bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of the temperature conversion rate on the deformation processes of the shape memory effect and transformation plasticity
Authors: Khlopkov E A , Zhurbenko P N , Tikhomirov A A , Volkov G A , Zatulsky G Z , Vyunenko Yu N
Published: December 2019

The influence of the temperature conversion speed on the mechanical characteristics of metals with shape memory is mentioned in connection with the dissipative properties of this materials class. This paper presents the different cooling and heating regimes research results of ring-shaped force elements and spiral drives demonstrating the possibility of this parameter influence on their deformation characteristics in the temperature range of martensitic transformation.
The dynamic of cooling of cast iron in the cristllizer in condition of the semi-continuous production process bimetallic band “steel-cast iron”
Authors: Lihoshva V P , Shmatko A V , Savin V V , Savina L A , Tymoshenko A N
Published: December 2019

The dynamics of hard crust formation is investigated in the liquid melt by contact with the working walls of the copper crystallizer under conditions of continuous production of bimetallic products such as “band” at different speeds of the process. The optimal speed is identifying to achieve maximum performance with the satisfactory quality of the finished products. Recommendations for increase speed of carrying out process are offered.
Superhydrophobic coating based on silicone resin SILRES® MSE 100
Authors: Loganina V I
Published: December 2019

The anti-icing properties of coatings based on the developed composition are considered. It was shown, that after wetting during 72 hours, the coatings based on the proposed composition retained a superhydrophobic effect. The wetting angle on the mortar substrate was more than 150 degrees. Adhesion of coatings to the substrate after wetting amounted to 1 point. Information is given about the results of evaluation of the adhesion of ice to a superhydrophobic metal surface. It is shown, that the force of detachment of a drop of water on a superhydrophobic metal surface is 3 times less. It ensures easier rolling of a drop of water from the surface and its anti-icing properties. It is established, that the adhesion of ice to the superhydrophobic surface is less compared to the hydrophilic one. It is shown, that there is no difference in the rate of ice evaporation on a hydrophilic and superhydrophobic surface.
Structural and analytical mesomechanics of fracture
Authors: Malinin V G , Malinina N A , Malinin V V , Malukhina O A
Published: December 2019

Developing methodology of structural-analytical theory of strength, this article outlines methods for constructing a variant of defining equations of structural-analytical mesomechanics of failure, based on a rational synthesis of the main achievements of continuum mechanics, physics of plasticity and strength of solids, and other related disciplines. Loaded material is considered as a multi-level system in which micro, meso and macro levels are organically interconnected. Each scale level is characterized by its mechanisms and laws of deformation, the evolution of structure and damaging.

A method for constructing a two-level fracture criterion is being developed, which takes into account the hierarchical nature of the development of damaging and mutual influence of structural concentrators zones (SCZ) and macro stress concentrators. In order to take into account the influence of SCZ at the mesoscale level, experimentally justified tensor parameters of the magnetomechanical effect are introduced: magnetic distortion tensor and tensor intensity of intrinsic magnetic field of dispersion that occurs in the SCZ of the loaded body. Possible directions for the development of fracture mesomechanics are discussed.
Structural and analytical mesomechanics of alloys with shape memory effect in the concept of interacting levels of deformation and destruction
Authors: Malinin GV , Malinin V G , Malinin N A , Malukhina O A
Published: December 2019

This article presents the results of the development of structural-analytical mesomechanics based on the concept of interacting multi-level (micro, meso and macro) plastic flow, the evolution of structural damage and martensitic phase transformations. It presents a system of constitutive relations, which take into account the mutual influence of plastic deformations, processes of destruction and structural phase transformations of martensitic nature for alloys with shape memory effect (SME).
The calculation of beam-wall made of material with shape memory effect by the finite element method
Authors: Malinin G V , Malinina N A , Malukhina O A
Published: December 2019

In present article application of a method of finite elements for calculation of beamwall, executed from a material with effect of memory of the form (SME) is considered. The equations of structural-analytical mesomechanics were used as defining relations.
Improving the efficiency of a vapor refrigerating machine with a screw compressor while adjusting the performance
Authors: Noskov A N , Tarasenkov D S , Arendateleva S I , Zawadzki I M
Published: December 2019

When using an air condenser in a refrigeration machine, the condensation temperature significantly depends on the parameters of the outside air. To ensure stable operation of the throttling device, the condensation temperature must be maintained and remain no lower than a certain value. This leads to unnecessary energy consumption for steam compression in the compressor. The article presents a scheme of a refrigerating machine with a screw compressor which allows to reduce energy consumption for cold production by reducing the condensation pressure when the ambient temperature drops and installing a pump in front of a throttle device. Operation of the refrigerating machine with a screw oil-filled compressor with full capacity on different modes has peculiarities. The article describes the regulator of the screw compressor, which consists of a spool and two butterfly valves. This design allows for adjustment of the geometric degree of compression with full performance and allows to get arbitrary laws of change with decreasing performance. The article presents the dependences of cooling capacity, effective power and coefficient of performance at full and 50% performance of a screw compressor with a decrease in condensation temperature. Experimental and calculated characteristics of a refrigeration oil-filled screw compressor operating on Freon R22 were used. Using a scheme of a vapor refrigerating machine with a screw compressor pump in front of the throttle valve can significantly increase the energy efficiency of its work.
Simulation investigation of a heat pump, operating on a low-temperature source of heat and a constant condensation pressure
Authors: Rachkovskiy N O , Tatarenko Iu V , Mitropov V V , Naumova O S , Bordashev K A
Published: December 2019

