Irradiation Interval Research Articles

Double-pulse laser peening as a surface enhancement technology

In this paper, we discuss double-pulse laser peening (DPLP) as surface enhancement technology. Although single-pulse laser peening (SPLP) has yielded excellent results across various applications, its processing performance and efficiency are limited. The DPLP technique involves two laser pulses with a controlled irradiation interval and intensity, enhancing laser absorption through the plasma plume and generating high-amplitude laser-induced shock waves. This study involved conducting DPLP experiments on stainless steel, comparing the outcomes with those of conventional SPLP to assess DPLP’s functionality. After the initial prepulse irradiation, the subsequent main pulse was timed and irradiated onto the stainless steel. We evaluated the surface hardness to ascertain the impact of laser peening. The findings indicated that the surface hardness achieved with DPLP was up to 64% greater than that with SPLP. Additionally, the surface hardness achieved through DPLP depended on the delay time between the pulses and the intensity of the initial prepulse. These findings suggest that DPLP can significantly enhance surface hardness, providing a potential pathway for improving material performance in various industrial applications. Furthermore, simulation experiments of DPLP were performed using a one-dimensional simulation code that calculates the laser-matter interaction during the peening process. The pressure profiles generated by the simulation closely matched the experimentally derived hardness profiles, confirming the simulation’s ability to predict the mechanical effects induced by DPLP on the target sample and assist in further optimization of the DPLP process.

Optimisation of Interfacial Modification by Two-Stage Microwave Irradiation.

Microwave-assisted de-emulsification is attractive in the processes of petroleum production and refining. The main advantage of microwaves is their direct influence on the surfactant layer at the oil/water interface. Previously, an effective interfacial modification was demonstrated by pulsed microwave irradiation. However, the effect of the modification diminished during the off interval of the pulse irradiation. In this study, two-stage microwave irradiation with different powers and durations was applied as a method to maintain an interfacial effect. The power of the second stage was changed to optimise the modification. Quick modification was obtained by high-power irradiation followed by low-power irradiation. It was confirmed a sustained modification was maintained by a moderate power of the second irradiation. This observation indicates a re-adsorption or re-structure process after the first irradiation is suppressed by the second irradiation. The results open new opportunities to optimise microwave operation in oil/water systems.

Clinical overview of phototherapy for neonatal hyperbilirubinaemia.

The most efficient emission spectrum of light for phototherapy is blue-green light emission diode light with peak emission at 478 nm. In the irradiance interval of phototherapy, the relationship between efficacy and irradiance is almost linear, and it is negatively related to the haemoglobin. The action sites of phototherapy are the extravascular compartment and cutaneous blood. The most immature neonates treated aggressively had not only a lower frequency of neurodevelopmental impairment than conservatively treated, but also greater mortality. Intermittent and continuous phototherapy are assumed to be equally efficient. Home-based fibreoptic phototherapy is effective and safe. Important progress is still occurring in phototherapy.

Photovoltaic Power Prediction Based on Irradiation Interval Distribution and Transformer-LSTM

Accurate photovoltaic power prediction is of great significance to the stable operation of the electric power system with renewable energy as the main body. In view of the different influence mechanisms of meteorological factors on photovoltaic power generation in different irradiation intervals and that the data-driven algorithm has the problem of regression to the mean, in this article, a prediction method based on irradiation interval distribution and Transformer-long short-term memory (IID-Transformer-LSTM) is proposed. Firstly, the irradiation interval distribution is calculated based on the boxplot. Secondly, the distributed data of each irradiation interval is input into the Transformer-LSTM model for training. The self-attention mechanism of the Transformer is applied in the coding layer to focus more important information, and LSTM is applied in the decoding layer to further capture the potential change relationship of photovoltaic power generation data. Finally, sunny data, cloudy data, and rainy data are selected as test sets for case analysis. Through experimental verification, the method proposed in this article has a certain improvement in prediction accuracy compared with the traditional methods under different weather conditions. In the case of local extrema and large local fluctuations, the prediction accuracy is clearly improved.

