bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the maximum shear modulus (G0) for different bender-soil coupling loads
Authors: de Paula Caio de Mattos Azevedo , Carnavale Thiago de Souza
Published: October 2020

The current paper aims to test the effects of vertical loads on the maximum shear modulus (G0). The tests were undertaken with unsaturated soils in unconfined conditions. As a material, was used a set of granite-gneiss soil samples collected in the Quinta do Paraiso Campus, at the Centro Universitário Serra dos Órgãos (UNIFESO), Teresópolis – Brazil. To perform it, cylindrical samples were submitted to bender elements under four vertical loads (200 g, 400 g, 500 g, and 600 g). Further, the readings were done with the same amplitude and frequency values. The results revealed a decrease in the shear wave’s velocity reducing the volumetric water content. Besides, the shear modulus increased with the vertical loads’ addition.
A new approach of accounting for impedance effects in Gardner’s method of determining the hydraulic conductivity of unsaturated soils
Authors: Stanic Filip , Delage Pierre , CUI Yu Jun , Laure Emmanuel DE , Versini Pierre-Antoine , Schertzer Daniel , Tchiguirinskaia Ioulia
Published: October 2020

Based on tests carried out on a specific device allowing to determine the water retention and transport properties of granular media at low suctions, an alternative approach to Kunze and Kirkham’s method of accounting for the impedance effects due to the high air entry value ceramic disk when using Gardner’s method is proposed. Impedance effects are accounted for by proposing analytical solutions to the equations governing water transfers occurring within the specimen and the ceramic disk. By using some experimental data obtained on a volcanic granular substrate used for urban green roofs, the method is successfully compared to Kunze and Kikham’s graphical method. Its advantages are to be simpler of use and not operator dependent. A detailed examination of the performance of our method compared to those of Gardner and Kunze and Kirkham is carried out based on experimental data, that confirm its validity.
Electric Conductivity Probes to Study Change in Degree of Saturation - Bench Top Laboratory Tests
Authors: Kazemiroodsari Hadi , Yegian Mishac K. , Alshawabkeh Akram N. , Gokyer Seda
Published: October 2020

Sand characteristics such as liquefaction susceptibility can be affected as a result of change in degree of saturation of sand. New liquefaction mitigation technique by inducing partial saturation in sands is introduced by Yegian et al in 2007[1]. This technique requires to monitor changes in degree of saturation of sand. By nature, changes in degree of saturation of sand can lead in changes in its electric conductivity. Electric conductivity is the property of a material that represents its ability to conduct electric current. Fully saturated sand can conduct electric current better than sand with lower degree of saturation. Therefore, the change in measured electric conductivity can be used to calculate the change in degree of saturation of sand. In 1942, Gus Archie [2] expressed that the electric conductivity of soil is a function of its porosity, degree of saturation, tortuosity and electric conductivity of pore fluid. Using Archie’s law electrical conductivity can be related to the degree of saturation in sands. Typically, electric conductivity probes and meters are instruments which are used to measure electric conductivity. Using electrical conductivity probes, sets of bench top tests were conducted on Ottawa sand to study the relation between degree of saturation and electric conductivity in sand. Partial saturation in sands were created by pouring dry sand into sodium percarbonate solution with a known initial concentration. By nature, sodium percarbonate in water, generates oxygen gas bubbles in time. The changes in electric conductivity in the specimen were measured using electric conductivity meters and probes. In addition, changes in degree of saturation of the specimen were measured using soil phase relations equations. Measured electric conductivity data and calculated degree of saturations were correlated to explore relation between electric conductivity and degree of saturation. This paper presents results of bench top tests, and suggests a relationship between, final degree of saturation of sand and initial concentration of sodium percarbonate solution
Experimental and numerical analysis of soil desiccating cracks in compacted and non-compacted specimens
Authors: Cordero Josbel , Najdi Abdallah , Encalada David , Prat Pere C. , Ledesma Alberto
Published: October 2020

This paper presents the results and analysis of two cracking tests carried on specimens of silty clay. One specimen was prepared in slurry conditions without applying energy and the other specimen was compacted. They were dried in an environmental chamber at a constant temperature and relative humidity to study the effect of the initial consistency on the cracking behaviour. Weight measurements and photographic images taken at regular intervals documented the evolution of the specimens. THM models were then carried to capture the unsaturated flow in the porous medium due to evaporation, and its resulting shrinkage. All the numerical analyses were coupled, incorporating the effect of porosity change on the balance equations and the constitutive model. The transfer coefficients in the imposed drying boundary condition were based on calculations of aerodynamic surface resistances, taking into consideration the new fronts for evaporation created by the cracks. The constructed numerical model results capture the gravimetric water content loss and the occurring shrinkage for both specimen conditions.
Determination of hydraulic conductivity and shear strength properties of unsaturated residual soil from flysch rock mass
Authors: Peranić Josip , Moscariello Mariagiovanna , Cuomo Sabatino , Arbanas Željko
Published: October 2020

