Cell Size Research Articles

Direct single-cell observation of a key Escherichia coli cell-cycle oscillator.

Initiation of DNA replication in Escherichia coli is coupled to cell size via the DnaA protein, whose activity is dependent on its nucleotide-bound state. However, the oscillations in DnaA activity have never been observed at the single-cell level. By measuring the volume-specific production rate of a reporter protein under control of a DnaA-regulated promoter, we could distinguish two distinct cell-cycle oscillators. The first, driven by both DnaA activity and SeqA repression, shows a causal relationship with cell size and divisions, similarly to initiation events. The second one, a reporter of DnaA activity alone, loses the synchrony and causality properties. Our results show that transient inhibition of gene expression by SeqA keeps the oscillation of volume-sensing DnaA activity in phase with the subsequent division event and suggest that DnaA activity peaks do not correspond directly to initiation events.

Numerical investigation on flow-induced wall shear stress variation of metastatic cancer cells in lymphatics with elastic valves.

Hematogenous metastasis occurs when cancer cells detach from the extracellular matrix in the primary tumor into the bloodstream or lymphatic system. Elucidating the response of metastatic tumor cells in suspension to the flow conditions in lymphatics with valves from a mechanical/fluidic perspective is necessary. A physiologically relevant computational model of a lymphatic vessel with valves was constructed using fully coupled fluid-cell-vessel interactions to investigate the effects of lymphatic vessel contractility, valve properties, and cell size and stiffness on the variations in magnitude and gradient of the flow-induced wall shear stress (WSS) experienced by suspended tumor cells. Results indicated that the maximum WSSmax increased with the increments in cell diameter, vessel contraction amplitude, and valve stiffness. The decrease in vessel contraction period and valve aspect ratio also increased the maximum WSSmax. The influence of the properties of the valve on the WSS was more significant among the factors mentioned above. The maximum WSSmax acting on the cancer cell when the cell reversed the direction of its motion in the valve region increased by 0.5-1.4 times that before the cell entered the valve region. The maximum change in WSS was in the range of 0.004-0.028 Pa/µm depending on the factors studied. They slightly exceeded the values associated with breast cancer cell apoptosis. The results of this study provide biofluid mechanics-based support for mechanobiological research on the metastasis of metastatic cancer cells in suspension within the lymphatics.

Effect of the lattice structures on mechanical characterisation of additively manufactured Ti-6Al-4V for biomedical application

ABSTRACT In the last decades, most investigations in titanium bone implantology have applied lattice structures instead of dense materials to reduce weight and obtain the mechanical properties similar to human bones. However, there is still a need for more research on the optimal design of lattice titanium implants with proper mechanical behaviour and heat treatment investigations, which directly affects the mechanical, microstructural, and morphological characteristics. The present study aims to examine the effect of densities and unit cell sizes for Selective Laser Melting (SLM)-printed lattice structures created by MSLattice. TPMS lattice structures including Diamond, Gyroid, and Primitive generated by MSLattice software were subsequently printed using Ti-6Al-4 V ELI. Tensile testing of DTi (dense) produced an ultimate tensile strength of 1241.58 ± 23.92 MPa and a Yield strength of 1151 ± 8.6 MPa, while its compression test resulted in an ultimate value of 1424.8 ± 20.13 MPa. The increase in density from 20% to 30% has resulted in a doubling of some mechanical properties. The lattice structure of the Gyroid at 30% density presented a UCS value of 143.96 ± 0.89 MPa as the highest, while that of the Diamond at 20% density presented the lowest with 46.89 ± 0.43 MPa. The values for energy absorption and plateau stress follow in a precise sequence.

Incorporating boron distribution variations in microdosimetric kinetic model-based relative biological effectiveness calculations for boron neutron capture therapy.

