bluuebunny/crossref_metadata_2025 huggingface dataset:
Two unbound granular materials stiffness analysis with staged repeated load CBR test
Authors: Salmi Abdelaziz , Bousshine Lahbib , Lahlou Khaled
Published: August 2019

Design methods of flexible pavements in many countries are based on linear elastic behaviour model for Unbound Granular Materials (UGM). In this context, parameters required to characterize an UGM in structural analysis of pavements are Stiffness modulus and Poisson ratio (E and ν). This paper presents a study of two UGM stiffness. Finite element simulation of repeated load CBR (RL-CBR) test has allowed to derive equation used in calculation of materials equivalent modulus based on laboratory RL-CBR Outputs. The staged RL-CBR test is used to evaluate material stiffness for different stress states to highlight its influence on UGM stiffness and compare studied materials. Also, this paper shows that even if two materials are different according to the current road authority specifications, they can represent similar stiffness.
A mesh-free approach for the simulation of incompressible flows
Authors: Rammane M. , Mesmoudi S. , Tri A. , Braikat B. , Damil N.
Published: August 2019

In this work, we propose to investigate numerically the incompressible flows by the Asymptotic Numerical Method (ANM) with the Moving Least Square (MLS). The mathematical formulation is based on theNavier-Stokes equations written in a strongly formulation to avoid all difficulties of the numerical integration. The used algorithm is developed to investigate the effective of the ANM with the MLS in the strongly formulation.
Transient energy growth of channel flow with cross-flow
Authors: Benyza J. , Lamine M. , Hifdi A.
Published: August 2019

The effect of a uniform cross flow (injection/ suction) on the transient energy growth of a plane Poiseuille flow is investigated. Non-modal linear stability analysis is carried out to determine the two-dimensional optimal perturbations for maximum growth. The linearized Navier-Stockes equations are reduced to a modified Orr Sommerfeld equation that is solved numerically using a Chebychev collocation spectral method. Our study is focused on the response to external excitations and initial conditions by examining the energy growth functionG(t)and the pseudo-spectrum. Results show that, the transient energy of the optimal perturbation grows rapidly at short times and decline slowly at long times when the cross-flow rate is low or strong. In addition, the maximum energy growth is very pronounced in low injection rate than that of the strong one. For the intermediate cross-flow rate, the transient energy growth of the perturbation, is only possible at the long times with a very high-energy gain. Analysis of the pseudo-spectrum show that the non-normal character of the modified Orr-Sommerfeld operator tends to a high sensitivity of pseudo-spectra structures.
Interfacial instability of two inviscid fluid layers under quasi-periodic oscillations
Authors: Eljaouahiry A. , Arfaoui A. , Assoul M. , Aniss S.
Published: August 2019

We investigate the eﬀect of horizontal quasi-periodic oscillations on the stability of two immiscible fluids of different densities. The two fluid layers are confined in a cavity of infinite extension in the horizontal directions. We show in the inviscid theory that the linear stability analysis leads to the quasi-periodic Mathieu equation, with damping, which describes the evolution of the interfacial amplitude. Thus, we examine the eﬀect of horizontal quasi-periodic vibration, with two incommensurate frequencies, on the stability of the interface. The numerical study shows the existence of two types of instability: the Kelvin-Helmholtz instability and the quasi-periodic resonances. The numerical results show also that an increase of the frequency ratio has a distabilizing eﬀect on the Kelvin-Helmholtz instability and curves converge towards those of the periodic case.
Numerical simulation of coupeld heat transfer through a concrete hollow brick
Authors: Jamal B. , Boukendil M. , Abdelbaki A. , Zrikem Z.
Published: August 2019

The present study aims to investigate coupled heat transfer by natural convection and conduction through a concrete hollow brick. The governing equations for conservation of mass, momentum and energy are discretized by the finite volume approach and solved by the SIMPLE algorithm. The numerical simulations were conducted to investigate the effect of Rayleigh number (103≤ Ra ≤ 107) on the heat transfer and fluid flow within the structure.
Use of the corrected plane wave model for the determination of the reflection coefficient during horizontal plate swell interaction
Authors: Amimi M. , Naasse S. , Chahine C.
Published: August 2019

The main objective of this work, is to calculate variations of the reflection coefficient of the regular wave by a submerged horizontal plate, using the corrected plane wave model, by choosing appropriately the immersion and the relative length of the plate. It is shown that with this correction the reflection coefficient has a good agreement with the experimental results (Brossard et al., Liu C.R).
Numerical simulation of Effect of Contact Pressure on Gas Diffusion Layers deformation of a PEM Fuel Cell
Authors: Atifi A. , El Bikri K. , Ettouhami M.
Published: August 2019

In this study, a two-dimensional, Finite Element model has been implemented based numerical modeling simulations to predict mechanical behavior of a representative unit of fuel cell stack deformation under three levels of contact pressure between GDL and bipolar plate assuming that the GDL deformation as a combination of elastic deformation and fibers slippage. The intrusion of the GDL into the channel was estimated. Indeed, with orthotropic behavior of the GDL, the proposed nonlinear orthotropic model converges towards the models of the literature as a function of the contact pressure level between the bipolar plate and the GDL (Gas Diffusion Layers).
Gear mesh geometry effect on performance improvement for external gear pumps
Authors: Ivanov Viktor , Karaivanov Dimitar , Ivanova Svitlana , Volkova Mariia
Published: August 2019