The simulation investigation was carried out at the “Vapor Compression Heat Pump” stand, which allows simulating the annual cycle of operation of the heat pump. Values and further calculations were determined by the operating characteristics of the cycle. Calculations were made according to generally accepted dependencies. As a result of simulating the annual cycle of the heat pump operation, the operational and energy characteristics of the heat pump were determined under the specified conditions: maintaining the specified condensing pressure pc
=1,31 MPa and the changing temperature of the low-potential heat source – water tw4, which varied from from – 0,3ºC to + 10,1ºC. Based on the obtained data, it was estimated the change in the heat pump coefficient of performance (COP) as a function of the low–grade heat source temperature, as well as the application potential of renewable energy sources.
Electrochemical metallization of molybdenum alloys
Authors: Tikhonov A A , Arendateleva S I , Perepelitsa T I
Published: December 2019

The experimental data about influence of chemical and electrochemical operations of surface treatment of alloys of molybdenum on adhesion and solderability of electroplatings are provided. Influence of structures and the modes of electrolytes on quality of coverings, adhesion and solderability of the coverings applied on molybdenum alloys is studied. It is proved that use of combination in one electrolyte of two operations: electrochemical etching and at once the carried-out operation of copper plating, leads to increase in adhesion of coverings to molybdenum alloys. It occurs because the oxide layer is rather fully pitted during anodic dissolution, and the most important, it doesn’t manage to be formed before deposition again as it occurs in many other known technological processes. The developed technology of galvanic metallization of molybdenic alloys allows: to reduce the number of technological operations, to increase efficiency of process, to use cheaper inventory, to increase adhesion of electroplatings to alloys of molybdenum and to improve their solderability.
Optimal Plastic Analysis of Structures under Uncertain Conditions
Authors: Rad Majid Movahedi
Published: December 2019

In this study optimum plastic shakedown analysis of framed steel structures with semi-rigid connections (SRC) between beam and columns subjected to multi-parameter static loading presented. Since shakedown analysis does not provide information concerned with the accumulated residual displacements, complementary strain energy of the residual force (CSERF) considered as constrain to evaluate the post yield behavior of framed steel structures. The constraints on the CSERF are modelled using probabilistic and deterministic methods. To evaluate the maximum shakedown load-multipliers a numerical example is introduced, shakedown load-multipliers are calculated and safe loading domains of the framed steel structure are illustrated. The numerical results show that the constraints on CSERF, SRC and probabilistic given constraints can influence on the value of the shakedown load-multipliers.
Evaluation of Visual Preference for Seasonal Streetscape Design Using 3D Simulation Technology
Authors: Hyunjin Chun , Yue Wang
Published: December 2019

As 3D technology advances, many designers are using 3D technology in their design research. Environment designers, in particular, conduct public design research using 3D simulation technology. In the field of environmental design, green space is an important factor in determining the image of public design. Green space, however, has different visual preferences as the seasons change. Thus, this research aimed to analyze the visual preferences of streetscape according to the seasons change using 3D simulation technology. The result of the study shows that the autumn image of maple background and ginkgo background are more preferred than the winter image of maple background and ginkgo background. In conclusion, the change of seasons is a crucial factor in determining the visual preference of the landscape. Designers, therefore, should consider the variation of seasons as well as the shape of streetscape to improve the visual preference of a streetscape. These findings could also be applied as theoretical data to conduct the public design.
Research on UX Evaluation Model of Computer Input Devices (Keyboard and Mouse) Based on AHP
Authors: Huang Zhaohui , Li Haoda
Published: December 2019

With the rapid development of the Internet, there are more and more computer input devices for different usage scenarios, and a lot of factors need to be considered comprehensively when users select computer input devices. At present, there are still some problems need to be solved in this field: how to evaluate the user experience of computer input devices in order to give reasonable suggestions to consumers when making purchasing decisions; how can design and development personnel find the shortcomings of design solutions in the design decision process? Aiming at the above problems, a user experience evaluation system for computer input devices is proposed.

Firstly, based on the user experience 5E model proposed by Whitney Quesenbury, the user experience evaluation system of computer input device was constructed by using the questionnaire method, interview method, and expert opinion method. Then, the user experience evaluation model of computer input device was constructed by AHP.

