bluuebunny/crossref_metadata_2025 huggingface dataset:
Muscle Function and Coordination of Amputee Stair Ascent
Authors: Harper Nicole G. , Wilken Jason M. , Neptune Richard R.
Published: July 2018

Ascending stairs is challenging following transtibial amputation due to the loss of the ankle muscles, which are critical to human movement. Efforts to improve stair ascent following amputation are hindered by the limited understanding of how the prosthesis and remaining muscles contribute to stair ascent. This study developed a three-dimensional (3D) muscle-actuated forward dynamics simulation of amputee stair ascent to identify the contributions of individual muscles and the passive prosthesis to the biomechanical subtasks of stair ascent. The prosthesis was found to provide vertical propulsion throughout stair ascent, similar to nonamputee plantarflexors. However, the timing differed considerably. The prosthesis also contributed to braking, similar to the nonamputee soleus, but to a greater extent. However, the prosthesis was unable to replicate the functions of nonamputee gastrocnemius, which contributes to forward propulsion during the second half of stance and leg swing initiation. To compensate, the hamstrings and vasti of the residual leg increased their contributions to forward propulsion during the first and second halves of stance, respectively. The prosthesis also contributed to medial control, consistent with the nonamputee soleus but not gastrocnemius. Therefore, prosthesis designs that provide additional vertical propulsion as well as forward propulsion, lateral control, and leg swing initiation at appropriate points in the gait cycle could improve amputee stair ascent. However, because nonamputee soleus and gastrocnemius contribute oppositely to many subtasks, it may be necessary to couple the prosthesis, which functions most similarly to soleus, with targeted rehabilitation programs focused on muscle groups that can compensate for gastrocnemius.
A Finite Element Approach to Calculate Temperatures Arising During Cryogenic Turning of Metastable Austenitic Steel AISI 347
Authors: Becker Steven , Hotz Hendrik , Kirsch Benjamin , Aurich Jan C. , Harbou Erik V. , Müller Ralf
Published: July 2018

In this paper, an inverse method is presented to evaluate the inner workpiece temperature distribution during cryogenic turning of metastable austenitic steel AISI 347 utilizing a FE representation of the process. Temperature data during the experiments are provided by thermocouples and a commercial thermography system. A constant cutting speed at two varying feeds is investigated. Inverse parameter verification by aligning simulated and experimental data in a least squares sense is achieved. A heat flux from tool to workpiece as well as heat transfer coefficients for forced convection by air and by carbon dioxide as cryogenic coolant are identified for each set of cutting parameters. Rigid body rotation in the model is considered applying convective time derivatives of the temperature field. Unphysical oscillations occurring in regions of high Péclet numbers are suppressed utilizing a streamline-upwind/Petrov–Galerkin scheme.
Inverse Dynamics for Discrete Geometric Mechanics of Multibody Systems With Application to Direct Optimal Control
Authors: Björkenstam Staffan , Leyendecker Sigrid , Linn Joachim , Carlson Johan S. , Lennartson Bengt
Published: July 2018

In this paper, we present efficient algorithms for computation of the residual of the constrained discrete Euler–Lagrange (DEL) equations of motion for tree structured, rigid multibody systems. In particular, we present new recursive formulas for computing partial derivatives of the kinetic energy. This enables us to solve the inverse dynamics problem of the discrete system with linear computational complexity. The resulting algorithms are easy to implement and can naturally be applied to a very broad class of multibody systems by imposing constraints on the coordinates by means of Lagrange multipliers. A comparison is made with an existing software package, which shows a drastic improvement in computational efficiency. Our interest in inverse dynamics is primarily to apply direct transcription optimal control methods to multibody systems. As an example application, we present a digital human motion planning problem, which we solve using the proposed method. Furthermore, we present detailed descriptions of several common joints, in particular singularity-free models of the spherical joint and the rigid body joint, using the Lie groups of unit quaternions and unit dual quaternions, respectively.
Simulation of the Friction Coefficient of Paper-Based Wet Clutch With Wavy Separators
Authors: Yoshizumi Fumitaka , Tani Hirofumi , Sanda Shuzo
Published: July 2018

To simulate the change rate of the friction coefficient μ with respect to the sliding speed V, that is, the μ-V slope, a model combining macroscale and microscale phenomena is proposed. The macroscale model obtains distributions of the fluid pressure and fiber contact pressure over the whole engagement face, and the microscale model obtains the friction coefficient of each fiber contact through a detailed model for single-protuberance fiber contact. An experiment was conducted to obtain the μ-V slope by changing the wave height of separator faces, and the simulation and experimental results were compared. The combined model is advantageous for representing experimental μ-V relationships at small and large wave heights in comparison with models using only the macroscale behavior. Both experimental and simulation results showed the μ-V slope becoming more negative with increasing wave height. The simulation results revealed possible causes for the negative slope. In the wavy separator, the fluid friction that contributes to the positive slope is difficult to achieve due to the large film thickness, and the load-sharing ratio of the fiber contact tends to decrease due to wedge action of the fluid film. These phenomena shift the μ-V slope to the negative.
Surrogate Fuels Formulation for FACE Gasoline Using the Nuclear Magnetic Resonance Spectroscopy
Authors: Yu Jin , Gou Xiaolong
Published: July 2018