The parameters of the involute and cycloidal gearing which influence on fluid volume at the tooth space are analysed. It is established that to a greater extent on the flow rate of the pump with involute gearing is influenced by the radial clearance coefficient and the profile shift coefficient. The radii ratio of the auxiliary and pitch circles, as well as the radial clearance coefficient, mainly affect the flow rate of the pump with cycloidal gearing. Since the gear module is determined for reasons of pump flow rate, the teeth has a significant safety factor for contact stress and especially bending stress. This allows a wide variation of the gearing parameters in greater limits than in transmissions. The dependences of the fluid volume at the tooth space in the cycloidal gearing on the radial clearance coefficient, on the radii ratio of the auxiliary and pitch circles, on the fillet radius coefficient, is found. The boundaries of the variation of the gearing parameters were established taking into account the bending strength of the teeth. The analysis is carried out using the finite element method. Recommendations for the use of cycloidal gearing in external gear pumps have been developed.
Optimal design of helical reducers for cement equipment
Authors: Gudov Evgeniy , Lagutin Sergey
Published: August 2019

The trends in raising the technical level of multistage helical reducers for drives of cement, metallurgical and other heavy equipment are considered. An interactive method for optimizing the geometrical parameters of reducers with various gear ratios is proposed, which ensures equal strength of the stages in contact and bending endurance. It is shown that an increase in the hardness of the teeth requires an increase of the module and helical angle of the teeth, limitation of gear ratios, and to reduce the difference in center distances of adjacent stages. When creating a new generation of reducers, the transition to gears with carburized teeth leads to an increase in load capacity of 2.5-3 times. The examples of gear drive design for rotary kilns and ball mills are considered.
Modeling of vibration transmission through impact elements
Authors: Krupenin Vitaly
Published: August 2019

Rod waveguides are important technical objects that serve to transmit vibrations between machine elements. Such a transfer is determined by their design features and can be both desirable and harmful. The article deals with the problem of modeling the propagation of a monoharmonic wave through a rod waveguide, in which a discontinuity appeared, and a shock pair was formed. The features of the formation of polyharmonic waves and manifested nonlinear effects leading to a fundamental distortion of the dynamic pattern are described. The method of time-frequency analysis of vibration impact processes, which determine the dynamics of the system, is used. A calculation scheme and examples are given.
Optimization of transport vehicle transmission vibroacoustic characteristics
Authors: Taratorkin Alexander , Derzhanskii Victor , Taratorkin Igor
Published: August 2019

One of the main sources of vibroacoustic emissions is the transmission of a transport vehicle. Providing a high level of fuel economy performance and an acceptable level of power-train noise and vibration (NVH) is a complex engineering task and a real professional challenge for NVH specialists. The purpose of the research is to provide the required level of vibroacoustic characteristics of the transport vehicle transmission being developed at the design stage through a feasible correction of structural characteristics. To achieve this goal requires deeper understanding the dynamic phenomena of NVH, as well as expansion of the virtual design methods. We used multiphase analytical methods that allow us to estimate operation dynamics and vibroacoustic response of the transmission. Based on application of advanced CAE methods, a structural analysis and subsequent calculation of acoustic radiation is performed using the example of an automatic transmission (AT) prototype which is being developed for a vehicle of category N. The ability to control acoustic emissions is demonstrated by adjusting the structural (modal) parameters of the transmission case. Engineering solutions (configuration modifications) are being worked out to change the structural state (Limit state design) of the AT configuration (structural optimization) to ensure an acceptable level of acoustic emissions. For the gearbox in question, the first 50 waveforms (mode shapes, wave mode)were identified in the frequency range up to 8 kHz. The analysis made it possible to conclude that the greatest contribution to the integral noise level is made by wave forms at a frequency of 950 Hz, the internal partitions of the gearbox housing; at a frequency of 1324 Hz, the side walls of the shaft part of the gearbox and at a frequency of 1439 Hz are connected oscillations of the side walls and partitions between the shaft part of the gearbox and the demultiplier. To suppress these vibrations, additional finning of the partition between the shaft part of the automatic gearbox and the demultiplier was installed, as well diagonal reinforcing ribs were introduced into the design of the automatic gearbox side walls and the distributor cap. The performed measures allowed significantly reducing the integral level of acoustic pressure.
Work of the planetary gear trains as differentials and their capabilities
Authors: Arnaudov Kiril , Petrov Stefan , Hristov Emiliyan
Published: August 2019

Planetary gear trains can work differently, namely, with F=1 degree of freedom, i.e. as reducers or multipliers, and also with F=2 degrees of freedom, i.e. as differentials. Moreover, with a two-motor drive they work as a summation planetary gear train and with a one-motor drive, they work as a division planetary gear train. The most popular application of planetary gear trains is as a differential which is bevel and is produced globally in millions of pieces. Some of the cylindrical planetary gear trains can also be used as differentials. Although less often, they are used in heavy wheeled and chain vehicles such as trailer trucks, tractors and tanks. They are also very suitable for lifting machines with a two-motor drive which provides maximum security for the most responsible cranes, such as the metallurgical ones. Initially the paper presents some simple, i.e. single-carrier cylindrical planetary gear trains, both with external and internal meshing, driven by 2 motors. Their kinematic capabilities and velocity, respectively, are considered to realize the necessary gear ratio. Finally, the case of a compound two-carrier planetary gear train is considered, which is composed of 2 simple planetary gear trains. This shows that not only the simple planetary gear trains, i.e. the single-carrier ones, can work as differentials.
Hyperboloid gear transmissions: innovations, experimental and manufacture realization
Authors: Abadjiev Valentin , Abadjieva Emilia
Published: August 2019

