bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequency of thyroid disorders in patients with menstrual irregularities presenting to the OPD in tertiary care hospital.
Authors: Nousheen Irshad  , Shazia Naseeb  , Saira Shaikh  , Sanoober Kazi  , Shighraf Iftikhar  , Adiya Dossal
Published: April 2024

Objective: To determine the frequency of thyroid disorders in patients with menstrual irregularities presenting to the OPD in tertiary care hospital. Study Design: Cross Sectional study. Setting: Department of Outpatients Obstetrics & Gynaecology, Ward 8, Jinnah Postgraduate Medical Center, Karachi, Pakistan. Period: July 30, 2021 to January 29, 2022. Methods: All patients who met the inclusion criteria and visited JPMC, Karachi were enrolled in the study. After providing a thorough explanation of the procedure, risks, and benefits of the study, informed consent was obtained. The study involved conducting detailed history and examination, as well as recommending relevant laboratory investigations such as thyroid and ultrasound pelvic/TVS profiles. Results: 150 women of thyroid disorders in patients with menstrual irregularities were included with mean age was 33.72±7.62 years, mean height was 1.69±0.07 meter, mean weight was 76.60±12.70 kg, mean BMI was 26.78±4.13 kg/m2, mean parity was 2.84±2.05 and mean duration of menstrual irregularity was 0.82±0.07 days. Positive family history of thyroid disorder was found to be in 15 (10.0%). Positive history of thyroid surgery was noted in 26 (17.3%) patients. Thyroid disorder was noted in 57 (38.0%) cases. In distribution for type of thyroid disorder, subclinical hypothyroidism was noted in 37 (64.9%), 9 (15.8%) overt hypothyroidism, 11 (19.3%) subclinical hyperthyroidism while overt hyperthyroidism was noted in 0 (0.0%). In distribution of menstrual complain, amenorrhea was noted in 3 (5.3%), 3 (5.3%) oligomenorrhea, 7 (12.3%) metrorrhagia, 32 (56.1%) menorrhagia while polymenorrhea were noted in 12 (21.1%) cases. Conclusion: It is to be concluded that thyroid disorder is frequently observed in patients experiencing menstrual irregularities, as indicated by the study. However, further research is required to validate these finding.
Frequency of hospital acquired malnutrition at a tertiary care pediatric hospital.
Authors: Hina Rajani  , Misbah Anjum
Published: April 2024

Objective: To determine the frequency of hospital acquired malnutrition in hospitalized pediatric population. Design: Cross-sectional study. Setting: Department of Pediatrics, National Institute of Child Health, Karachi, Pakistan. Period: January 2023 to June 2023. Methods: The inclusion criteria were children (irrespective of gender) aged between 1 and 12 years who were admitted for at least 48 hours. Weight of the children was measured daily from the time of admission to discharge. The hospital-acquired malnutrition rate was determined by dividing the patients with decreased weight-for-height (WFH) or body mass index (BMI) z-scores by total samples, then multiplying by 100. Results: In a total of 367 children, the mean age was 6.4±2.8 years whereas 203 (55.4%) children were boys. Hospital stays ranged from 2 to 19 days, with a mean of 18±6.9 days. At the time of discharge, the mean weight to be 17.6±6.53 kg, indicating a mean weight drop of 1.3±1.14 kg from admission to discharge. Weight reduction during hospitalization was observed in all age groups, with the highest percentage observed in children aged 2 to 5 years (77.7%) and the lowest in those aged 1 to 2 years (38.9%). Significant changes were observed in both WFH z-scores (mean difference -1.06, ± 1.69, p<0.001) for children under 60 months and BMI z-scores (mean difference -1.07, ± 4.63, p=0.023) for children over 60 months from admission to discharge. Conclusion: Hospital acquired malnutrition is common among pediatric patients and deteriorates when a child is hospitalized without attention to adequate nutritional support. Weight loss shows direct correlation with duration of hospitalization.
Frequency of incidental findings of COVID 19 pneumonia on CT scan chest in patients undergoing CT imaging for some other indications.
Authors: Bushra Ujala  , Istikhar Ali Sajjad  , Nida Pervaiz
Published: April 2024

Objectives: To determine the frequency of incidental findings of COVID 19 pneumonia on CT scan chest in patients undergoing CT imaging for some other indications. Study Design: Descriptive, Cross sectional study. Setting: Department of Radiology, Allied Hospital, Faisalabad. Period: 4th August 2021 to 3rd February 2022. Methods: A total of 100 patients referred to radiology department for CT scan chest, individuals ranging from 15 to 65 years old, encompassing both male and female genders were included. Individuals with symptoms of COVID-19 and CRF were excluded. After taking informed consent, demographic features like age, gender, BMI, smoking (yes/no) were noted. Subsequently, all patients underwent a chest CT scan, revealing the inadvertent discovery of COVID-19 pneumonia. Results: In my study, frequency of incidental findings of COVID-19 pneumonia on chest CT scans among individuals undergoing CT imaging were consolidation (55.0%), ground glass opacities (80.0%), reticular pattern (47.0%) and air bronchograms (41.0%). Conclusion: This study concluded that ground glass opacities and consolidation are the commonest incidental observations of COVID-19 pneumonia on chest CT scans.
Evaluation of Dormancy Mechanism in Teak (Tectona grandis Linn.f) True Seeds Collected from Multiple Provenances and Forest Types of India
Authors:   1Directorate of Research, TNAU, Coimbatore-3, Tamil Nadu, S Venkatesan , P Masilamani ,   2Agricultural Engineering College & Research Institute, TNAU, Kumulur, Tiruchirappalli - 621 712, Tamil Nadu, V Rajan Babu ,   3Anbil Dharmalingam Agricultural College and Research Institute, TNAU, Tiruchirappalli -27, Tamil Nadu, T Eevera ,   4Agricultural College and Research Institute, TNAU, Coimbatore-03, Tamil Nadu, P Janaki ,   4Agricultural College and Research Institute, TNAU, Coimbatore-03, Tamil Nadu, S Sundareswaran ,   Agricultural Engineering College & Research Institute, TNAU, Kumulur, Tiruchirappalli - 621 712, Tamil Nadu, P Rajkumar ,   Agricultural Engineering College & Research Institute, TNAU, Kumulur, Tiruchirappalli - 621 712, Tamil Nadu
Published: April 2024