Gamma radiation-induced alterations in nanocrystalline titanium nitride (TiN) particles: A structural perspective

The effect of gamma radiation on the structure of nanocrystalline TiN particles was studied. Initially, nanocrystalline TiN particles were exposed to gamma radiation at doses of 50 kGy, 200 kGy, 900 kGy and 3.5 MGy. The crystal structure of non-irradiated and irradiated samples with different doses of gamma rays was studied by X-ray diffraction method. As a result of the determination analysis of the X-ray diffraction spectra by the Rietvield method, the dependence of the lattice parameters on the radiation dose was established. The effect of gamma irradiation on the size of crystallites was determined by the Scherrer equation. The amorphization occurred in nanocrystalline TiN particles was calculated by the method of integration of diffraction peaks. It was determined that 2.5% amorphization occurred in the specified irradiation interval.

Photochemical characterization of rate laws, rate constants and photonicities in optically–dense, multiphoton–reactive systems

A novel method for characterizing the rate constants k and photonicities n of multiphoton–induced reactions in optically dense media is presented. Conventionally, k and n are calculated by irradiating samples of identical absorbance with different incident initial intensities I0,0 and characterizing the rates of change in absorbance, with incident rate constants k0,0 being proportional to I0,0n for n–photon processes. In our method,I0,0n is replaced by a longitudinally–and–temporally–averaged nth–order intensityIx,tn¯=1-10-nA¯2.303nA¯I0,0n which accounts for the exponential decrease in intensity across the optical pathlength due to the average absorbance A¯ over an irradiation interval of duration t.We demonstrate the utility of Ix,tn¯ by contrasting longitudinally–and–temporally–averaged rate constants kx,t and photonicities nx,t with incident rate constants k0,0 and photonicities n0,0 for the 532 nm, two–photon induced photodegradation of β–carotene in CCl4 solvent. Because the actinic intensity declines more rapidly with x in high (A ∼ 1.0) than low (A ∼ 0.2) absorbance samples, the incident rates R0,0=k0,0I0,0n are faster in the low absorbance samples: i.e., k0,0(A532 = 0.2) > k0,0(A532 = 1.0). In significant contrast, we find that kx,t(A532 = 1.0) ∼ kx,t(A532 = 0.2). indicating that kx,t provides better estimates of the rate constant than k0,0. As with kx,t, we find that the photonicities are minimally affected by A532; i.e., n0,0 ∼ nx,t for both low and high absorbance samples. Hence, the dependence of the rate on the actinic absorbance is incorporated principally into the incident rate constants k0,0; kx,t, n0,0 and nx,t are largely unaffected by A532. We detail potential applications of our method to both multiphoton–induced chemical synthesis and multiphoton–induced photodynamic therapy scenarios, as high absorbance samples are advantageous for both of these applications.

A novel approach to enhance the ionic conductivity of silver nanoparticles incorporated PVA:NaBr polymer electrolyte films via fast neutron irradiation

This study investigates the unprecedented impact of fast neutron irradiation on the structural, electrical, and morphological properties of solid polymer electrolytes (SPEs). The SPE, a poly (vinylalcohol) (PVA)-sodium bromide (NaBr) based matrix with the incorporation of silver nanoparticles (AgNPs), was prepared via a solution casting method and subjected to various time intervals of fast neutron irradiation. X-ray diffraction (XRD) analysis revealed a distinct trend in the polymer electrolyte sample's amorphous phase, with decreased levels at lower neutron fluence and augmented levels at higher fluences. Fourier transform infrared (FTIR) spectroscopy highlighted plausible interactions leading to chain scission and cross-linking. Optical investgations below 300 nm exhibited increased absorbance and a shifted position of the surface plasmon resonance peak correlated with AgNPs. Validation of structural changes in the Ag-incorporated PVA-NaBr system was supported by reduced bandgap and elevation in Urbach energy, corroborating FTIR findings. Enhanced thermal stability was confirmed using thermogravimetric (TGA) analysis. Morphological modification upon irradiation were evident via Field emission scanning electron microscope (FESEM). Transport properties evaluated by Nyquist plot fitting showcased escalating room temperature conductivity with neutron fluence, and the highest conductivity obtained was 4.38 × 10−3 S/cm, an order higher than the pristine sample. Transference number measurements (TNM) indicated that the primary charge carriers are ions rather than electrons. This novel approach confirms that neutron irradiation can be used as a potential way to obtain highly conductive polymer electrolyte films.