This paper takes computer input equipment as the research object and studies the user experience evaluation method of computer input device through the combination of qualitative and quantitative research methods. Established a more scientific user experience evaluation system to guide the design and development personnel in the design decision process. And provides reasonable suggestions for consumers to purchase and has certain reference value in the field of user experience evaluation research.
The Development of Shop Documentation Plug-In Based on NX Software
Authors: Zhao Jiaqi , Yang Xiaodong , Wu Ligeng
Published: December 2019

Shop documentation is a document filled with all relevant information of product processing, which is playing an important role in CNC machining. At present, although shop documentation could be generated from 3D modelling software, the contents in shop documentation are usually not up to operators’ requirement. On this condition, the data structure of shop documentation should be rebuilt, and a new approach of generating shop documentation should be created as soon as possible. In this paper, the data structure of shop documentation is redesigned to make sure that the document contains the most suitable information, and a new kind of shop documentation plug-in is developed in Siemens NX software at the same time, which could generate PDF-format shop documentation very fluently. The plug-in is programmed by C++, using the function library of NX software which is called NX Open C. Finally, an example of generating shop documentation in NX software is given to prove that the shop documentation plug-in works properly.
Design Method of Function-Structure Integrated Lattice Structure
Authors: Li G X , Zhang M , Zhao C , Jin X , Luo W P
Published: December 2019

Structure lightweight has always been a hot topic in the field of engineering. Lattice structure has characteristics of light weight, high specific stiffness and high specific strength because of its high porosity and low relative density. It has been widely used in structural lightweight design. In addition, lattice structure has broad application prospects in advanced industrial equipment, due to the potential of anti-vibration, anti-impact, heat transfer and heat dissipation, zero/negative thermal expansion, electromagnetic wave absorption, sound absorption and noise reduction. In this paper, a design method of function-structure integrated lattice structure is proposed, topology optimization and variable density lattice filling technology are studied, the research methods of multi- functional characteristics of lattice structures are discussed, and the related simulation and experimental methods are introduced, which is of certain reference significance to the development of technology in this field.
A Study on the Characteristics of Road Landscape for 3D Design Developing Process
Authors: Hyunjin Chun , Yue Wang
Published: December 2019

Due to Asia’s economic growth and industrialization, there has being a growing interest in road landscapes recently. In the meanwhile, aesthetic aspects in road design are becoming more and more important as 3D design technology advancing. With a view to the above, designers must consider both the structural engineering and the aspect of aesthetics when conceiving new urban roads blueprint. Much more in-depth studies are expected to focus on the aesthetics of roads by utilizing 3D design technology. In light of this, this study was centred on the landscape preferences of road in modern cities from the perspective of building height and planting type alongside. The main results of the study were summarized as follows: The images of H:W=1:3 and H:W=1:1 were more highly preferred than the rest seven images on the grounded that the lower buildings seemed to have better correspondence with the surroundings. And the image of planting with 7.5 meter-interval received the highest evaluation for visual preference on account that this interval provides road landscape with a visual image of stability. In conclusion, this study results illustrated that ratio of building height to road width and the planting interval on footpath were the crucial elements in landscape design. Furthermore, this study also make efforts to present a methodology for 3D design develoement.
Optimizing the Process of Multi-wire Sawing Silicon Rods with Consolidated Abrasive Diamonds Based on RSM
Authors: Chaohua Wu , Ye Wang , Ming Guo , Shun Liu , Jiangjing Lin , Chunliang Fu , Bin Zhou
Published: December 2019

In order to improve the processing efficiency and processing quality of silicon rods, and to optimize the process parameters during the cutting process of silicon rods, the sawing force of wire saw is studied from the aspects of cutting deformation and friction. Meanwhile, the mathematic model is established between the sawing force and some cutting process parameters. Besides, the quadratic regression model is also established by Box-Behnken center combination experiment and the response surface methodology(RSM), which can reflect the wire saw speed, workpiece feed rate and wire saw radius of the interaction of three process parameters on the wire saw sawing force. The results show that the model can accurately predict the sawing force and optimize the process parameters during the cutting process as well.
A Shifting Strategy That Reduces the Number of Shifts for Urban Conditions
Authors: Jia-Wei Sheng , Yi-Hui Gu , Jin-Yue Tian
Published: December 2019

Nowadays, urban conditions have become the main operating conditions for vehicles. Urban traffic congestion leads to a higher rate of vehicle idle speed and frequent shifts. This paper proposes a new shifting strategy in order to effectively improve the problem of frequent shifting, which is called flexible shift. In view of the fact that the electric vehicle cancels the clutch, shifting is completed directly by the control of the motor during the shifting process. Reducing the number of shifts can effectively reduce wear and increase the life of the transmission, which can be realized by the flexible shift. This paper uses MATLAB to simulate the shifting times of this shift strategy under FTP conditions. The simulation results show that electric vehicles with flexible shifting control strategy can significantly reduce the number of shifts, improve comfort, reduce hardware loss, and do not reduce economic efficiency.
Use of Articulated Transport Systems in the Mining Industry
Authors: Bazhenov E E , Chernyshev D O , Bazhenova L V
Published: December 2019

