rotations are allowed and also matches the known lower bound of approximability. Our approach makes strong use of a PTAS for a related 2D knapsack problem and a new algorithm that can pack instances into two bins if OPT = 1.