bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypothalamic kinin B1 receptor mediates orexin system hyperactivity in neurogenic hypertension
Authors: Parekh Rohan Umesh , White Acacia , Leffler Korin E. , Biancardi Vinicia C. , Eells Jeffrey B. , Abdel-Rahman Abdel A. , Sriramula Srinivas
Published: October 2021

Brain orexin system hyperactivity contributes to neurogenic hypertension. We previously reported upregulated neuronal kinin B1 receptor (B1R) expression in hypertension. However, the role of central B1R activation on the orexin system in neurogenic hypertension has not been examined. We hypothesized that kinin B1R contributes to hypertension via upregulation of brain orexin-arginine vasopressin signaling. We utilized deoxycorticosterone acetate (DOCA)-salt hypertension model in wild-type (WT) and B1R knockout (B1RKO) mice. In WT mice, DOCA-salt-treatment increased gene and protein expression of orexin A, orexin receptor 1, and orexin receptor 2 in the hypothalamic paraventricular nucleus and these effects were attenuated in B1RKO mice. Furthermore, DOCA-salt- treatment increased plasma arginine vasopressin levels in WT mice, but not in B1RKO mice. Cultured primary hypothalamic neurons expressed orexin A and orexin receptor 1. B1R specific agonist (LDABK) stimulation of primary neurons increased B1R protein expression, which was abrogated by B1R selective antagonist R715 but not by the dual orexin receptor antagonist, ACT 462206, suggesting that B1R is upstream of the orexin system. These data provide novel evidence that B1R blockade blunts orexin hyperactivity and constitutes a potential therapeutic target for the treatment of salt-sensitive hypertension.
Sex-specific associations of body composition measures with cardiac function and structure after 8 years of follow-up
Authors: Remmelzwaal Sharon , Beulens Joline W. J. , Elders Petra J. M. , Stehouwer Coen D. A. , Handoko M. Louis , Appelman Yolande , van Empel Vanessa , Heymans Stephane R. B. , van Ballegooijen A. Johanne
Published: October 2021

We investigated the prospective associations of body composition with cardiac structure and function and explored effect modification by sex and whether inflammation was a mediator in these associations. Total body (BF), trunk (TF) and leg fat (LF), and total lean mass (LM) were measured at baseline by a whole body DXA scan. Inflammatory biomarkers and echocardiographic measures were determined both at baseline and follow-up in the Hoorn Study (n = 321). We performed linear regression analyses with body composition measures as determinant and left ventricular ejection fraction (LVEF), left ventricular mass index (LVMI) or left atrial volume index (LAVI) at follow-up as outcome. Additionally, we performed mediation analysis using inflammation at follow-up as mediator. The study population was 67.7 ± 5.2 years and 50% were female. After adjustment, BF, TF and LF, and LM were associated with LVMI with regression coefficients of 2.9 (0.8; 5.1)g/m2.7, 2.3 (0.6; 4.0)g/m2.7, 2.0 (0.04; 4.0)g/m2.7 and − 2.9 (− 5.1; − 0.7)g/m2.7. Body composition measures were not associated with LVEF or LAVI. These associations were not modified by sex or mediated by inflammation. Body composition could play a role in the pathophysiology of LV hypertrophy. Future research should focus on sex differences in regional adiposity in relation with diastolic dysfunction.
The influence of gestational weight gain after bariatric procedures on selected pregnancy outcomes: a single center study
Authors: Walędziak Maciej , Kacperczyk-Bartnik Joanna , Bartnik Paweł , Czajkowski Krzysztof , Kwiatkowski Andrzej , Różańska-Walędziak Anna
Published: October 2021

Pregnancy after bariatric surgery is known to be associated with a higher risk of small for gestational age infants (SGA) and maternal anemia. 71 patients with a history of bariatric surgery, who had at least one pregnancy ended with a delivery of a single live-born neonate after the bariatric surgery were included in the study. The main endpoints were gestational weight gain (GWG), GWG as % of the maternal weight at the beginning of pregnancy (GWG%), maternal anemia, SGA and large for gestational age infants (LGA), neonatal intensive care unit admission (NICU). GWG% was 23.8% ± 14.1 in the LGA group vs 13.9% ± 11.0 in the normal weight neonates group; p < 0.03. Patients diagnosed with anemia before pregnancy had higher GWG% than patients without pre-pregnancy anemia (20.1% ± 11.1 vs 13.4% ± 11.6); p < 0.05. GWG% was higher in patients, whose infants were admitted to NICU (25.3% ± 17.6 vs 14.1% ± 11.0; p < 0.04). GWG% can be considered a risk predictor of the LGA and NICU admissions in bariatric patients. Anemia diagnosed before pregnancy is associated with higher GWG%.
Design and comparative characterization of RecA variants
Authors: del Val Elsa , Nasser William , Abaibou Hafid , Reverchon Sylvie
Published: October 2021