Teak drupes were collected from seven geographical locations spread over four forest types (dry deciduous, moist deciduous, very moist deciduous, and semi-deciduous) from India. In order to study the dormancy mechanism associated with teak true seeds. The true seeds present inside the drupes from each provenance were extracted without causing any damage to the true seeds. The extracted true seeds were used to study the morphological and physiological characteristics. The true seeds were carefully inoculated in MS medium to observe germination. Twenty-eight days after sowing, the result revealed that Andhra Pradesh provenance recorded the highest true seed germination of 58 percent compared to all other provenances. These results clearly indicate that not only physical and mechanical dormancy is involved in teak for decreased germination but also morphological/physiological dormancy plays a major role in teak true seed germination.
Numerical Study of GFRP-reinforced Concrete Beams with Straight and Hooked-end Bar Lap Splices
Authors: Mirzabagheri Sara , (Sam) Salem Osama
Published: April 2024

Glass fibre-reinforced polymer (GFRP) has been increasingly used as the main reinforcement in concrete structures due to its durability and resistance to corrosion. However, there is a lack of data regarding the bond behaviour of GFRP bars with 180-degree hooked ends used in flexure concrete elements. To investigate the effects of the hooked ends of GFRP bars on the bond strength with concrete, beams reinforced with GFRP bars with straight and hooked-end lap splices at the midspan were modelled using ABAQUS/Standard software. The finite element models were validated using the experimental results of four full-size concrete beams. Two beam specimens had straight-end bars, while the other two had hooked-end bars. Sensitivity analysis was performed to find the proper values for model verification, such as dilation angle and mesh density. According to the outcomes of the parametric study conducted in this research, changing the length of the bar lap splices in the range of 15 to 40 times the bar diameter had a negligible effect on the beam’s overall behaviour. Increasing the number of reinforcing bars from 3 to 5 increased the beam flexural strength by about 33%, whereas increasing the diameter of the bars from 10 to 20 mm doubled the beam strength.
Pengaruh Service Quality, Learning Quality, dan Word of Mouth Terhadap Keputusan Wali Murid Memilih SD Negeri Tunggak Kecamatan Bojonegara
Authors: Ambiya Buya Aina , Muhamad Suhaemi  , Fatah Abdul
Published: April 2024

Penelitian ini bertujuan untuk mengetahui apakah service quality, learning quality, dan word of mouth berpengaruh terhadap keputusana wali murid memilih SD Negeri Tunggak Kecamatan Bojonegara. Penelitian ini dilakukan dengan menggunakan metode kuantitatif. Metode pengambilan sampel yang digunakan adalah menggunakan metode probability sampling dengan teknik simple random sampling. Sampel dalam penelitian ini adalah wali murid SD Negeri Tunggak yang berjumlah 72 responden. Hasil penelitian menunjukkan bahwa 1) service quality berpengaruh signifikan terhadap keputusan wali murid memilih SD Negeri Tunggak, 2) learning quality berpengaruh signifikan terhadap keputusan wali murid memilih SD Negeri Tunggak, 3) word of mouth berpengaruh signifikan terhadap keputusan wali murid memilih SD Negeri Tunggak, 4) service quality, learning quality, dan word of mouth secara bersama-sama berpengaruh secara signifikan terhadap keputusan wali murid memilih SD Negeri Tunggak. Berdasarkan hasil penelitian dapat disimpulkan bahwa service quality, learning quality, dan word of mouth berpengaruh secara parsial dan simultan terhadap keputusan wali murid memilih SD Negeri Tunggak.
Kata Kunci : Service Quality, Learning Quality, Word of Mouth, Keputusan Pembelian
Comparison of the Effectiveness of Ductus Arteriosus Stenting and Systemic-to-Pulmonary Artery Shunt Placement in a Cohort of Newborns with Duct-Dependent Pulmonary Circulation
Authors: Mykhailovska Anzhelika O. , Motrechko Oleksandra O. , Kurkevych Andrii K. , Maksymenko Andrii V.
Published: April 2024

In newborns with congenital heart defects and duct-dependent pulmonary circulation, the first stage of palliative intervention may involve the systemic-to-pulmonary artery shunt (SPAS) placement or the patent ductus arteriosus (PDA) stenting. SPAS placement is a traditional method, but the trend towards reducing the invasiveness of surgical interventions has led to PDA stenting use as a preferred method to ensure a reliable source of pulmonary blood flow.

The aim. To compare pre- and postoperative indicators, complications, and long-term outcomes in two groups of patients after SPAS placement and PDA stenting.

