bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical solution of Biot equations in quasistatic state for seismic attenuation estimation in anisotropic media
Authors: Solovyev S. A. , Novikov M. A. , Lisitsa V. V.
Published: October 2022

An algorithm for numerical upscaling elastic properties of fractured-porous media in low-frequency range is presented. To do so, the algorithm to solve Biot equations in quasi-static state is developed. Paper describes the following aspects: stating the problem of the poroelastic media upscaling to obtain frequency-dependent stiffness tensor, corresponding to the visco-elastic media; the finite-difference approximation of the considered boundary-value problem; peculiarities of the numerical solution of the SLAE with numerical experiments and performance analysis. Numerical experiments are performed to observe the influence of fracture connectivity and fracture-filling material properties on frequency-dependent seismic attenuation in fractured porous fluid-saturated media.
NDM-net for seismic modelling: data-based optimization of the training dataset
Authors: Gadylshin K. G. , Lisistsa V. V. , Vishnevskiy D. M. , Gadylshina K. A.
Published: October 2022

This paper presents a new method to construct the optimal training dataset for the numerical dispersion mitigation network. The dataset is designed to preserve the prescribed maximal NRMSdistance between any seismogram from the entire dataset and those from the training dataset. So, the training dataset is constructed only using the precomputed coarse-mesh solution; thus, it does not require any additional simulations. Our numerical experiments illustrate that the suggested approach may reduce the number of common-shot gathers in the training set by the factor of four compared to the datasets using uniformly distributed shots. However, the areas with high model and seismograms variability are oversampled by the proposed approach without gaining extra accuracy, which requires further study.
Application of Lomax rays to approximate a propagation of the broadband signals
Authors: Neklyudov D. A. , Protasov M. I.
Published: October 2022

In this paper we consider a method for calculating frequency-dependent rays, which allows to approximate effectively the propagation of a broadband signal. A comparative analysis of this method with the standard ray method and the finite-difference method is carried out. It is shown to be promising for solving seismic problems.
Full waveform inversion of the scattered wavefield: resolution analysis
Authors: Gadylshin K. G. , Protasov M. I.
Published: October 2022

The paper studies the influence of the scattered component of the wavefield on the full waveform inversion results. For different scenarios, the contribution of scattered waves was investigated. Utilizing the one step of the quasi-Newton FWI method, we demonstrate that scattered wavefields bring helpful information in the context of the solution of the inverse dynamical problem.
Analysis of seismic inversion after depth migration for recovery of the low-frequency component of the model
Authors: Dmitrachkov D. K.
Published: October 2022

Seismic inversion is used in practice as a tool for predicting reservoir properties. It allows one to extract a model with a high level of detail from seismic data, i.e. high-frequency component of the model. In this case, the input data are the time processing results, and the issues related to the low-frequency component of the model are not considered usually. In the presented work, a model-based seismic inversion algorithm is implemented. The input data for the inversion are the depth image results in true amplitudes and the depth migration velocity model. The possibilities of seismic inversion are numerically investigated to refine the low-frequency component of the model. Experiments were carried out using synthetic seismic data got for realistic Sigsbee model.
Suppression of surface waves in seismic data based on the search for the main components of the wave field in the frequency-time domain
Authors: Azarov A. V. , Serdyukov A. S. , Yablokov A. V.
Published: October 2022

Suppression of surface wave interference is a necessary step in the processing of land seismic data. Traditional methods, such as single-channel band-pass filtering and multi-channel FK filtering, often fail to separate the desired signal from interference. The proposed method of suppressing surface waves based on the analysis of the main components of the wave field in the time-frequency domain shows the best results. The method is based on the model of surface wave propagation in horizontally layered media, however, numerical experiments were carried out demonstrating the applicability of the method in horizontally heteronode three-dimensional media. A software package "PF Seism" has been developed and registered, which implements the proposed method for suppressing surface waves.
Experience in the use of the fertile soil layer for the reclamation of non-ferrous metallurgy waste (Kemerovo region)
Authors: Edelev A. V. , Sokolov D. A. , Yurkevich N. V. , Stepanova M. V.
Published: October 2022

The article shows the results of experiments on biological reclamation of a pilot production site. Wastes from hydrometallurgical processing of clinkers from the Belovsky zinc plant (Kemerovo region) were chosen as objects. Various approaches were considered, in which the technogenic soil and its mixture with a humus substrate were sown with yellow sweet clover and awnless brome. As a result of the analysis of samples, the degree of soil acidity, cation exchange capacity, fractional composition, concentrations of mobile phosphorus and potassium, organic carbon, and the content of mobile forms of elements in an acetate-ammonium buffer solution were determined. The results obtained were evaluated according to agrochemical gradations and hygienic standards. The conducted studies allow us to conclude that technogenic soil is a substrate with unfavorable physical and agrochemical properties. Mixing man-made soil with a fertile soil layer does not improve its properties.
Experimental study of the formation of a mud cake and its characteristics on the example of the Jurassic oil reservoir
Authors: Evmenova D. M. , Yeltsov I. N. , Golikov N. A.
Published: October 2022