RecA plays a central role in DNA repair and is a main actor involved in recombination and activation of the SOS response. It is also used in the context of biotechnological applications in recombinase polymerase isothermal amplification (RPA). In this work, we studied the biological properties of seven RecA variants, in particular their recombinogenic activity and their ability to induce the SOS response, to better understand the structure–function relationship of RecA and the effect of combined mutations. We also investigated the biochemical properties of RecA variants that may be useful for the development of biotechnological applications. We showed that Dickeya dadantii RecA (DdRecA) had an optimum strand exchange activity at 30 °C and in the presence of a dNTP mixture that inhibited Escherichia coli RecA (EcRecA). The differences between the CTD and C-tail of the EcRecA and DdRecA domains could explain the altered behaviour of DdRecA. D. radiodurans RecA (DrRecA) was unable to perform recombination and activation of the SOS response in an E. coli context, probably due to its inability to interact with E. coli recombination accessory proteins and SOS LexA repressor. DrRecA strand exchange activity was totally inhibited in the presence of chloride ions but worked well in acetate buffer. The overproduction of Pseudomonas aeruginosa RecA (PaRecA) in an E. coli context was responsible for a higher SOS response and defects in cellular growth. PaRecA was less inhibited by the dNTP mixture than EcRecA. Finally, the study of three variants, namely, EcPa, EcRecAV1 and EcRecAV2, that contained a combination of mutations that, taken independently, are described as improving recombination, led us to raise new hypotheses on the structure–function relationship and on the monomer–monomer interactions that perturb the activity of the protein as a whole.
Predicting kinetics of water-rich permeate flux through photocatalytic mesh under visible light illumination
Authors: Shrestha Bishwash , Ezazi Mohammadamin , Rad Seyed Vahid , Kwon Gibum
Published: October 2021

Membrane-based separation technologies are attractive to remediating unconventional water sources, including brackish, industrial, and municipal wastewater, due to their versatility and relatively high energy efficiency. However, membrane fouling by dissolved or suspended organic substances remains a primary challenge which can result in an irreversible decline of the permeate flux. To overcome this, membranes have been incorporated with photocatalytic materials that can degrade these organic substances deposited on the surface upon light illumination. While such photocatalytic membranes have demonstrated that they can recover their inherent permeability, less information is known about the effect of photocatalysis on the kinetics of the permeate flux. In this work, a photocatalytic mesh that can selectively permeate water while repelling oil was fabricated by coating a mixture of nitrogen-doped TiO2 (N-TiO2) and perfluorosilane-grafted SiO2 (F-SiO2) nanoparticles on a stainless steel mesh. Utilizing the photocatalytic mesh, the time-dependent evolution of the water-rich permeate flux as a result of photocatalytic degradation of the oil was studied under the visible light illumination. A mathematical model was developed that can relate the photocatalytic degradation of the organic substances deposited on a mesh surface to the evolution of the permeate flux. This model was established by integrating the Langmuir–Hinshelwood kinetics for photocatalysis and the Cassie–Baxter wettability analysis on a chemically heterogeneous mesh surface into a permeate flux relation. Consequently, the time-dependent water-rich permeate flux values are compared with those predicted by using the model. It is found that the model can predict the evolution of the water-rich permeate flux with a goodness of fit of 0.92.
Inferior survival outcomes of pancreas transplant alone in uremic patients
Authors: Shyr Bor-Uei , Shyr Bor-Shiuan , Chen Shih-Chin , Shyr Yi-Ming , Wang Shin-E.
Published: October 2021

Theoretically, pancreas transplant alone in uremic (PTAU) patients could also be one of the options for those waiting for both pancreas and kidney grafts, but it has never been reported. There were 160 cases of pancreas transplant in this study, including 16% PTAU. The 5-year patient survival was 66.2% after PTAU, 94.5% after SPK, 95.8% after PAK, and 95.4% after PTA. Rejection of pancreas graft was significantly lower in PTAU group (3.8%), followed by 16.7% in pancreas after kidney transplant (PAK), 29.8% in simultaneous pancreas and kidney transplant (SPK) and 37.0% in pancreas transplant alone (PTA). Fasting blood sugar and serum HbA1c levels after PTAU were not significantly different from those by other subgroups. The 5-year death-censored pancreas graft survival was 100% after PTAU and PAK, and 97.0% after SPK and 77.9% after PTA. However, the 5-year death-uncensored pancreas graft survival was 67.0% after PTAU, 100% after PAK, 91.3% after SPK, and 74.0% after PTA. The superior graft survival in the PTAU group was achieved only if deaths with a functioning graft were censored. In conclusion, given the inferior patient survival outcome, PTAU is still not recommended unless SPK and PAK is not available. Although PTAU could be a treatment option for patients with diabetes complicated by end-stage renal disease (ESRD) in terms of surgical risks, endocrine function, and immunological and graft survival outcomes, modification of the organ allocation policies to prioritize SPK transplant in eligible patients should be the prime goal.
Motion cues from the background influence associative color learning of honey bees in a virtual-reality scenario
Authors: Lafon Gregory , Howard Scarlett R. , Paffhausen Benjamin H. , Avarguès-Weber Aurore , Giurfa Martin
Published: October 2021

Honey bees exhibit remarkable visual learning capacities, which can be studied using virtual reality (VR) landscapes in laboratory conditions. Existing VR environments for bees are imperfect as they provide either open-loop conditions or 2D displays. Here we achieved a true 3D environment in which walking bees learned to discriminate a rewarded from a punished virtual stimulus based on color differences. We included ventral or frontal background cues, which were also subjected to 3D updating based on the bee movements. We thus studied if and how the presence of such motion cues affected visual discrimination in our VR landscape. Our results showed that the presence of frontal, and to a lesser extent, of ventral background motion cues impaired the bees’ performance. Whenever these cues were suppressed, color discrimination learning became possible. We analyzed the specific contribution of foreground and background cues and discussed the role of attentional interference and differences in stimulus salience in the VR environment to account for these results. Overall, we show how background and target cues may interact at the perceptual level and influence associative learning in bees. In addition, we identify issues that may affect decision-making in VR landscapes, which require specific control by experimenters.
In vivo human retinal swept source optical coherence tomography and angiography at 830 nm with a CMOS compatible photonic integrated circuit
Authors: Rank Elisabet A. , Nevlacsil Stefan , Muellner Paul , Hainberger Rainer , Salas Matthias , Gloor Stefan , Duelk Marcus , Sagmeister Martin , Kraft Jochen , Leitgeb Rainer A. , Drexler Wolfgang
Published: October 2021