Slopes in flysch deposits areas wide within Europe are highly prone to landslide occurrence. Depending on the material properties and climate conditions, instabilities in a form of earthflows, shallow and deep-seated landslides were observed in these formations. Typically, slope instabilities occurred after prolonged periods of rainfall. The Rječina River Valley, Croatia, built in flysch formation, is well known by several landslides occurred in the past. The weathering process of flysch rock mass and local climate conditions resulted in a specific engineering geological profile of the valley, with the unsaturated residual soil covering the bedrock. Although the behaviour of residual soil is important for a landslide triggering both through the rainfall infiltration process and (unsaturated) shear strength, hydro-mechanical properties of this material in unsaturated conditions were not investigated in the past. This paper summarizes the results of different laboratory tests performed on intact samples for hydro-mechanical characterization of the residual soil from flysch rock mass. It was found that the unique shear strength envelope could be used to determine failure conditions both for saturated and unsaturated conditions. The results obtained from strain-controlled and wetting tests performed in conventional and modified direct shear apparatuses indicated high values of the apparent cohesion that the near-surface soil can experience due to the increase of matric suction. The hysteresis effects and hydraulic paths to which soil was exposed to in the past were found to affect the soil behaviour, while the soil formation process results with a complex soil structure that imposes the necessity of using intact soil samples for proper hydraulic characterization of the soil.
Unsaturated Shear Strength of Compacted Clayey Soil via Suction-controlled Ring Shear Testing
Authors: Hoyos Laureano R. , Yepes Jairo E. , Velosa Claudia L. , Puppala Anand J.
Published: October 2020

An experimental program has been undertaken to assess both peak and residual shear strength parameters of statically compacted, moderate plasticity clayey soil under suction-controlled conditions, resulting in a defined set of suction-dependent peak and residual failure envelopes over a relatively wide range of suction states, from 0 to 300 kPa. The experimental program was accomplished in a servo/suction-controlled ring shear apparatus, which is suitable for testing unsaturated soils under large deformations via the axis-translation technique. Test results substantiate the crucial role that has been observed to be played by the imposed matric suction on the residual shear strength of compacted clayey soils. For the range of net normal stress (0-200 kPa) and matric suction (0-300 kPa) states investigated, the increase in either peak or residual shear strength, with increasing matric suction, was found to be manifestly nonlinear. Furthermore, a distinct correspondence was observed between the nonlinearity of the peak shear strength envelope, with respect to increasing matric suction, and the soil-water retention properties of the clayey soil. Results, in general, suggest that a conceptual residual shear strength framework for unsaturated soils, similar to that postulated for peak shear strength, can eventually be formulated as more experimental evidence of this kind is made available.
Comparison between Soil-Water Characteristic Curves based on filter paper method and grain-size distribution/volume-mass prediction: An evaluation of input data stemmed from hydrometer and Cilas grain-size analyser
Authors: Felipe da Silva André Marcos , de Souza Carnavale Thiago
Published: October 2020

The current paper aims to present a comparison between soil-water characteristic curves based on the filter paper method and on a volume-mass estimation. Additionally, this research consists in comparing grain size distributions by sieving/hydrometer and by sieving/Cilas (particle-size analyser model 1092), when it comes to determining the soil-water characteristic curves by a volume-mass prediction on the Soil Vision software. As materials, were used two sets of colluvial soils sampled at the Campus Quinta do Paraiso -Centro Universitário Serra dos Órgãos (UNIFESO), Teresópolis – Brazil. The results showed that the soil-water characteristic curves related to the filter paper method or grain size distribution estimation are different. However, the tests performed by sieving/Cilas are more efficient than the results based on sieving/hydrometer, concerning its uses as input data for soil-water characteristic curves estimations. In conclusion, even considering the estimation method was not able to depict the same results such as obtained by the filter paper method, the use of Cilas is a procedure that can improve the quality of the predicted soil-water characteristic curve.
Laboratory testing of seepage in concrete
Authors: Pap Miklós , Mahler András , Nehme Salem Georges
Published: October 2020

Due to the construction of underground structures and hazardous waste storages, understanding and modelling of water flow through concrete has become a major topic for life-span analyses. The water retention curve (WRC) is an essential unsaturated soil function, which can be determined not only for soil samples, but also for other porous media. This paper deals with the determination of drying water retention curve for six different concrete mixtures that provide a substantial characteristic for the investigation and modelling of seepage through the pores of concrete. According to the complex pore system of the concrete, the bimodal function of van Genuchten (1980) and Fredlund and Xing (1994) models were used for curve fitting. The fitted curves were used to estimate the permeability function using Fredlund et. al (1994) model.
Effects of temperature, test duration and heat flux in thermal conductivity measurements under transient conditions in dry and fully saturated states
Authors: Aljundi K. , Vieira A. , Maranha J. , Lapa J. , Cardoso R.
Published: October 2020

In shallow geothermal energy systems (SGES) thermal conduction can be considered the dominant process in the heat transfer between the primary circuit (borehole heat exchanger or thermoactive geostructure) and the surrounding ground. Thus, a proper characterization of soil thermal properties, namely of its thermal conductivity, is mandatory for evaluating this energy exchange. There are difficulties associated to the assessment of soil thermal conductivity by laboratory methods related, among other factors, to the samples’ quality and to the measuring method itself. The purpose of this work is to analyse the effect of changing test control parameters in thermal conductivity measurements in transient conditions by means of a high accuracy thermal probe in both dry and fully saturated states. In order to eliminate potential measurements’ deviations and errors due to sample variability the same reconstituted samples were used several times. In each condition the sand samples were systematically tested under different ambient temperatures (10ºC, 20ºC, and 40ºC) controlled by means of a climatic chamber. The effects of changing the tests heating time and imposed thermal fluxes were also analysed.
Effect of Elevated Temperatures on Lateral Earth Pressures in Unsaturated Soils
Authors: Thota Sannith Kumar , Vahedifard Farshid
Published: October 2020