Study on frictional behavior of SiCf/SiC composite clad tube clamping condition under nuclear irradiation

Silicon carbide fiber reinforced silicon carbide matrix (SiCf/SiC) composite is the key cladding material of nuclear fuel, which determines the safety and reliability of nuclear fuel storage and transportation. The replacement of its storage and transportation scenario needs to be completed by the manipulator, but the application of SiCf/SiC wear, fracture, and nuclear leakage in the snatching process of brittle-flexible-rigid contact in the irradiation environment has been seriously restricted due to unclear understanding of the damage mechanism. Therefore, the effects of irradiation dose and clamping load on the friction characteristics of the contact interface between SiCf/SiC clad tube are studied in this paper, and the effects of irradiation parameters and clamping force on the static friction coefficient of the contact interface between the clad tube and flexible nitrile are obtained. Based on the Greenwood-Williamson tribological model, a numerical model of the shape and structure of the contact micro-convex at the micro-scale of the clamping interface is constructed by introducing the multi-surface integral, and finally verified by experiments. The research results show that there is a unique “Irradiation suppression zone” under the clamping condition of SiCf/SiC cladding tube under the nuclear irradiation environment, and the growth of static friction coefficient slows down until stagnates after irradiation reaches a certain extent (600 kGy), and there will be a decline when the irradiation dose continues to increase, among which the clamping force of 15.2 N within the irradiation interval of 1,000 kGy can meet the safety of nuclear environment operation. The results of this paper can provide an important theoretical basis and application guidance for the safe operation of SiCf/SiC cladding tubes in the storage and transportation clamping process.

Generation of whole tumor cell vaccine for on-demand manipulation of immune responses against cancer under near-infrared laser irradiation

The therapeutic efficacy of whole tumor cell vaccines (TCVs) is modest, which has delayed their translation into personalized immunotherapies in the clinic. Here, we develop a TCV platform based on photothermal nanoparticle-loaded tumor cells, which can be rationally applied to diverse tumor types to achieve on-demand boost of anti-tumor immune responses for inhibiting tumor growth. During the fabrication process, mild photothermal heating by near-infrared (NIR) laser irradiation induces the nanoparticle-bearing tumor cells to express heat shock proteins as endogenous adjuvants. After a single vaccination at the back of tumor-bearing mice, non-invasive NIR laser irradiation further induces mild hyperthermia at vaccination site, which promotes the recruitment, activation, and antigen presentation by dendritic cells. Using an indicator we term fluctuation of tumor growth rate, we determine appropriate irradiation regimens (including optimized irradiation intervals and times). This TCV platform enables on-demand NIR manipulation of immune responses, and we demonstrate potent therapeutic efficacy against six murine models that mimick a range of clinical scenarios, including a model based on humanized mice and patient-derived tumor xenografts.

Microwave Technology, Its Use and Heating of Composite Aerated Concrete Blocks

This paper aims to test the method of using microwave technology for drying aerated concrete masonry. Furthermore, the propagation of microwave technology through irradiated elements and the effectiveness of eliminating the moisture of the given blocks were examined. There are various discussions about the potential use of this technology in civil engineering. However, they are often based on inaccurate, superficial knowledge. The cause is usually based on a lack of access to accurate professional knowledge. Although the potential use of microwave technology (MWT) has been known for many decades, its use in civil engineering tends to be of marginal interest. The research and tests are mostly carried out by private facilities, which protect the obtained knowledge as their “know how”. For this reason, VUT Brno teamed up with an implementation company and conducted several dozen experiments with repeated measurements of the effect of MWT on various building materials. Moreover, a number of different tests with drying of building materials, as well as the elimination of biotic pests in buildings have been carried out. However, the vast majority were experiments carried out in laboratory conditions, i.e., under precisely given boundary conditions, which were often very far from the conditions in real construction practice. Therefore, the goal of this experiment was to verify the use of microwave technology during the drying and heating of building materials. The experiments on the heating and drying of aerated concrete parts were divided into several phases, in which the dependence of the depth of heating on the time intervals of irradiation was verified. It was clearly concluded that the drying of this material by microwaves is very effective and efficient, particularly from time and financial viewpoints. Therefore, this technology can be successfully used in construction practice, which has started to be often used with reconstructions.