The work is devoted to the possibility and prospects of the use of all-wheels drive articulated transport systems in the mining complex. A comparative analysis of the traditional methods of exporting minerals in open pit mining and the method of using active trailed elements are given. The trailer has a load factor several times higher than the same rate for mining dump trucks. The use of an active trailer makes it possible to reduce the mass of the tractor and trailer by almost 40 tons and increase the specific power of the road train.
Development and implementation of a software and hardware complex of the controls automation into the self-driving car system based on the "GAZelle NEXT" vehicle
Authors: Voronin M M , Anisimov P A , Zolotov A V
Published: December 2019

This article describes the stages and the results of automation of the car controls, as part of the self-driving car based o n the light commercial vehicle (LCV) car class. Some aspects of automation of the car equipped with a manual transmission are touched upon. A block diagram of the automation system of the vehicle controls is provided. The variant of integration of modules of controls automation in the base car is shown. The description of the lower level program is given.
Investigation of collision warning possibilities by means of GNSS receivers of Android smartphones
Authors: Kulikov Roman , Chugunov Alexander , Zamolodchikov Vladimir
Published: December 2019

Using of raw GNSS measurements in Andoid smartphones for precise mututal positioning of vehicles on a road is considered in the Paper. Field experiments with two moving vehicles and pedestrian were conducted. 15 kinds of general maneuvers were provided (overtaking, turn, oncoming traffic, etc.). Smartphone measurements were logged and post-processed to get mutual positioning estimations during maneuvering. Smartphone estimations were compared with precision GNSS receivers measurements.
Application of systems of telematics on commercial vehicles
Authors: Saleh H M , Nuzhdin R V , Kurochkin S V
Published: December 2019

The analysis of systems of telematics of commercial transport is provided in article, the factors influencing its application ways of development of the systems "Fleet management" in Russia are offered and also the pilot model of telematic system, more available from the economic point of view, with function of forecasting of technical condition of the rolling stock on the basis of expert system is presented.
Application of assessment techniques of reliability of the designed steering system based on the real one
Authors: Yusupov R.R. , Alexeev A.V. , Yarzhemsky A.D. , Korchazhkin M.G. , Brovkin A.S.
Published: December 2019

The paper analyses and assesses the designed steering system reliability based on the real one. An analysis of the basic diagram and components’ eventual failures was made. Based on the built structural diagram of the steering the reliability level was estimated. Measures to enhance the system reliability were suggested.
Comparison of the forest machine mover average and nominal pressure on the soil
Authors: Khitrov E G , Andronov A V
Published: December 2019

The purpose of this article is to investigate the relationship between the estimated values of nominal and average wheeled mover pressure on the ground and a rigid bearing surface. Research methods are mathematical analysis, computational experiment, and calculated data approximation. The article presents and compares methods of calculating average mover pressure in deformable soils, medium mover pressure on a rigid base, and nominal pressure on soil. According to the calculations results, it was found that the average mover pressure on firm soils almost corresponds to the estimate of the mover pressure on a rigid base. The nominal pressure is lower than the pressure on the rigid base by 40-50 kPa. The average pressure estimate on moderate soils is close to the nominal pressure. The average pressure on weak soils in the load range of 10-20 kN is close to the nominal pressure, at high values of wheel load the average pressure on the soils category is estimated to be twice less than the nominal pressure of the mover on the soils. It has been established by calculation that the average pressure of the wheeled mover on the deformable forest soils and on a rigid base is connected with the value of the mover nominal pressure on the soils, used by the foreign researchers. The dependences are linear and include correction factors, the values of which are determined by the mover parameters (wheel width and diameter, tyre pressure, and wheel load) and the forest soil category. The received equations allow simplifying the interaction estimates comparison process of forest machine movers on the soils, given within the domestic and foreign techniques limits.
Improvement of car repairability based on the material destruction assessment during its operation
Authors: Kuzmin N.A. , Goncharova D.A. , Pachurin G.V. , Filippov A.A. , Korotunova I.A.
Published: December 2019

Parts and structural elements of vehicles during operation are affected by cyclic loads and various temperatures. At the same time, more than 80% of all types of metal structures destruction are fatigue-like, which leads to huge financial losses, and often to fatal accident. Therefore, issues of improving the reliability and safe operation of automobile parts subjected to cyclic loads in air at different temperatures are important in modern industrial science. That’s why, it is necessary to know the laws of fatigue behavior of structural materials obtained by different types and modes of technological processing in specific operating conditions in order to predict their operational reliability increase.

Changes in the metal during fatigue are directly reflected on the curves of changes in the samples current deflection, since they reflect the antogonism of two mutually opposite processes - hardening and softening, directly related to the processes that occur in the material structure during fatigue.