An efficient surrogate fuel formulation methodology, which directly uses the chemical structure information from nuclear magnetic resonance (NMR) spectroscopy analysis, has been proposed. Five functional groups, paraffinic CH2, paraffinic CH3, aromatic C-CH, olefinic CH-CH2, and cycloparaffin CH2, have been selected to show the basic molecular structure of the fuels for the advanced combustion engines (FACE) fuels. A palette that contains six candidate components, n-heptane, iso-octane, toluene, 2,5-dimethylhexane, methylcyclohexane, and 1-hexene, is chosen for different FACE fuels, based on the consideration that surrogate mixtures should provide the representative functional groups and comparable molecular sizes. The kinetic mechanisms of these six candidate components are chosen to assemble a detailed mechanism of each surrogate fuel for FACE gasoline. Whereafter, the accuracy of FACE A and F surrogate models was demonstrated by comparing the model predictions against experimental data in homogeneous ignition, jet stirred reactor oxidation, and premixed flame.
Computational Design of Gradient Paths in Additively Manufactured Functionally Graded Materials
Authors: Kirk Tanner , Galvan Edgar , Malak Richard , Arroyave Raymundo
Published: July 2018

Additive manufacturing (AM) has enabled the creation of a near infinite set of functionally graded materials (FGMs). One limitation on the manufacturability and usefulness of these materials is the presence of undesirable phases along the gradient path. For example, such phases may increase brittleness, diminish corrosion resistance, or severely compromise the printability of the part altogether. In the current work, a design methodology is proposed to plan an FGM gradient path for any number of elements that avoids undesirable phases at a range of temperatures. Gradient paths can also be optimized for a cost function. A case study is shown to demonstrate the effectiveness of the methodology in the Fe–Ni–Cr system. Paths were successfully planned from 316 L Stainless Steel (316 L SS) to pure Cr that either minimize path length or maximize separation from undesirable phases. Examinations on the stochastic variability, parameter dependency, and computational efficiency of the method are also presented. Several avenues of future research are proposed that could improve the manufacturability, utility, and performance of FGMs through gradient path design.
Unsteady Conjugate Heat Transfer Investigation of a Multistage Steam Turbine in Warm-Keeping Operation With Hot Air
Authors: Łuczyński Piotr , Toebben Dennis , Wirsum Manfred , Mohr Wolfgang F. D. , Helbig Klaus
Published: July 2018

In pursuit of flexibility improvements, General Electric has developed a product to warm-keep high/intermediate pressure steam turbines using hot air. In order to optimize the warm-keeping operation and to gain knowledge about the dominant heat transfer phenomena and flow structures, detailed numerical investigations are required. For the sake of the investigation of the warm-keeping process as found in the presented research, single and multistage numerical turbine models were developed. Furthermore, an innovative calculation approach called the equalized timescales method (ET) was applied for the modeling of unsteady conjugate heat transfer (CHT). In the course of the research, the setup of the ET approach has been additionally investigated. Using the ET method, the mass flow rate and the rotational speed were varied to generate a database of warm-keeping operating points. The main goal of this work is to provide a comprehensive knowledge of the flow field and heat transfer in a wide range of turbine warm-keeping operations and to characterize the flow patterns observed at these operating points. For varying values of flow coefficient and angle of incidence, the secondary flow phenomena change from well-known vortex systems occurring in design operation to effects typical for windage, like patterns of alternating vortices and strong backflows. Furthermore, the identified flow patterns have been compared to vortex systems described in cited literature and summarized in the so-called blade vortex diagram. The analysis of heat transfer in turbine warm-keeping operation is additionally provided.
Review of Thermal Packaging Technologies for Automotive Power Electronics for Traction Purposes
Authors: Broughton Justin , Smet Vanessa , Tummala Rao R. , Joshi Yogendra K.
Published: July 2018

Due to its superior electrical and thermal characteristics, silicon carbide power modules will soon replace silicon modules to be mass-produced and implemented in all-electric and hybrid-electric vehicles (HEVs). Redesign of the power modules will be required to take full advantage of these newer devices. A particular area of interest is high-temperature power modules, as under-hood temperatures often exceed maximum silicon device temperatures. This review will examine thermal packaging options for standard Si power modules and various power modules in recent all-electric and HEVs. Then, thermal packaging options for die-attach, thermal interface materials (TIM), and liquid cooling are discussed for their feasibility in next-generation silicon carbide (SiC) power modules.
Diagonal Mode van der Pauw Stress Sensors: Proof of Diagonal-Mode Conjecture
Authors: Jaeger Richard C. , Suhling Jeffrey C. , Chen Jun
Published: July 2018

The conjecture discussed in our previous paper [Jaeger, R. C., Motalab, M., Hussain, S., and Suhling, J. C., 2014, “Four-Wire Bridge Measurements of Silicon van der Pauw Stress Sensors,” ASME J. Electron. Packag., 136(4), p. 041014; Jaeger, R. C., Motalab, M., Hussain, S., and Suhling, J. C., 2018, Erratum: “Four-Wire Bridge Measurements of Silicon van der Pauw Stress Sensors,” ASME J. Electron. Packag., 140(1), p. 017001] was backed up by measurements and simulation results, but not mathematically proven. A proof based upon two-port impedance parameter reciprocity is presented with additional experimental confirmation.
Stokes Flow Within Networks of Flow Branches
Authors: Hellou Mustapha , Lominé Franck
Published: July 2018