This work is a review of researches carried out by the authors on prototyping processes and testing of hyperboloid gears. These activities are preceded by modeling for synthesis and design of these gear sets. It contains also a description of the innovative and inventive activities of the authors over the years. The twenty-five years period of studying hyperboloid gear mechanisms with an exact linear contact between the active tooth surfaces is entirely subordinated to the transfer of the obtained scientific results into scientifically applied and applied ones, in order to create adequate innovative products. The time interval of the researches, done from 1980 to 1990, is divided into two parts: - till 1985, the actions are oriented into transforming a part of the obtained scientific - applied results into technological innovations in the field of high-reduction gear mechanisms; - the period 1985 -1990 is identified with attempts to implement these gear transmissions into various technological devices and transport machines. From a practical view point, the 1980-1990 interval covers all activities for elaboration of functional models of reductors and technological models of high-reduction gears of type Helicon. The time period after 1990 is characterized by the elaboration of three types of Helicon reductors.
Comparative research of diesel engine at working with anamegators
Authors: Komitov Georgi , Kehayov D.
Published: August 2019

In conditions of the high petrol dependence, depletion of natural resources and environmental pollution, the questions with the implementation of the various options for reducing costs in the operation of engines, and at the same time reducing the discharged into the atmosphere harmful emissions are very topical. This article looks at the work of a diesel engine running on standard diesel fuel, an anamegator for fuel and a fuel and oil anamegators. Anamagators are relatively unknown additives in our market that improve some of the engine performance. They are complex chemicals that are added to fuels and complexly improve the burning process. They applied to all liquid and gaseous fuels and all types of oils. As a result of the conducted experiments are received the dependencies of the hourly fuel consumption, the carbon dioxide, the carbon oxide, the smoke, etc. through the change of power.
Defining parameters for control of extruding wire by friction process
Authors: Hasan Nuray , Gradinarov Deyan
Published: August 2019

Friction stir extrusion is an innovative direct-recycling technology for metal machining chips. During the process a specifically designed rotating tool is plunged into a cylindrical matrix containing the scraps to be recycled. The stirring action of the tool prompts solid bonding related phenomena allowing the back extrusion of a full dense rod. This process results to be particularly relevant because allows the reuse of the scrap without any previous treatment. Experiments have been carried out in order to investigate the influence of the process parameters on the extrudes quality and a numerical model has been developed in order to simulate the evolution of the material flow.
A study on prediction & validation of meshing gear pair backlash under various manufacturing and assembly errors
Authors: Karba Bahadır , Yıldırım Nihat , Erdoğan Fatih , Vardar Mert
Published: August 2019

Backlash is a need for proper gear mesh but also a defect if not controlled closely. Few studies have focused on controlling backlash with some mechanical solutions that can be applied. Few other studies have shown interest in estimation of minimum / maximum variable backlash. The operating backlash of meshing gears is affected by many factors among which runouts, pitch errors and tooth thicknesses are the three most pronounced manufacturing errors. All these three parameters are the measurable ones once the gears are manufactured. Center distance and phasing of meshing gears are the examples of assembly errors which may affect the operating backlash. A software has been developed to predict likely maximum and minimum backlash of a gear pair selected arbitrarily and assembled together. For the validation of software predictions an experimental setup is needed for backlash measurements. Thus, a special test rig is designed and constructed for experimental measurements of the operating backlash under some manufacturing and assembly errors of a gear pair. Good agreements have been achieved between backlash predictions and measurements thus validating the in-house prepared software for backlash calculations.
Research of working capacity of pulsed variable-speed drives
Authors: Sharkov Oleg , Koryagin Sergey , Velikanov Nikolay
Published: August 2019

The paper presents the results of experimental researches of the basic working capacity characteristics of pulsed variable-speed drives - gear ratio, efficiency factor, and reliability of the eccentric free-wheel mechanisms When conducting research, the main working capacity parameters of the pulsed variable-speed drive (independent factors) changed according to the design of experiment in the range: the load applied to the output shaft was from 250 to 2.750 N·m; adjustable gear ratio - from 20 to 180. It was established that the reliability of the eccentric free-wheel mechanisms is guaranteed when making mechanisms of 100Cr6 steel with hardness not lower than HRCЭ 58…62 with a module of at least 0.75 mm. It was shown that the yield surface, which characterizes the change in the gear ratio of the pulsed variable-speed drive, can be described by a model using first-order polynomials. It was established that with increasing load, a slight increase (at 1.0...9.9%) occurs in the adjusted gear ratio, which has a character close to linear. It was concluded that with an increase in load, the increase in efficiency factor is non-linear and equals 1.8...2.6 times, an increase in the gear ratio causes its linear decrease by 1.13...1.64 times in the dependence close to a linear one. Empirical dependences are obtained to determine the magnitude of the gear ratio and efficiency factor.
Optimum Design of Structural Parameters for Thin-walled Metal Container
Authors: Hongbo Liao , Dan Yang , Fenglong Yin , Xiaodong Liang , Erkang Li , Ye Sun
Published: August 2019