Using the geophysical and hydrodynamic compatibility model allows to reduce ambiguity of the solution of the inverse problem and to increase the reliability of productive layer parameters definition. It includes the parameters of permeability and porosity of the filter cake, which significantly affect the result of filtration modeling, but are not determined during the drilling. To investigate the process of formation of a mud cake, to study its properties and to determine the main parameters, the authors of the article carried out a series of experiments on a setup assembled at IPGG SBRAS, on core samples of low-permeability sandstone extracted from the YUS collector. The results of experiment with core samples from the Tevlinsko-Russinskoe and Russinskoe oil fields.
Inductive and orientational effects of geomagnetic variations in the southwest of the Zarechenskaya magnetic anomaly (eastern coast of lake Baikal)
Authors: Konyaev E. S. , Dyadkov P. G.
Published: October 2022

Tectonomagnetic monitoring is most often carried out in areas where bodies with anomalous values of magnetic properties (magnetic susceptibility and remanent magnetization) are located, since they are indicators of changes in the stress state of the Earth's crust. However, when performing modular measurements, secondary effects of geomagnetic variations arise, the amplitude of which exceeds the expected magnetoelastic effect. A method was proposed for determining the coefficients of the linear dependence of the magnitude of the secondary effects of geomagnetic variations on the components of these variations. The singular value decomposition method was applied to identify the optimal periods of variations for calculating the coefficients. After excluding secondary effects from the results of observations at the stations Zarechye-1 and Sukhaya-2, it was possible to reduce the root-mean-square deviation of the difference values of the modulus of the magnetic induction vector between these points and the Enkhaluk base station by 4 times.
Experimental determination of effective thermal properties of soils in situ
Authors: Fadeeva I. I. , Karin Y. G.
Published: October 2022

The report presents a description of an attempt to create a measuring device for determining the thermal properties of soils in situ (in situ). The method of determining soils thermal properties consists in creating by linear source of constant radial heat flux and measuring temperature by two electrical cable (wich is parallel to the heater and locate at distances of 5 (1st cable) and 10 (2 th cable) cm from the heater) with 7 soldered temperature sensors with 20 cm from each other. The measurements were taken on November 1, 2021 before the onset of frost and after frost on April 11, 12, 2022. The thermal state of the soil in a certain place and time is characterized by the ambient temperature, the presence of solar radiation, the ability of the soil to absorb solar radiation, the presence of sources/sinks of heat, and the ability of the soil to absorb and transfer heat, which in the mathematical description corresponds to its thermal properties, which we want to determine.
Petro-geological way of thinking: new 21st-century aspects
Authors: Zapivalov N. P.
Published: October 2022

The article discusses a new approach to the processes of oil formation. The author offers his own paradigm, or angle of vision into origin and life (space-time dynamics) of an oil and gas play. Special attention is paid to the analysis of risks and uncertainties in the petroleum business
Determination of rational parameters of drilling and blasting operations with floor-chamber and sub-storey development systems
Authors: Koltyshev V. N.
Published: October 2022

The parameters of drilling and blasting operations (BVR) with a floor-chamber system of development and sub-storey collapse at various sites of the Sheregeshevsky field are considered. Rational parameters of the BVR for these development systems are given. It was found that in the case of a sub-storey collapse, the specific consumption for secondary crushing is lower (11 g / t) than in the case of a floor-chamber development system (from 66 to 208 g/t).
On the effect of the asymmetry of the shape of the falls on the stress state of the rock mass
Authors: Krasnovsky A. A.
Published: October 2022

The issues of the influence of the asymmetric arrangement of fallouts relative to the working on the stress state of the rock mass are discussed. The modelling of the stress state of the rock mass and lining was carried out when filling the formed volume of falls in the roof and sides of the working with phenolic resins. The analysis of the received results of calculations is carried out. The nature of the distribution of stress fields in the support and the rock mass and their change depending on the geometric shapes of the area filled with phenolic resins have been established.
Lab-scale simulation of hydraulic fracturing: some outcomes
Authors: Leontiev A. V. , Rubtsova E. V. , Skulkin A. A.
Published: October 2022

The paper describes the lab-scale physical simulation of hydraulic fracturing in measurement holes. The tests were carried out using cubical polymethyl methacrylate specimens with faces of 200 mm. The open-end or dead-end holes with diameter of 12 mm were made in the test specimens. In the preset intervals in the holes, the longitudinal or latitudinal (ring-wise) slots with depths up to 3 mm were precut to initiate and orient created fractures. Hydrofracturing was carried out using prototype tools for sealing a test interval in a hole (packer-to-packer spacing) and to feed it with power fluid under pressure. The model specimens were tested under different triaxial loading conditions on a special testing machine. The representative cases of the created fracture growth in the model specimens were analyzed. The physical simulation outcomes can be used in formulation and solution of analytical problems on HF stress measurement, as well as to improve procedures and equipment involved in this method of stress control in underground mines.
Justification of the parameters of ring models in the decomposition of the ventilation network of an extended metro line for the calculation of air distribution
Authors: Lugin I. V. , Pavlov S. A. , Irgibaev T. I.
Published: October 2022