Stokes flow in the branches of structured looped networks with successive identical square loops and T-junction branches is studied. Analytical expressions of the flow rate in the branches are determined for network of one, two, three, or four loops with junction head loss neglected relative to regular one. Then, a general expression of the flow rate is deduced for networks with more loops. This expression contains particularly a sequence of coefficients obeying to a recurrence formula. This sequence is a part of the fusion of Fibonacci and Tribonacci sequences. Furthermore, a general formula that expresses the quotient of flow rate in successive junction flow branches is given. The limit of this quotient for an infinite number of junction branches is found to be equal to 2+3. When the inlet and outlet flow rates are equal, this quotient obeys to a sequence of invariant numbers whatever the ratio of flow rate in the outlet branches is. Thus, the flow rate distribution for any configuration of inlet and outlet flow rates can be calculated. This study is also performed using Hardy–Cross method and a commercial solver of Navier-Stokes equation. The analytical results are approached very well with Hardy–Cross method. The numerical resolution agrees also with analytical results. However, the difference with the numerical results becomes significant for low flow rate in the junction branches. The flow streamlines are then determined for some inlet and outlet flow rate configurations. They particularly illustrate that recirculation flow takes place in branches of low flow rate.
Design of Magnetic Bearing Control System Based on Active Disturbance Rejection Theory
Authors: Jin Chaowu , Guo Kaixuan , Xu Yuanping , Cui Hengbin , Xu Longxiang
Published: July 2018

At present, most of the magnetic bearing system adopts the classical proportional–integral–derivative (PID) control strategy. However, the external disturbances, system parameter perturbations, and many other uncertain disturbances result in PID controller difficult to achieve high performance. To solve this problem, a linear active disturbance rejection controller (LADRC) based on active disturbance rejection controller (ADRC) theory was designed for magnetic bearing. According to the actual prototype parameters, the simulation model was built in matlab/simulink. The step and sinusoidal disturbances with PID and LADRC control strategies were simulated and compared. Then, the experiments of step and sinusoidal disturbances were performed. When control parameters are consistent, the experiment showed that the rotor displacement fluctuation decreased by 28.6% using the LADRC than PID control under step disturbances and decreased by around 25.8% under sinusoidal disturbances. When the rotor is running at 24,000 r/min and 27,000 r/min, the displacement of rotor is reduced by around 15% and 13.7%, respectively. Rotate the rotor with step disturbances and sinusoidal disturbances. It can also be seen that LADRC has the advantages of fast response time and good anti-interference. The experiments indicate that the LADRC has better anti-interference performance compared with PID controller.
Thermomechanical Model Reduction for Efficient Simulations of Rotor-Stator Contact Interaction
Authors: Guérin Nicolas , Thorin Anders , Thouverez Fabrice , Legrand Mathias , Almeida Patricio
Published: July 2018

Turbomachinery rotor–stator unilateral contact induced interactions play a growing role in lifecycle analysis and thus motivate the use of accurate numerical prediction tools. Recent literature confirmed by ongoing in-house experiments have shown the importance of thermomechanical coupling effects in such interactions. However, most available (possibly reduced-order) models are restricted to the sole mechanical aspects. This work describes a reduction technique of thermomechanical models involving unilateral contact and frictional contact occurrences between rotor and stator components. The proposed methodology is grounded on Guyan and Craig–Bampton methods for the reduction of the structural dynamics in conjunction with Krylov subspace techniques, and specifically the Craig–Hale approach, for the reduction of the thermal equations. The method has the capability to drastically reduce the size of the model while preserving accuracy. It stands as a reliable strategy to perform simulations of thermomechanical models with localized mechanical and thermal loads.
Second-Order Cone Programming Approach to Design of Linkage Mechanisms With Arbitrarily Inclined Hinges
Authors: Ohsaki Makoto , Kanno Yoshihiro , Yamaoka Yuki
Published: July 2018

An optimization approach is presented for generating linkage mechanisms consisting of frame members with arbitrarily inclined hinges. A second-order cone programming (SOCP) problem is solved to obtain the locations and directions of hinges of an infinitesimal mechanism. It is shown that the primal and dual SOCP problems correspond to the plastic limit analysis problems based on the lower-bound and upper-bound theorems, respectively, with quadratic yield functions. Constraints on displacement components are added to the dual problem, if a desirable deformation is not obtained. A finite mechanism is generated by carrying out geometrically nonlinear analysis and, if necessary, adding hinges and removing members. Effectiveness of the proposed method is demonstrated through examples of two- and three-dimensional mechanisms.
An Adaptive Directional Boundary Sampling Method for Efficient Reliability-Based Design Optimization
Authors: Meng Zeng , Zhang Dequan , Liu Zhaotao , Li Gang
Published: July 2018

Due to the nested optimization loop structure and time-demanding computation of structural response, the computational accuracy and cost of reliability-based design optimization (RBDO) have become a challenging issue in engineering application. Kriging-model-based approach is an effective tool to improve the computational efficiency in the practical RBDO problems; however, a larger number of sample points are required for meeting high computational accuracy requirements in traditional methods. In this paper, an adaptive directional boundary sampling (ADBS) method is developed in order to greatly reduce the computational sample points with a reasonable accuracy, in which the sample points are added along the ideal descending direction of objective function. Furthermore, only sample points located near the constraint boundary are mainly selected in the vicinity of the optimum point according to the strategy of multi-objective optimization; thus, substantial number of sample points located in the failure region is neglected, resulting in the improved performance of computational efficiency. Four numerical examples and one engineering application are provided for demonstrating the efficiency and accuracy of the proposed sampling method.
Some Recent Advances in Engineering Fracture Modeling for Turbomachinery
Authors: Craig McClung R. , Lee Yi-Der , Sobotka James C. , Moody Jonathan P. , Bhamidipati Vikram , Enright Michael P. , Benjamin Guseman D. , Thomas Colin B.
Published: July 2018