In order to further increase the volume, reduce the weight and manufacturing cost, the key structural parameters of thin-walled metal packing container are optimized. The instability conditions under circumferential external pressure and axial load are analyzed, a mathematical model with the constraint of critical instability strength, the maximum volume and minimum mass as the objective is constructed. Multi-objective optimization method with nonlinear constraints is used to solve the key structural parameters, such as wall thickness, diameter and height, and the optimization result is calculated by fgoalattain() function in the Matlab optimization toolbox. The instability pressure test system is constructed, the instability pressure of the optimized thin-wall metal packing container is tested. The results show that the unstable pressure is higher than 120kPa, which are better than the design index.
Digital NBC Protection System BIT Optimization Design
Authors: Guangsheng Li , Bo Ou , Jianyuan Wang
Published: August 2019

BIT technology is an important means of system and equipment fault detection, location and isolation. This paper takes the digital NBC protection system as the research object, and carries out research on the optimization design based on BIT technology. Based on the structural division of the digital NBC protection systems and the analysis of typical failure modes, combined with the weighted cost index function and the selection method of the improved special hierarchically optimized optimal test set, the calculation and comparison of the indices of the actual digitalized NBC protection systems was conducted. Determine the optimal test set, and finally design the BIT circuit for the selected optimal test set.
Study on 3D-IDS Based Spacecraft Development Mode
Authors: Xiaolun ZHOU , Haifeng CHEN , Ganggang HAO , Cheng LUO , Wei ZHU
Published: August 2019

The functions, applications, developments and current application mode of IDS2.x system are generally introduced in this paper. Then the development mode of spacecraft based on IDS2.x system is described. The existing problems especially the information redundancy of mechanical interface and their effects are pointed out. A new solution is proposed by developing 3D-IDS system. The central functions of 3D-IDS system are shown in this study. A new application mode of 3D-IDS system is explored and described by showing how to fill in, countersign and apply with 3D-IDS file. The 2D drawing and sketch are removed from 3D-IDS system to avoid information redundancy of mechanical interface. The consistency between 3D model and the parameters of IDS file can be guaranteed by the interface tool. The efficiency of filling in, countersigning and applying has been improved significantly, which greatly promotes the coordination and total efficiency of spacecraft system design departments and equipment design departments.
Spezialisierte Hochschulambulanz mit Querschnittscharakter:
Die Poliklinik für Plastische und Ästhetische Chirurgie
Authors: Dastagir Khaled , Limbourg Anne , Tecklenburg Andreas , Vogt Peter M.
Published: August 2019

Hintergrund Hochschulambulanzen haben eine zentrale Position in der
Behandlung, Lehre und Erforschung spezieller und komplexer Erkrankungen inne.
Der tägliche Betrieb einer universitären Poliklinik für Plastische, Ästhetische,
Hand- und Wiederherstellungschirurgie weist ein weitgefächertes Diagnosespektrum
der zugewiesenen Patienten aus. Unsere Hypothese war, dass das Diagnosespektrum
über den fachspezifischen Charakter hinaus weitreichend interdisziplinär ist und
ein hohes Maß an differenzierter und erweiterter klinischer Kompetenz
vermittelt.

Methode Die epidemiologischen Daten und Diagnosen der Patienten, die sich
zwischen 2013–2014 in unserer Ambulanz vorstellten, wurden anhand des
Arztbriefs, der medizinischen Akte und der Leistungsverschlüsselung (ICD)
katalogisiert. Eine Unterteilung der Diagnosen erfolgte nach Zugehörigkeit zu
den medizinischen Fachdisziplinen.

Ergebnisse Von 2013 und 2014 wurden 9272 Patienten mit 821 verschiedene
ICDs behandelt. Eine operative Haupt- oder Nebendiagnose bestand in 57 % der
Fälle. In 36 % der Diagnosen lagen internistische Krankheitsbilder vor, während
7 % aus dem Bereich Dermatologie, Neurologie, Psychiatrie, Zahnmedizin und
Augenheilkunde stammten. Die Alterschirurgie umfasste 22 %, postonkologische
Folgen 7 %, postoperatives Komplikationsmanagement 6 %, einer Z. n.
konservativer Behandlung 3 % und angeborene Fehlbildungen 3,0 % der Diagnosen.
Bei 29 % der vorgestellten Patienten stellten wir eine plastisch-chirurgische
Behandlungsindikation.

Schlussfolgerung Unsere Analyse zeigt, dass in einer Hochschulambulanz für
Plastische und Ästhetische Chirurgie, ein Patientenkollektiv mit komplexen
Erkrankungen und einem breiten Spektrum an Haupt- und Nebendiagnosen behandelt
wird. Dieses Spektrum bildet bei Ärzten eine breite Kompetenz aus und ist
aufgrund der Interdisziplinarität und Vermittlung von differentialdiagnostischen
Algorithmen und Untersuchungstechniken für die allgemeine Ausbildung von
Studierenden besonders geeignet.
Nutzungsakzeptanz einer Online-Intervention zur Verbesserung depressiver Symptome bei Menschen mit Adipositas
Authors: Löbner Margrit , Stein Janine , Rechenberg Theresia , Förster Franziska , Dorow Marie , Keller Jana , Weidauer Enrico , Riedel-Heller Steffi G.
Published: August 2019

Ziel der Studie Untersuchung der Nutzungsakzeptanz und assoziierter Faktoren in Bezug auf den Einsatz einer ungeleiteten Online-Intervention bei Menschen mit Adipositas und komorbiden depressiven Symptomen.