Photooxidative Behavior of Polystyrene Nanocomposites Filled with Two-Dimensional Molybdenum Disulfide.

This study aimed to investigate how an ultralow content of a molybdenum disulfide (MoS2) two-dimensional particle affects the photodegradation mechanism of polystyrene (PS). Here, an accelerated weathering study was presented on neat polystyrene and its nanocomposites produced with 0.001, 0.002, 0.003 and 0.005 wt% of molybdenum disulfide (MoS2) exposed for various irradiation intervals (up to 8 weeks). The polymer photo-transformations were monitored using size exclusion chromatography (SEC), infrared spectroscopy (FTIR), and UV-Vis spectroscopy. The FTIR and UV/Vis results indicate that the PS degradation mechanism was not altered by the presence of MoS2 particles; however, the degradation reactions were slowed down at higher MoS2 contents (>0.003%). The SEC results proved the stabilizer effect due to MoS2 particles, where M¯n, M¯w, and M¯w/M¯n values after 8 weeks were less modified when compared with the neat PS results. The MoS2 acted as a UV stabilizer, and these two-dimensional particles acted by deactivating the free radicals generated by the PS matrix, even considering the low amount of the filler (<0.005 wt%).

Development of 3D-Printed Collagen Scaffolds with In-Situ Synthesis of Silver Nanoparticles.

UV-irradiation method has grown as an alternative approach to in situ synthetize silver nanoparticles (AgNPs) for avoiding the use of toxic reducing agents. In this work, an antimicrobial material by in situ synthesizing AgNPs within 3D-printed collagen-based scaffolds (Col-Ag) was developed. By modifying the concentration of AgNO3 (0.05 and 0.1 M) and UV irradiation time (2 h, 4 h, and 6 h), the morphology and size of the in situ prepared AgNPs could be controlled. As a result, star-like silver particles of around 23 ± 4 μm and spherical AgNPs of 220 ± 42 nm were obtained for Ag 0.05 M, while for Ag 0.1 M cubic particles from 0.3 to 1.0 μm and round silver precipitates of 3.0 ± 0.4 μm were formed in the surface of the scaffolds at different UV irradiation times. However, inside the material AgNPs of 10-28 nm were obtained. The DSC thermal analysis showed that a higher concentration of Ag stabilizes the 3D-printed collagen-based scaffolds, while a longer UV irradiation interval produces a decrease in the denaturation temperature of collagen. The enzymatic degradation assay also revealed that the in situ formed AgNPs act as stabilizing and reinforcement agent which also improve the swelling capacity of collagen-based material. Finally, antimicrobial activity of Col-Ag was studied, showing high bactericidal efficiency against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. These results showed that the UV irradiation method was really attractive to modulate the size and shape of in situ synthesized AgNPs to develop antimicrobial 3D-printed collagen scaffolds with different thermal, swelling and degradation properties.