Recent advances in practical engineering methods for fracture analysis of turbomachinery components are described. A comprehensive set of weight function (WF) stress intensity factor (SIF) solutions for elliptical and straight cracks under univariant and bivariant stress gradients has been developed and verified. Specialized SIF solutions have been derived for curved through cracks, cracks at chamfered and angled corners, and cracks under displacement control. Automated fracture models are available to construct fatigue crack growth (FCG) life contours and critical initial crack size (CICS) contours for all nodal locations in two-dimensional or three-dimensional (2D or 3D) finite element (FE) models.
The Impact of Inlet Distortion and Reduced Frequency on the Performance of Centrifugal Compressors
Authors: Grimaldi A. , Michelassi V.
Published: July 2018

This paper discusses the impact of inlet flow distortions on centrifugal compressors based upon a large experimental data base in which the performance of several impellers in a range of corrected flows and corrected speeds have been measured after been coupled with different inlet plenums technologies. The analysis extends to centrifugal compressor inlets including a side stream, typical of liquefied natural gas applications. The detailed measurements allow a thorough characterization of the flow field and associated performance. The results suggest that distortions can alter the head by as much as 3% and efficiency of around 1%. A theoretical analysis allowed to identify the design features that are responsible for this deviation. In particular, an extension of the so-called “reduced-frequency,” a coefficient routinely used in axial compressors and turbine aerodynamics to weigh the unsteadiness generated by upstream to downstream blade rows, allowed to determine a plenum-to-impeller reduced frequency that correlates very well with the measured performance. The theory behind the new coefficient is discussed together with the measurement details and validates the correlation that can be used in the design phase to determine the best compromise between the inlet plenum complexity and impact on the first stage.
Analytical Non-Newtonian Oldroyd-B Transient Model for Pretransient Turbulent Flow in Smooth Circular Lines
Authors: Hullender David A.
Published: July 2018

A new approach for obtaining a normalized closed-form frequency domain analytical model for the non-Newtonian shear thinning effects on the pressure and shear stress transients in a pretransient turbulent flow of fluids in smooth circular lines is formulated. The Oldroyd-B model is utilized to analyze these shear thinning effects on these transients. The process of converting the analytical frequency domain model to the time domain using an inverse frequency algorithm commonly used in system identification is explained and demonstrated. The boundary conditions at the ends of the line are defined by the flow and pressure variables, which are in general functions of time or defined by causality relationships. Corresponding equations for the transient changes in the velocity profile and shear stress are also formulated. Two examples demonstrating the application versatility of the model and the sensitivity of the transients to the shear thinning parameters are included. For these specific examples, the sensitivity of the pressure and velocity transients is observed to be relatively low compared to the sensitivity of the wall shear stress. Insight into when the non-Newtonian complexities associated with shear thinning need to be included in a model for fluid transients considering the mode frequencies and/or the input frequencies is provided. The analytical model can easily be simplified for laminar flow and Newtonian fluids.
Patient, Scan Thyself.
Authors: Marini Ariana
Published: July 2018

This article focuses on efforts made by different companies and research teams in combining technologies to improve medical diagnosis. Performing some Star Trek-style medical diagnostics may take nothing more than a clever smartphone app. In order to claim the prize, however, teams will have to combine multiple technologies and miniaturize them into a device that can fit in the palm of a hand. The main goal of the X Prize competition is to give consumers, healthcare providers, and insurers new resources to improve healthcare quality and patient outcomes. Pulsewave MAX, an advance over the company’s Pulsewave heartbeat and pulse measuring system, is bulky compared with other X Prize contenders; its sensors are embedded in an arm cuff and finger clip and were designed for immobile hospital patients. Apps can use smartphone cameras to look at other vital signs. Scandu is building on its existing technology in its entry for the Tricorder X Prize. A Cornell University associate professor of mechanical engineering, David Erickson, has led a team that developed a device that works with a smartphone application to detect cholesterol by analyzing color changes in a test strip.
LNG Fuel: Experiences and Challenges — Addressing Tanks Under Accommodation and Bunkering
Authors: Teo Tony
Published: July 2018

The presentation describes some of the challenges involved with the usage of LNG as a marine fuel. Today there are 37 vessels in operation in Norway and 35 of them have tanks under deck or accommodation. With the higher LNG Fuel investments for new-buildings, it makes good environmental and business sense to ensure that the vessels are additionally designed with energy efficiency, in line with IMO’s latest regulation towards CO2 reduction. In addition to the environmental benefit of using LNG, this gives further longer term economic benefits.

Various passenger Ro-Ro ferries with tanks under accommodation are described. In understanding how the tanks under accommodation and passenger areas are safely designed and accepted by IMO, the properties and the facts about LNG are illustrated to give a clear understanding on how the risks are relatively easy to mitigate and manage. Risk is a function of the likelihood of occurrence versus consequence. The mitigation methods in lowering the probability from occurrence are described. A look at the component in the LNG fuel propulsion system that is really critical and how this is mitigated is examined.