This study introduces the MKM_B model, an approach derived from the MKM model, designed to evaluate the biological effectiveness of Boron Neutron Capture Therapy (BNCT) in the face of challenges from varying microscopic boron distributions. The model introduces a boron compensation factor, allowing for the assessment of compound Biological Effectiveness (CBE) values for different boron distributions. Utilizing the TOPAS simulation platform, the lineal energy spectrum of particles in BNCT was simulated, and the sensitivity of the MKM_B model to parameter variations and the influence of cell size on the model were thoroughly investigated. The CBE values for 10B-boronphenylalanine (BPA) and 10B-sodium (BSH) were determined to be 3.70 and 1.75, respectively. These calculations were based on using the nucleus radius of 2.5 μm and the cell radius of 5 μm while considering a 50% surviving fraction. It was observed that as cell size decreased, the CBE values for both BPA and BSH increased. Additionally, the model parameter rd was identified as having the most significant impact on CBE, with other parameters showing moderate effects. The development of the MKM_B model enables the accurate prediction of CBE under different boron distributions in BNCT. This model offers a promising approach to optimize treatment planning by providing increased accuracy in biological effectiveness.

The characteristics of autolysins associated with cell separation in Bacillus subtilis.

The peptidoglycan hydrolases responsible for the cell separation of Bacillus subtilis cells are collectively referred to as autolysins. However, the role of each autolysin in the cell separation of B. subtilis is not fully understood. In this study, we constructed a series of cell separation-associated autolysin deficient strains and strains overexpressing the transcription factors SlrR and SinR, and the morphological changes of these strains in liquid culture were observed. The results showed that the absence of D,L-endopeptidases CwlS and LytF only increased the cell chain length in the early exponential phase. The absence of D,L-endopeptidase LytE or N-acetylmuramyl-L-alanine amidase LytC can cause cells to form chains throughout the growth of B. subtilis, although the cell chain length was significantly shortened during the stationary phase. However, the absence of peptidoglycan N-acetylglucosaminidase LytD only caused minor defect in cell separation. Therefore, we concluded that LytE and LytC were the major autolysins that ensure the timely separation of B. subtilis daughter cells, whereas CwlS, LytF, and LytD were the minor autolysins. In addition, overexpression of the transcription factors SinR and SlrR in the cwlS lytF lytC lytE mutant enabled B. subtilis cells to form ultra-long chains in the vegetative phase, and its biomass level was basically the same as that of the wild type. This led to the conclusion that besides inhibiting the expression of lytC and lytF, the SinR-SlrR complex also has other potential mechanisms to inhibit cell separation.IMPORTANCEIn this study, the effects of CwlS, LytC, LytD, LytF, LytE, and SinR-SlrR complex on the cell separation of Bacillus subtilis at different growth phases were studied, and an ultra-long-chained B. subtilis strain was constructed. In microbial fermentation, due to its large cell size, this ultra-long-chained B. subtilis strain may be more likely to be precipitated or intercepted during the removal of bacterial process with centrifugation and membrane filtration as the main methods, which is crucial to improve the purity of the product.

On the Potential of Manufacturing Multi-Material Components with Micro/Nanocellular Structures via the Hybrid Process of Electromagnetic Forming Injection Foaming

Abstract Multi-material design with a combination of solid and foam structures offers a promising avenue for reducing component weight while enhancing their functionalities. However, the complexity of multi-stage manufacturing processes poses significant challenges to adopting such approaches. To address these challenges, this paper introduces an innovative concept known as Electromagnetic Forming Injection Foaming (EFIF), which integrates injection molding, forming, and foaming processes into a single hybrid process. This process begins with a simultaneous filling-forming phase, followed by supercritical fluid (SCF) assisted foaming controlled by electromagnetic forming. Through a series of experimental and analytical studies, this work investigates the feasibility and effectiveness of EFIF. First, the impact of pressure drop rate and pressure drop on cell size and density is examined through a specialized experimental setup enabling performing injection, forming, and foaming processes in a single operation. The potential influence of electromagnetic forming on foam injection molding is explored through experiments focusing on the effects of a polymer layer between sheet metal blank and the electromagnetic coils. Additionally, an analytical study evaluates the EFIF process by calculating expected pressure drop rates under different processing conditions and their influence on cell nucleation rates. The results showed the possibility of achieving pressure drop rates up to 1.5×105 bar/sec, resulting in nucleation rates up to 1.77×109 nuclei/cm3sec. Overall, this paper highlights the potential of EFIF to merge existing technologies into a scalable solution for manufacturing multi-material components with micro- to nanocellular polymer foams.