Materials and methods. This single-center retrospective study included 82 newborns who underwent SPAS placement (Group I) and 47 patients who underwent PDA stenting (Group II) from 2015 to 2023. Baseline clinical data were similar in both groups. The arterial blood oxygen saturation (SaO2) was significantly lower in the PDA stenting group compared to the SPAS group (65.7 ± 11.1% vs. 79.2 ± 10.6%, respectively) (p < 0.00001). There was higher percentage of genetic/concomitant pathology in Group II, 13 (27.6%) versus 10 (12.2%), p = 0.02.

Results. There was no statistically significant difference between the analyzed patient groups in clinical status indicators in the postoperative period, including: the duration of artificial lung ventilation (165.5 ± 94 and 150 ± 113 in groups I and II, respectively) (p = 0.87) and length of stay in the intensive care unit (14 ± 7 and 13.6 ± 9.4 days) (p = 0.76). However, SaO2 was higher in Group I than in Group II (81 ± 5.5% vs. 85 ± 4.6%, respectively) (p = 0.02). Before the next stage of surgical correction, the Nakata index in Group II was significantly higher than that in Group I (225 ± 87.4 mm2/m2 vs. 168 ± 35.9 mm2/m2, respectively) (p = 0.048). The percentage of reoperations was higher in Group II (17 [36.1%] versus 14 [17.1%]), however, the overall (14.9% and 26.8%) and late (9.1% and 19.5%) mortality rates were lower in Group II.

Conclusion. Considering the similar results in both patient groups, stenting may be an effective option to increase the pulmonary blood flow in newborns. Due to its minimally invasive procedure, this method may be a choice for premature newborns and children with complex comorbidities. However, SPAS placement remains an important palliative intervention, particularly in cases where ductus arteriosus is tortuous and in congenital heart defects with complex intracardiac anatomy postponing radical correction until older age.
Safety of One-Stage Atrioventricular Junction Ablation after Pacemaker Implantation for Left Bundle Branch Pacing
Authors: Perepeka Eugene O. , Sikhnevych Roman A.
Published: April 2024

Atrial fibrillation (AF) is one of the most common arrhythmias. Atrioventricular (AV) junction ablation combined with pacemaker implantation has become an accepted, effective strategy for the treatment of symptomatic tachysystolic AF resistant to drug therapy, especially in the elderly. Left bundle branch (LBB) pacing is a physiological alternative to right ventricular pacing.

The aim. This study evaluated the effectiveness and safety of a one-stage application of the implantation system for LBB pacing and ablation of the AV junction.

Materials and methods. For the period from January 2023 to February 2024, LBB pacing was applied in 8 patients at the National Amosov Institute of Cardiovascular Surgery in the context of treatment of chronic tachysystolic form of AF with subsequent ablation of the AV junction, as a strategy to control heart rate.

Results. In all the patients, LBB pacing criteria were achieved: Qr or qR in V1 QRS complex morphology type during pacing (100%); St-V6RWPT interval < 80 ms (mean 75.8 ± 13.9 ms); the difference between the intervals St-V1RWPT – St-V6RWPT > 44 ms (mean 55.57 ± 10.09 ms). In 3 out of 8 patients (37%) it was possible to register LBB potential. Mean paced QRS width in the studied group was 130 ± 18.02 ms. The mean intraoperative LBB pacing threshold was 1.71 ± 0.39 V for 0.4 ms, the anodal pacing threshold was 3.25 ± 0.5 V for 0.4 ms (we could demonstrate it in 6 out of 8 patients [75%]). Intraoperative lead perforation through the interventricular septum could be observed in 2 out of 8 cases (25%), but after that it was possible to successfully reimplant the lead in the area of the LBB. In all the patients of the studied group, it was possible to successfully perform radiofrequency ablation of the AV junction with the aim of heart rate control in chronic tachysystolic AF. There was no endocardial lead dislodgement in the postoperative period in any of the patients.

Conclusions. In the studied group, no complications and hemodynamic disturbances were observed in the acute postoperative period and during follow-up one week after the pacemaker implantation for LBB pacing and AV junction ablation. Intraoperative transseptal perforation of the endocardial lead did not complicate reimplantation of the lead in the LBB area. A single-stage pacemaker implantation for LBB pacing and AV junction ablation can significantly shorten the patient’s stay in a medical institution. The subject requires further research on a larger number of patients with long-term follow-up.
Obtaining and studying in situ composite material “chitosan-titanium dioxide” for agriculture
Authors:   Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Baikin A. S. , Melnikova A. A. ,   Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences,   All-Russian Research Institute of Phytopathology, Sergeeva K. S. ,   ll-Russian Research Institute of Phytopathology, Baryshev A. S. ,   Federal Research Center “Institute of General Physics named after. A.M. Prokhorov Russian Academy of Sciences”, Pobedonostsev R. V. ,   Federal Research Center “Institute of General Physics named after. A.M. Prokhorov Russian Academy of Sciences”, Kaplan M. A. ,   Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Baranova D. D. ,   All-Russian Research Institute of Phytopathology, Andreevskaya V. M. ,   All-Russian Research Institute of Phytopathology, Zhelezova S. V. ,   All-Russian Research Institute of Phytopathology, Kolmakov A. G. ,   Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Sevostyanov M. A. ,   Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences,   All-Russian Research Institute of Phytopathology
Published: April 2024