Another concern in the widespread use of small scale LNG is with the crew competence level related to LNG bunkering. The various methods of bunkering are described. Some developments towards safety and competence development in the industry are described.

The presentation concludes with some of the key elements included in the Crew Competence Standard.

Paper published with permission.
Post Macondo Safety and Regulatory Issues: Human Factors From an Organizational Development and Senior Management Perspective
Authors: Grossweiler Philip , Costello David , Graham Kevin
Published: July 2018

Regulations governing the safety of drilling and offshore production operations have changed since the Macondo spill. This paper suggests management level perspectives on the nexus of human factors and safety management systems including an overview of ideas from: Congressional Testimony; the Bipartisan Policy Center inputs to the Presidents Commission on the Spill; the National Academy of Engineering and National Research Council Deepwater Horizon Report, and workshops and initiatives by RPSEA (Research Partnership to Secure Energy for America), SPE, and ASME. The value of benchmarks from risk management practices from the aviation, nuclear power, and financial community are also discussed. The paper will also consider questions as to what management might consider reducing risk and treating risk management as not just a cost center, but as a way to integrate safety management systems into improving corporate performance for all stakeholders.

Paper published with permission.
Experiences From Seven Years of DP Software Testing
Authors: Pivano Luca , Smogeli Øyvind
Published: July 2018

This paper summarizes experiences from independent HIL testing of DP system software on more than 80 DP drilling, shuttle tanker, supply, anchor handling, construction and special purpose vessels. The paper includes examples of typical findings and a comprehensive analysis of finding statistics. The analysis shows how errors and weaknesses in core software and system configuration are distributed on the different functions in the DP system, as well as the potential consequence these errors could have had if they had not been identified and solved through early testing. The presented experiences demonstrate that independent testing of control systems using HIL testing technology is an important and effective service to ensure safe and reliable operation of offshore vessels.

Paper published with permission.
BET 2: Antiemetic use in paediatric sedation with ketamine
Authors: Dunlop Lisa , Hall Dani
Published: July 2018

A short cut review was carried out to see if administering anti-emetics reduced the incidence of vomiting when sedating children for procedures. The author, date and country of publication, patient group studied, study type, relevant outcomes, results study weaknesses of these papers are tabulated. Three randomised, controlled trials were found and one cohort study. The studies suggested that administration of an anti-emetic was associated with a reduced risk of vomiting during the procedural sedation.
SOCIAL BEHAVIOR OF GROUP DEFENSE IN A PREDATOR–PREY SYSTEM WITH DELAY
Authors: LI XIAOJIE , LV YUNFEI , PEI YONGZHEN
Published: July 2018

This paper proposes a mathematical model describing the dynamics of both Antarctic krill and Blue whale population where Antarctic krill species (prey) has group defense when they aggregate in herds in order to provide a self-defense from Blue whale species (predator). Firstly, a sufficient condition for the global asymptotical stability of the positive equilibrium is given using Poincaré–Bendixson theorem excluding periodic solution. Furthermore, we discuss the existence of Hopf-bifurcation and give criteria for stability switches through the study of a first-order exponential polynomial characteristic equation. Finally, some numerical simulations are given to illustrate our results.
Market Impact: A Systematic Study of Limit Orders
Authors: Said Emilio , Ayed Ahmed Bel Hadj , Husson Alexandre , Abergel Frederic
Published: July 2018

This paper is devoted to the important yet little explored subject of the market impact of limit orders. Our analysis is based on a proprietary database of metaorders — large orders that are split into smaller pieces before being sent to the market. We first address the case of aggressive limit orders and then that of passive limit orders. In both cases, we provide empirical evidence of a power law behavior for the temporary market impact. The relaxation of the price following the end of the metaorder is also studied, and the long-term impact is shown to stabilize at a level of approximately two-thirds of the maximum impact. Finally, a fair pricing condition during the life cycle of the metaorders is empirically validated.
Consumerism
Authors: Meneley Anne
Published: July 2018

The article investigates how consumerism is perceived as an unremarkable part of quotidian existence, as a patriotic duty at various moments, as an indicator of social class, and as a means of semiotic self-fashioning. In consumerism, the tension between the sumptuary restraint on conspicuous consumption, which characterized the early Protestant ethic, and the dependence of capitalism itself on boundless commodity circulation, emerges again and again. I investigate how certain forms of consumerism, relating to excess and improper storage, are reclassified in medical terms. I also investigate modes of strategic consumerism, which try to bridge the gap between producer and consumer, and how certain forms of performative labor are themselves consumed. I close with a few reflections on sites for future study: shopping as a form of underrecognized labor, and an auto-ethnographic turn for academics, inspecting the reach of consumerism into academic practices and universities themselves.
Assembly and Positioning of the Oocyte Meiotic Spindle
Authors: Mogessie Binyam , Scheffler Kathleen , Schuh Melina
Published: July 2018