The piston effect of trains on air distribution and air exchange in tunnel and passenger structures of the metro with a single-track tunnel is in second place after the action of mechanical tunnel ventilation. When the tunnel fans are turned off (for example, during the cold season in an area with a sharply continental climate), almost the entire ventilation load is provided by the piston action. Since all elements of the metro ventilation network are connected by tunnels under the generally accepted scheme of longitudinal ventilation, the mutual influence of the ventilation modes of neighboring metro sections is very significant. Therefore, in order to obtain the correct result of air distribution modeling, at least 8 runs with stations should be included in the calculation scheme, which leads to increased requirements for computing power and calculation time. The article considers the decomposition of an extended metro line using ring models and justifies the number of calculated sections with stations for different train frequencies. A comparison of the calculation results for the ring and linear models is given. Calculations are performed using network methods for calculating air distribution.
Mineral resource base of the eastern part of the Novosibirsk region: about development scenarios
Authors: Gavrilov V. L. , Nemova N. A. , Cheskidov V. I. , Reznik A. V. , Karpov V. N.
Published: October 2022

The mineral resource base of the most developed eastern part of the Novosibirsk region is considered. Information on the distributed subsoil fund and volumes of extraction of solid minerals is presented. It is shown that in the current state and in the medium term for enterprises, the most significant in terms of economic efficiency are: anthracite and coal, placers. On the basis of the former, a new efficient large-scale production has already been created or can be organized, focused primarily on export deliveries, mainly to the Asia-Pacific region. Mining from alluvial deposits, subject to competitive grades of useful components, can also be effective, but its scale is limited at the current level of exploration by the size of reserves suitable for extraction. Common minerals are mainly of regional importance, they are consumed by its road construction complex, and prices are formed taking into account the insignificant influence of the external market. An increase in requirements for environmental protection is noted, leading to the objective need for the most accurate assessments of alternative long-term use of land for various purposes in the region. It is shown that such work should be based on more complete knowledge about the current and expected life cycle impact on the environment of the mining complex itself and the industries associated with the consumption of its products.
Determination of the stress-strain state of the impeller of a mine axial fan in the transition to a single-disk impeller
Authors: Panova N. V.
Published: October 2022

This article discusses the application of topological optimization methods in the design of the impeller housing using the ANSYS software package. The transition from a two-disk to a single-disk scheme of the fan impeller is considered. When optimizing the impeller, the minimum compliance is used as the objective function, and the change in the internal structural volume is taken as the optimization parameter, with restrictions on the external geometry of the impeller.
Simulation modeling and analysis of air-percussion machine with adjustable impact capacity
Authors: Plokhikh V. V. , Danilov B. B. , Cheshchin D. O.
Published: October 2022

The paper proposes a new layout of an air-percussion tool with the possibility to change parameters of the impulsive force impact directly during its operation. It is necessary for realization of adaptable technologies, creation of robotic drilling equipment sets and implementation of the unmanned technologies. The results of the research of the operating cycle dynamics of the new layout obtained using the simulation model in the ITISimX program are presented.
Influence of Support Surface Shape of a Stationarily Installed Elastic Valve on the Change in Pre-impact Velocity of Impact Machine Striker
Authors: Rechkin А. А. , Danilov B. B.
Published: October 2022

The dynamic contact problem of the interaction between the impact machine striker and a conical annular elastic valve made of elastomer (rubber), which choks the reverse motion chamber in impact machines for mining and construction, is considered. The influence of the shape of the valve support surface on the drop in the pre-shock velocity of the striker during contact interaction is studied. Variants of the shape of the supporting surface of the valve are founded, at which the smallest drop in velocity is observed. For two variants, the dependence of the change in the decrease of the pre-impact velocity with an increase in the elastic properties of the elastomer was obtained. It is proved that with an increase in the elastic properties of the material, the drop in pre-impact velocity increases linearly, and for support surface shape that previously showed a smaller velocity drop, the pre-impact velocity drops less with increasing modulus of elasticity.
Improvement of lead-zinc ore mining waste processing
Authors: Rostovtsev V. I. , Kondratiev S. A.
Published: October 2022

Expansion of mineral reserves and resources in Russia is currently connected with larger scale commercialization of rebellious ore and mining waste, and the percentage of the latter continuously grows. Due to the complex material constitution of minerals, their similar physicochemical and processing properties, as well as because of deficient ore pre-treatment, up to 20% of valuable minerals and metals are lost with tailings, mostly with very fine particles less than 10 µm. It is of the great concern to improve processing technologies for ore and mining waste. This research aims to analyze mineral compositions of tailings after lead-zinc ore flotation, and to identify causes of lead and zinc losses with the flotation tailings. The technology tests reveal that the losses lead and zinc in the form of micron size grains of galena (PbS) and wurtzite (ZnS) are connected with their aggregation with other minerals (quartz, pyrite, magnetite, etc.). The tests with physical (radiation) treatment show dissociation ability of aggregates with subsequent separation of minerals by flotation. The presence of magnetic magnetite in flotation tailings makes it possible to implement magnetic separation to increase the contents of lead and zinc in the concentrate. The scientific novelty and practical significance of this research consists in the proved expediency of radiation treatment of minerals and mining waste toward modification of their processibilty to ensure reduction in loss of valued components with tailings and to enhance environmental safety of mining waste.
On the change in the strength properties of quaternary deposits in the sides of the quarry under the influence of natural and climatic factors
Authors: Rublev D. E.
Published: October 2022