Methodik Quantitative längsschnittliche Pilotuntersuchung zur Nutzungsakzeptanz (Baseline vor Zugang zur Online-Intervention; Follow-up nach 3 Monaten) bei N = 46 Probanden.

Ergebnisse Mittlere bis hohe Nutzungsakzeptanz konnte gegenüber der Online-Intervention gezeigt werden. Die Nutzungsaufnahmerate lag bei 76,1 %, die Rate der vollständigen Bearbeitung bei 22,9 %. Positive Assoziationen zur Nutzungsakzeptanz konnten u. a. im Hinblick auf Persönlichkeitsmerkmale und den Bezug einer Erwerbsminderungsrente gezeigt werden.

Schlussfolgerung Online-Interventionen für Menschen mit Adipositas und komorbiden depressiven Symptomen können einen ergänzenden Behandlungsbaustein darstellen. Assoziierte Faktoren von Nutzungsakzeptanz sollten bei der Implementierung von Online-Interventionen beachtetet werden.
Arbeitstätigkeit nach einer Rückenmarksläsion
– Daten aus dem Ambulatorium einer paraplegiologischen
Rehabilitationsklinik
Authors: Hug Kerstin , Hummel Beate , Rinaldo Carmen , Saleh Christian , Lochmann Holger , Hund-Georgiadis Margret
Published: August 2019

Ziel Anhand von ambulanten Routinedaten und eines ICF-basierten
Fragebogens wurden Einflussfaktoren auf die Arbeitstätigkeit nach
einer Rückenmarksläsion überprüft.

Methodik Die retrospektive Auswertung basierte auf einer Stichprobe
von 290 Patienten mit Querschnittlähmung, davon 43%
arbeitstätig. In bivariaten Analysen und multiplen
Regressionsmodellen wurden 15 mögliche Einflussfaktoren
evaluiert.

Ergebnisse Negative Zusammenhänge mit der
Arbeitstätigkeit zeigten sich für die Faktoren
„Alter bei Rückenmarksläsion“ (OR: 0,96,
95%-KI: 0,93–0,99, p<0,002) und „Probleme
beim Zurücklegen von Entfernungen“ (OR: 0,44,
95%-KI: 0,25–0,79, p<0,006). Ein ähnlicher
Trend bestand für „Schwierigkeiten beim
Einkaufen“.

Schlussfolgerungen Die Resultate weisen darauf hin, dass neben dem
Alter bei Rückenmarksläsion auch Aspekte der
Mobilität für die Arbeitstätigkeit von Personen mit
Querschnittlähmungen entscheidend sind. Interventionen zur
Verbesserung der Mobilität sollten daher in der
Langzeitrehabilitation einen hohen Stellenwert einnehmen.
Immune and Hormonal Response to High-intensity Exercise During Orienteering
Authors: Araujo Nayara Costa , Neto Anibal Monteiro Magalhães , Fujimori Mahmi , Bortolini Miguel Sordi , Justino Allisson Benatti , Honorio-França Adenilda Cristina , Luzía França Eduardo
Published: August 2019

Orienteering is an endurance sport that combines physical and cognitive activity, during which the athlete must complete a course with several points distributed over unknown terrain in the shortest possible time. A number of studies have investigated the body’s physiological adaptations to the stress caused during competition, but not the immunological changes. To that end, the present study evaluated the immunological, physiological and pathological responses in athletes performing high-intensity physical exercise during an orienteering race. The 30 athletes tested belonged to the elite orienteering category and participated in the regional championship. Cortisol levels were determined before and after the competition to assess stress response, as were the cytokines IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ and IL-17 to evaluate the immune response. Cortisol levels increased after the competition, indicating a stress condition. IFN-γ, IL-6 and IL-10 levels also rose post competition. The results indicate that orienteers are exposed to high stress levels, and that this condition affects their immune and endocrine systems, triggering a predominantly anti-inflammatory response, likely an athlete’s mechanism of adaptation to the stress imposed by high-intensity physical exercise.
Minimal-activity PET/CT for efficacy control after SIRT (MAPECSI) – clinical implementation of a resource-saving, liver-focused protocol
Authors: Gühne Falk , Drescher Robert , Seifert Philipp , Freesmeyer Martin
Published: August 2019

Aim SIRT is an established treatment option for liver malignancies. Metabolic information can provide additional knowledge about tumoral characteristics and treatment response. FDG-PET/CT was shown to be advantageous for pre-/post-SIRT evaluation. However, whole-body PET/CT is an elaborate procedure. The aim of the study was to optimize clinical efficacy assessment after SIRT with a low-dose, low-cost protocol for focused diagnostic work-up.

Methods An abdomen-only minimal-activity FDG-PET/CT protocol (MA-PET) was established as an alternative for clinically indicated whole-body PET/CT scans. After administering 40 MBq of F-18-FDG one bed position was scanned for 15 minutes. Scans were acquired before (initial scan), one month after (interim scan) and three months after SIRT (follow-up scan). Metabolic tumor activity was evaluated and was compared to standard CT follow-up results.