Fertilizable eggs develop from diploid precursor cells termed oocytes. Once every menstrual cycle, an oocyte matures into a fertilizable egg in the ovary. To this end, the oocyte eliminates half of its chromosomes into a small cell termed a polar body. The egg is then released into the Fallopian tube, where it can be fertilized. Upon fertilization, the egg completes the second meiotic division, and the mitotic division of the embryo starts. This review highlights recent work that has shed light on the cytoskeletal structures that drive the meiotic divisions of the oocyte in mammals. In particular, we focus on how mammalian oocytes assemble a microtubule spindle in the absence of centrosomes, how they position the spindle in preparation for polar body extrusion, and how the spindle segregates the chromosomes. We primarily focus on mouse oocytes as a model system but also highlight recent insights from human oocytes.
MiR-195/-16 Family Enhances Radiotherapy via T Cell Activation in the Tumor Microenvironment by Blocking the PD-L1 Immune Checkpoint
Authors: Tao Zhen , Xu Shaohua , Ruan Hailong , Wang Tao , Song Wen , Qian Li , Chen Ke
Published: July 2018

Background/Aims: Radiotherapy is the standard treatment option for advanced prostate cancer. Unfortunately, despite significant advances in radiation delivery, prostate cancer radioresistance occurs in a large proportion of patients undergoing radiotherapy. As a way to enhance radiotherapy effectiveness, research advances into the mechanisms regulating the immune response have revived interest in combination radiation and immune-based therapies. Methods: miR-195/-16 family and PD-L1 levels were analyzed in samples from a GSE21032 data set. Kaplan-Meier analysis was used to evaluate the difference in biochemical recurrence-free survival associated with miR-195 and miR-16 expression. qRT-PCR and western blot were used to evaluate the miR-195, miR-16 and PD-L1 expression. Then, we used bioinformatics analysis and luciferase reporter assay to predict and confirm the miR-195 and miR-16 target gene. Finally, we elucidate the miR-195 and miR-16 function on immune evasion in the DU145/T cell co-culture model and syngeneic mouse model treated with radiotion through qRT-PCR, western blot, Flow cytometry and ELISA. Results: High levels of miR-195 and miR-16 were positively correlated with the biochemical recurrence-free survival of prostate cancer patients. miR-195 and miR-16 were inversely correlated with PD-L1, PD-1, CD80 and CTLA-4 expression. Further mechanistic investigations revealed that miR-195 and miR-16 inhibited PD-L1 expression. Additionally, restoration of miR-195 and miR-16 expression enhanced radiotherapy via T cell activation in the tumor microenvironment by blocking PD-L1 expression. This synergistic effect of immunotherapy and radiotherapy was associated with the proliferation of functional cytotoxic CD8+ T cells and inhibition of myeloid-derived suppressor cells and regulatory T cells. Conclusions: Our data revealbiological and functional interactions between immunotherapy and radiotherapy through the miR-195/-16 family regulatory cascade.
MicroRNA-374a Inhibits Aggressive Tumor Biological Behavior in Bladder Carcinoma by Suppressing Wnt/β-Catenin Signaling
Authors: Chen Xiaoliang , Jia Chunshu , Jia Chunyi , Jin Xingyi , Gu Xinquan
Published: July 2018

Background/Aims: microRNA (miR)-374a plays a crucial role in cancer progression by promoting the metastasis and proliferation of various types of malignant tumors. Because its role in bladder cancer is unknown, we investigated whether miR-374a affects the progression of bladder cancer and studied the underlying mechanism. Methods: The Cancer Genome Atlas was used to analyze the clinical relevance of miR-374a. Quantitative PCR, western blotting, and luciferase and immunofluorescence assays were used to detect the expression patterns, downstream targets, and function of miR-374a in bladder cancer cells. Apoptosis was evaluated by flow cytometry after cisplatin treatment. Results: Via in silico analysis, low levels of miR-374a were associated with poor prognosis in bladder cancer patients with distant metastasis. WNT5A was a direct target of miR-374a in two bladder cancer cell lines. miR-374a mimic abrogated the metastatic potential and invasiveness of bladder cancer cells via WNT5A downregulation in both T24 and TCCSUP human bladder cancer cells; the opposite was observed with miR-374a inhibitor. In addition, miR-374a treatment reduced the phosphorylation and nuclear translocation of β-catenin. Cisplatin treatment significantly increased the apoptosis rate. Expression levels of cancer stemness-related proteins were reduced in miR-374a mimic-pretreated cells. Conclusion: Lower expression of miR-374a is associated with poor prognosis and miR-374a improves tumor biological behavior in bladder cancer cells, suggesting that miR-374a might be a novel small-molecule therapeutic target.
Гігієнічний стан порожнини рота в дітей, які проживають у різних екологічних умовах
Authors: Lagoda L. S.
Published: July 2018