In the course of the study, granules of the composite material “chitosan - titanium dioxide” with different content of titanium dioxide nanoparticles for agricultural use were obtained. The average granule diameter was 35 mm. It is shown that a change in the concentration of titanium dioxide nanoparticles in a composite material within the studied limits does not affect the structure of its surface. Experiments were carried out in situ on the seeds of cucumber (Cucumis sativus). It was noted that during the first three weeks, the composite material has an inhibitory effect on plant growth, and then, after the beginning of the dissolution of the granules, it has a growth-stimulating effect. The best growth rates were observed when two granules of a composite material were added to the soil with a ratio of chitosan to titanium dioxide of 3 to 1. It was concluded that the obtained granules of a composite material can have a positive effect on the processes of plant growth and formation.
Application of promising catalysts of amorphous molybdenum sulfide in the creation of p-Si and pn-Si photocathodes for hydrogen production in an acid solution
Authors:   National Research Nuclear University “MEPhI”, Nevolin V. N. , Rubinkovskaya O. V. ,   National Research Nuclear University “MEPhI”, Fominski D. V. ,   National Research Nuclear University “MEPhI”, Romanov R. I. ,   National Research Nuclear University “MEPhI”, Fominski V. Yu. ,   National Research Nuclear University “MEPhI”
Published: April 2024

The chemical state of MoSx catalytic layers and interfaces with p-type silicon (p-Si) and p-n-junction silicon (pn-Si) at various stages of the preparation and operation of photocathodes has been studied. The SiOx oxide layer formed at the interface noticeably suppressed the photocurrent for p-Si cathodes, but its removal in HF solution provided high photocurrents exceeding the values characteristic of pn-Si cathodes at zero potential. Studies of the energy bands showed that at all stages (after the formation of the photocathode, pre- and post-treatment in acid solutions), the configuration of the energy bands for the p-Si and np-Si photocathodes provided charge transfer for the evolution of hydrogen according to the Z-scheme. The difference in the characteristics of the p-Si and pn-Si photocathodes was due to the possible dependence of the photovoltage in the p-Si surface layer on the state of the interface with the catalyst film, which had no effect on the photovoltage in pn-Si.
Modification of polyvinyltrimethylsilane films by the 40 kHz glow discharge plasma
Authors:   Enikolopov Institute of Synthetic Polymer Materials Russian Academy of Siences, Zinoviev A. V. , Piskarev M. S. ,   Enikolopov Institute of Synthetic Polymer Materials Russian Academy of Siences, Gilman A. B. ,   Enikolopov Institute of Synthetic Polymer Materials Russian Academy of Siences, Skryleva E. A. ,   National University of Science and Technology MISIS, Senatulin B. R. ,   National University of Science and Technology MISIS, Gatin A. K. ,   Semenov Federal Research Center for Chemical Physics Russian Academy of Sciences, Syrtsova D. A. ,   Topchiev Institute of Petrochemical Synthesis RAS, Teplyakov V. V. ,   Topchiev Institute of Petrochemical Synthesis RAS, Kuznetsov A. A. ,   Enikolopov Institute of Synthetic Polymer Materials Russian Academy of Siences
Published: April 2024

The process of polyvinyltrimethylsilane films surface modification by the low temperature low-pressure 40 kHz discharge with a filtered atmospheric air as a working gas has been studied. .It was found that the plasma treatment the surface of the samples acquired a stable hydrophilicity property. The chemical structure of the original and modified films was studied by X-ray photoelectron spectroscopy, and the morphology was studied by atomic force microscopy It was shown that the discharge treatment leads to increase in surface roughness and the formation of SiOx layer on the surface, however, to a lesser extent than after processing by direct current discharge. The study of the gas transport properties of the modified samples showed that the selectivity for the O2/N2 pair is somewhat lower than that of the films treated by direct current discharge, but at the same time, the gas separation parameters are more stable over time.
Structure of Al82Cu7Fe11 alloy after high-speed quenching
Authors:   Baikov Institute of Metallurgy and Material Science of RAS, Bakhteeva N. D. , Todorova E. V. ,   Baikov Institute of Metallurgy and Material Science of RAS, Umnov P. P. ,   Baikov Institute of Metallurgy and Material Science of RAS, Chueva T. R. ,   Baikov Institute of Metallurgy and Material Science of RAS, Gamurar N. V. ,   Baikov Institute of Metallurgy and Material Science of RAS, Petrakova N. V. ,   Baikov Institute of Metallurgy and Material Science of RAS, Sviridova T. A. ,   National University of Science and Technology “MISIS”
Published: April 2024

Structural analysis methods (metallographic, X-ray diffraction, differential scanning microscopy) were used to complex research of the structure Al82Cu7Fe11 alloy obtained melt spinning method in the form of ribbons. It was shown that a multiphase amorphous-nanocrystalline structure of high dispersity, which includes an aluminum-based solid solution, intermetallic compounds Fe4Al13, CuAl2, and a small amount of a quasi-crystalline Al – Fe – Cu phase with a tenth-order symmetry axis (decagonal) is formed in the alloy. The parameters of the crystal lattices and volume fractions of the phases were certified. Was shown that the main structural component alloy is iron aluminide, the which content varies from 68 wt. % to 61 wt.% over the ribbon cross section from the contact to the free surface. The temperatures of phase transformations in the alloy during heating were determined. A comparative analysis of the structure composition and morphology of the phases formed in rapidly quenched ribbons and crystallized under equilibrium conditions same composition ingot was carried out. The difference in the alloys structure after various methods of crystallization was established. The microhardness of the ingot main structural components has been determined. Iron aluminide has a maximum hardness 780 HV. It was shown that the high alloy hardness 615 HV after high-speed quenching is provided formed multiphase amorphous-nanocrystalline structure state.
Influence of crosslinking agents on matrix properties of hydrogel structures based on sodium alginate
Authors:   Institute of Photon Technologies Federal Scientific Research Centre Crystallography and Photonics RAS, Khvorostina M. A. ,   Federal State Budgetary Scientific Institution “Research Centre for Medical Genetics”, Algebraistova P. Y. ,   Institute of Photon Technologies Federal Scientific Research Centre Crystallography and Photonics RAS, Nedorubova I. A. ,   Federal State Budgetary Scientific Institution “Research Centre for Medical Genetics”, Bukharova T. B. ,   Federal State Budgetary Scientific Institution “Research Centre for Medical Genetics”, Goldshtein D. V. ,   Federal State Budgetary Scientific Institution “Research Centre for Medical Genetics”, Teterina A. Y. ,   Baikov Institute of Metallurgy and Materials Science, Komlev V. S. ,   Baikov Institute of Metallurgy and Materials Science, Popov V. K. ,   Institute of Photon Technologies Federal Scientific Research Centre “Crystallography and Photonics” Russian Academy of Sciences, Federal Scientific Research Centre “Crystallography and Photonics” Russian Academy of Sciences
Published: April 2024