Photonic integrated circuits (PIC) provide promising functionalities to significantly reduce the size and costs of optical coherence tomography (OCT) systems. This paper presents an imaging platform operating at a center wavelength of 830 nm for ophthalmic application using PIC-based swept source OCT. An on-chip Mach–Zehnder interferometer (MZI) configuration, which comprises an input power splitter, polarization beam splitters in the sample and the reference arm, and a 50/50 coupler for signal interference represents the core element of the system with a footprint of only $$(12 \times 5)\;{\text {mm}}^2$$

(
12
×
5
)

mm

2

. The system achieves 94 dB imaging sensitivity with 750 $$\upmu $$
μ
W on the sample, 50 kHz imaging speed and 5.5 $$\upmu $$
μ
m axial resolution (in soft tissue). With this setup, in vivo human retinal imaging of healthy subjects was performed producing B-scans, three-dimensional renderings as well as OCT angiography. These promising results are significant prerequisites for further integration of optical and electronic building blocks on a single swept source-OCT PIC.
Attenuation model of tunnel blast vibration velocity based on the influence of free surface
Authors: Jia Baoxin , Zhou Linli , Cui Jiaojiao , Chen Hao
Published: October 2021

In tunnel blasting excavation, it is important to clarify the attenuation law of blast wave propagation and predict the blast vibration velocity effectively to ensure safe tunnel construction and protection design. The effects of the free surface area its quantity on the blast vibration velocity are considered, and free surface parameters are introduced to improve the existing blast vibration velocity prediction formula. Based on the Tianhuan railway Daqianshiling tunnel project, field blast vibration monitoring tests are performed to determine changes in the peak blasting vibration velocity based on the blast distance and free surface area. LS-DYNA is used to establish tunnel blasting excavation models under three operating conditions; subsequently, the attenuation law of blast vibration velocity and changes in the vibration response spectrum are analysed. Results show that the free surface area and number of free surfaces enable the blast vibration velocity to be predicted under various operating conditions: a smaller free surface area results in a narrower frequency band range, whereas more free surfaces result in a narrower frequency band range. The improved blast vibration velocity prediction formula is validated using field and numerical test data. It is indicated that the improved formula is applicable to various tunnelling conditions.
Development of a novel humanized mouse model for improved evaluation of in vivo anti-cancer effects of anti-PD-1 antibody
Authors: Katano Ikumi , Hanazawa Asami , Otsuka Iyo , Yamaguchi Takuya , Mochizuki Misa , Kawai Kenji , Ito Ryoji , Goto Motohito , Kagawa Takahiro , Takahashi Takeshi
Published: October 2021

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer in the clinic. Further discovery of novel drugs or therapeutic protocols that enhance efficacy requires reliable animal models that recapitulate human immune responses to ICI treatment in vivo. In this study, we utilized an immunodeficient NOG mouse substrain deficient for mouse FcγR genes, NOG-FcγR−/−mice, to evaluate the anti-cancer effects of nivolumab, an anti-programmed cell death-1 (PD-1) antibody. After reconstitution of human immune systems by human hematopoietic stem cell transplantation (huNOG-FcγR−/−mice), four different programmed death-ligand 1 (PD-L1)-positive human cancer cell lines were tested. Among them, the growth of three cell lines was strongly suppressed by nivolumab in huNOG-FcγR−/−mice, but not in conventional huNOG mice. Accordingly, immunohistochemistry demonstrated the enhanced infiltration of human T cells into tumor parenchyma in only nivolumab-treated huNOG-FcγR−/−mice. Consistently, the number of human T cells was increased in the spleen in huNOG-FcγR−/−mice by nivolumab but not in huNOG mice. Furthermore, human PD-L1 expression was strongly induced in the spleen of huNOG-FcγR−/−mice. Collectively, our results suggest that the anti-cancer effects of anti-PD-1 antibodies can be detected more clearly in NOG-FcγR−/−mice than in NOG mice.
Establishment of high-throughput screening HTRF assay for identification small molecule inhibitors of Skp2-Cks1
Authors: Hu Kaizhao , Li Xiao-Jing , Asmamaw Moges Dessale , Shi Xiao-Jing , Liu Hong-Min
Published: October 2021

S-phase kinase associated protein 2 (Skp2), a member of the F-box family that constitute the largest known class of ubiquitin E3 specificity components, is responsible for recognizing and recruiting cyclin-dependent kinase inhibitor p27 for its ubiquitination in the presence of the small accessory protein cyclin-dependent kinase regulatory subunit 1(Cks1). Skp2 is overexpressed in esophageal carcinoma tissues and closely related with tumor poor prognosis, and perturbation of the Skp2-Cks1 interaction by inhibitors or RNAi could inhibit the proliferation and metastasis of tumor cells. Therefore, inhibition of Skp2 function by small-molecule compounds targeting Skp2-Cks1 interaction is emerging as a promising and novel anti-cancer strategy. In this study, we establish an improved high-throughput screening platform to screen Skp2 inhibitors targeting Skp2-Cks1interaction, which may provide a new therapeutic approach for the clinic.
Limitations of the transmitted photonic spin Hall effect through layered structure
Authors: Miao Chong , Wang Dongxue , Herrmann Eric , Zheng Zhiyuan , Huang Haochong , Gao Hua
Published: October 2021