Daily irradiation versus irradiation at two- to three-day intervals in stereotactic radiotherapy for patients with 1-5 brain metastases: study protocol for a multicenter open-label randomized phase II trial

BackgroundRadiobiological daily changes within tumors are considered to be quite different between stereotactic radiotherapy (SRT) (e.g., 50 Gy in 4 fractions) and conventional radiotherapy (e.g., 60 Gy in 30 fractions). We aim to assess the optimal interval of irradiation in SRT and compare outcomes of daily irradiation with irradiation at two- to three-day intervals in SRT for patients with one to five brain metastases (BM).MethodsThis study is conducted as a multicenter open-label randomized phase II trial. Patients aged 20 or older with one to five BM, less than 3.0 cm diameter, and Karnofsky Performance Status ≥70 are eligible. A total of 70 eligible patients will be enrolled. After stratifying by the number of BMs (1, 2 vs. 3–5) and diameter of the largest tumor (< 2 cm vs. ≥ 2 cm), we randomly assigned patients (1:1) to receive daily irradiation (Arm 1), or irradiation at two- to three-day intervals (Arm 2). Both arms are performed with total dose of 27-30 Gy in 3 fractions. The primary endpoint is an intracranial local control rate, defined as intracranial local control at initially treated sites. We use a randomized phase II screening design with a two-sided α of 0∙20. The phase II trial is positive with p < 0.20. All analyses are intention to treat. This study is registered with the UMIN-clinical trials registry, number UMIN000048728.DiscussionThis study will provide an assessment of the impact of SRT interval on local control, survival, and toxicity for patients with 1–5 BM. The trial is ongoing and is recruiting now.Trial registrationUMIN000048728. Date of registration: August 23, 2022.https://center6.umin.ac.jp/cgi-bin/ctr/ctr_view_reg.cgi?recptno=R000055515.

Atmospheric-pressure plasma-assisted powder jet deposition for thick hydroxyapatite film formation —Effect of atmospheric-pressure plasma jet

Powder jet deposition (PJD) is a spray coating method and can perform under an environment of atmospheric pressure and room temperature. The deposition environment is advantageous for clinical use and the PJD process has been tried to apply to dental treatment by using fine particles of hydroxyapatite. However, its deposition rate is significantly low compared with other heating and/or vacuum processes. We, therefore, applied an atmospheric-pressure plasma jet (APPJ) to the PJD process to increase its deposition rate without changing the environment. The experimental results illustrate that the APPJ assistance provided the effect of increasing the deposition rate on the PJD process, while the effect of the APPJ irradiation time was saturated within 15 s. Additionally, the interval of the APPJ irradiation and the PJD process also had a significant effect on the deposition rate, i.e., the shorter the interval was, the larger the deposition rate got. These results are in accord with our assumption of the effect of the APPJ irradiation on increasing the PJD rate.

Self-regulated non-reciprocal motions in single-material microstructures.

Living cilia stir, sweep and steer via swirling strokes of complex bending and twisting, paired with distinct reverse arcs1,2. Efforts to mimic such dynamics synthetically rely on multimaterial designs but face limits to programming arbitrary motions or diverse behaviours in one structure3-8. Here we show how diverse, complex, non-reciprocal, stroke-like trajectories emerge in a single-material system through self-regulation. When a micropost composed of photoresponsive liquid crystal elastomer with mesogens aligned oblique to the structure axis is exposed to a static light source, dynamic dances evolve as light initiates a travelling order-to-disorder transition front, transiently turning the structure into a complex evolving bimorph that twists and bends via multilevel opto-chemo-mechanical feedback. As captured by our theoretical model, the travelling front continuously reorients the molecular, geometric and illumination axes relative to each other, yielding pathways composed from series of twisting, bending, photophobic and phototropic motions. Guided by the model, herewe choreograph a wide range of trajectories by tailoring parameters, including illumination angle, light intensity, molecular anisotropy, microstructure geometry, temperature and irradiation intervals and duration. We further show how this opto-chemo-mechanical self-regulation serves as a foundation for creating self-organizing deformation patterns in closely spaced microstructure arrays via light-mediated interpost communication, as well as complex motions of jointed microstructures, with broad implications for autonomous multimodal actuators in areas such as soft robotics7,9,10, biomedical devices11,12 and energy transduction materials13, and for fundamental understanding of self-regulated systems14,15.