A comparative study of gelation processes in aqueous solutions of sodium alginate initiated by their chemical crosslinking with divalent ions Ca2+ or Ba2+ was carried out. 3D cryoprinted hydrogel scaffolds of certain architectonics were formed from the studied compositions containing various concentrations of crosslinking agents. It is shown that the increase in the crosslinking agent concentration from 2 to 10 wt. % leads to the improvement in the strength characteristics of alginate structures. At the same time, scaffolds crosslinked with 10 % aqueous solutions of both CaCl2 and BaCl2 retain their structural stability during 21 days of incubation in a culture medium at a temperature of 37 °C. During in vitro experiments on cultures of mesenchymal stem cells derived from rat adipose tissue, samples crosslinked with Ba2+ ions were found to demonstrate a moderate cytotoxic effect and showed their inability to maintain cell adhesion, unlike non-toxic scaffolds crosslinked in CaCl2 aqueous solutions. In vivo analysis of experimental samples on an intramuscular implantation model for male Wistar rats also confirmed moderate cytotoxicity of alginate scaffolds formed using Ba2+ ions as crosslinking agents. The results obtained allow us to assert that of all the studied by us materials, sodium alginate crosslinked with a 10% CaCl2 aqueous solution can be considered the most promising for various biomedical applications.
Thermodynamic analysis of chlorination aluminum oxide
Authors:   Baikov Institute of Metallurgy and Materials Science of the Russian Academy of Sciences, Vetchinkina T. N.
Published: April 2024

Thermodynamic analysis of aluminum oxide chlorination is of theoretical and practical interest and is performed for the main possible reactions of interaction with chlorine. The process is possible only in the direction of decreasing (decreasing) the Gibbs energy (∆G). The condition ∆G0 determines the principal possibility of carrying out the process under specified conditions and is determined only by the initial and final state of the system. The calculated values of the Gibbs energy and the equilibrium constant in the temperature range 400 – 1000 K show that in the presence of a reducing agent, the equilibrium of reactions is shifted towards the formation of aluminum chloride. It was found that the changes in the Gibbs energy of chlorination reactions of polymorphic modifications of Al2O3 increases in the series: γ-Al2O3, Al2O3 am., δ-Al2O3, α-Al2O3. It is possible to effectively assess the basic laws of obtaining anhydrous aluminum chloride in the reacting system by evaluating the change in the ratio of the initial components. Thermodynamic analysis of Al – O – C – Cl and Al – O – C – Cl – Si – Na systems with different component ratios was performed. The latter system is a rough alumina containing sodium aluminosilicate. It is shown that the 100 % yield of the target products with the full use of chlorine corresponds to the stoichiometry of their chemical interaction. The possibility of selective chlorination of Al2O3 and SiCl4 has been determined. As calculations have shown, sodium oxide is completely converted into chloride, which makes it possible to use the residue from chlorination to obtain aluminum-silicon alloys without sodium impurities.
Features of the grain-subgrain structure of TI49.8NI50.2 alloy after megaplastic deformation by abc pressing and subsequent annealing
Authors:   Institute of Strength Physics and Materials Science of Siberian Branch of the Russian Academy of Sciences, Krukovskii K. V. , Lotkov A. I. ,   Institute of Strength Physics and Materials Science of Siberian Branch of the Russian Academy of Sciences, Grishkov V. N. ,   Institute of Strength Physics and Materials Science of Siberian Branch of the Russian Academy of Sciences, Gusarenko A. A. ,   Institute of Strength Physics and Materials Science of Siberian Branch of the Russian Academy of Sciences, Bobrov D. I. ,   Institute of Strength Physics and Materials Science of Siberian Branch of the Russian Academy of Sciences
Published: April 2024

The features of the grain-subgrain structure of Ti49.8Ni50.2 (at. %) alloy after megaplastic deformation by multi-axial forging at 573 K and subsequent annealing were investigated by the method of backscattered electron diffraction. It is shown that the best detection of the patterns of the grain-subgrain structure of the Ti49.8Ni50.2 alloy after a given true deformation e = 9.55 and annealing at 773 K for 2 hours, it is observed in areas without martensitic relief on the surface of the samples. It was found that the clearest diffraction patterns of backscattered electrons are observed in the central part of the grains, and with distance from the center of the grain, the quality of the Kikuchi lines deteriorates. The calculation of the equivalent grain diameter showed that the average grain size is 0.203 ± 0.053 microns. The grains have mainly an ellipse shape with an axis ratio of 0.48. Elongated grains along their length have a discrete-continuous disorientation of the crystal structure, which can reach 5 degrees per 1 micrometer.
Experimental determination of the effective filament length for composites manufactured using additive technologies
Authors:   Blagonravov Mechanical Engineering Research Institute of the Russian Academy of Sciences, Vlasov D. D. , Plugatar T. P. ,   Blagonravov Mechanical Engineering Research Institute of the Russian Academy of Sciences, Polyakov A. E. ,   Blagonravov Mechanical Engineering Research Institute of the Russian Academy of Sciences, Tatus N. A. ,   Blagonravov Mechanical Engineering Research Institute of the Russian Academy of Sciences
Published: April 2024