In this paper, we show theoretically that the spin-dependent transverse shift of the transmitted photonic spin Hall effect (SHE) through layered structure cannot exceed half of the incident beam waist. Exact conditions for obtaining the upper limit of the transmitted SHE are clarified in detail. In addition, different from the popular view in many investigations, we find that there is no positive correlation between the spin-dependent transverse displacement and the ratio between the Fresnel transmission coefficients (tp, ts). In contrast, the optimal transmission ratio is determined by the incident angle and the beam waist. Moreover, two conventional transmission structures are selected and studied in detail. The characteristics of the transverse displacements obtained are in very good agreement with our theoretical conclusions. These findings provide a deeper insight into the photonic spin Hall phenomena and offer a guide for future related research.
Prostaglandin-E2 receptor-4 stimulant rescues cardiac malfunction during myocarditis and protects the heart from adverse ventricular remodeling after myocarditis
Authors: Takakuma Akira , Nishii Mototsugu , Valaperti Alan , Hiraga Haruto , Saji Ryo , Sakai Kazuya , Matsumura Reo , Miyata Yasuo , Oba Nozomu , Nunose Fumiya , Ogawa Fumihiro , Tamura Kouichi , Takeuchi Ichiro
Published: October 2021

Cardioprotective effect of prostaglandin-E2 receptor-4 (EP4) stimulation on the ischemic heart has been demonstrated. Its effect on the heart affected by myocarditis, however, remains uncertain. In this study, we investigated therapeutic effect of EP4 stimulant using a mouse model of autoimmune myocarditis (EAM) that progresses to dilated cardiomyopathy (DCM). EP4 was present in the hearts of EAM mice. Treatment with EP4 agonist (ONO-0260164: 20 mg/kg/day) improved an impaired left ventricular (LV) contractility and reduction of blood pressure on day 21, a peak myocardial inflammation. Alternatively, DCM phenotype, characterized by LV dilation, LV systolic dysfunction, and collagen deposition, was observed on day 56, along with activation of matrix metalloproteinase (MMP)-2 critical for myocardial extracellular matrix disruption, indicating an important molecular mechanism underlying adverse ventricular remodeling after myocarditis. Continued treatment with ONO-0260164 alleviated the DCM phenotype, but this effect was counteracted by its combination with a EP4 antagonist. Moreover, ONO-0260164 inhibited in vivo proteolytic activity of MMP-2 in association with up-regulation of tissue inhibitor of metalloproteinase (TIMP)-3. EP4 stimulant may be a promising and novel therapeutic agent that rescues cardiac malfunction during myocarditis and prevents adverse ventricular remodeling after myocarditis by promoting the TIMP-3/MMP-2 axis.
Synthetic amorphous calcium phosphates (ACPs): preparation, structure, properties, and biomedical applications
Authors: Dorozhkin Sergey V.
Published: October 2021

Amorphous calcium phosphates represent a metastable amorphous state of other calcium orthophosphates possessing variable compositional but rather identical glass-like physical properties.
An intrinsically thermogenic nanozyme for synergistic antibacterial therapy
Authors: Sun Caixia , Wang Wenqian , Sun Xiaolian , Chu Weihua , Yang Jun , Dai Jianjun , Ju Yanmin
Published: October 2021

An enzymatic antibacterial strategy based on yolk–shell Fe2C@Fe3O4thermogenic nanozymes.
Procyanidin A1 and its digestive products prevent acrylamide-induced intestinal barrier dysfunction via the MAPK-mediated MLCK pathway
Authors: Yan Fangfang , Chen Wanbing , Zhao Li , Lu Qun , Wang Chengming , Liu Rui
Published: October 2021

The mechanism of procyanidin A1 and its digestive products in inhibiting acrylamide-induced intestinal barrier damage.
Microstructural details of spindle-like lithium titanium phosphate revealed in three dimensions
Authors: Zhang Qian , Schierholz Roland , Dzieciol Krzysztof , Yu Shicheng , Tempel Hermann , Kungl Hans , Eichel Rüdiger-A.
Published: October 2021

The microstructure of spindle-like LiTi2(PO4)3 particles was investigated on the nanoscale in three dimensions by a combination of FIB-SEM tomography with (S)TEM-EDS and -EELS.
Vertically oriented mesoporous silica film modified fluorine-doped tin oxide electrode for enhanced electrochemiluminescence detection of lidocaine in serum
Authors: Liang Renchuan , Jiang Jinghang , Zheng Yanyan , Sailjoi Ajabkhan , Chen Jie , Liu Jiyang , Li Hongxue
Published: October 2021

Sensitive detection of lidocaine in serum is realized using enhanced electrochemiluminescence based on a vertically oriented mesoporous silica film modified fluorine-doped tin oxide electrode.
Estimation of rolling work of adhesion at the nanoscale with soft probing using optical tweezers
Authors: Lokesh Muruga , Vaippully Rahul , Nalupurackal Gokul , Roy Srestha , Bhallamudi Vidya P. , Prabhakar Anil , Roy Basudev
Published: October 2021