The features of changing the properties of quaternary deposits in the sides of the quarry under the influence of climatic factors during rainfall and drying of the soil as a result of drainage and evaporation of moisture are considered. Using the methods of seismodeformation monitoring based on the records of seismic signals and metric measurements of the displacement of the reference points on the edges of the side in the fault zone, the limits of the change in the hodographs and the rate of displacement of the soil during its moistening and drying are determined. The spread of hodographs in the range from 15 to 25% is essential for the development of erosion and requires control to prevent emergencies. These results indicate the natural self-organization of the destruction of rocks of the marginal part of the side of the quarry under the influence of seasonal natural and climatic factors due to changes in the strength of the near-surface layers of the soil.
Study of the influence of vibration treatment of coal cores as a way to increase gas permeability
Authors: Rybalkin L. A. , Serdyukov S. V.
Published: October 2022

This paper provides the results of a series of experimental studies on seismic action’s effect on the permeability of coal and hydraulic fractures. The experiments have been carried out using solid coal cores, cores with single through longitudinal cracks simulating drainage hydraulic fractures and cores with the single fractures propped with a low-density proppant designed to intensify the degassing of coal seams. The patterns of the seismic impact on the gas permeability of coal under the conditions of all-round compression have been established in accordance with the results of experiments. Also, the experimental results reveal certain patterns of increase of the drainage cracks’ gas permeability observed when the cracks are propped with proppant and are under the low intensity seismic effect under the conditions of all-round compression. The studies show that the effectiveness of seismic action increases with an increase in the accumulated exposure time, followed by stabilization and persistence of the positive effect for at least 3 - 7 days after the cessation of exposure. The obtained results provide the opportunity to assess the possibility of using seismic action to intensify the degassing of non-propped hydraulic fractures in coal mines.
Selecting ratios of chemical agents for flotation mixtures
Authors: Semyanova D. V.
Published: October 2022

Improvement of a reagent mode is one of the common affordable methods of stimulating flotation efficiency. The present scientific knowledge proves the promising nature of combining chemical agents. The combinations of flotation agents are advantageous for the increased recovery, higher separation quality, reduced consumption of reagents, etc. In this regard, it is of the current concern to elaborate the methods to select reagents and to determine their ratios for composing efficient combinations. This paper, using the earlier proposed physisorption mechanism which explains correlation of flotation activity and surface tension, suggests combining chemical agents with regard to an interaction parameter. This can make it possible to mixture components at such ratio that ensures the synergistic effect at the gas-liquid interface.
Numerical studies of the features of the propagation of a hydraulic fracture from a side-tracked well
Authors: Azarov A. V. , Serdyukov S. V. , Patutin A. V.
Published: October 2022

The paper considers the problem of hydraulic fracture propagation from a well with a side track. A simplified mathematical model for the analysis of the problem is proposed. Numerical studies of hydraulic fracture propagation for various model parameters using the extended finite element method (XFEM) have been carried out. It is shown that a hydraulic fracture can develop in the plane containing the main and side wells at low values of stress anisotropy. The trajectories of crack propagation are given depending on the stress state of the medium.
Gambaran Kadar Debu Respirabel pada Pekerja Bagian Produksi di PT. Bintang Manunggal Persada Kelurahan Buluri Kota Palu
Authors: Sunuh Herlina , Subagyo Indro
Published: October 2022

Pendahuluan: Debu merupakan salah satu partikel yang melayang di udara. Pada peristiwa  polusi udara baik di dalam maupun udara ambien (Indoor and Out Door Pollution) Debu merupakan parameter yang dijadikan sebagai salah satu indikator pencemaran yang menyatakan tingkat bahaya baik bagi lingkungan maupun terhadap kesehatan dan keselamatan kerja. Tujuan: Penelitian ini bertujuan untuk memberikan  gambaran kadar debu respirabel pada pekerja di bagian produksi PT. Bintang Manunggal Persada Kelurahan Buluri. Metode: Penelitian ini merupakan jenis penelitian deskriptif dengan pendekatan observasional, dari populasi yaitu 26 orang responden bagian produksi dengan jumlah sampel sebesar 5 orang yang pengambilannya dilakukan  menggunakan Kriteria inklusi yaitu mereka yang bersedia dijadikan sebagai responden. Hasil: Hasil penelitian menunjukkan bahwa dari pengukuran kadar debu pada pekerja bagian produksi di PT. Bintang Manunggal Persada dengan menggunakan Personal Dust Sampler, menunjukkan bahwa 4 responden  memenuhi persyaratan dan 1 responden tidak memenuhi persyaratan karena hasil pengukuran yang menunjukkan, jumlah kadar debu yang masuk melalui zona pernapasan melebihi NAB 3,0mg/m3. Kesimpulan: Berdasarkan hasil analisa disimpulkan bahwa dari 5 orang responden diperoleh I orang dengan kadar debu respirabel melebihi Nilai Ambang. Debu respirabel memiliki risiko yang cukup tinggi terhadap terjadinya keluhan kesehatan seperti gangguan pernafasan.
Peningkatan Pengetahuan tentang Sanitasi Total Berbasis Masyarakat (STBM) pada Kepala Keluarga di Desa Bale Kecamatan Tanantovea Kabupaten Donggala
Authors: Bungawati Andi
Published: October 2022