This article presents the results of an experimental and theoretical study aimed at studying the adhesive properties of the filament – matrix interface. The experiment on pulling a filament out of a polymer matrix was carried out for materials manufactured by additive technology. The purpose of the study was to determine the limiting shear stresses at the carbon filament-polymer matrix interface, as well as the influence of the length of the “embedding” of the filament on the pulling force. For this purpose, specimens were made with different lengths of filament “embedding”. The tensile experiment was carried out on a universal testing machine and the load-displacement diagram was recorded. To estimate the displacement fields, the digital image correlation (DIC) method was used. In the process of testing, pictures of displacement and strain fields on the surface of the specimen were obtained, from which it is possible to assess the processes occurring on the surface of the filament-matrix interface. The typical fields of strain when pulling a single thread from the matrix array are shown. The length of the filament at which the load-bearing capacity of the composite is realized more efficiently and the load is close to the limit for the filament itself was determined experimentally. Based on experimental data, the minimum effective length of filament “embedding” was calculated when manufacturing composite structural elements using additive methods.
Carprofen Attenuates Postoperative Mechanical and Thermal Hypersensitivity after Plantar Incision in Immunodeficient NSG Mice
Authors: Alamaw Eden D , Casey Kerriann M , Tien Krystal , Franco Benjamin D , Gorman Gregory , Cotton Renee M , Nagamine Claude , Jampachaisri Katechan , Sharp Patrick , Pacharinsak Cholawat , Huss Monika K
Published: March 2024

Immunodeficient NSG mice are reported to be less responsive to buprenorphine analgesia. Here, we used NSG mice to compare the efficacy of the commonly used dose of carprofen (5 mg/kg) with 5 and 10 times that dose (25 and 50 mg/kg) for attenuating postoperative mechanical and thermal hypersensitivity following an incisional pain model. Male and female NSG mice (n = 45) were randomly assigned to one of 4 groups and received daily subcutaneous injections for 3 d: saline (5 mL/kg), 5 mg/kg carprofen (Carp5), 25 mg/kg carprofen (Carp25), and 50 mg/kg carprofen (Carp50). Mechanical and thermal hypersensitivity were assessed 24 h before and at 4, 24, and 48 h after surgery. Plasma carprofen concentrations were measured in a separate group of mice (n = 56) on days 0 (at 2, 4, 12, and 23 h), 1, and 2 after the first, second, and third doses, respectively. Toxicity was assessed through daily fecal occult blood testing (n = 27) as well as gross and histopathologic evaluation (n = 15). Our results indicated that the saline group showed both mechanical and thermal hypersensitivity throughout the study. Carp5 did not attenuate mechanical or thermal hypersensitivity at any time point. Carp25 attenuated mechanical and thermal (except for the 4-h time point) hypersensitivity. Carp50 attenuated only thermal hypersensitivity at 24 h. Fecal occult blood was detected in 1 of 8 Carp25-treated mice at 48 and 72 h. Histopathologic abnormalities (gastric ulceration, ulcerative enteritis, and renal lesions) were observed in some Carp50-treated mice. Plasma carprofen concentrations were dose and time dependent. Our results indicate that Carp25 attenuated postoperative mechanical and thermal hypersensitivity more effectively than Carp5 or Carp50 in NSG mice with incisional pain. Therefore, we recommend providing carprofen at 25 mg/kg SID for incisional pain procedures using immunodeficient NSG mouse.
Noise and Vibration Generation and Response of Mice (Mus musculus) to Routine Intrafacility Transportation Methods
Authors: Cordingley Jessica R , Nemzek Jean , Qi Nathan
Published: March 2024

Intrafacility transport of mice is an essential function for both laboratory and husbandry personnel. However, transport may induce a stress response that can alter research findings and negatively impact animal welfare. To determine minimally adverse intrafacility transport methods, in-cage noise and vibration exposure during transport on a variety of transport vehicles (hand carrying, stainless steel rack, flatbed cart, metal teacart, plastic teacart, and a cart with pneumatic wheels) were measured. Under-cage and in-cage padding was tested for its ability to decrease noise and vibration on each vehicle. Behavioral (open field test and elevated plus maze) and corticosterone responses of mice were then measured following transport on the most adverse (metal teacart) and least adverse (pneumatic cart) methods of multicage transport. Behavioral measures showed no difference between transported mice and untransported mice in both single- and group-housed settings. Plasma corticosterone was significantly elevated in mice transported on the metal teacart immediately following transport and continued to have elevated trends in circadian peaks during the 48 h of sampling. The cart with pneumatic wheels was most effective at reducing noise and vibration, reflected in posttransport corticosterone readings that remained equivalent to those in untransported mice. This study demonstrates that mitigation of noise and vibration during cart transport may decrease the impact of transport on certain stress parameters in mice.
PENINGKATAN HASIL BELAJAR SISWA MELALUI MODEL PEMBELAJARAN THE POWER OF TWO DALAM PEMBELAJARAN TEMATIK
Authors: Budi M. Satria
Published: April 2024