Conventionally, the work of adhesion at the nanoscale is estimated using an atomic force microscope with a tip of the size of 10 nm.
Americium preferred: lanmodulin, a natural lanthanide-binding protein favors an actinide over lanthanides
Authors: Singer Helena , Drobot Björn , Zeymer Cathleen , Steudtner Robin , Daumann Lena J.
Published: October 2021

In need of environmentally friendly methods for the separation and recycling of lanthanides and actinides, the binding of the protein lanmodulin to lanthanides and actinides was studied using time resolved laser induced fluorescence spectroscopy.
Hydrogenated anatase TiO2 single crystals: defects formation and structural changes as microscopic origin of co-catalyst free photocatalytic H2 evolution activity
Authors: Will Johannes , Wierzbicka Ewa , Wu Mingjian , Götz Klaus , Yokosawa Tadahiro , Liu Ning , Tesler Alexander B. , Stiller Markus , Unruh Tobias , Altomare Marco , Schmuki Patrik , Spiecker Erdmann
Published: October 2021

A model identifying defects formation and structural as well as chemical changes as crucial parameters for a co-catalyst free photocatalytic H2 evolution activity in epitaxial grown anatase single crystals is presented.
Pt current collectors artificially boosting praseodymium doped ceria oxygen surface exchange coefficients
Authors: Ma Yuxi , Burye Theodore E. , Nicholas Jason D.
Published: October 2021

Here, Pt current collectors were shown to dramatically increase the oxygen surface exchange coefficient (kchem) of Pr0.1Ce0.9O2−x, suggesting they are likely responsible for a significant portion of the kchem variation in the literature.
A self-preserving pitted texture enables reversible topographic evolution and cycling on Zn metal anodes
Authors: Xu Yuanlin , Wang Chen , Shi Yu , Miao Guoxing , Fu Jing , Huang Yunhui
Published: October 2021

A self-preserving pitted texture with a high depth-to-width ratio enables reversible topographic evolution, uniform electrodeposition, and reversible cycling on Zn metal anodes.
A rational study of the influence of Mn2+-insertion in Prussian blue nanoparticles on their photothermal properties
Authors: Cahu Maëlle , Ali Lamiaa M. A. , Sene Saad , Long Jérôme , Camerel Franck , Ciancone Mathieu , Salles Fabrice , Chopineau Joël , Devoisselle Jean-Marie , Felix Gautier , Cubedo Nicolas , Rossel Mireille , Guari Yannick , Bettache Nadir , Larionova Joulia , Gary-Bobo Magali
Published: October 2021

NazMnxFe1−x[Fe(CN)6]1−y□y·nH2O nanoparticles with various amounts of Mn2+ were synthesized and their in vitro and in vivo photothermal properties studied.
A new insight into the ZIF-67 based triboelectric nanogenerator for self-powered robot object recognition
Authors: Hajra Sugato , Sahu Manisha , Padhan Aneeta Manjari , Swain Jaykishon , Panigrahi Basanta Kumar , Kim Hang-Gyeom , Bang Sang-Won , Park Sukho , Sahu Rojalin , Kim Hoe Joon
Published: October 2021

The ZIF-67 based additively manufactured triboelectric nanogenerator to shed light upon the room temperature solvent assisted synthesis, physiochemical properties and self-powered robot object detection.
Statistical descriptive analysis of three climate variables; Precipitation, temperature and relative humidity. Study cases (Innaouene watershed; Morocco)
Authors: Moumen Zineb , Elhassnaoui Ismail , Daid Fatima
Published: October 2021

Hydrological data are mandatory for the elaboration of studies related to water management. Statistical analysis is a crucial step for the grasping of the distribution of data range. The presented study consists on applying statistical descriptive analysis on three climate variable; precipitation, temperature and relative humidity. Two gages stations were used; Bab Marzouka and Idriss First in Innaouène watershed. The obtained results underlines that the temporal variation exposes an overall rising trend in the temperature and a decreasing trend in the rainfall and relative humidity over the fours studied decades, it also uncovers the intra-seasonal fluctuation, humid and rainy in the winter and sec and dry in the summer, the autumn and the spring are considered as transition season where the temperature is moderated. The spatial variation is marked by a slight decreasing in precipitation and increasing of temperature moving from the middle part of the watershed to the downstream, which could be explained by the topographic variation and its impact on the climate. High altitude are generally marked by high precipitation and lower temperature comparing to lowlands areas.
Effect of the main active volcanoes on aerosol optical properties
Authors: Meziane Rajae , Diouri Mohammed , Ben-tayeb Abdelmoula , Steli Hanae , Salhi Ouassila
Published: October 2021

Processing of the measurements obtained by the AERONET network of the optical parameters characteristic of the atmospheric aerosol carried out makes it possible to compare the optical effects of 2020 volcanic eruptions to those results for 2019 concerning Mexico City and Mauna Loa site. Both the monthly spectral means of AOD and the monthly means of fine and coarse volume concentration show an increase for the months of January and February 2020 (Volcanic eruption period) compared to the same period in 2019 at Mexico City. Those corresponding to Mauna-Loa seem not sensible with very low values. The effects of ashes of the two-studied volcano are very different, led to a low increase in optical depth comparatively to the contribution of anthropogenic aerosol at MexicoCity (low continental spread) and led to a nonsignificate effect at Mauna-Loa (high marine spread).
Application of the HEC-HMS hydrological model in the Beht watershed (Morocco)
Authors: Daide Fatima , Afgane Rachida , Lahrach Abderrahim , Chaouni Abdel-Ali , Msaddek Mohamed , Elhasnaoui Ismail
Published: October 2021