Pendahuluan: Sanitasi menjadi salah satu tujuan pembangunan berkelanjutan SDGs meskipun dilapangan menunjukkan kemajuan yang masih lambat. Strategi Nasional Kebijakan STBM mengacu pada strategi percepatan yang bertujuan untuk mengejar target SDGs. Poster dipilih sebagai media penyuluhan karena ekonomis dan mudah dipahami dan bisa berfungsi sebagai pengingat bagi sasaran. Tujuan: Tujuan penelitian untuk mengetahui efektifitas poster untuk meningkatkan pengetahuan tentang STBM pada kepala keluarga di Desa Bale Kabupaten Donggala. Metode: Jenis penelitian ini adalah metode eksperimen semu dengan pendekatan pre-test and post-test one group design. Sampel dalam peneltian ini adalah 41 responden yang masuk dalam anggota populasi menggunakan teknik sampling random sederhana. Penelitian ini dilaksanakan di Desa Bale Kabupaten  Donggala. Hasil: Hasil penelitian dengan menggunakan uji paired sampel t-test didapatkan bahwa skor pengetahuan kepala keluarga sebelum diberikan penyuluhan menggunakan poster, yaitu sebesar 26,82 dan pengetahuan kepala keluarga sesudah diberikan poster yaitu sebesar 31,40. Kesimpulan: Pemberian poster memberikan pengaruh terhadap pengetahuan kepala keluarga mengenai STBM karena nilai p-value yang didapatkan 0,000 < 0,05.
Numerical treatment of singularly perturbed parabolic partial differential equations with nonlocal boundary condition
Authors: Wondimu Getu Mekonnen , Woldaregay Mesfin Mekuria , Dinka Tekle Gemechu , Duressa Gemechis File
Published: October 2022

This paper presents numerical treatments for a class of singularly perturbed parabolic partial differential equations with nonlocal boundary conditions. The problem has strong boundary layers atx= 0 andx= 1. The nonstandard finite difference method was developed to solve the considered problem in the spatial direction, and the implicit Euler method was proposed to solve the resulting system of IVPs in the temporal direction. The nonlocal boundary condition is approximated by Simpsons13rule. The stability and uniform convergence analysis of the scheme are studied. The developed scheme is second-order uniformly convergent in the spatial direction and first-order in the temporal direction. Two test examples are carried out to validate the applicability of the developed numerical scheme. The obtained numerical results reflect the theoretical estimate.
Does the sizing of current cervical disc arthroplasty systems match Chinese cervical anatomic dimensions?
Authors: Wang Lu , Bai Meng , Li Xing-Bin , Wang Zhao-Rui , Wang Bang , Huang Ai-Bing
Published: October 2022

Objective: The objectives of this study were to analyze the computed tomography (CT) scan imaging data of the cervical spine from healthy volunteers and to correlate the measurements to the dimensions of current cervical disc arthroplasty systems.

Methods: A total of 130 participants (78 males and 52 females) with a mean age of 41.0 years (range 18.0–66.0 years) who had undergone computed tomography scans of the cervical spine were included. The linear parameters of the C3 to C7 levels, including anterior-posterior diameter (AP), middle disc height (DH), anterior disc height (ADH), posterior disc height (PDH) and center mediolateral diameter (ML), were measured. The analysis was conducted comparing different cervical levels, sexes, and age groups. Known dimensions from eight cervical disc arthroplasty systems were compared with the morphologic data.

Results: A total of 520 vertebral segments were measured. The mean values for the measured parameters were as follows: anterior-posterior diameter 16.08 ± 1.84 mm, mediolateral diameter 16.13 ± 1.99 mm, anterior disc height 3.88 ± 1.11 mm, disc height 5.73 ± 1.00 mm, posterior disc height 2.83 ± 0.94 mm, and mediolateral diameter/anterior-posterior diameter 1.01 ± 0.13. All parameters except for posterior disc height were significantly different across the different cervical levels (p < 0.05). There were also significant sex differences in terms of the linear parameters. No differences were found in the majority of parameters among the different age groups (p > 0.05), except for anterior-posterior diameter at the C6/7 level. A comparison of the bone dimensions from the study data and the dimensions of the implants indicated the presence of a size mismatch in the currently available cervical disc prostheses.

Conclusion: There is a large discrepancy between the cervical anatomical data of Chinese patients and the sizes of currently available prostheses. The dimensions collected in this study could be used to design and develop appropriate disc prostheses for Chinese patients.
First quantitative dosages: Strong correlations between non-5-HT2Rs serotonin receptors on normal human heart valves
Authors: Schussler Olivier , Maroteaux Luc , Jashari Ramadan , Falcoz Pierre , Alifano Marco , Lecarpentier Yves , Launay Jean-Marie
Published: October 2022

Objectives

Although critical in animal and human development and pathology, a measurement of the quantitative expression of 5-HTR serotonin receptors on animal or human valvular tissues has never been performed.

Methods

Quantification of the most frequent 5-HTRs reported as being present in human peripheral tissue was performed using radiolabeled agonists/antagonists. A membrane protein extract from normal human valves (aortic/mitral/tricuspid and some pulmonary) and associated diseased left myocardium, all unusable in clinics, were obtained from the Homograft bank.