Penelitian ini bertujuan untuk mengetahui peningkatan hasil belajar siswa melalui model pembelajaran The Power Of Two pada pembelajaran tematik di kelas V Madrasah Ibtidaiyah An Nizham Kota Jambi. Penelitian ini merupakan penelitian tindakan kelas (PTK) yang bersifat deskriptif kualitatif, dengan mengambil latar Madrasah Ibtidaiyah An Nizham Kota jambi, sedangkan objek penelitian adalah meningkatkan hasil belajar pada pembelajaran tematik dengan menggunakan model The Power Of Two. Penelitian ini dilakukan dalam dua siklus dan melalui empat tahapan yang mencakup: (1) Perencanaan, (2) Pelaksanaan, (3) Observasi dan (4) Refleksi. Data diperoleh melalui observasi, wawancara, tes mengerjakan soal dan dokumentasi. Analisis data dilakukan dengan menggunakan hasil tes belajar siklus I dan Siklus II, hasil pelaksanaan  pada tindakan siklus I menunjukkan bahwa seluruh kegiatan pembelajaran belum mencapai target yang diharapkan meskipun mengalami peningkatan pada siklus I dibandingkan pra siklus, karena rata-rata persentase hasil belajar siswa pada prasiklus 40% dan siklus I yaitu 60% yang menunjukan hasil belajar siswa masih dibawah 75%. Siklus II telah menunjukkan hasil yang memuaskan baik dari aktivitas belajar siswa maupun dari hasil belajar siswa telah mencapai ketuntasan sebesar 93%, artinya tindakan perbaikan untuk proses pembelajaran telah mencukupi dan mencapai Kriteria Ketuntasan Minimal yang diharapkan yaitu 75%.
ИМПУЛЬСНАЯ МЕХАНОХИМИЯ
Authors:   Институт синтетических полимерных материалов им. Н.С. Ениколопова Российской академии наук, Александров А. И.
Published: April 2024

Рассмотрено новое направления в механохимии — импульсная механохимия, которое было заложено академиком Н. С. Ениколоповым в 1991 г. работой «Непосредственный переход химической энергии в механическую без термолизации».
ЛЮМИНЕСЦЕНТНЫЕ СВОЙСТВАФОТООТВЕЖДЕННЫХ ПОЛИМЕРНЫХ МАТРИЦ,СОДЕРЖАЩИХ ОРГАНИЧЕСКУЮ ФЛУОРЕСЦЕНТНУЮ ДИАДУ
Authors:   Федеральное государственное учреждение науки Федеральный исследовательский центр химической физики им. Н. Н. Семенова Российской академии наук, ЗАЙЧЕНКО Н.Л. , МАТВЕЕВА И.А. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ШАШКОВА В.Т. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ЛЮБИМОВ А.В. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ЛЮБИМОВА Г.В. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, КОЛЬЦОВА Л.С. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ШИЕНОК А.И. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН
Published: April 2024

К числу важных материалов для новых технологий, безусловно, относятся органические люминесцентные материалы, которые широко используются в связи с прогрессом искусственного освещения, дисплеев, разработкой флуоресцентных биомедицинских инструментов, люминесцентной дефектоскопии и для многих специальных целей.
НАУЧНЫЕ ПРИНЦИПЫ ПЕРЕРАБОТКИ ПОЛИМЕРОВ И РЕЦЕПТУРОСТРОЕНИЕ КОМПОЗИТОВ
Authors:   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, МЯСОЕДОВА В.В.
Published: April 2024

Создание новых композитных материалов на основе сортированных твердых коммунальных отходов (ТКО) и техногенных вторичных ресурсов актуально в научно-практическом плане. В октябре 2023 г. Указом Президента РФ утверждена Новая Климатическая доктрина Российской Федерации, которая представляет собой систему взглядов на цели, основные принципы борьбы с изменением климата и является основой для выработки климатической политики. В докладе уделено значительное внимание научной обоснованности предпринимаемых мер по смягчению антропогенного глобального воздействия на климат.
ВОЗМОЖНОСТИ МЕТОДА ПОЛИМЕРИЗАЦИОННОГОНАПОЛНЕНИИ ДЛЯ СИНТЕЗА КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ НА ОСНОВЕ ПОЛИОЛЕФИНОВ И ДЛЯ МОДИФИКАЦИИИХ СВОЙСТВ
Authors:   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, НОВОКШОНОВА Л.А.
Published: April 2024

Эффективным методом получения композиционных материалов на основе полиолефинов, в том числе сверхвысокомолекулярного полиэтилена (СВМПЭ), и микро- и нанонаполнителей практически любого типа является метод полимеризационного наполнения (полимеризации in situ), разработанный в ИХФ РАН по предложению Н. С.Ениколопова, запатентованный в России и за рубежом. Согласно этому методу, наполнитель вводится в полимер непосредственно в процессе его синтеза путем полимеризации мономера (этилена, пропилена) на поверхности частиц наполнителя, активированной катализатором полимеризации.
ВЛИЯНИЕ ЗАЦЕПЛЕНИЙ НА ПОЛУЧЕНИЕ ОРИЕНТИРОВАННЫХ ПОЛИМЕРНЫХ ВОЛОКОН
Authors:   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ПЕТРОВ А.И. , ЛЕЛЕКОВА В.А. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, РУДЯК В.Ю. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ЧЕРТОВИЧ А.В. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН
Published: April 2024