Results 50 lobar SIRT procedures in 37 patients were analysed. HCC (28), hepatic metastases (15) and CCC (7) were treated. In 18 liver lobes initial MA-PET did not show hypermetabolic lesions, 32 liver lobes underwent interim and follow-up MA-PET. All 114 MA-PET were technically feasible. Mean radiation dose was 1.9 mSv. 64 % of HCC presented low metabolism at baseline, whereas metastases and CCC were all clearly PET-positive. Majority of radiated liver tumors showed at least partial metabolic response. PET/CT results diverged from follow-up CT in 63 % of cases.

Conclusion Minimal-Activity FDG-PET/CT of the liver is a feasible tool for efficacy assessment after SIRT with low financial and radiation burden. It provides additional information to morphologic imaging modalities, which can be helpful in response appraisal and treatment planning.
Developing Infographics to Facilitate HIV-Related Patient–Provider Communication in a Limited-Resource Setting
Authors: Stonbraker Samantha , Halpern Mina , Bakken Suzanne , Schnall Rebecca
Published: August 2019

Background Productive patient–provider communication is a recognized component of high-quality health care that leads to better health outcomes. Well-designed infographics can facilitate effective communication, especially when culture, language, or literacy differences are present.

Objectives This study aimed to rigorously develop infographics to improve human immunodeficiency virus (HIV)-related patient–provider communication in a limited-resource setting. A secondary purpose was to establish through participant feedback that infographics convey intended meaning in this clinical and cultural context.

Methods We adapted a participatory design methodology, developed in a high-resource setting, for use in the Dominican Republic. Initially, content to include was established using a data-triangulation method. Then, infographics were iteratively generated and refined during five phases of design sessions with three stakeholder groups: (1) 25 persons living with HIV, (2) 8 health care providers, and (3) 5 domain experts. Suggestions for improvement were incorporated between design sessions and questions to confirm interpretability of infographics were included at the end of each session.

Results Each participant group focused on different aspects of infographic designs. Providers drew on past experiences with patients and offered clinically and contextually relevant recommendations of symbols and images to include. Domain experts focused on technical design considerations and interpretations of infographics. While it was difficult for patient participants to provide concrete suggestions, they provided feedback on the meaning of infographics and responded clearly to direct questions regarding possible changes. Fifteen final infographics were developed and all participant groups qualitatively confirmed that they displayed the intended content in a culturally appropriate and clinically meaningful way.

Conclusion Incorporating perspectives from various stakeholders led to the evolution of designs over time and generated design recommendations that will be useful to others creating infographics for use in similar populations. Next steps are to assess the feasibility of using infographics to improve clinical communication and patient outcomes.
Educational Program to Improve Drug Adherence in Pediatric Epilepsy Patients and Caregivers in Limited Resource Area
Authors: Saengow Vitchayaporn Emarach , Pavarojkit Pavaree , Phonsing Sukussara
Published: August 2019

Poor drug adherence can lead to poor seizure control in pediatric epilepsy patients. Patients' knowledge about drug compliance is the cornerstone to improving drug adherence. In the past, several educational programs have involved multidisciplinary teams, including many specialists, who were recruited to spread and improve awareness about good drug adherence; however, there are few studies conducted in a limited resource country. This paper aims to outline a new program created by our clinicians. The epilepsy alert system (EAS) is an accessible educational program for pediatric epilepsy patients and caregivers, which is suitable for limited resource areas and evaluates the benefit of EAS on drug adherence. The EAS consists of a 20-minute-long educational program, co-led by a pediatric neurologist, a pediatrician, and a pharmacist, using simple tools such as an epilepsy diary and an epilepsy card. Epileptic children aged 1 month to 15 years who visited a pediatric epilepsy clinic between August 1, 2017 and September 30, 2018 were included. Drug adherence was evaluated using the four-item Morisky's Medication Adherence Scale. Comparison of drug adherence occurred prior to and at a 3- and 6-month follow-up, after participants received the educational program. A total of 108 patients were enrolled. Of these, the participants' mean age was 7 years and 6 months. Males constituted 59.3% of the cohort. The most common seizure type is focal epilepsy and 22.4% of the cohort had intractable epilepsy. 41% of participants had a “poor” adherence at baseline. After recruited to EAS, the poor drug adherence was significantly decreased to 23 and 14% at the 3- and 6-month follow-up, respectively. EAS is a suitable educational program for clinicians to employ when trying to improve drug adherence in pediatric epilepsy patients and caregivers in a limited resource area.
Bauaktivitäten Deutscher Kliniken: Leichte Stagnation
Authors: Kucera Martin
Published: August 2019

Es gibt immer weniger Krankenhäuser in Deutschland. Wie steht es mit den Bauaktivitäten im Gesundheitswesen? Der Münchner Informationsdienstleister Schwab Marketing registriert in seiner aktuellen Marktstudie für 2019 erneut einen Anstieg der Baumaßnahmen – allerdings weniger als noch vor einem Jahr.
Universitätsklinikum des saarlandes: Innovativer Klinikneubau für Homburg
Authors: Kerle Ulrich
Published: August 2019