Results

We analyzed 5-HT1AR/5-HT1B/DR/5-HT2AR/5-HT2BR/5-HT 2CR/5-HT4R/5-HT7R from 28 hearts. We confirmed the presence of tissue and measured the quantitative content for respective proteins in femtomol/mg of protein extracts: for 5-HT2AR (35.9+/−0.7), 5-HT2BR (28.8+/−1.3) but also a newly observed and robust expression for 5-HT4R (38+/−4.2). We identified one, 5-HT1ARs (4.9+/−0.3), and the possible expression, but at a very low level, of previously reported 5-HT1B/DRs (1.3+/−0.5) as well as the new 5-HT7Rs (3.5+/0.1) and 5-HT2CRs (1.2+/−0.1). Interestingly, by using univariate analysis, we were able to observe many correlations between the different 5-HTR levels of expression especially between 5-HT1AR/5-HT1B/DR and also between 5-HT4R/5-HT7R, but none were observed between 5-HT2AR and 5-HT2BR. Using multivariate analyses for a specific 5-HTR level of expression, after adjustment for implantation sites and other 5-HTRs, we found that 5-HT1AR was correlated with 5-HT1B/DR;5-HT4R with 5-HT7R and 5-HT1AR;5-HT2BR with 5-HT2AR only. For 5-HT2C, no correlation was observed.

Conclusion

5-HT2AR/5-HT2BR and 5-HT4R were all observed to have a high and equal level of expression on human valves, but that of 5-HT1AR was more limited. Since these non-5-HT2Rs are coupled with different G-proteins, with specific signaling, theoretically they may control the main 5-HT2R signaling (i.e., PLC/DAG-PKC-ERK/Ras/Src signaling) involved in valvular fibrosis and degeneration.
Similar clinical outcomes with transcatheter aortic valve implantation and surgical aortic valve replacement in octogenarians with aortic stenosis
Authors: Kolar Tadeja , Lakič Nikola , Kotnik Aleša , Štubljar David , Fras Zlatko , Bunc Matjaž
Published: October 2022

Background

Transcatheter aortic valve implantation (TAVI) is the preferred treatment option for severe aortic stenosis in the elderly and in patients with comorbidities. We sought to compare outcomes after TAVI and surgical aortic valve replacement (SAVR) in octogenarians.

Methods

In this retrospective cohort study conducted at our tertiary center, clinical data were gathered before and after TAVI and SAVR procedures performed from January 2013 to May 2019; follow-up completed in March 2021. The primary outcome was 1-year mortality. Patients were stratified according to Society of Thoracic Surgeons (STS) score and procedure type. Propensity score-based matching was also performed.

Results

Of 542 patients who matched the inclusion criteria, 273 underwent TAVI and 269 SAVR. TAVI patients were older (85.8 ± 3.0 vs. 82.2 ± 2.2 years; P < 0.001) and had a higher mean STS score (5.0 ± 4.0 vs. 2.8 ± 1.3; P < 0.001) and EuroSCORE II (5.3 ± 4.1 vs. 2.8 ± 6.0; P < 0.001). Rates of postoperative permanent pacemaker insertion (15.0% vs. 9.3%; P = 0.040) and paravalvular leak (9.9% vs. 0.8%; P < 0.001) were higher and acute kidney injury lower (8.8% vs. 32.7%; P < 0.001) after TAVI, with no difference between treatment groups for major bleeding (11.0% vs. 6.7%; P = 0.130) or 30-day mortality (5.5% vs. 3.7%; P = 0.315). A statistically significant difference was found between TAVI and SAVR in low- and intermediate-risk groups when it came to occurrence of paravalvular leak, acute kidney injury, and new onset AF (all P < 0.001).

Conclusion

This analysis of an octogenarian “real-life” population undergoing TAVI or SAVR (with a biological valve) showed similar outcomes regarding clinical endpoints in low- and medium-risk (STS score) groups.
Traveltime-based microseismic event location using artificial neural network
Authors: Anikiev Denis , Waheed Umair bin , Staněk František , Alexandrov Dmitry , Hao Qi , Iqbal Naveed , Eisner Leo
Published: October 2022

Location of earthquakes is a primary task in seismology and microseismic monitoring, essential for almost any further analysis. Earthquake hypocenters can be determined by the inversion of arrival times of seismic waves observed at seismic stations, which is a non-linear inverse problem. Growing amounts of seismic data and real-time processing requirements imply the use of robust machine learning applications for characterization of seismicity. Convolutional neural networks have been proposed for hypocenter determination assuming training on previously processed seismic event catalogs. We propose an alternative machine learning approach, which does not require any pre-existing observations, except a velocity model. This is particularly important for microseismic monitoring when labeled seismic events are not available due to lack of seismicity before monitoring commenced (e.g., induced seismicity). The proposed algorithm is based on a feed-forward neural network trained on synthetic arrival times. Once trained, the neural network can be deployed for fast location of seismic events using observed P-wave (or S-wave) arrival times. We benchmark the neural network method against the conventional location technique and show that the new approach provides the same or better location accuracy. We study the sensitivity of the proposed method to the training dataset, noise in the arrival times of the detected events, and the size of the monitoring network. Finally, we apply the method to real microseismic monitoring data and show that it is able to deal with missing arrival times in efficient way with the help of fine tuning and early stopping. This is achieved by re-training the neural network for each individual set of picked arrivals. To reduce the training time we used previously determined weights and fine tune them. This allows us to obtain hypocenter locations in near real-time.
Stereology of gonadotropin-releasing hormone and kisspeptin neurons in PACAP gene-deficient female mice
Authors: Barabás Klaudia , Kovács Gergely , Vértes Viola , Kövesdi Erzsébet , Faludi Péter , Udvarácz Ildikó , Pham Dániel , Reglődi Dóra , Abraham Istvan M. , Nagy Zsuzsanna
Published: October 2022