Summary. Studies have shown that oral hygiene plays an important role in the emergence of caries and periodontal disease. Excessive accumulation of plaque is the main pathogenetic factor in the emergence of carious process. As a result of the enzymatic activity of microorganisms in plaque, acids are released that contribute to the development of the carious process of solid tissues.The aim of the study – to estimate hygienic state of a cavity of mouth at children who live in different environmental conditions of the Volyn region.Materials and Methods. The results of the stomatological examination of 1210 children are presented in this article. Among the surveyed there were 598 children living on the territory affected by radioactive contamination due to the accident at the Chornobyl Nuclear Power Plant (Liubeshiv and Manevychi), 306 children living on the territory of the technogenic loading due to coal emissions (Novovolynsk) and 306 children living in the conventionally clean area of Lutsk. The teeth were damaged by caries according to the following indices: prevalence of caries of teeth (in %) and caries intensity according to KPV indices. The hygienic state of the cavity of the mouth was estimated by the index of hygiene of Fedorov-Volodkin.Results and Discussion. The analysis of the results showed that (32.86±2.20) % of children living in radioactively contaminated areas have poor oral hygiene, while in children of conditionally clean Lutsk this figure is lower and is, on average, (17.34±3.03) %. With a satisfactory level of oral hygiene, nearly the same number of children was detected: (30.99±2.98) % and (24.91±2.82) % in radioactive contaminated areas. It was found that the good hygiene of the oral cavity of children was almost identical in Novovolynsk city – (29.46±2.56) % and in radioactive contaminated territories (27.96±2.72) % and the highest rate was found among schoolchildren in Lutsk – (38.25±3.40).Conclusions. The results of the study of oral hygiene in children revealed an unsatisfactory condition in a much larger number of children living in radiation.
Обґрунтування вибору малоінвазивних оперативних втручань при врослому нігті у хворих на цукровий діабет
Authors: Kryzhevskiy V. V. , Tsyganenko O. O. , Shevchuk M. V. , Rybianets Y. V. , Ivanchenko R. V. , Chegol I. N. , Toan N. L.
Published: July 2018

Мета роботи: навести приклад використання малоінвазивного методу ARCADA при лікуванні оніхокриптозу у хворих на цукровий діабет.
Спосіб оперативного втручання у хворих на хронічний панкреатит із біліарною гіпертензією
Authors: Pylypchuk V. I.
Published: July 2018

Мета роботи: оцінити безпосередні та віддалені результати запропонованого методу хірургічного лікування хворих на хронічний панкреатит (ХП) із біліарною гіпертензією (БГ).Матеріали і методи. Проаналізовано результати хірургічного лікування 170 хворих на ускладнені форми ХП, у 60 (35,3 %) хворих ХП ускладнився БГ. Операцію Фрея виконано 29 (48,3 %) хворим, яких було розділено на дві групи: I група – 16 (55,2 %) хворих, яким застосовано стандартний метод операції, II група – 13 (44,8 %) хворих, яким використано запропонований метод втручання.Результати досліджень та їх обговорення. Проведений статистичний аналіз показав відсутність достовірної різниці між ранніми післяопераційними ускладненнями у хворих обох груп дослідження (р > 0,05). Показники якості життя у пацієнтів на ХП з БГ у віддаленому післяопераційному періоді були достовірно кращими порівняно з передопераційними (р < 0,05). Проте достовірної різниці в показниках якості життя пацієнтів між групами у віддалені терміни після операції не виявлено (р > 0,05). Показники фізичного та психологічного здоров’я були кращими у групі пацієнтів, у яких застосовано запропонований метод операції. Запропонований метод оперативного втручання (варіант реконструктивного етапу операції Фрея, який полягає в накладанні панкреато-ентеро-дуоденоанастмозу на ізольованій вставці тонкої кишки з гепатикоентероанастомозом на петлі кишки за Ру) у хворих на ХП із БГ є фізіологічним, дозволяє надійно усунути явища БГ та отримати добрі результати у віддалені після операції терміни.
Проблема діагностики малосимптомного холедохолітіазу в пацієнтів із гострим калькульозним холециститом
Authors: Terletskyi O. M. , Kolomiytsev V. I.
Published: July 2018

Мета роботи: покращити результати діагностики малосимптомного холедохолітіазу.Матеріали і методи. Проведено аналіз діагностики та лікування 167 пацієнтів з гострим калькульозним холециститом та підозрою на холедохолітіаз у період із 2007 до 2016 р.Результати досліджень та їх обговорення. Пацієнти з гострим калькульозним холециститом та малосимптомним холедохолітіазом найчастіше скаржилися на біль у правій підреберній та епігастральній ділянках (95,8 %), підвищення температури тіла (47,9 %) та загальну слабість (87,4 %) і лише у 4 (2,3 %) пацієнтів спостерігали тріаду Шарко (жовтяниця, лихоманка, дрощі). При аналізі біохімічних показників крові спостерігали підвищення рівня білірубіну лише у 38 (22,7 %) пацієнтів, а лужної фосфатази у 131 (78,4 %) та гамаглютамілтранспептидази у 139 (83,2 %) пацієнтів. За результатами УЗД підозра на холедохолітіаз виникла у 68,8 % пацієнтів; діаметр загальної жовчної протоки склав в середньому (9,0±0,21) мм. Не виявлено УЗД-ознак гіпертензії або іншої біліарної протокової патології у 52 (31,1 %) пацієнтів. Серед 41 пацієнта за допомогою МРХПГ діагностовано холедохолітіаз у 30 (73,2 %) хворих. Під час ЕРХПГ виявлено конкременти у 97,8 % пацієнтів. Ускладнення після проведення лікувальної ЕРХПГ виникли у 5 (3,6 %) пацієнтів.
Особливості місцевих імунних реакцій у порожній кишці при пострезекційній портальній гіпертензії
Authors: Tatarchuk L. V.
Published: July 2018