Near-surface unsaturated soils can be exposed to elevated temperatures due to soil-atmospheric interactions under drought events, wildfires, heatwaves, and warm spells, or the heat induced by emerging geotechnical and geo-environmental technologies such as geothermal boreholes and thermally active earthen systems. Elevated temperatures can affect the hydro-mechanical characteristics of unsaturated soils, which in turn can alter lateral earth pressures developed in the backfill soil. The main objective of this study is to quantify the effect of elevated temperatures on active and passive earth pressures of unsaturated soils. For this purpose, the paper presents the derivation of an analytical framework to extend Rankine’s earth pressure theory to account for the effect of temperature under hydrostatic conditions. The equations are derived by incorporating the effect of temperature into the soil water retention curve and a suction stress-based effective stress representation. The proposed effective stress equation considers the temperature-induced changes in the contact angle, surface tension, and enthalpy of immersion. To investigate the impact of temperature on active and passive earth pressures, the proposed method is then used in a set of parametric studies to determine active and passive earth pressure profiles for three hypothetical soils of clay, silt, and sand at different temperatures. Results suggest that elevated temperatures can cause variation in active and passive earth pressures for all the soils considered. The findings of this study can contribute toward analyzing earth retaining structures subjected to elevated temperatures.
Implementation of biocementation for a partially saturated problematic soil of the UK railway network
Authors: Safdar Muhammad Umair , Mavroulidou Maria , Gunn Michael J. , Gray Christopher , Purchase Diane , Garelick Jonathan , Payne Ian
Published: October 2020

This paper refers to biocementation of a problematic soil of the UK railway network as a potential stabilisation technique of this soil using indigenous ureolytic bacteria. The soil is peat, a soft foundation soil also subject to oxidation wastage. As the peat is under existing embankments, electrokinetics (EK) is proposed as a promising technique to implement treatments. In the context of unsaturated soils the paper thus focuses on two particular aspects relevant for the implementation of treatments and the stability of this soil, namely: a) the effect of degree of saturation of the peat on the bio-electrokinetic treatment ; b) the soil water retention curve of the soil affecting flow and transport; these are relevant as we focus on understanding and modelling the implementation of treatments through electrokinetics; moreover for the peat it is of importance to understand moisture exchange in the vadose zone and control groundwater table levels (e.g. during electrokinetics) in order to prevent further oxidation. After isolation and screening of indigenous microorgansisms Bacillus licheniformis was selected for further testing. The results in terms of unconfined compressive strength, CaCO3 content, swelling and compression behaviour and water retention proved the feasibility of biocementation using this indigenous microorganism. Ongoing work is assessing the required treated soil characteristics and related required biocementation degree to solve UK rail's peat foundation problems. Upscaling of the techniques towards in situ implementation is also planned in the next stage of the research.
Benefits and drawbacks of applied direct currents for soil improvement via carbonate mineralization
Authors: Terzis Dimitrios , Hicher Patrick , Laloui Lyesse
Published: October 2020

The study presented herein adopts a new vision of the processes involved in carbonate mineralization induced by MICP from an electrochemical and crystal growth perspective. More precisely a specific line of focus refers to the species involved in the bio-chemical reactions and especially their net particle charge. By altering electro-chemical conditions via the application of direct electric currents, we observe distinctive trends related to: (i) overall reaction efficiency; (ii) carbonate mineralization/dissolution and (iii) spatial distribution of precipitates. The study introduces the concept of EA-MICP which stands for Electrically Assisted MICP as a means of improving the efficiency of soil bio-consolidation and overcoming various challenges which were previously reported in conventional MICP-based works. Results reveal both the detrimental and highly beneficial role that electric currents can hold in the complex, reactive and transport processes involved. An interesting finding is the “doped” morphology of calcite crystals, precipitated under electric fields, validated by microstructural observations.
Use of class C fly ash for stabilization of fine-grained soils
Authors: Turan Canan , Javadi Akbar , Vinai Raffaele , Shariatmadari Nader , Farmani Raziyeh
Published: October 2020

Fine-grained soils may have undesired characteristics such as high swelling potential and low strength, thus requiring improvements. One of the stabilization methods involves the use of fly ash. Fly ash is a waste material obtained from burning coal in thermal power plants. The use of fly ash is encouraged as an alternative material for soil stabilization, due to its features such as pozzolanic properties and economic availability. This paper describes the results of an experimental study on stabilization of a clayey soil with fly ash. Unconfined compressive strength (UCS), triaxial and consolidation tests were carried out on samples of kaolinite mixed with class C fly ash at different percentages and cured for 1, 7, and 28 days, in order to study the effects of class C fly ash on the mechanical behaviour of the stabilized soil. The results showed that the inclusion of fly ash significantly improves the strength characteristics of the soil. Curing time was also found to have a significant effect on improving the properties of the soil.
Daily variations of the refractive index in the south of the Vitim plateau in different seasons of the year
Authors: Bazarova Aryuna , Atutov Evgeniy , Bazarov Alexander , Bashkuev Yuri
Published: October 2020