The hypothalamic gonadotropin-releasing hormone (GnRH)–kisspeptin neuronal network regulates fertility in all mammals. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide isolated from the hypothalamus that is involved in the regulation of several releasing hormones and trop hormones. It is well-known that PACAP influences fertility at central and peripheral levels. However, the effects of PACAP on GnRH and kisspeptin neurons are not well understood. The present study investigated the integrity of the estrous cycle in PACAP-knockout (KO) mice. The number and immunoreactivity of GnRH (GnRH-ir) neurons in wild-type (WT) and PACAP KO female mice were determined using immunohistochemistry. In addition, the number of kisspeptin neurons was measured by counting kisspeptin mRNA-positive cells in the rostral periventricular region of the third ventricle (RP3V) and arcuate nucleus (ARC) using the RNAscope technique. Finally, the mRNA and protein expression of estrogen receptor alpha (ERα) was also examined. Our data showed that the number of complete cycles decreased, and the length of each cycle was longer in PACAP KO mice. Furthermore, the PACAP KO mice experienced longer periods of diestrus and spent significantly less time in estrus. There was no difference in GnRH-ir or number of GnRH neurons. In contrast, the number of kisspeptin neurons was decreased in the ARC, but not in the R3PV, in PACAP KO mice compared to WT littermates. Furthermore, ERα mRNA and protein expression was decreased in the ARC, whereas in the R3PV region, ERα mRNA levels were elevated. Our results demonstrate that embryonic deletion of PACAP significantly changes the structure and presumably the function of the GnRH–kisspeptin neuronal network, influencing fertility.
Wheat straw biochar and its performance in treatment of phenanthrene containing water and microbial remediation of phenanthrene contaminated soil
Authors: Ding Chengcheng , Gan Yonghai , Luo Jun , Cui Yibin
Published: October 2022

In recent years, biochar has been considered as an effective adsorbent and soil conditioner due to its abundant carbon and high porosity. This study applied a kind of biochar from wheat straw pyrolysis to remediate phenanthrene-contaminated water and soil. The performance of the biochar in the removal of phenanthrene was discussed by liquid phase adsorption and soil incubation experiments. Furthermore, this work explored the enhancement effect of wheat straw biochar on soil microbial numbers and soil properties. The result of liquid phase adsorption indicated, 92.2% of phenanthrene was removed after incubating 0.6 g/L of wheat straw biochar for 4 h. Pseudo-second-order kinetic model (R2 = 0.99823) and Langmuir isotherm model (R2 = 0.99577) described the removal of phenanthrene by wheat straw biochar well. In soil incubation experiment with an initial phenanthrene content of 11.2 mg/kg, 89.1% of phenanthrene was removed at biochar dosage of 12% (w/w, wheat straw biochar/soil) after 30 days of incubation. In addition, the number of soil microorganisms, soil pH and organic matter (SOM) content increased after wheat straw biochar treatment. At the dosage of 12%, soil microbial count increased to 9.8 × 108 CFU/g-soil, soil pH increased by 1.8 units and SOM increased by 8.5 folds. The addition of wheat straw biochar not only improved soil quality, but also reduced the proportion of phenanthrene components, which could provide theoretical support for the resource utilization of agricultural waste.
Using ecosystem integrity to maximize climate mitigation and minimize risk in international forest policy
Authors: Rogers Brendan M. , Mackey Brendan , Shestakova Tatiana A. , Keith Heather , Young Virginia , Kormos Cyril F. , DellaSala Dominick A. , Dean Jacqueline , Birdsey Richard , Bush Glenn , Houghton Richard A. , Moomaw William R.
Published: October 2022

Several key international policy frameworks involve forests, including the Paris Agreement on Climate Change and the Convention on Biological Diversity (CBD). However, rules and guidelines that treat forest types equally regardless of their ecosystem integrity and risk profiles in terms of forest and carbon loss limit policy effectiveness and can facilitate forest degradation. Here we assess the potential for using a framework of ecosystem integrity to guide policy goals. We review the theory and present a conceptual framework, compare elements of integrity between primary and human-modified forests, and discuss the policy and management implications. We find that primary forests consistently have higher levels of ecosystem integrity and lower risk profiles than human-modified forests. This underscores the need to protect primary forests, develop consistent large-scale data products to identify high-integrity forests, and operationalize a framework of ecosystem integrity. Doing so will optimize long-term carbon storage and the provision of other ecosystem services, and can help guide evolving forest policy at the nexus of the biodiversity and climate crises.
Case Report: Tracheal stenosis due to fibrotic bridges in a post-tracheostomy COVID-19 patient
Authors: Zuccatosta Lina , Zamacona Borja Recalde , Porcarelli Francesco , Mei Federico , Gonnelli Francesca , Gasparini Stefano , Di Marco Berardino Alessandro
Published: October 2022