This article presents the possible analysis of the fatigue failure kinetics of some test structural materials using the curves of the samples current deflection. The assessment of structural materials destruction allows us to choose structural materials for car parts, taking the conditions of its operation, types and modes of its manufacturing technology into account in order to increase its maintainability and service life.
Cactus material-based adsorbents for the removal of heavy metals and dyes: a review
Authors: Amari Abdelfattah , Alalwan Basem , Eldirderi Moutaz M , Mnif Wissem , Ben Rebah Faouzi
Published: December 2019

Cactus is cultivated in many regions over the world. Because of its chemical composition and its valuable nutritional and biological characteristics, cactus finds applications in different sectors such as the pharmaceutical and the food industries. Interestingly, cactus materials (cladodes, fruit seeds, peel, etc) have been explored for their probable use as adsorbents for the removal of toxic heavy metals and dyes from wastewater. Various preparations methods were used to produce cactus material-based biosorbents. These biosrbents have been investigated and successfully used for the elimination of both heavy metal and dyes from aqueous solutions. Related results showed very promising pollutant removal efficiency associated with an interesting adsorption capacity similar to other materials from various origins. This paper explores various cactus biosorbents preparations. Furthermore, their efficiency in depollution and factors controlling the adsorption capacity will be discussed.
Respecting and circumventing presidential term limits in sub-Saharan Africa: A comparative survey
Authors: Reyntjens Filip
Published: December 2019

This article offers a survey of political dynamics surrounding the issue of presidential term limits in a large sample of Sub-Saharan African countries over a long period of time. It examines empirically how political regimes have dealt with this issue by observing or circumventing limits, and it links these developments with the democratic quality in the countries at the time they occurred. Beyond legal texts, this study examines the empirical reality of term limits. It finds that effective term limits are less prevalent in practice than in constitutional texts. This is followed by an analysis of the incumbency bias, showing that incumbents who run often win at the election, but that transfers of power are more frequent in the absence of an incumbent. The article then considers the cost-benefit analyses leaders engage in when deciding to stay or to go, as well as the risks of overstaying. Domestic protest and international pressure generally have a limited impact on this choice. The article finally makes clear that political paths across Africa are very divergent, a feature also seen in the longevity of presidents.
Tradition in transformation: the classical curriculum in the colonial and early national American college
Authors: Fisher Gary F
Published: December 2019

Narratives of decline dominate histories of classical education. Changes or developments in the way classics have been taught are commonly understood in terms of the supposedly inexorable decline of classical learning. The American colleges at the end of the eighteenth century are subject to the same interpretation. After the Revolution, the colleges and their classics-oriented curriculum were subject to new pressures to reform the education they offered to better reflect the values of the new nation. These calls for reform are commonly understood as attacks on the classics that sought to diminish their role in, or even remove them from, the college curriculum. This essay will subject materials such as entrance requirements, curricula, and reformist literature to a critical re-reading. Rather than examining the extent to which the position of the classics diminished relative to other subjects during this period, it will show how the content of the classical curriculum was reformed and refined to better realize its pedagogical potential and ensure its relevance to the changing needs of students.
Comment on: Incidence of Adverse Psychiatric Events During the Treatment of Inflammatory Bowel Disease With Biologic Therapies: A Systematic Review
Authors: Salwen-Deremer Jessica K , Speed Brittany C
Published: December 2019

Lay Summary

In this article, we comment on work by Jain and colleagues. They found that there are very few instances of increased anxiety and depression in drug trials for IBD. We believe these rates are likely higher and discuss supporting literature.
Impact of Diflubenzuron on Bombus impatiens (Hymenoptera: Apidae) Microcolony Development
Authors: Camp A A , Batres M A , Williams W C , Lehmann D M
Published: December 2019

Reliance on the honey bee as a surrogate organism for risk assessment performed on other bees is widely challenged due to differences in phenology, life history, and sensitivity to pesticides between bee species. Consequently, there is a need to develop validated methods for assessing toxicity in non-Apis bees including bumble bees. The usefulness of small-scale, queenless colonies, termed microcolonies, has not been fully investigated for hazard assessment. Using the insect growth regulator diflubenzuron as a reference toxicant, we monitored microcolony development from egg laying to drone emergence using the Eastern bumble bee Bombus impatiens (C.), a non-Apis species native to North America. Microcolonies were monitored following dietary exposure to diflubenzuron (nominal concentrations: 0.1, 1, 10, 100, and 1,000 µg/liter). Microcolony syrup and pollen consumption was significantly reduced by diflubenzuron exposure. Pupal cell production was also significantly decreased at the highest diflubenzuron concentration assessed. Ultimately, diflubenzuron inhibited drone production in a concentration-dependent manner and a 42-d 50% inhibitory concentration (IC50) was determined. None of the dietary concentrations of diflubenzuron tested affected adult worker survival, or average drone weight. These data strengthen the foundation for use of this methodology, and provide valuable information for B. impatiens; however, more work is required to better understand the utility of the bumble bee microcolony model for pesticide hazard assessment.
Real-time image-guided electromagnetic navigation bronchoscopy dual-marker technique to localize deep pulmonary nodules in a hybrid operating room
Authors: Cheng Chuan , Fang Hsin-Yueh , Wen Chih-Tsung , Chao Yin-Kai
Published: December 2019