Рассмотрен вопрос о формировании зацеплений по ходу полимеризации и последующему влиянию сетки зацеплений на спекание и формирование ориентированного полимерного волокна. При построении аналитических теорий и компьютерном моделировании мы ориентировались на сверхвысокомолекулярный полиэтилен (СВМПЭ) и получение ориентированных волокон «сухим» методом из спеченного расплава.
НАНЕСЕНИЕ ТОКОПРОВОДЯЩИХ ДОРОЖЕКНА ДИЭЛЕКТРИЧЕСКИЙ ПЛАСТИК С ПОМОЩЬЮ ЛАЗЕРА
Authors:   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, БУЗИН Н.В. , КИСЕЛЕВ А.Г. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ГРИДНЕВ А.А. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, КРАШЕНИННИКОВ В.Г. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН
Published: April 2024

В последнее время наблюдается растущий интерес к привлечению лазеров в производстве электронных компонент и интегрированных монтажных плат с целью упрощения производства и снижения веса электронных приборов.
ПОЛУЧЕНИЕ И ИССЛЕДОВАНИЕ СВОЙСТВ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ НА ОСНОВЕ ПОЛИЛАКТИДА И ПОЛИЭТИЛЕНА НИЗКОЙ ПЛОТНОСТИ, СОДЕРЖАЩИХ УГЛЕРОДНЫЕ НАНОНАПОЛНИТЕЛИ
Authors:   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ГАСЫМОВ М.М. , РОГОВИНА С.З. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, КУЗНЕЦОВА О.П. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ЛОМАКИН С.М. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН,   Институт биохимической физики им. Н. М. Эмануэля Российской академии наук,   Институт синтетически полимерных материалов им. Н. С. Ениколопова Российской академии наук, ШЕВЧЕНКО В.Г. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН,   Институт синтетически полимерных материалов им. Н. С. Ениколопова Российской академии наук, БЕРЛИН А.А. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН
Published: April 2024

Создание композиций на основе полимеров и наполнителей различной природы вызывает в настоящее время большой интерес. Получение композиций с использованием в качестве наполнителей производных графита позволяет создавать материалы с улучшенным комплексом свойств, что может значительно расширить сферы применения синтетических и природных полимеров различных классов.
СОВРЕМЕННЫЕ ПОДХОДЫ К ОПРЕДЕЛЕНИЮ УСТАЛОСТНОЙ ДОЛГОВЕЧНОСТИ БИТУМНЫХ КОМПОЗИТОВ
Authors:   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ГОРБАТОВА В.Н. , КРАСОТКИНА И.А. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ДУДАРЕВА Т.В. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ГОРДЕЕВА И.В. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН
Published: April 2024

Усталостное растрескивание один из главных дефектов дорожного полотна. Считается, что образование трещин для данного типа разрушения характерно при средних климатических температурах эксплуатации дорожных покрытий. Существующие методы определения усталостных характеристик неоднократно подвергались критике как за отсутствие корреляции с реальными условиями эксплуатации дорожного полотна, так и за недостатки модели обработки данных.
ВЛИЯНИЕ ВЕЛИЧИНЫ МОЛЕКУЛЯРНОЙ МАССЫ ПЭВП НА СВОЙСТВА КОМПОЗИТОВ НА ОСНОВЕ СВМПЭ, МОДИФИЦИРОВАННЫХ ДВУХСЛОЙНЫМ ПОКРЫТИЕМ СВМПЭ/ПЭВП НА ЧАСТИЦАХ НАПОЛНИТЕЛЯ
Authors:   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ГУСАРОВ С.С. , КУДИНОВА О.И. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, МАКЛАКОВА И.А. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ГРИНЕВ В.Г. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ЛАДЫГИНА Т.А. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, НОВОКШОНОВА Л.А. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН
Published: April 2024

С целью модификации свойств композиционных материалов на основе сверхвысокомолекулярного полиэтилена (СВМПЭ) методом полимеризационного наполнения получены композиции с двухслойным покрытием на поверхности частиц наполнителя, состоящим из СВМПЭ и более низкомолекулярного полиэтилена высокой плотности (ПЭ), путем последовательной двухстадийной полимеризации этилена на поверхности активированных частиц наполнителя. Слой СВМПЭ расположен непосредственно на поверхности наполнителя, а ПЭ является внешним слоем в реакторных частицах композита.
ВЛИЯНИЕ ГЕРМЕТИЗИРУЮЩЕГО ПОЛИМЕРНОГО СЛОЯ НА ТЕРЩИНОСТОЙКОСТЬ УГЛЕПЛАСТИКОВПРИ ЦИКЛИЧЕСКОМ НАГРУЖЕНИИ
Authors:   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ДЖАНГУРАЗОВ Э.Б. , КОРОХИН Р.А. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ТРЕТЬЯКОВ И.В. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, КИРЕЙНОВ А.В. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, ЮРКОВ Г.Ю. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН, СОЛОДИЛОВ В.И. ,   Федеральное государственное бюджетное учреждение науки Федеральный исследовательский центр химической физики им. Н.Н. Семенова РАН
Published: April 2024

Углепластики (УП) обладают одновременно высокой прочностью, модулем упругости и сравнительно небольшой плотностью. Это свойство углепластиков делает возможным получение сосудов с высокой массовой эффективностью, работающих под давлением. К наиболее перспективным сосудам относят безлейнерные баллоны для хранения газов. Однако композитные материалы характеризуются меньшей герметичностью по сравнению, например, с однородными полимерами и металлами.