This work focused on the collection and preparation of the data required for the hydrological modelling of the Beht catchment area, which covers an area of 4560 km2 with a perimeter of 414 km, by combining the various spatial technologies, in particular geographical information systems (GIS), remote sensing, and digital terrain models (DTM), with hydrological models in order to prepare for spatial hydrological modelling used for flood forecasting. The methodology consists, at first, in the automatic extraction of the sub-basins and the drainage network. Then, edit these data using the HEC-GEO-HMS extension, and the preparation of the land use and land cover data for the elaboration of a Curve Number (CN) map of Beht watershed, then the import of the basin model into the Hydrologic Modeling System (HEC-HMS) to simulate the surface runoff using six extreme daily time series events.
Sorption of bisphenol A from aqueous solutions using natural adsorbents: isotherm, kinetic and effect of temperature
Authors: Hadoudi Nouhaila , Amhamdi Hassan , Ahari M’hamed
Published: October 2021

Emerging organic micropollutants, such as bisphenol A (BPA), have raised concerns about their negative impact on human health and ecological safety. This review article aims to demonstrate and highlight recent advances in adsorption applications for bisphenol A, a toxic environmental pollutant commonly found in wastewater. There are many reasons to use non-toxic materials and eco-friendly technologies to remove this pollutant from sewage. [1] Several adsorbents previously used have shown significant efficiency and performance for the removal of BPAs, and current research is directed towards the development of low-cost treatment processes using materials such as clays and Chitosan. The properties of the adsorbent can be adjusted by changing their surface for an optimized performance. In addition, the efficiency of the adsorption process depends on various parameters such as solution pH, the pollutant concentration, contact time, temperature, nature and dose of the adsorbent, which are also discussed. In addition, we critically review the isothermal, kinetic and thermodynamic approaches. [2]
Development of Resource-Saving Technological Processes for Manufacturing Rings by the Compression Method
Authors: Lavrinenko V. Yu. , Polyakov A. O.
Published: October 2021

Based on the developed methodology for designing technological processes for producing annular parts by compression, we developed technological processes for manufacturing parts "Flange" and "Thrust ring", which make it possible to increase the material utilization factor (MUF) and reduce material consumption. A comparative analysis of MUF in the manufacture of annular parts by cutting and punching rings with cutting and punching of an oval workpiece and subsequent compression.
Investigation of the Pipe Weld for Brittle Metal Fracture
Authors: Kulnevich V.B. , Mal’kova E.V.
Published: October 2021

The article presents the results of studies of artificial strain aging of pipe steels. The effect of deformation aging on the mechanical properties of steel during tensile tests has been determined.
Experimental Study of Features of Thin-Walled Pipes Sizing in the Line of a Pipe Rolling Plant with an Automatic Mill
Authors: Belyaev S.Yu. , Fedulov A.A. , Chernyshev Yu.M. , Kuznetsov V.I. , Bulganina M.Yu.
Published: October 2021

The aim of the study is to establish the actual level of working loads on the roll drive line of the sizing mill installed as part of the PRP-220 with an automatic mill, when switching to the production of steel pipes from increased strength group. The study is based on a complex experimental and theoretical analysis. After the processing of the results of experimental studies a comparison of the most loaded sizing route for a thin-walled pipe with a diameter of 244.5 mm and a wall thickness of 8.9 mm (D/S = 27.5) made of steel of strength group “D” was made with the route for a pipe with a diameter of 177.8 mm and a wall thickness of 9.2 mm (D/S = 19.3) from steel of strength group “E”. Graphs of the observed processes are presented, as well as calculated predictive values of sizing of thin-walled pipes for steel of strength group “E”, obtained on the basis of an experimental-theoretical analysis of the growth of flow stress. Recommendations have been given for improving the equipment of the PRP-220 sizing mill for the production of pipes with increased diameters from steels of increased strength groups.
New Composite Materials With a “Liquid” Matrix
Authors: Kosenko Ekaterina , Nelyub Vladimir
Published: October 2021

A new polymer composite material composed of a fibre reinforced filler and two types of matrices: thermosetting (epoxy) and elastomeric (organosilicon) is introduced. The main purpose of the elastomeric matrix is stress relaxation and slowdown and prevention of crack growth in the composite material under dynamic loads, including bending and delamination. In this study, a finite element model of such composite is developed and its stress-strain state is calculated depending on the elastic characteristics of the elastomer. It was established that the addition of an elastomeric matrix in the composite allows to stop the crack growth, and significantly increase the durability of such materials.
Analysis of Wear-Resisting Properties of a Sintered Sample Obtained from Steel X13 Machined Using EDM
Authors: Ageev E.V. , Khardikov S.V. , Loktionova O.G. , Kolmykov V.I.
Published: October 2021

The article presents the results of a study of the wear resistance of sintered specimens from electroerosive powder of steel X13, obtained in butyl alcohol. The friction coefficient was 0.950, the width of the wear groove was 455.9 µm, the depth of the wear groove was 6 µm, the wear factor of the sample was 1.676x10-6 mm3 N-1m-1.
Electric Spark Alloying of Radiant Coils for Pyrolysis Furnaces
Authors: Taymarov Mikhail , Saltanaeva Elena
Published: October 2021