Herein, we describe a Dyna-computed tomography-guided electromagnetic navigation bronchoscopy technique aimed at localizing deep pulmonary nodules. The method was implemented in a hybrid operating room and required the use of 2 markers (a near-infrared dye as a surface marker and a microcoil as a deep marker).
Naturally Derived Polyphenols Protect Against Corticosterone-Induced Changes in Primary Cortical Neurons
Authors: Donoso Francisco , Ramírez Valerie T , Golubeva Anna V , Moloney Gerard M , Stanton Catherine , Dinan Timothy G , Cryan John F
Published: December 2019

Background

Polyphenols are phytochemicals that have been associated with therapeutic effects in stress-related disorders. Indeed, studies suggest that polyphenols exert significant neuroprotection against multiple neuronal injuries, including oxidative stress and neuroinflammation, but the mechanisms are unclear. Evidence indicates that polyphenol neuroprotection may be mediated by activation of Nrf2, a transcription factor associated with antioxidant and cell survival responses. On the other hand, in stress-linked disorders, Fkbp5 is a novel molecular target for treatment because of its capacity to regulate glucocorticoid receptor sensitivity. However, it is not clear the role Fkbp5 plays in polyphenol-mediated stress modulation. In this study, the neuroprotective effects and mechanisms of the naturally derived polyphenols xanthohumol and quercetin against cytotoxicity induced by corticosterone were investigated in primary cortical cells.

Methods

Primary cortical cells containing both neurons and astrocytes were pre-incubated with different concentrations of quercetin and xanthohumol to examine the neuroprotective effects of polyphenols on cell viability, morphology, and gene expression following corticosterone insult.

Results

Both polyphenols tested prevented the reduction of cell viability and alterations of neuronal/astrocytic numbers due to corticosterone exposure. Basal levels of Bdnf mRNA were also decreased after corticosterone insult; however, this was reversed by both polyphenol treatments. Interestingly, the Nrf2 inhibitor blocked xanthohumol but not quercetin-mediated neuroprotection. In contrast, we found that Fkbp5 expression is exclusively modulated by quercetin.

Conclusions

These results suggest that naturally derived polyphenols protect cortical cells against corticosterone-induced cytotoxicity and enhance cell survival via modulation of the Nrf2 pathway and expression of Fkbp5.
Quadratic Chabauty and Rational Points II: Generalised Height Functions on Selmer Varieties
Authors: Balakrishnan Jennifer S , Dogra Netan
Published: December 2019

We give new instances where Chabauty–Kim sets can be proved to be finite, by developing a notion of “generalised height functions” on Selmer varieties. We also explain how to compute these generalised heights in terms of iterated integrals and give the 1st explicit nonabelian Chabauty result for a curve $X/\mathbb{Q}$ whose Jacobian has Mordell–Weil rank larger than its genus.
Histidine 131 in presenilin 1 is the pH-sensitive residue that causes the increase in Aβ42 level in acidic pH
Authors: Cai Tetsuo , Hatano Aki , Kanatsu Kunihiko , Tomita Taisuke
Published: December 2019

Alzheimer disease (AD) is the most common neurodegenerative disease worldwide. The pathological hallmark of AD is the presence of senile plaques in the brain, which are accumulations of amyloid-β peptide (Aβ) ending at the 42nd residue (i.e. Aβ42), which is produced through multistep cleavage by γ-secretase. Thus, methods to regulate γ-secretase activity to attenuate the production of Aβ42 are in urgent demand towards the development of treatments for AD. We and others have demonstrated that γ-secretase activity is affected by its localization and ambient environment. In particular, an increase in Aβ42 production is correlated with the intracellular transport of γ-secretase and endosomal maturation-dependent luminal acidification. In this study, we focused on the mechanism by which γ-secretase affects Aβ42 production together with alterations in pH. Histidine is known to function as a pH sensor in many proteins, to regulate their activities through the protonation state of the imidazole side chain. Among the histidines facing the luminal side of presenilin (PS) 1, which is the catalytic subunit of γ-secretase, point mutations at H131 had no effect on the Aβ42 production ratio in an acidic environment. We also observed an increase in Aβ42 ratio when histidine was introduced into N137 of PS2, which is the corresponding residue of H131 in PS1. These results indicated that H131 serves as the pH sensor in PS1, which contains γ-secretase, to regulate Aβ42 production depending on the luminal pH. Our findings provide new insights into therapeutic strategies for AD targeting endosomes or the intracellular transport of γ-secretase.
Treatment of Breast Fibroadenoma with Ultrasound-Guided High-Intensity Focused Ultrasound Ablation: A Feasibility Study
Authors: Brenin David R , Patrie James , Nguyen Jonathan , Rochman Carrie M
Published: December 2019

Objective

Breast fibroadenomas (FAs) are common, benign, and often bothersome. Current management includes observation or surgical excision. This study evaluated the safety and feasibility of ultrasound-guided high-intensity focused ultrasound ablation for the treatment of FAs.

Methods

Twenty women with a palpable, biopsy-confirmed FA were enrolled in a prospective trial, and they underwent treatment utilizing an ultrasound-guided high-intensity focused ultrasound ablation device. Tumors were greater than 1 cm in diameter, with volumes of 0.3–10 cc. Safety, treatment experience, toxicity, cosmesis, and change in tumor size on palpation and ultrasound measurement were obtained before and after treatment at 3, 6, and 12 months.