Das Universitätsklinikum des Saarlandes hat einen modernen Klinikneubau für Innere Medizin (IMED) auf seinem Campus geschaffen. Der Großbau wurde mit einer Investition von 157 Millionen Euro umgesetzt und vereint alle Disziplinen der Inneren Medizin in der Mitte des weitläufigen Geländes. Die Zentralisierung bringt Synergieeffekte und viele Vorteile für Patienten, Beschäftigte und Studierende.
Droplet re-icing characteristics on a superhydrophobic surface
Authors: Chu Fuqiang , Gao Sihang , Zhang Xuan , Wu Xiaomin , Wen Dongsheng
Published: August 2019

Water icing is a natural phase change phenomenon which happens frequently in nature and industry and has negative effects on a variety of applications. Deicing is essential for iced surfaces, but even for a nanoengineered superhydrophobic surface, deicing may be incomplete with many adherent unmelted ice droplets which have potential for reicing. Here, we focused on the reicing characteristics of droplets on a solid superhydrophobic surface, which has lacked attention in previous studies. Our results show that the nucleation and ice crystal growth characteristics of a reicing droplet are quite different from those of a first-time icing droplet. During reicing, secondary nucleation due to fluid shear always occurs first on the edges of unmelted ice, accompanied by fast-growing ice crystals that can trigger heterogeneous nucleation when in contact with the solid surface. The reicing takes place under very small supercooling (less than 0.5 °C), and the superhydrophobic surface does not play a key role, meaning that any current icephobic surfaces lose their features, which poses great challenges for anti-icing. In addition, because of the small supercooling, no recalescence phenomenon appears during reicing and the droplet remains transparent instead of clouding. Owing to the unmelted ice floating on the top of the droplet, the droplet shape after reicing is also distinguishing from that after normal icing, but the pointy tip formation during reicing and normal icing shows a uniformity. These results shall deepen the understanding of the anti-icing and deicing physics.
Macroscopic dynamics of superfluid turbulence
Authors: Nemirovskii S. K.
Published: August 2019

The hydrodynamic problems of superfluid fluid containing chaotic tangles of quantized vortex filaments are discussed. The construction of such hydrodynamics crucially depends on the statistics of vortex tangles, and two important cases are presented. The first corresponds to a tangle that consists of entirely chaotic vortex filaments. This case is implemented in counterflowing helium, and is referred to as Vinen turbulence. In the construction of macroscopic dynamics, the system of equations is closed by the Vinen equation for the density of vortex filaments. The second, referred to as the Hall–Vinen–Bekarevich–Khalatnikov case, corresponds to a situation where the system contains bundles of polarized vortex filaments. In this instance, the system is closed by the Feynman equation that relates density of vortex filaments with the vorticity of superfluid velocity. Problems related to the application of both approaches are discussed.
Corrections to thermodynamics of the system of magnetically charged anyons
Authors: Sobko Bohdana , Rovenchak Andrij
Published: August 2019

In this paper, we calculate the thermodynamics of the system of anyons with magnetic charges in the magnetic field. We demonstrate how the contribution of the energy spectrum correction due to magnetic charges affects the second virial coefficient and the magnetic susceptibility. Dependences of the respective corrections as functions of temperature and the anyonic parameter are presented.
On the magnetoelectric effect in paramagnetic NH2(CH3)2Al1−xCrx(SO4)2 · 6H2O crystals
Authors: Kapustianyk V. , Loboda N. , Eliyashevskyy Yu. , Semak S.
Published: August 2019

The recently reported ability to induce and tune a sign of the magnetoelectric (ME) interactions in NH2(CH3)2Al1−xCrx(SO4)2 · 6H2O crystals as a function of Cr content is further investigated here. The ME coupling and its larger absolute value for the sample with larger Cr content agrees qualitatively with thermodynamic Landau analysis. However, quantitative estimation implies other contributions as well. The observed nontrivial magnetic field dependence of ferroelectric transition can be explained within the model that takes into account influence of the arising local deformation of the lattice on the two types of DMA group responsible respectively for the ferroelectric and antiferroelectric ordering.
Ballistic quantum spin separator
Authors: Zhitlukhina E. , Belogolovskii M. , Seidel P.
Published: August 2019

Spin-dependent ballistic transport in a mesoscopic three-terminal Y-shaped setup with a spin-discriminating ferromagnetic membrane in one of the outgoing leads is studied using the Landauer–Büttiker formalism. Our calculations, performed at sufficiently low temperatures when thermal effects and magnon scattering become vanishingly small, predict a strong quantum-interference caused enhancement of a spin-filtering effect originally arising due to the band-structure mismatch between the ferromagnetic metal and the lead. Finally, we discuss its possible applications for an efficient injection of a spin-polarized current into a superconductor and for self-controlled spin currents in quantum spintronic networks.
Self-Assembly of Uniform Branched Gold Nanoparticles Induced by Using Thiol-Terminated Poly(ethylene glycol)
Authors: Jia Wenfeng , Wu Junwen
Published: August 2019