Currently, the petrochemical industry uses furnaces to produce ethylene, the main element of which is radiant coils designed for the decomposition of straight-run gasoline into pyrolysis gas, which is the main product for producing ethylene. In radiant coils, the gasoline decomposition process must take place at a temperature of about 800 °C with a high heating rate in order to avoid coking of the coils. Heat is supplied by radiation from the inner lining of the furnaces heated by the flame of flat-flame gas burners. For radiant heat transfer to occur, the surface of the coils must have a high degree of blackness. This article presents the developed technology for coating heating surfaces with shungite and the results of increasing their emissivity to intensify radiant heat transfer. Measurements of the emissivity after electrospark alloying were carried out by the radiation method, according to which, according to Kirchhoff’s law, the emissivity is equal to the emissivity at equal temperatures.
Multifractal Formalism in Tasks of Dynamic Plasticity
Authors: Kuznetsov Aleksander , Savenkov Georgii , Stolyarov Vladimir
Published: October 2021

The application of the multifractal parameterization method for comparing structural changes observed in an optical microscope on steel St.3 subjected to severe plastic deformation and high-rate superplastic deformation is investigated.
Risk Analysis is a Prerequisite for Quality Management of Traction Rolling Stock Repairs
Authors: Gaponov Vladimir , Kuznetsov Dmitriy , Khvostikov Andrey , Alekhin Roman
Published: October 2021

The paper considers a new version of IRIS ISO/TS 22163:2017 standard in relation to the quality of repair of complex equipment in the railway industry. It is shown that the new version of ISO/ TS 22163:2017 standard provides for the need of organizations to conduct risk analysis and accounting in their work. The authors propose to consider as an example a well-established analysis of the types and consequences of potential defects in FMEA process. The use of FMEA analysis made it possible to consider the significance of various risks of the quality of traction rolling stock repair, as well as to establish the importance of quality control operations for impregnation of a traction motor.
Development of Construction and Repair Materials Used in Transport and Technological Machines Operating in the Arctic
Authors: Kosenko Ekaterina , Baurova Natalia , Zorin Vladimir , Konoplin Alexander
Published: October 2021

Increasing the pace of development of the Arctic zone, among other tasks, requires the attraction of significant production resources to improve the transport network, in particular, road construction equipment and technological equipment. Extreme climatic conditions, including low air temperatures and strong winds, are features of the Arctic zone. In this regard, there is a need to form a methodological basis for the development of construction and repair materials for use in the Arctic. To solve this problem, based on the results of mechanical tests at temperatures of +20°C, -30°C and -50°C, the possibility of using carbon fiber plastics with various types of hybrid matrices for the manufacture of mechanical engineering products operating in extreme conditions of the Arctic and the creation of reinforcing linings during their repair. The indicators of manufacturability during repairs under the conditions of constant exposure to negative temperatures using polymeric materials are considered.
The Potential Contamination Scenarios simulation in Case of the Water Chlorination Technological Process Violation in the Urban Environment
Authors: Lapshina Irina , Usenko Olga , Zhidkova Alena
Published: October 2021

The research raise the question of the need to analyse and model the processes associated with the emission of the emergency-chemical hazardous substance (ECHS) in the urban environment. Because the assessment of the environmental pollution, the early and prompt prediction of the scale of contamination in the event of releases is the potent poisonous substance (PPS) into the environment in case of accidents (destructions) at chemically hazardous facilities remains an urgent issue. We emphasize that in order to ensure the life of any settlement, there is a need for the availability of drinking water that meets sanitary standards and hygienic rules. Chlorination is traditionally used in most of the country's settlements. To take timely measures to eliminate accidents with the emission of chlorine, the most accurate results of calculating the main indicators are necessary, such as the depth of the zone of contamination of PPS, the amount of the poisonous substance in primary and secondary clouds, the area of contamination, etc. The method of calculating these indicators is based on the use of reference tables and the coefficient method, which are convenient enough for the manual method. However, in emergencies, when serious threats to the life and health of people arise, and the situation can deteriorate rapidly, there is an acute shortage of time for a general assessment of the situation, making decisions on the organization of the rescue measures. It is obvious that the staff simply will not have enough time for scrupulous calculations, and a stressful situation, in addition, with a high degree of probability will provoke serious errors and inaccuracies.
Investigation of the Causes of Premature Failure of the Suspension and Brake System of Buses “Volgabus”
Authors: Popov A. V. , Chernova G. A. , Velikanova M. V. , Khvan N. S.
Published: October 2021

The article gives a performance measurement ofthe suspension and brake system of buses “Volgabus-5270GH” on the basis of bus removals with different mileage values. Scheduled maintenance and repair system implies the elimination of buses removals and repair works between MO1 (MO - Maintenance Operations) and MO2. The authors have analysed malfunctions in the suspension and brake system. Based on many researches, it has been established that the resource of components and parts of the vehicles in kilometers of run, under proper operation, obeys the law of normal distribution. It has been determined that premature buses removals are also possible under condition of high-quality manufacturing and timely performance of maintenance with the influence of operating factors of the route network of the town Volzhsky. The analysis of bus driving modes on the main routes and their possible connection with the suspension and brake system failures has been carried out. Recommendations are given to improve the performance of the buses.
Developing an Algorithm for Selecting Experts That Determine Technical Characteristics of Technological Equipment
Authors: Feofanov A.N. , Busheva A.G.
Published: October 2021