Results

All of the 20 patients completed therapy. Pretreatment mean tumor volume was 1.8 cc (standard deviation = 1.23, range 0.57–5.7). Half of the patients reported a painful mass before treatment. All adverse events were well tolerated and transient, with the most common being mild pain, reported by 15 of 20 patients during treatment, and 14 of 20 at the day-7 postprocedure follow-up. Mean pain score during treatment was 16, and at day 7, it was 12.2, on a scale from 0 to 100 (100 = worst pain). Mean patient satisfaction was 4.4 on a scale of 1–5 (5 = most satisfied). Mean likelihood of recommending treatment was 4.7 (5 = most likely). At the 12-month postprocedure follow-up, the mean reduction in volume of the FA was 65.5% on ultrasound; the mass was no longer palpable in 80% of the patients; no patients reported pain; and cosmesis was rated as excellent in all patients.

Conclusion

Ultrasound-guided high-intensity focused ultrasound ablation appears to be effective, safe, and well tolerated for the treatment of FAs. A larger multicenter clinical trial is currently under way.
Using the SEER-Medicare Data to Assess Incident Chronic Myeloid Leukemia and Bladder Cancer Cases Missed by Cancer Registries
Authors: Lam Clara J K , Warren Joan L , Nielsen Matthew , Smith Angela , Boyd Eric , Barrett Michael J , Mariotto Angela B
Published: December 2019

The growing use of oral systemic therapies and transition of some cancer treatments to the outpatient setting makes capturing all cancer case patients more difficult. We aim to develop algorithms to identify potentially missed incident case patients and estimate impact on incidence rates. We reviewed claims from SEER-Medicare 5% noncancer control patient sample to identify potentially missed chronic myeloid leukemia (CML) and bladder case patients based on diagnosis codes, cancer-related treatments, and oncology consultations. Observed rates of definite missed CML and definite and probable missed bladder case patients were calculated and the impact of missed case patients of these two cancers on SEER 65+ incidence rates were estimated. From 2008 to 2015, the algorithm estimated 781 definite CML case patients missed, increasing the number by 10.7%. From 2007 to 2015, the algorithm estimated 4629 definite and 5772 probable bladder case patients missed, increasing the number by 3.8% to 8.1%. Our algorithms offer potential methods for identifying missed case patients and validating the completeness of cancer registries.
Chronic Graft Versus Host Myopathies: Noninflammatory, Multi-Tissue Pathology With Glycosylation Disorders
Authors: Pestronk Alan
Published: December 2019

Myopathies during chronic graft-versus-host disease (cGvHD) are syndromes for which tissue targets and mechanisms of muscle damage remain incompletely defined. This study reviewed, and pathologically analyzed, 14 cGvHD myopathies, comparing myopathology to other immune myopathies. Clinical features in cGvHD myopathy included symmetric, proximal weakness, associated skin, gastrointestinal and lung disorders, a high serum aldolase (77%), and a 38% 2-year survival. Muscle showed noninflammatory pathology involving all 3 tissue components. Perimysial connective tissue had damaged structure and histiocytic cells. Vessel pathology included capillary loss, and reduced α-l-fucosyl and chondroitin sulfate moieties on endothelial cells. Muscle fibers often had surface pathology. Posttranslational glycosylation moieties on α-dystroglycan had reduced staining and abnormal distribution in 86%. Chondroitin-SO4 was reduced in 50%, a subgroup with 3-fold longer times from transplant to myopathy, and more distal weakness. cGvHD myopathies have noninflammatory pathology involving all 3 tissue components in muscle, connective tissue, small vessels, and myofibers. Abnormal cell surface glycosylation moieties are common in cGvHD myopathies, distinguishing them from other immune myopathies. This is the first report of molecular classes that may be immune targets in cGvHD. Disordered cell surface glycosylation moieties could produce disease-related tissue and cell damage, and be biomarkers for cGvHD features and activity.
Factors Associated With Single and Recurrent Bacteremia in Childhood Brucellosis
Authors: Ben-Shimol Shalom , Farahvar Salar , Fruchtman Yariv , Justman Naphtali
Published: December 2019

Background

Data regarding risk factors of bacteremic brucellosis, and specifically recurrent bacteremia, are scarce. We assessed patients with childhood brucellosis, differentiating between those having culture-negative, single-bacteremic, and recurrent-bacteremic episodes.

Methods

The medical files of pediatric brucellosis patients, from 2005 through 2014, were reviewed retrospectively. Univariate and multivariate analyses were performed to compare demographic and clinical characteristics of culture-negative, single-bacteremic, and recurrent-bacteremic (≥30 days between positive cultures) episodes.