Laser Assisted Synthesis of Surfactant-Free Au-Ag Alloy Nanoparticles in Water

Surfactant-free nontoxic Au-Ag alloy nanoparticles were synthesized via re-irradiation of laser generated mono metallic colloidal mixtures with 532 nm radiations from Nd: YAG nanosecond laser. The impact of re-irradiating laser energy in alloy formation kinetics was investigated. The alloy formation process was analyzed with UV-Visible absorption spectra at different time intervals of laser irradiation. The generated nanoparticles were characterized with dynamic light scattering size analysis, zeta potential studies, and HRTEM imaging. Photothermal properties of the samples were investigated employing thermal lens method. Alloy formation became faster with a slight blue shift in the plasmonic band wavelength with increase in irradiation energy. Reduction in nanoparticle size and stability were also observed at high irradiation energies.

Determination of Flumethrin and Tau-Fluvalinate Pyrethroid Insecticides in Surface and Groundwater by Photochemically Induced Fluorescence (PIF)

Flumethrin and tau-fluvalinate pyrethroid insecticides were determined in natural water using photochemically induced fluorescence (PIF). As these pesticides are not naturally fluorescent, PIF using ultraviolet irradiation was employed to produce highly fluorescent derivatives. This method was optimized for irradiation interval, solvent and pH. The calibration curves were linear with limits of detection (LOD) from 0.5 to 73.8 ng mL−1 without matrix effects. Applications were carried out in aqueous solutions on tap water, seawater, well water and river water from Niayes, Senegal and the Brest, France using solid phase extraction and standard addition procedures. The samples were analyzed with mean recoveries between 99.0 and 109.0%. The analytical performances of these systems were favorable compared with published photoinduced fluorescence methods for the determination of pyrethroids. The results show that the developed PIF method is suitable for the determination of trace organic pollutants in natural waters.

UV-A and UV-B banning highly soluble photocrosslinkable thermotropic liquid crystalline copolyesters with ether linkage in the backbone

Four random copolyesters were synthesized by the polycondensation of a chalcone diol 3-(4-hydroxy-3methoxyphenyl)-1-(4-hydroxyphenyl)prop-2-en-1-one (HMPP) with the common diacid, namely, 4,4′-oxybis(benzoic acid) with two varying diacids (terephthalic acid and isophthalic acid) and two varying diols (1,4-dihydroxyanthraquinone and 1,5-dihydroxyanthraquinone). The chalcone diol was synthesized by acid-catalyzed Claisen-Schmidt reaction. These four random copolyesters were synthesized by solution polycondensation technique and were characterized by qualitative solubility tests and viscosity measurements. The monomeric moieties incorporated in the copolyester backbone was established by FT-IR, 1H NMR and 13C NMR spectroscopic techniques. Tg, Tm and Tiso were determined by DSC thermograms and found to be in the range of 59–97 °C, 123–143 °C and 160–252 °C, respectively. The copolyesters displayed nematic phase without involving methylene-flexible spacers in the polymeric backbone. The phase transition was found to be reproducible on heating and cooling above Tm. The photocrosslinking ability was ascertained by recording UV spectra at different time intervals of irradiation of UV light from 150-watts, 365-nm mercury lamp at room temperature in DMF. Herein, for the first time, we report the synthesis and characterization of a series of novel photosensitive liquid crystalline chalcone polymers without spacer chains. In addition to these, density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations have been performed to ascertain the cross-linking nature of the synthesized polymer from computed absorption spectra. All these polyesters exhibit a good photocrosslinking property by absorbing UV-A light. They continue to absorb UV-B light (which is more dangerous to human skin and eyes) after the crosslinking. As these polymers filter UV-A and UV-B rays one after another, a switching system can be evolved from these materials. These polymers exhibit high thermal stability and UV filtering ability at both UV-A and UV-B regions and have good solubility ensuring their application-oriented nature.