The urgency of the problem of studying the refractive properties of the troposphere is determined by the increasing rate of use of radio meteorological parameters in the design and operation of GLONASS-GPS and GSM radio-electronic systems in various physical and climatic regions of the Earth, in particular in eastern Russia. Specialists are faced with an urgent need to study the laws governing the propagation of VHF-UHF radio waves taking into account the influence of all layers of the atmosphere as a medium with a variable refractive index. The article presents the calculation of the refractive index N based on meteorological data of the atmospheric-soil measuring complex, located on the measuring station in the Eravninsky district of the Republic of Buryatia. The dependences of the refractive index on atmospheric pressure, water vapor elasticity, and absolute air temperature are established.
Earth electric field negative anomalies as earthquake precursors
Authors: Smirnov Sergey
Published: October 2020

In fair weather conditions, electric field potential gradient in the near-ground air takes positive values. Negative anomalies occur under the influence of different ionizing processes such as galactic cosmic ray flux and radioactive gas emanation from the ground. In the conditions of calm geomagnetic state and fair weather, anomalies can be used for earthquake forecast. In the paper, the efficiency of earthquake forecast based on negative anomalies is under the study. It was obtained that the efficiency of such a forecast during any weather conditions is 10%.
Analysis of energy characteristics of acoustic emission signals during uniaxial compression of geomaterial samples
Authors: Sychev Vladimir , Bogomolov Leonid , Kulkov Dmitriy
Published: October 2020

Acoustic emission (AE) signals were obtained during deformation by uniaxial compression of specimens of various geomaterials. Experiments on uniaxial compression were carried out on a low-noise lever setup with water leakage, where the maximum load on the sample does not exceed 250 kN. The received signals were digitized by an 8-channel USB 3000 ADC unit with a width of 14 bits and a maximum sampling rate of 3 MHz. The energy distribution functions of AE signals are considered. The maximum amplitude of the AE waveform was selected as the energy characteristic of the AE signal. The flow of AE events is considered from the viewpoint of nonequilibrium thermodynamics using the Tsallis statistics. To describe the energy distribution function of the AE signals, we used a modified model of a stick-slip earthquake source -”discontinuous sliding” of two plates over each other along a fault in the presence of friction and the principle of maximum entropy. The model is used to quantify long-range correlations arising in the flow of earthquakes. It is shown that the AE signal flow is a system with memory and longrange correlations. The analysis of the behavior of the Tsallis parameter was carried out throughout the experiment.
Construction of complex shell models of MHD turbulence in computer algebra systems
Authors: Feshchenko Liubov , Vodinchar Gleb
Published: October 2020

The paper describes the developed by authors technique for construct-ing complex shell models of turbulence. The compilation of the equa-tions of this model and its exactly solution are implemented using by computer algebra system. The technique allows one to vary the sizes of nonlocality of nonlinear interaction in the space of scales, expressions for shell analogues of conservation laws, and the nature of stationary solutions with different power distribution.
Experience in synchronous observation of seismic-strain oscillations of the Earth by the spaced laser interferometers
Authors: Aleksandrov Dmitriy , Dubrov Mstislav , Kravtsov Vasiliy , Larionov Igor
Published: October 2020

The first results of unique experiments on the synchronous registration of seismic-strain oscillations of the Earth’s surface by three laser interferometers-deformographs (strainmeters) spaced 6740 km apart are presented. Two 100-meter laser interferometers at the Fryazino site (Moscow Region) and the 18-meter laser strainmeter at the observation point of Karymshina (Kamchatka Peninsula) were applied. The frequency-stabilized and thermally controlled lasers and the interferogram registration systems of compensation and modulation types providing an absolute instrumental resolution of 0.1-0.01 nm were used. The results of data analysis in sessions of synchronous operation of these instruments during 2016-2020 were obtained and discussed.
Forbush-storm classification of the events as a device for the solar wind diagnostics
Authors: Shadrina Lyudmila P.
Published: October 2020

The geoeffectiveness of the solar wind is usually determined on Earth by such phenomena in the geomagnetic field as storms and substorms. The second, no less significant effect is a sharp decrease in the intensity of galactic cosmic rays (GCR) Forbush effects. A joint examination of these effects in the geomagnetic field and in the GCR makes it possible to obtain additional diagnostic features, since they carry different information. The behavior of the geomagnetic field reflects changes in the magnetosphere, while the GCR intensity depends on the spatial configuration of the magnetic field in the heliosphere. To carry out such work, it is proposed to use the Forbush-Storm classification — a catalog of geophysical events in the geomagnetic field and cosmic rays. The catalog shows the dates and time of the beginning of the events of a decrease in the Dst geomagnetic field index and in GCR intensity from 1996 to 2017, for 2 cycles of solar activity. It is shown that these two types of terrestrial manifestations of interplanetary disturbances can occur simultaneously or separately.
Overview of processing and analysis methods for pulse geophysical signals
Authors: Lukovenkova Olga , Senkevich Yury , Solodchuk Alexandra , Shcherbina Albert
Published: October 2020