Branched gold nanoparticles with a sufficiently monodisperse distribution of size and shape were successfully synthesised using a tree-type multi-amine-head surfactant (C18N3) with a 100% yield using a seed-mediated method. C18N3 coated branched gold nanoparticles possess a positive zeta potential of ~40eV, which can keep branched gold nanoparticles stable in aqueous solution for several months without precipitation and transfiguration. However, C18N3 molecules were partially replaced by thiol-terminated poly(ethylene glycol) (mPEG-SH), due to the branched morphology of the as prepared gold nanoparticles, to make branched gold nanoparticles passivated by the adsorbing polymer with a positive zeta potential (17eV). The mPEG-SH passivated branched gold nanoparticles behaved as quasi-hard particles to overcome the restrictions of the rotational and positional degrees of freedom in neighbouring nanoparticles at high volume fractions, which favours the hydrophilic thiol-terminated poly(ethylene glycol) polymer passivated branched gold nanoparticles to self-arrange into close-packed 2D ensembles. Thus, the as prepared branched gold nanoparticles and their ensembles possess significant potential in bio-labelling, imaging, biosensing, therapeutic applications, and surface-enhanced Raman scattering.
Coupling wildfire spread and erosion models to quantify post-fire erosion before and after fuel treatments
Authors: Salis Michele , Del Giudice Liliana , Robichaud Peter R. , Ager Alan A. , Canu Annalisa , Duce Pierpaolo , Pellizzaro Grazia , Ventura Andrea , Alcasena-Urdiroz Fermin , Spano Donatella , Arca Bachisio
Published: August 2019

Wildfires are known to change post-fire watershed conditions such that hillslopes can become prone to increased erosion and sediment delivery. In this work, we coupled wildfire spread and erosion prediction modelling to assess the benefits of fuel reduction treatments in preventing soil runoff. The study was conducted in a 68000-ha forest area located in Sardinia, Italy. We compared no-treatment conditions v. alternative strategic fuel treatments performed in 15% of the area. Fire behaviour before and after treatments was estimated by simulating 25000 wildfires for each condition using the minimum travel time fire-spread algorithm. The fire simulations replicated historic conditions associated with severe wildfires in the study area. Sediment delivery was then estimated using the Erosion Risk Management Tool (ERMiT). Our results showed how post-fire sediment delivery varied among and within fuel treatment scenarios. The most efficient treatment alternative was that implemented near the road network. We also evaluated other factors such as exceedance probability, time since fire, slope, fire severity and vegetation type on post-fire sediment delivery. This work provides a quantitative assessment approach to inform and optimise proactive risk management activities intended to reduce post-fire erosion.
Dietary restriction improves proteostasis and increases life span through endoplasmic reticulum hormesis
Authors: Matai Latika , Sarkar Gautam Chandra , Chamoli Manish , Malik Yasir , Kumar Shashi Shekhar , Rautela Umanshi , Jana Nihar Ranjan , Chakraborty Kausik , Mukhopadhyay Arnab
Published: August 2019

Significance

The endoplasmic reticulum (ER) deteriorates with age and fails to mount an effective stress response against misfolded proteins (UPR
ER
), leading to protein folding disorders. However, preconditioning the ER using a mild ER stress (ER hormesis) can protect against future insults. We show that dietary restriction, an intervention that protects against protein misfolding disorders and increases life span across species, uses ER hormesis as a mechanism of action. Simply mimicking the ER hormesis in
Caenorhabditis elegans
by transient treatment with pharmacological reagents leads to delayed age-onset failure of UPR
ER
, better capacity to process misfolded proteins, and increased life span. We also show that this process may be conserved in a mammalian cellular model of neurodegenerative disease.
Single-cell RNA-seq identifies a reversible mesodermal activation in abnormally specified epithelia of p63 EEC syndrome
Authors: Soares Eduardo , Xu Quan , Li Qingqing , Qu Jieqiong , Zheng Yuxuan , Raeven Henriette H. M. , Brandao Karina O. , Petit Isabelle , van den Akker Willem M. R. , van Heeringen Simon J. , Aberdam Daniel , Tang Fuchou , Zhou Huiqing
Published: August 2019

Mutations in transcription factor p63 are associated with developmental disorders that manifest defects in stratified epithelia including the epidermis. The underlying cellular and molecular mechanism is however not yet understood. We established an epidermal commitment model using human induced pluripotent stem cells (iPSCs) and characterized differentiation defects of iPSCs derived from ectrodactyly, ectodermal dysplasia, and cleft lip/palate (EEC) syndrome patients carrying p63 mutations. Transcriptome analyses revealed stepwise cell fate transitions during epidermal commitment: Specification from multipotent simple epithelium to basal stratified epithelia and ultimately to the mature epidermal fate. Differentiation defects of EEC iPSCs caused by p63 mutations occurred during the specification switch from the simple epithelium to the basal-stratified epithelial fate. Single-cell transcriptome and pseudotime analyses of cell states identified mesodermal activation that was associated with the deviated commitment route of EEC iPSCs. Integrated analyses of differentially regulated genes and p63-dependent dynamic genomic enhancers during epidermal commitment suggest that p63 directly controls epidermal gene activation at the specification switch and has an indirect effect on mesodermal gene repression. Importantly, inhibitors of mesodermal induction enhanced epidermal commitment of EEC iPSCs. Our findings demonstrate that p63 is required for specification of stratified epithelia, and that epidermal commitment defects caused by p63 mutations can be reversed by repressing mesodermal induction. This study provides insights into disease mechanisms underlying stratified epithelial defects caused by p63 mutations and suggests potential therapeutic strategies for the disease.