Sucrose promotes cone enlargement via the TgNGA1-TgWRKY47-TgEXPA2 module in Torreya grandis.

Cone enlargement is a crucial process for seed production and reproduction in gymnosperms. Most of our knowledge of cone development is derived from observing anatomical structure during gametophyte development. Therefore, the exact molecular mechanism underlying cone enlargement after fertilization is poorly understood. Here, we demonstrate that sucrose promotes cone enlargement in Torreya grandis, a gymnosperm species with relatively low rates of cone enlargement, via the TgNGA1-TgWRKY47-TgEXPA2 pathway. Cell expansion plays a significant role in cone enlargement in T. grandis. 13C labeling and sucrose feeding experiments indicated that sucrose-induced changes in cell size and number contribute to cone enlargement in this species. RNA-sequencing analysis, transient overexpression in T. grandis cones, and stable overexpression in tomato (Solanum lycopersicum) suggested that the expansin gene TgEXPA2 positively regulates cell expansion in T. grandis cones. The WRKY transcription factor TgWRKY47 directly enhances TgEXPA2 expression by binding to its promoter. Additionally, the NGATHA transcription factor TgNGA1 directly interacts with TgWRKY47. This interaction suppresses the DNA-binding ability of TgWRKY47, thereby reducing its transcriptional activation on TgEXPA2 without affecting the transactivation ability of TgWRKY47. Our findings establish a link between sucrose and cone enlargement in T. grandis and elucidate the potential underlying molecular mechanism.

Scale‐dependent mechanical performance variations in polylactic acid lattice structures fabricated via additive manufacturing

AbstractThe objective of this research is to explore the scale effect on the mechanical properties of sheet‐based triply periodic minimal surface (TPMS) uniform lattice structures fabricated with PLA (polylactic acid) under quasi‐static loading conditions. The scale dependency was evaluated by two additional breakdown categories, namely, wall thickness effect and unit cell size effect. Deformation mechanisms and failure modes as well as mechanical properties including stiffness, yield strength, first peak stress, and energy absorption based on the categories of wall thickness, unit cell size, and scale were evaluated experimentally. The assessment of the scale effect involved considering the combined influence of wall thickness and unit cell size. In addition, numerical analysis was also performed to investigate the stress distributions and compare with the experimental results for certain geometries. Ultimately, the relation between the normalized mechanical properties and relative density is evaluated and categorized, which can be used as an indication for future design practices.

OsMYB14, an R2R3-MYB Transcription Factor, Regulates Plant Height through the Control of Hormone Metabolism in Rice

Plant growth must be regulated throughout the plant life cycle. The MYB TF family is one of the largest TF families and is involved in metabolism, lignin biosynthesis and developmental processes. Here, we showed that OsMYB14, a rice R2R3-MYB TF, was expressed in leaves and roots, especially in rice culm and panicles, and that it localized to the nucleus. Overexpression of OsMYB14 (OsMYB14-ox) in rice resulted in a 30% reduction in plant height compared to that of the wild type (WT), while the height of the osmyb14-ko mutant generated using the CRISPR/Cas9 system was not significantly different. Microscopic observations of the first internode revealed that the cell size did not differ significantly among the lines. RNA-seq analysis revealed that genes associated with plant development, regulation, lipid metabolism, carbohydrate metabolism, and gibberellin and auxin metabolic processes were downregulated in the OsMYB14-ox line. Hormone quantitation revealed that inactive GA19 accumulated in OsMYB14-ox but not in the WT or knockout plants, suggesting that GA20 generation was repressed. IAA and IAA-Asp accumulated in OsMYB14-ox and osmyb14-ko, respectively. Indeed, real-time PCR analysis revealed that the expression of OsGA20ox1, encoding Gibberellin20 oxidase 1, and OsGH3-2, encoding IAA-amido synthetase, was downregulated in OsMYB14-ox and upregulated in osmyb14-ko. A protein binding microarray (PBM) revealed the presence of a consensus DNA-binding sequence, the ACCTACC-like motif, in the promoters of the OsGA20ox1 and GA20ox2 genes. These results suggest that OsMYB14 may act as a negative regulator of biological processes affecting plant height in rice by regulating GA biosynthesis and auxin metabolism.