The paper discusses the processing and analysis methods for the geoacoustic and electromagnetic emission pulse signals recorded for more than 20 years at the IKIR FEB RAS geodynamic proving ground (Kamchatka Peninsula). The methods for pulse detection, waveform reconstruction, pulse time-frequency analysis using adaptive sparse approximation, structural description of pulse waveforms and pulse classification are proposed. To detect pulses, the adaptive threshold scheme is used. It adjusts to the noise level of a processed signal. To analyze time-frequency structure of the pulses, the adaptive matching pursuit algorithm is used. To identify pulse waveform, the structural description method is proposed. It encodes pulses with special image matrices. The method of the identified pulses classification is considered. Since the methods for pulse structure analysis are sensitive to noise and distortions, the authors propose the method for pulse waveform reconstruction based on wavelet filtering. The geophysical signal information features determined during the analysis can be used to search for anomalies in the data, and then establish a relationship between these anomalies and deformation process dynamics, in particular, with earthquake development processes.
Some features of acoustic and electric responses of near-surface sedimentary rocks during deformations by seismic waves from strong earthquakes (Mw > 6.5)
Authors: Mishchenko Mikhail , Rulenko Oleg , Marapulets Yuriy
Published: October 2020

Acoustic and electric responses of near-surface sedimentary rocks are considered. They were recorded during the deformations by seismic waves from six earthquakes with magnitude Mw = 6.6-7.7 at the distances of 131-728 km from epicenters in Kamchatka region. Behavior of both responses during soil displacement and displacement velocity during wave propagation are un-der the analysis. The dependence of intensity and character of the responses manifestation on earthquake magnitude and the distance to its source had been discovered by the authors earlier and is confirmed in the work. It was discov-ered that the occurrence of acoustic response in kilohertz range correlates well with the behavior of soil displacement velocity vector and its spectrum.
Nanosecond laser-induced breakdown assisted by femtosecond laser pre-ionization in air: the effect on spatial resolution and continuous radiation
Authors: Li Bo , Li Xiaofeng , Zhu Zhifeng , Gao Qiang
Published: October 2020

Laser-induced breakdown spectroscopy (LIBS) is a powerful technique for quantitative diagnostics of gases. The spatial resolution of LIBS, however, is limited by the volume of plasma. Here femtosecond-nanosecond dual-pulsed LIBS was demonstrated. Using this method, the breakdown threshold was reduced by 80%, and decay of continuous radiation was shortened. In addition, the volume of the plasma was shrunk by 85% and hence, the spatial resolution of LIBS was significantly improved.
The efficacy and safety of underwater endoscopic mucosal resection for ≥10-mm colorectal polyps: systematic review and meta-analysis
Authors: Li De-feng , Lai Ming-Guang , Yang Mei-feng , Zou Zhi-yuan , Xu Jing , Peng Ru-mei , Xiong Feng , Wei Cheng , Zhang Ding-guo , Xu Zheng-lei , Wang Li-sheng , Yao Jun
Published: October 2020

Background Underwater endoscopic mucosal resection (UEMR) is a promising strategy for nonpedunculated colorectal polyp removal. However, the efficacy and safety of the technique for the treatment of ≥ 10-mm colorectal polyps remain unclear. We aimed to comprehensively assess the efficacy and safety of UEMR for polyps sized 10–19 mm and ≥ 20 mm.

Methods PubMed, EMBASE, and the Cochrane Library databases were searched for relevant articles from January 2012 to November 2019. Primary outcomes were the rates of adverse events and residual polyps. Secondary outcomes were the complete resection, en bloc resection, and R0 resection rates.

Results 18 articles including 1142 polyps from 1093 patients met our inclusion criteria. The overall adverse event and residual polyp rates were slightly lower for UEMR when removing colorectal polyps of 10–19 mm vs. ≥ 20 mm (3.5 % vs. 4.3 % and 1.2 % vs. 2.6 %, respectively). The UEMR-related complete resection rate was slightly higher for colorectal polyps of 10–19 mm vs. ≥ 20 mm (97.9 % vs. 92.0 %). However, the en bloc and R0 resection rates were dramatically higher for UEMR removal of polyps of 10–19 mm vs. ≥ 20 mm (83.4 % vs. 36.1 % and 73.0 % vs. 40.0 %, respectively). In addition, univariate meta-regression revealed that polyp size was an independent predictor for complete resection rate (P = 0.03) and en bloc resection (P = 0.01).

Conclusions UEMR was an effective and safe technique for the removal of ≥ 10-mm nonpedunculated colorectal polyps. However, UEMR exhibited low en bloc and R0 resection rates for the treatment of ≥ 20-mm polyps.
20 Years of Follow-up Alloimmunization and Hemolytic Disease in Newborn: Has Anything Changed in the Field Over the Years?
Authors: Raguz Marjana Jerkovic , Prce Zeljka , Bjelanovic Vedran , Bjelanovic Ivana , Dzida Sanja , Mabic Mirela
Published: October 2020

Objective of the study is to research the epidemiological aspects of maternal alloimmunization against erythrocyte antigens of fetuses (AB0, Rhesus, Lewis, Kell, Duffy and others) and to identify the most common types of hemolytic disease of the newborn (HDN) in the West Herzegovina region.