Tracheal stenosis is a common complication of prolonged endotracheal intubation or tracheostomy, that can be classified as simple (without cartilage involvement) or complex (with cartilaginous support involvement). We report a case of a post-COVID-19 tracheal stenosis with fibrotic bridges between the tracheal walls, creating a net within the lumen and causing significant respiratory distress. The absence of cartilaginous support involvement allowed a definitive bronchoscopic treatment with complete and permanent resolution of stenosis.
Regulation mechanism of ferroptosis and its research progress in tumor immunotherapy
Authors: Xu Jing , Lin Xiaolin , Han Ting , Zhou Qingqing , Su Yang , Jiang Shuqing , Xiao Xiuying , Liu Tengfei
Published: October 2022

Ferroptosis is a novel regulatory cell death, which is characterized by iron dependency and mainly caused by accumulation of intracellular lipid peroxides and reactive oxygen species. Ferroptosis plays an important role in the occurrence and development of a variety of malignant tumors, especially in anti-tumor treatment. As an emerging treatment method, the immunotherapy has been widely applied in the clinical practice, and the role of ferroptosis in tumor immunotherapy has been gradually explored. This study aims to illustrate the features of ferroptosis, and its role in anti-tumor immunotherapy and potential clinical application.
Participant characteristics associated with the effects of a physical and cognitive training program on executive functions
Authors: Tirkkonen Anna , Törmäkangas Timo , Kulmala Jenni , Hänninen Tuomo , Neely Anna Stigsdotter , Sipilä Sarianna
Published: October 2022

Background

Physical and cognitive interventions have been shown to induce positive effects on older adults’ executive functioning. However, since participants with different background characteristics may respond differently to such interventions, we investigated whether training effects on executive functions were associated with sex, training compliance, and age. We also investigated if change in global cognition was associated with physical and cognitive training intervention-induced changes in executive functions.

Methods

Exploratory data from a randomized controlled trial were analyzed. Participants were 70–85-year-old men and women who received a 12-month physical (PT) or physical and cognitive training (PTCT) intervention. Measurements of executive functions related to inhibition (Stroop), set shifting (Trail Making Test B) and updating (Verbal Fluency) were performed at baseline and 12 months. Data were analyzed using a longitudinal linear path model for the two measurements occasion.

Results

Stroop improved significantly more in women and participants in the low compliance subgroup who received PTCT than in counterparts in the PT subgroup (difference –8.758, p = 0.001 and difference –8.405, p = 0.010, respectively). In addition, TMT B improved after the intervention in the low compliance PTCT subgroup and worsened in the corresponding PT subgroup (difference –15.034, p = 0.032). No other significant associations were observed.

Conclusion

Executive functions in women and in the participants, who only occasionally engaged in training showed greater improvement after the PTCT than PT intervention. However, the additional extra benefit gained from the PTCT intervention was uniquely expressed in each executive function measured in this study.
Fluctuation of depressive symptoms in cognitively unimpaired participants and the risk of mild cognitive impairment 5 years later: Results of the Heinz Nixdorf Recall study
Authors: Jokisch Martha , Schramm Sara , Weimar Christian , Moebus Susanne , Gronewold Janine , Dragano Nico , Jöckel Karl-Heinz
Published: October 2022

Background

Depression might be an independent risk factor for cognitive decline, a prodromal dementia symptom or a reaction to cognitive/functional impairment.

Objective

To investigate the association between (1) depressive symptoms and (2) depressive symptom patterns over 13 years with incident mild cognitive impairment (MCI) 5 years later.

Materials and methods

We included 724/823 cognitively unimpaired men/women who participated in the population-based Heinz Nixdorf Recall study (t1: 2005–2008, ø62.9 years; t2: 2010–2015, ø68.1 years). Depressive symptoms were assessed in the study center and during six postal follow-ups using the short form of the Center for Epidemiologic Studies Depression Scale (CES-D). Relative risks (RR; 95% confidence intervals) for MCI at t2 (men/women: 71/76) were estimated for CES-D at t1 (linear and dichotomized at ≥17, cut-off for clinically relevant depressive symptoms) and CES-D fluctuations over 13 years (stable low, large fluctuations, stable high/stable around cut-off) using log-linear regression models with Poisson working likelihood adjusted for age, sex, education, diabetes mellitus, coronary heart disease, and stroke.

Results

Fully adjusted risk for MCI at t2 (per CES-D point increase at t1) was elevated for the total cohort (1.053, 1.031–1.076), men (1.046, 1.012–1.081), and women (1.059, 1.029–1.090). Applying the dichotomized CES-D, risk for MCI was substantially increased for the total cohort [2.22 (1.38–3.58)] and in women [2.59 (1.46–4.58)]. Large CES-D fluctuations and stable high/stable around cut-off were associated with increased RR for MCI in the total cohort and in women compared to stable low symptoms.

Conclusion

Depressive symptoms predicted MCI in cognitively unimpaired participants of our population-based study. Adequate treatment of depression may therefore contribute to the maintenance of normal cognition and delay dementia onset.