Design and analysis of Minkowski fractal shaped metasurface absorber with broadband and polarization-insensitive characteristics using a tunable graphene layer for terahertz applications

The proposed research article’s main goal is to demonstrate a terahertz (THz) broadband absorber for high-speed wireless communication applications. The proposed structure is a compact one and possesses three layers. The ground layer acts as a metal reflector, lossy silicon acts as a dielectric material and finally a graphene layer in the shape of a minkowski fractal acts as a radiating patch for the proposed design. We have chosen a thickness of 5 μm for the lossy silicon which has a dielectric constant of 11.90. The bottom layer of the proposed design contains a good conductive material like gold with a conductivity of 4.561 e+007 s m−1 with a thickness of 0.2 μm. The thickness of a monolayer graphene is one nanometer, and the overall unit cell size of the proposed structure is 12 × 12 μm2. Because of its symmetrical nature, the proposed absorber offers a broad response to both TM and TE modes irrespective of any polarization angle. The proposed absorber can operate in the terahertz frequency range and has achieved two broad frequency bands from 3.34–3.98 THz and 4.6–5.30 THz, with an absorption percentage greater than 90. We can observe peak absorption frequencies at 3.60 THz and 5.04 THz, which exhibit an absorption percentage close to unity. Additionally, we validated the proposed broadband absorber using an equivalent circuit approach and verified it using the ADS tool.

Fabrication and Characterization of PLA/PBAT Blends, Blend-Based Nanocomposites, and Their Supercritical Carbon Dioxide-Induced Foams

In this study, a twin-screw extruder was used to fabricate poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blends and blend-based nanocomposites with carbon nanotube (CNT) or nanocarbon black (CB) as nanofillers. The fabricated samples were subsequently treated with supercritical carbon dioxide (scCO2) to fabricate the corresponding foams. Bi-phasic morphology and selective distribution of CNTs or CBs in the PBAT phase were observed in the blends/composites through scanning electron microscopy. After the scCO2 treatment, the selective foaming of the PBAT phase in the prepared blends/composites was confirmed. The cellular structure of PBAT phase in scCO2-treated blends is similar to the size/shape of PBAT domains in untreated blends or treated neat PBAT foam. The addition of CNTs or CBs in the blends led to a slight reduction in cell size of the foamed PBAT phase, demonstrating CNT/CB-induced cell nucleation. Differential scanning calorimetry (DSC) results showed that CNTs and CBs played as nucleating agents and increased the initial crystallization temperature up to 14 °C compared with neat PBAT for PBAT in different composites during cooling. The scCO2 treatment induced the bimodal stability of PBAT crystals in different samples, which melted mainly in two temperature regions in DSC studies. Thermogravimetric analyses revealed that compared with parent blends, the addition of CNTs or CBs increased the temperature at 80 wt.% loss (degradation of PBAT portion) up to 6 °C. The electrical resistivity decreased by more than six orders of magnitude for certain CNT- or CB-added composites compared with the parent blends. The hardness of the blends slightly increased after forming the corresponding composites and then declined after the scCO2 treatment.

Interplay of Size, Deformability, and Device Layout on Cell Transport in Microfluidics.