This article discusses the main ways of selecting candidates for expert groups. The qualities necessary for an expert are indicated. Questionnaires have been developed, the answers to which will help to form a database of candidates. An algorithm is presented, with the help of which experts are selected according to given conditions.
Numerical Simulation of Conjugate Heat Exchange at Gas Flowing in a Well
Authors: Al’es Michael , Makarov Sergey , Karpov Alexandr
Published: October 2021

A mathematical model is offered for conjugate heat exchange when gas flows in the section of a vertical well. The motion of the medium is described using a two-dimensional axisymmetric stationary formulation based on boundary-layer equations. The turbulent gas flowing due to the reservoir energy is considered. Natural gas is taken as a travelling medium. The numerical simulation results are presented in the form of the dependences of the flow temperature and gas density along the radius of the well on the external factors of the heat exchange changing along the well height. The results describe the thermobaric state of the well in the condition of the conjugate heat exchange of the produced natural gas flow and tubed well depending on the external thermal conditions.
The choice of Methods of Dynamic Errors Compensation in Motion Control of Elastic Mechatronic Systems
Authors: Kuznetsov N. K. , Iov I. A. , Iov A. A. , Dolgih E. S.
Published: October 2021

In this paper, using the example of a two-mass calculation scheme, which can be used to describe the dynamic properties of many mechatronic systems with elastic elements, we present the results of research on finding control actions that provide compensation of dynamic errors based on solving the inverse dynamic problems according to a given law of change of the force in an elastic element. It is shown that the found control actions in the form of time dependences make it possible not to impose any restrictions on the methods of their technical implementation and thereby provide a comprehensive solution the problem of compensating for dynamic errors caused by elastic deformations of mechanical elements.
Development of a Lever Mechanism for Loading a Suspended Conveyor
Authors: Kutlubaev Ildar , Macko Elena , Usov Igor , Panfilova Olga
Published: October 2021

The issue of mechanization of hanging of long components of self-installing rock bolt (SIRB) type has been considered. The possibility of usage of slider-crank mechanism for these purposes has been proved. Linear dimensions of lever mechanism that meet the requirements defined by the applied motor and SIRB parameters have been determined on the ground of parametric synthesis. The performed force analysis has proved the application of fluid power drive.
System Analysis and Solution of Energy Efficiency Problems in Machine-Building Production
Authors: Gavrilova A.A. , Matveeva E.A. , Salov A.G.
Published: October 2021

The article discusses application of system analysis to identify and solve the problems of energy efficiency of machine-building enterprises. The increase in the efficiency of a machine-building enterprise is influenced by many factors, among which tariffs and prices for energy services have a significant impact. The increase in tariffs for these services has a direct impact on the increase in cost. Energy efficiency objectives also include: high energy capacity of products; insufficient efficiency of generation, transportation and distribution of energy resources; low reliability of power supply; insufficient volume or low reliability of information on the energy infrastructure operation. As a result of the system analysis, directions have been identified that enable one to increase energy efficiency, which leads to a decrease in the cost of production, and, consequently, to an increase in the profit of the enterprise. Directions for increasing the energy efficiency of machine-building enterprises can be identified as a result of system studies of the activities of all divisions of the main, auxiliary and service industries. The greatest effect from energy-saving measures is achieved in the process of rational energy consumption, which is advisable to implement at machine-building enterprises. Reduced production output caused by the global economic crisis that began in 2008 and the impact of the 2020-2021 pandemic have resulted in the equipment operation at reduced loads and in off-design modes, which in turn has led to the auxiliary equipment consuming almost the same amount of energy as at nominal performance. This circumstance leads to an increase in costs. A mathematical model has been developed, in which a machine-building enterprise is considered as a set of functional elements and components with a hierarchical structure of connections between them, described in the form of a ‘6-tuple’.
Kinematics of the Maneuver of the Multifunctional Machine for Metallurgical Furnaces
Authors: Mityushov Evgeny , Zinovich Egor , Kosulin Maxim
Published: October 2021

The article proposes a simulation model of a loading machine for metallurgical furnaces and builds a mathematical model that makes it possible to find optimal trajectories of motion and obtain laws of change in kinematic, dynamic and inertial characteristics for a full operation cycle. The description of the machine motion is made taking into account the nonholonomy of the imposed connections and provides for the possibility of considering arbitrary laws of motion along optimal trajectories. Compliance with optimal working conditions is also ensured by the choice of a special law of motion between the nodal points on the trajectory of movement, corresponding to the change in the direction of movement of the loading machine. Based on the research results, a design scheme and a simulation model with an analytical description of the mechanism operation, including kinematic graphs, are proposed. A simulation model of a loading machine for metallurgical furnaces and a description of its operation modes are made by methods of analytical mechanics.
Scientific and Technical Aspects of Interference Fits Hydropress Assembling Automation Using Mechatronic Press
Authors: Romanov Alexander , Shchenyatsky Alexey , Zorina Oxana
Published: October 2021

The study object - technological process of interference fits assembling is identified, the scheme with oil supply from the end face is adopted as the technological scheme. Technological pressing equipment is considered, its applicability for hydropress assembling is evaluated. The main aspects of hydropress joints assembling on a base of mechatronic press are established: increasing of assembling performance, its stability. Mathematical models and an algorithm that regulate the process of liquid friction and formation of an oil layer between the contacting surfaces of joint mating parts are developed. The basic requirements for the regulation channels of control system that ensure the quality of hydropress fits during automated assembling are established.