Study Design The 20-year retrospective epidemiological study includes all pregnant women who had been immunologically tested and newborn treated for HDN.

Results The indirect antiglobulin (IAT) detected antibodies against antigens in 545 (1.8%) pregnant women of the 29 663 who were tested at the Department of Transfusion Medicine. During the 20-year-long study 310 (1.0%) newborn with HDN were treated. Our results indicate that 42% (230/545) of the pregnant women had AB0 immunization. The most common form of HDN is AB0 HDN 64% (199/310), whereas RhD HDN was treated in 19% (59/310) of the newborn infants. ETR was performed on 29 (19%) infants, 21 (72.4%) with AB0 HDN, and 7 (26%) with RhD HDN.

Conclusion This 20-year-long study concludes that, even though there has been significant progress in the prevention of immunization and proactive treatment of HDN, precautionary measures are still required as is the need for gynecologists and obstetricians to be active. The reasons for this are the non-existence of preventive measures for non-RhD immunization, the irregular immunological screening of RhD positive women in pregnancy in the region encompassed by the study in the past few years. The above raises new questions and recommends further research and monitoring of immunization and HDN treatment worldwide.
Systemische Ozontherapie in der integrativen Onkologie
Authors: Feldhaus Simon
Published: October 2020

Bei der komplementären Behandlung onkologischer Patienten stellen sich besondere Herausforderungen. Dazu ist ein vernetzter und sehr individueller Behandlungsansatz im Sinne der integrativen Medizin zwingend. In unserem Zentrum ist die Ozontherapie zentraler Bestandteil der begleitenden onkologischen Therapie. Ozon wirkt gefäßerweiternd, verbessert das Fließverhalten des Blutes sowie die Verformbarkeit der Erythrozyten und verbessert so die Durchblutung. Es hat zudem schmerzlindernde und antientzündliche Wirkungen. Die komplementäre onkologische Behandlung mit ihrem ganzheitlichen Ansatz führt erfahrungsgemäß zu einem wesentlich verbesserten Allgemeinzustand der Patienten, reduziert die Nebenwirkungen von Chemotherapie und Bestrahlung und verbessert erheblich die Lebensqualität.

Der Autor nennt die wichtigsten Studien, erläutert die Anwendung der Ozontherapie und die möglichen Erfolge anhand einer Kasuistik aus seiner Praxis.
In vitro Antileishmanial, Antitrypanosomal, and Anti-inflammatory-like Activity of Terminalia mollis Root Bark
Authors: Muganga Raymond , Bero Joanne , Quetin-Leclercq Joëlle , Angenot Luc , Tits Monique , Mouithys-Mickalad Ange , Franck Thierry , Frédérich Michel
Published: October 2020

This study aims at determining the in vitro antitrypanosomal, antileishmanial, antioxidant, and anti-inflammatory-like activities of Terminalia mollis root crude extracts. The antitrypanosomal and antileishmanial activities on Trypanosoma brucei brucei (strain 427) and promastigotes of Leishmania mexicana mexicana (MHOM/BZ/84/BEL46) were evaluated in vitro. The methanolic root bark extract and standards were profiled by HPLC-PDA, and the majority of compounds identified using literature data. The in vitro antioxidant and anti-inflammatory-like activities were determined by evaluating the effect of crude extracts on reactive oxygen species produced by phorbol 12-myristate 13-acetate-stimulated equine neutrophils using lucigenin-enhanced chemiluminescence and on purified equine myeloperoxidase activity measured by specific immunological extraction followed by enzymatic detection. The methanolic, aqueous crude extract, and aqueous
crude extract free of tannins exhibited good growth inhibition on Trypanosoma brucei brucei (IC50 3.72, 6.05, and 4.45 µg/mL respectively) but were inactive against Leishmania mexicana mexicana (IC50 > 100 µg/mL). Suramin (IC50 0.11 µg/mL) and amphotericin (IC50 0.11 µg/mL) were used as standard respectively for the antitrypanosomal and antileishmanial activity. Very interesting antioxidant and anti-inflammatory-like activities were observed with 50% hydroethanolic, aqueous crude extracts, and aqueous crude extract free of tannins as well as with pure punicalagin, gallic, and ellagic acid (IC50 0.38 – 10.51 µg/mL for 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid), chemiluminescence, and specific immunological extraction followed by enzymatic detection assays. The study results support traditional medicinal use of the plant for the treatment of parasitical disorders and revealed for the first
time the antitrypanosomal potential, anti-inflammatory-like, and antioxidant activity of Terminalia mollis root.
Effect of Protein and Carbohydrate Combined with Resistance Training on Muscular Adaptation
Authors: Santos Priscila Carvalho , Libardi Cleiton Augusto , Nóbrega Sanmy Rocha , de Carvalho Milena Barbon , Galan Bryan Steve Martinez , de Freitas Ellen Cristini
Published: October 2020