Microfluidics have been widely used for cell sorting and capture. In this work, numerical simulations of cell transport in microfluidic devices were studied considering cell sizes, deformability, and five different device designs. 
Among these five designs, deterministic lateral displacement device (DLD) and hyperuniform device (HU) performed better in promoting cell-micropost collision due to the continuously shifted micropost positions as compared with regular grid, staggered, and hexagonal layout designs. However, the grid and the hexagonal layouts showed best in differentiating cells by their size dependent velocity due to the size exclusion effect for cell transport in clear and straight paths in the flow direction. A systematic study of the velocity differentiation under different dimensionless groups was performed showing that the velocity difference is dominated by the micropost separation distance perpendicular to the direction of flow. Microfluidic experiments also confirmed the velocity differentiation results. The study can provide guiding principles for microfluidic design.

Effects of Different Synthetic and Organic Fertilizer Applications on the Micromorphological Characteristics of Maize (Zea mays L.) Leaves and Some Silage Quality Traits

Background: Fertilization is an important cultural practice used to support plant growth and development. Fertilizers provide plants with the nutrients they need, which help them to photosynthesize, grow and develop. Fertilizers are divided into two groups: organic and synthetic. Organic fertilizers are derived from organic materials such as manure, compost and bat guano. Synthetic fertilizers are produced using chemical methods. Methods: This study was conducted to determine the effects of different synthetic and organic fertilizer applications on silage quality and some micromorphological characteristics in maize plants. The study was conducted using a randomized complete block design with three replications. The RX-9292 silage maize variety was used as the plant material. Six different organic and synthetic fertilizer types with different contents (Control, Synthetic Fertilizer-1 (20 kg N, 8 kg P and 8 kg K per decare), Synthetic Fertilizer-2 (20 kg N, 10 kg P and 10 kg K per decare), Poultry Manure, Cattle Manure and Vermicompost). were used in the study. The ADF (%) (Acid Detergent Insoluble Fiber), NDF (%) (Neutral Detergent Insoluble Fiber), ADL (%) (Acid Detergent Insoluble Lignin), SDMR (%); (Silage Dry Matter Content) properties of the silage obtained were then examined. Additionally, the thickness of the cuticle, number and size of stoma-epidermis cells and stoma index of the leaves were measured and observed using Scanning Electron Microscopy. Result: As a result of the measurements and observations, it was found that both synthetic and organic fertilizer applications increased the yield and quality values in silage maize, but synthetic fertilizer applications were more advantageous than organic fertilizers. However, considering the environmental damage of synthetic fertilizers and the importance of organic fertilizer applications for animal health, organic fertilization is thought to be more appropriate.

Effects of Different Synthetic and Organic Fertilizer Applications on the Micromorphological Characteristics of Maize (Zea mays L.) Leaves and Some Silage Quality Traits

Background: Fertilization is an important cultural practice used to support plant growth and development. Fertilizers provide plants with the nutrients they need, which help them to photosynthesize, grow and develop. Fertilizers are divided into two groups: organic and synthetic. Organic fertilizers are derived from organic materials such as manure, compost and bat guano. Synthetic fertilizers are produced using chemical methods. Methods: This study was conducted to determine the effects of different synthetic and organic fertilizer applications on silage quality and some micromorphological characteristics in maize plants. The study was conducted using a randomized complete block design with three replications. The RX-9292 silage maize variety was used as the plant material. Six different organic and synthetic fertilizer types with different contents (Control, Synthetic Fertilizer-1 (20 kg N, 8 kg P and 8 kg K per decare), Synthetic Fertilizer-2 (20 kg N, 10 kg P and 10 kg K per decare), Poultry Manure, Cattle Manure and Vermicompost). were used in the study. The ADF (%) (Acid Detergent Insoluble Fiber), NDF (%) (Neutral Detergent Insoluble Fiber), ADL (%) (Acid Detergent Insoluble Lignin), SDMR (%); (Silage Dry Matter Content) properties of the silage obtained were then examined. Additionally, the thickness of the cuticle, number and size of stoma-epidermis cells and stoma index of the leaves were measured and observed using Scanning Electron Microscopy. Result: As a result of the measurements and observations, it was found that both synthetic and organic fertilizer applications increased the yield and quality values in silage maize, but synthetic fertilizer applications were more advantageous than organic fertilizers. However, considering the environmental damage of synthetic fertilizers and the importance of organic fertilizer applications for animal health, organic fertilization is thought to be more appropriate.