Мета роботи: дослідити особливості локальних імунних реакцій у порожній кишці при пострезекційній портальній гіпертензії.Матеріали і методи. Дослідження проведено на 45 щурах-самцях, які були розділені на 3 групи: 1-а група – 15 інтактних тварин, 2-а – 15 щурів після резекції лівої бокової частки – 31,5 % паренхіми печінки, 3-я – 15 тварин після резекції правої та лівої бокових часток печінки (58,1 %). Евтаназію тварин здійснювали кровопусканням в умовах тіопентал-натрієвого наркозу через 1 місяць від початку експерименту. Вирізані шматочки із порожньої кишки фіксували в 10 % нейтральному розчині формаліну і після відповідного проведення через етилові спирти зростаючої концентрації заливали у парафінові блоки. Гістологічні зрізи завтовшки 5–7 мкм після депарафінізації фарбували гематоксилін-еозином, за ван-Гізоном, Маллорі, Вейгертом, толуїдиновим синім. При виявленні плазматичних клітин-продуцентів Ig A, Ig M, Ig G, Ig E мікротомні зрізи порожньої кишки обробляли моноспецифічними антисироватками проти вказаних класів імуноглобулінів, кон’югованими із ізотіоціанатом флюоресцеїну, застосовуючи прямий метод Кунса з відповідними контролями, які вивчали за допомогою люмінісцентного мікроскопа “Люмам Р-8”. У люмінісцентному світлі рахували плазматичні клітини, що давали специфічне світіння, на 1 мм² слизової оболонки досліджуваного органа. Вміст секреторного Ig A (SIgA) визначали методом роздільної імунодифузії в агарі зі специфічною сироваткою проти SIgA. Кількісні показники обробляли статистично.Результати досліджень та їх обговорення. Через місяць після резекції 31,5 % паренхіми печінки локальні імунні реакції у слизовій оболонці порожньої кишки змінювалися незначно. Порушення локального імунного гомеостазу проявилося більш вираженим при резекції 58,1 % об’єму печінки. Так, чиcло плазматичних клітин з IgA у слизовій оболонці досліджуваного органа зменшилося на 26,6 %, рівень секреторного імуноглобуліну А знизився на 22,4 %, а плазмоцити-продуценти IgM, IgG, IgEЄ, відповідно, збільшилися на 70,1 %, у 3,8 та 4,6 раза. Ступінь змін місцевого гомеостазу відповідав глибині та поширенню гемодинамічних розладів, дистрофічним, некробіотичним, інфільтративним та склеротичним процесам у досліджуваному органі, тобто йому належить важлива роль у морфогенезі порожньої кишки при пострезекційній портальній гіпертензії. Отже, резекція 58,1 % паренхіми печінки призводить до пострезекційної портальної гіпертензії та виражених змін локального імунного гомеостазу в слизовій оболонці порожньої кишки, які характеризуються зниженням рівнів SIgA і кількості плазмоцитів-продуцентів IgA, значними порущеннями співвідношень між імуноцитами, що синтезують IgA, IgM, IgG, IgE, появою імунних комплексів у стромі та стінці судин. Ступінь змін місцевих імунних реакцій збігається з глибиною та поширенням гемодинамічних розладів, дистрофічними, некробіотичними, інфільтративними та склеротичними процесами у досліджуваному органі.
Особливості активації процесів ліпідної пероксидації в умовах краніоскелетної травми в щурів різного віку
Authors: Hudyma A. A. , Sushko Yu. I.
Published: July 2018

Мета роботи: з’ясувати вміст ТБК-активних продуктів ПОЛ у печінці в динаміці краніоскелетної травми в щурів різних вікових груп.Матеріали і методи. В експериментах на нелінійних білих щурах-самцях трьох вікових груп (статевонезрілі віком 100–120 днів, статевозрілі тварини віком 6–8 міс. і старі тварини віком 19–23 міс.) в умовах тіопетало-натрієвого наркозу моделювали краніоскелетну травму шляхом дозованого удару по черепу, еквівалентного для тварин різних вікових груп за тяжкістю ураження, який спричиняв закриту черепно-мозкову травму середнього ступеня тяжкості. Крім цього, дозованим ударом моделювали закритий перелом лівої стегнової кістки. Тварин, які вижили, в умовах тіопентало-натрієвого знеболення (80 мг·кг-1 маси тіла внутрішньоочеревинно) через 1, 3, 7, 14, 21 і 28 діб після нанесення травми виводили з експерименту методом тотального кровопускання з серця. У тканині печінки оцінювали активність процесів ліпідної пероксидації за вмістом ТБК-активних продуктів ПОЛ.Результати досліджень та їх обговорення. Моделювання краніоскелетної травми супроводжується активацією процесів ліпідної пероксидації в печінці в особин різного віку, яка тривала в часі і не досягає рівня контролю впродовж 28 діб. У статевонезрілих особин внаслідок краніоскелетної травми до 3 доби вміст ТБК-активних продуктів ПОЛ у печінці наростає повільніше, ніж в особин інших вікових груп, проте через 7 діб настає виснаження механізмів антиоксидантного захисту й ступінь приросту показника стає найбільшим. У подальшому, завдяки вмиканню механізмів довгострокової адаптації, показник знижується більш інтенсивно і стає вірогідно нижчим, ніж в інших вікових груп. Динаміка вмісту ТБК-активних продуктів ПОЛ у печінці у статевозрілих і старих щурів протягом перших 14 діб посттравматичного періоду є подібною зі стрімким зростанням показника протягом однієї доби експерименту і досягненням ним максимуму через 7 діб, який практично не змінювався до 14 доби. В подальшому показник знижується, проте у статевозрілих тварин більш інтенсивно, ніж у старих. Отримані результати слід враховувати при розробці експериментальних методів корекції травматичної хвороби із врахуванням віку.