The purpose was to compare the effects of protein (whey protein) and carbohydrate supplementation and protein alone both combined with resistance training on muscle strength, muscle mass and total training volume progression in untrained young men. Resistance training was performed using the leg press and knee extension until concentric failure (8−12 repetition maximum), three times a week for eight weeks. Muscle strength and muscle cross-sectional area were assessed before and after training. Total training volume progression was calculated considering the first and eighth week. Seventeen men completed the study (protein and carbohydrate, n=9, age 23.44 ± 4.56 years, weight: 62.13±6.17 kg, height: 1.75±0.02 m, body mass index: 20.29±2.08 kg/m2; protein, n=8, age 24.63±2.39 years, weight: 69.01±5.57 kg, height: 1.77±0.07 m; body mass index: 21.64±1.05 kg/m2. Both protocols showed similar increases in muscle strength (effect size: protein and carbohydrate=1.28; protein=0.97; p<0.001), muscle cross sectional area (effect size: protein and carbohydrate=0.66; protein=0.47; p<0.001) and total training volume progression (effect size: protein and carbohydrate=2.68; protein=1.63; p<0.001) after training. No differences were found between groups p>0.05). Protein and carbohydrate supplementation combined with resistance training does not induce greater gains in muscle strength, hypertrophy and total training volume compared to resistance training combined with protein alone in untrained individuals.
Synthesis and Structural Stability of α-Helical Gold(I)-Metallopeptidesy
Authors: Besenius Pol , Zengerling Lydia , Kemper Benedict , Hellmich Ute A.
Published: October 2020

The synthesis of hexa- and dodecapeptides functionalized with two Au(I)–phosphine complexes is reported. The high stability of the Au(I)–phosphine bond allowed orthogonal peptide-protecting-group chemistry, even when using hard Lewis acids like boron tribromide. This enabled the preparation of an Fmoc-protected lysine derivative carrying the Au(I) complex in a side chain, which was used in standard Fmoc-based solid-phase peptide synthesis protocols. Alanine and leucine repeats in the metallododecapeptide formed α-helical secondary structures in 2,2,2-trifluoroethanol–H2O and 1,1,1,3,3,3-hexafluoroisopropanol–H2O mixtures with high thermal stability, as shown by temperature-dependent CD spectroscopy studies.
Reductive Deuteration of Aromatic Esters for the Synthesis of α,α-Dideuterio Benzyl Alcohols Using D2O as Deuterium Source
Authors: Ma Xiaodong , An Jie , Luo Shihui , Weng Chaoqun , Ding Yuxuan , Ling Chen , Szostak Michal
Published: October 2020

α,α-Dideuterio benzyl alcohols are important building blocks for the synthesis of deuterium-labeled medicines and agrochemicals. We have developed the first general single-electron transfer reductive deuteration of readily commercially available aromatic esters for the synthesis of α,α-dideuterio benzyl alcohols using benign D2O and a mild single-electron donor SmI2. This operationally convenient method features very good functional group tolerance and high deuterium incorporations (>95% D2). The potential impact has been exemplified by the synthesis of numerous deuterium labeled building blocks of important bioactive compounds. Most crucially, the method represents the first example of selective reductive deuteration of benzylic-type ketyl radicals using mild and highly chemoselective lanthanide(II) reagents.
Atypical Presentation of Fulminating Subacute Sclerosing Panencephalitis: A Case Series
Authors: Dey Pranab K. , Ghosh Arindam
Published: October 2020

Subacute sclerosing panencephalitis (SSPE) is a rare and progressive inflammatory disease of central nervous system due to aberrant measles virus with an outcome that is nearly always fatal. In acute fulminant SSPE, the disease rapidly evolves leading to death within 3 months of the diagnosis. We report here four cases of fulminant SSPE with atypical presentations, two of them presented at very early age with history of congenital measles infection in first case and gait abnormality as initial symptom in second case; acute disseminated encephalomyelitis (ADEM) with refractory seizures in third case, unilateral myoclonus with hemiparesis in fourth case at the onset of disease, respectively. The typical periodic electroencephalographic (EEG) complexes, elevated cerebrospinal fluid (CSF), and serum antimeasles antibodies in our patients led to the diagnosis of SSPE. A high index of clinical suspicion in fulminant type with awareness of atypical features, EEG, and CSF studies are of paramount importance in establishing its diagnosis.
Regenerative Limb Salvage: A Novel Technique for Soft Tissue Reconstruction of Pediatric Extremities
Authors: Saeg Fouad , Chiccarelli Elvira N. , Hilaire Hugo St. , Lau Frank H.
Published: October 2020

Background In complex extremity wounds, free flap-based limb salvage (fLS) is the standard of care. However, fLS is resource- and cost-intensive, and the limited availability of pediatric microsurgical expertise exacerbates these challenges. Regenerative LS (rLS) addresses these barriers to care. The aim of this study was to quantify the efficacy, safety, and cost-effectiveness of rLS in complex pediatric extremity wounds.

Methods We conducted a retrospective cohort study of pediatric LS at a single hospital. Subjects were treated with fLS or rLS based on surgeon preference. Primary outcome measures were: definitive wound closure rates and time, rates of return to ambulation, number and length of procedures to achieve definitive closure, and rates of perioperative complications. Statistical analyses were performed utilizing the Wilcoxon Mann–Whitney U test with statistical significance set at p < 0.05.