A comparative study of the 5 mm-layer Vickers hardness model with bulk-fill resin-based composites

Aim: The aim of this study was to compare the Vickers hardness numbers (VHNs) of two bulk-fill resin-based composites (BFRBC) and a conventional hybrid resin-based composite (RBC) through the layers of a 5mm thickness model with two different light-curing time intervals.&#x0D; Methodology: In the present study, a sonic-activated and dual-cure BFRBC, and a conventional hybrid RBC were used. Semi-cylindrical specimens 4 mm in radius and 5 mm in height were prepared using a two-piece stainless-steel mold (n=10). The BFRBCs allowed a single 5mm increment to be introduced into the molds, whereas hybrid RBC was incremented (2+2+1 mm). Two different time intervals were applied for the light-curing (irradiance of 1200 mW/cm2) of each material (hybrid-sonic-activated bulk-fill, 20 s and 40 s; dual-cure bulk-fill, 7 s and 15 s). VHN measurements were carried out from top to bottom at every 1 mm of the specimen thickness. Data were analyzed using three-way and two-way ANOVA for the VHN and bottom/top ratios and Bonferroni correction for multiple comparisons (p=0.05).&#x0D; Results: For each layer and time interval groups, there was a significant difference between the materials. The highest VHN was found within hybrid groups, whereas dual-cure bulk-fill groups showed the lowest results. Sonic-activated bulk-fill had the lowest bottom/top ratios, which were significantly different from those of the other materials. There was no significant difference between the different time intervals for bottom/top ratios within each material.&#x0D; Conclusion: Increased irradiation intervals positively affected the VHN of hybrid and dual-cure bulk-fill. BFRBCs showed clinically acceptable bottom/top hardness ratios.&#x0D; &#x0D; How to cite this article: Aytaç Bal F, Ağaccıoğlu M, Demir O. A comparative study of the 5 mm-layer Vickers hardness model with bulk-fill resin-based composites. Int Dent Res 2021;11(2):172-9. https://doi.org/10.5577/intdentres.2021.vol11.no3.6&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Influence of non-ionizing radiation on protein metabolism in chickens

In practical terms, the idea of using an artificial magnetic field is of particular interest, which corresponds in its physical characteristics to the geomagnetic field of the Earth to combat the negative effects of hypogeomagnetic field. Further development of this idea is associated with the use and selection of hypo-, hypermagnetic fields acting on the body with experimental pathology. In this regard, the issue of influence of different duration of irradiation with an alternating pulsed electromagnetic field of ultra-low frequency (APEMF ULF) on the indicators that characterize metabolic processes in the body is insufficiently clarified. Therefore, the aim of research has been to study the effect of alternating pulsed electromagnetic field of ultra-low frequency on protein content and protein metabolism in the body of experimental chickens of the Dominant D959 cross. For this purpose, four experimental and control groups of 120-day-old chickens have been formed – 20 heads in each. The poultry has been kept in a specially equipped room with an alternating pulsed electromagnetic field of ultra-low frequency. The total protein content has been determined by the biuret method; protein fractions (albumins, globulins: alpha-1, alpha-2, beta, gamma) – by diffuse polyacrylamide gel (PAAG) electrophoresis; the content of creatinine, urea and uric acid has been performed by spectrophotometry using standard techniques. According to the results of research, it has been established that by selecting different regimens and duration of action of APEMF ULF, it is possible to influence protein metabolism in the body of chickens. Thus, on the 80th day of continuous irradiation of experimental chickens with APEMF ULF, regardless of the level of protein in the diet, in their blood revealed an increase in total protein, the relative content of globulin fraction mainly due to γ-globulins, and an increase in creatinine, urea and uric acids. When the period of continuous irradiation has been increased to 5 months, a negative effect on protein metabolism has been revealed, which has been manifested by a decrease in total protein content, relative albumin content, decrease in creatinine, urea and uric acid in the serum of experimental chickens. The combination of long-term (for 150 days) daily 60 minutes with weekly intervals of irradiation of chickens with APEMF ULF and their feeding with a 15% increase in protein levels in the diet caused a stimulating effect on protein metabolism and resistance of experimental chickens, with increasing, the relative content of globulins due to the γ-globulin fraction, as well as the main indicators of protein metabolism – creatinine, urea, uric acid. Key words: electromagnetic influence, chicken of Dominant D959 cross, total protein, protein fractions, creatinine, urea, uric acid.