Results

Of all 436 brucellosis cases, 22% were culture-negative, 72% were single-bacteremic, and 6% were recurrent-bacteremic. In a univariate analysis, single-bacteremic episodes were associated with fever (90% vs 65% and 40% in culture-negative and recurrent bacteremia, respectively) and elevated glutamic oxaloacetic transaminase (GOT) levels. Recurrent-bacteremic episodes were associated with anemia (26% vs 14% and 9% in single bacteremia and culture negative, respectively), elevated GOT, low immunoglobulin M (IgM) titers (56% vs 89% and 99%, respectively), and lower levels of adequate treatment (74% vs 94% and 86%, respectively). In multivariate analyses, single bacteremia was associated with fever (odds ratio [OR], 3.595, compared with culture negative), while recurrent bacteremia was inversely associated with IgM titers ≥1:160 (OR, 0.022 and 0.226 compared with culture negative and single bacteremia, respectively) and fever (OR, 0.108 compared with single bacteremia).

Conclusions

Brucellosis episodes are commonly complicated with bacteremia. Single-bacteremic episodes were associated with high-grade fever and elevated liver enzymes, possibly indicating high bacterial virulence. Recurrent-bacteremic episodes were associated with poor treatment at initial diagnosis, along with low rates of fever, low IgM titers, and high anemia rates, possibly indicating impaired host response. Physicians should consider treatment modifications for suspected recurrent-bacteremic brucellosis, including monitoring treatment adherence, and possibly administering prolonged treatment.
Human Genomic Diversity Where the Mediterranean Joins the Atlantic
Authors: Hernández Candela L , Pita Guillermo , Cavadas Bruno , López Saioa , Sánchez-Martínez Luis J , Dugoujon Jean-Michel , Novelletto Andrea , Cuesta Pedro , Pereira Luisa , Calderón Rosario
Published: December 2019

Throughout the past few years, a lively debate emerged about the timing and magnitude of the human migrations between the Iberian Peninsula and the Maghreb. Several pieces of evidence, including archaeological, anthropological, historical, and genetic data, have pointed to a complex and intermingled evolutionary history in the western Mediterranean area. To study to what extent connections across the Strait of Gibraltar and surrounding areas have shaped the present-day genomic diversity of its populations, we have performed a screening of 2.5 million single-nucleotide polymorphisms in 142 samples from southern Spain, southern Portugal, and Morocco. We built comprehensive data sets of the studied area and we implemented multistep bioinformatic approaches to assess population structure, demographic histories, and admixture dynamics. Both local and global ancestry inference showed an internal substructure in the Iberian Peninsula, mainly linked to a differential African ancestry. Western Iberia, from southern Portugal to Galicia, constituted an independent cluster within Iberia characterized by an enriched African genomic input. Migration time modeling showed recent historic dates for the admixture events occurring both in Iberia and in the North of Africa. However, an integrative vision of both paleogenomic and modern DNA data allowed us to detect chronological transitions and population turnovers that could be the result of transcontinental migrations dating back from Neolithic times. The present contribution aimed to fill the gaps in the modern human genomic record of a key geographic area, where the Mediterranean and the Atlantic come together.
Evolution of a Novel and Adaptive Floral Scent in Wild Tobacco
Authors: Guo Han , Lackus Nathalie D , Köllner Tobias G , Li Ran , Bing Julia , Wang Yangzi , Baldwin Ian T , Xu Shuqing
Published: December 2019

Many plants emit diverse floral scents that mediate plant–environment interactions and attain reproductive success. However, how plants evolve novel and adaptive biosynthetic pathways for floral volatiles remains unclear. Here, we show that in the wild tobacco, Nicotiana attenuata, a dominant species-specific floral volatile (benzyl acetone, BA) that attracts pollinators and deters florivore is synthesized by phenylalanine ammonia-lyase 4 (NaPAL4), isoflavone reductase 3 (NaIFR3), and chalcone synthase 3 (NaCHAL3). Transient expression of NaFIR3 alone in N. attenuata leaves is sufficient and necessary for ectopic foliar BA emissions, and coexpressing NaIFR3 with NaPAL4 and NaCHAL3 increased the BA emission levels. Independent changes in transcription of NaPAL4 and NaCHAL3 contributed to intraspecific variations of floral BA emission. However, among species, the gain of expression of NaIFR3 resulted in the biosynthesis of BA, which was only found in N. attenuata. This study suggests that novel metabolic pathways associated with adaptation can arise via reconfigurations of gene expression.
Staphylococcus aureus bloodstream infection in patients with prosthetic joint included in the prospective VIRSTA cohort study: frequency and time of occurrence of periprosthetic joint infection
Authors: Dufour Sébastien , Piroth Lionel , Chirouze Catherine , Tattevin Pierre , Becker Agathe , Braquet Pierre , Ferry Tristan , Duval Xavier , Le Moing Vincent ,   VIRSTA/AEPEI Study Group
Published: December 2019

Among 143 patients of the VIRSTA cohort study having Staphylococcus aureus bacteremia and an arthroplasty implanted for more than a year, S. aureus periprosthetic joint infection was observed in 19%. Signs of infection (pain and swelling) were always present, in median 1 day (extremes: 0- 21) after onset of bacteremia.