Results Over a 2-year period, nine consecutive patients presented with complex extremity wounds requiring fLS (n = 4) or rLS (n = 5). Demographics and wound characteristics were similar between groups. Compared with fLS, the rLS group achieved definitive wound closure 85.8% more quickly (13.8 vs. 97.5 days, p < 0.02), required 64.5% less operative time (132.6 vs. 373.0 minutes, p < 0.02), had fewer perioperative complications (0 vs. 5), and required fewer intensive care unit stays (0 vs. 1.3 days).

Conclusion These data indicate that rLS is a safe and efficacious option in pediatric patients requiring soft tissue reconstruction for LS. Use of this novel technique can restore the reconstructive ladder, thereby expand patient access to pediatric LS while minimizing morbidity and reducing LS-related resource utilization.
Time-dependent pseudo-bosonic coherent states
Authors: Mana Naima , Zaidi Omar , Maamache Mustapha
Published: October 2020

In order to construct time-dependent pseudo-bosonic coherent states, first, we extend the non-Hermitian integrals of motion method to cases where the quantum systems are described by time-dependent non-Hermitian Hamiltonians; second, we introduce a pseudo-bosonic annihilation operator defined as a time-dependent non-Hermitian linear invariant. The pseudo-bosons operators are a pseudo-Hermitian extension of usual boson operators. In fact, they are obtained from the modification of usual boson commutation relations where the annihilation and creation operators are related to their adjoint operators via the bounded Hermitian invertible operator or metric operator. Thus, the pseudo-bosonic coherent states are just obtained as eigenstates of the pseudo-bosonic annihilation operator. As an illustration, we study the time-dependent non-Hermitian Swanson Hamiltonian and we compare the obtained results with those in the literature (Swanson model but time-independent).
Peaking factor and external field dependence of n = 1 RWM forces on tokamak wall
Authors: Martynov A. A. , Medvedev S. Yu. , Drozdov V. V.
Published: October 2020

This paper finalizes the self-consistent study of the sideways force acting on the resistive wall due to eddy currents induced by n = 1 kink instability under variations of the external poloidal field and its impact on the force peaking factor as outlined in A. A. Martynov and S. Yu. Medvedev, Phys. Plasmas 27, 012508 (2020). A proper analytical treatment of the sideways forces for a large aspect ratio circular tokamak is limited to the case q < 1 with a dominating m/n = 1/1 mode and only weak coupling to sideband poloidal harmonics, which asymptotically does not contribute to the force. The present paper shows that in the 1D case, the net sideways force does not depend on variations of the external equilibrium poloidal field with a difference in the force peaking factor only: the corresponding analytic expressions have been derived. For realistic 2D cases, the behavior of both the net force and the peaking factor changes due to mode coupling and does depend on the variations of the equilibrium magnetic field at the wall. In particular, for q > 1 at the plasma boundary, the sideways force is generated by a sideband m/n = 1/1 harmonic, which gives lower net force as compared to the q < 1 case, but with a higher peaking. The numerically estimated magnitude of the sideways force density was found to be insignificant for ITER that calls for taking into account the plasma−wall contact in disruption modeling.
Nonlinear heterodyne photothermal radiometry for emissivity-free pyrometry
Authors: Chirtoc Mihai , Fleming Austin , Horny Nicolas , Ban Heng
Published: October 2020

This work sets the basis for nonlinear homodyne and heterodyne photothermal radiometry (PTR) as a form of active pyrometry. The intrinsic nonlinearity of thermo-optical conversion described by blackbody radiation laws generates intermodulation harmonics, among which the sum and difference frequencies are easily measured by lock-in amplifiers connected in series or in parallel. Double modulation heterodyne PTR avoids superposition with harmonics generated in nonlinear homodyne PTR by laser modulation distortion. Useful expressions are derived for the determination of temperature variations of the target relative to its absolute temperature, independently of emissivity. In order to determine one or the other temperature, calibration of one of them is necessary. The effects of spectral and temperature dependence of emissivity are also discussed. Local self-heating of a glassy carbon target could be estimated using two superposed laser sources modulated at 30 Hz and 40 Hz. This application opens the path to perform temperature-dependent thermophysical properties’ investigations in a non-contact manner, with a simple setup. Absolute temperature was determined on the surface of a Peltier element modulated at 0.1 Hz, at the location irradiated by a laser beam modulated at 1 Hz. Three data reduction methods (series, parallel, and transient configurations) yielded concordant results.
DESC: A stellarator equilibrium solver
Authors: Dudt D. W. , Kolemen E.
Published: October 2020

The new code DESC is presented to solve for fixed-boundary ideal magnetohydrodynamic equilibria in stellarators. The approach directly solves the equilibrium force balance as a system of nonlinear equations in the form f(x)=0. The independent variables x represent nested magnetic flux surfaces expressed in the inverse representation with toroidal flux coordinates, and the equations f(x) quantify equilibrium force balance errors at discrete points in real space. Discretizing with global Fourier–Zernike basis functions properly treats the magnetic axis and minimizes the number of coefficients needed to describe the flux surfaces. The pseudospectral method provides great flexibility in where the errors are evaluated, and the system of equations is efficiently solved with a Newton–Raphson iteration. Equilibria are computed and compared against VMEC for both axisymmetric and non-axisymmetric examples. The results show fast convergence rates and solutions with low errors throughout the plasma volume.