Hierarchical Composites Patterned via 3D Printed Cellular Fluidics

AbstractAdditive manufacturing of freeform structures containing multiple materials with deterministic spatial arrangement and interactions remains a challenge for most 3D printing processes, due to complex fabrication tool requirements and limitations in printability of some material classes. Here, a versatile method is reported to produce architected composites using the concept of cellular fluidics, in which lattices of unit cells are used as templating scaffolds to guide flowable infill materials in a programmed spatial pattern, upon which they are cured in place to produce a deterministically ordered multimaterial solid. The lattice design relies on the unit cell size, type, strut diameter, surface wetting, and distribution of cellular structures to control liquid flow and retention. Individual unit cells are tuned to achieve reliable infilling and combined into higher‐order architectures to achieve multiscale composite materials with disparate mechanical properties, including those considered non‐printable. Lattice design considerations for leveraging capillary phenomena and demonstrate several methods of patterning polymers in 3D‐printed cellular fluidic structures are presented. The concept of tuning the compressive response of an architected composite using a flexible‐elastomer as the lattice and a stiff‐epoxy as the infill material is illustrated.

Role of Piezo2 in Schwann Cell Volume Regulation and Its Impact on Neurotrophic Release Regulation.

Tactile perception relies on mechanoreceptors and nerve fibers, including c-fibers, Aβ-fibers and Aδ-fibers. Schwann cells (SCs) play a crucial role in supporting nerve fibers, with non-myelinating SCs enwrapping c-fibers and myelinating SCs ensheathing Aβ and Aδ fibers. Recent research has unveiled new functions for cutaneous sensory SCs, highlighting the involvement of nociceptive SCs in pain perception and Meissner corpuscle SCs in tactile sensation. Furthermore, Piezo2, previously associated with Merkel cell tactile sensitivity, has been identified in SCs. The goal of this study was to investigate the channels implicated in SC mechanosensitivity and the release process of neurotrophic factor secretion. Immortalized IFRS1 SCs and human primary SCs generated two distinct subtypes of SCs: undifferentiated and differentiated SCs. Quantitative PCR was employed to evaluate the expression of differentiation markers and mechanosensitive channels, including TRP channels (TRPV4, TRPM7 and TRPA1) and Piezo channels (Piezo1 and Piezo2). To validate the functionality of specific mechanosensitive channels, Ca2+ imaging and electronic cell sizing experiments were conducted under hypotonic conditions, and inhibitors and siRNAs were used. Protein expression was assessed by Western blotting and immunostaining. Additionally, secretome analysis was performed to evaluate the release of neurotrophic factors in response to hypotonic stimulation, with BDNF, a representative trophic factor, quantified using ELISA. Induction of differentiation increased Piezo2 mRNA expression levels both in IFRS1 and in human primary SCs. Both cell types were responsive to hypotonic solutions, with differentiated SCs displaying a more pronounced response. Gd3+ and FM1-43 effectively inhibited hypotonicity-induced Ca2+ transients in differentiated SCs, implicating Piezo2 channels. Conversely, inhibitors of Piezo1 and TRPM7 (Dooku1 and NS8593, respectively) had no discernible impact. Moreover, Piezo2 in differentiated SCs appeared to participate in regulatory volume decreases (RVD) after cell swelling induced by hypotonic stimulation. A Piezo2 deficiency correlated with reduced RVD and prolonged cell swelling, leading to heightened release of the neurotrophic factor BDNF by upregulating the function of endogenously expressed Ca2+-permeable TRPV4. Our study unveils the mechanosensitivity of SCs and implicates Piezo2 channels in the release of neurotrophic factors from SCs. These results suggest that Piezo2 may contribute to RVD, thereby maintaining cellular homeostasis, and may also serve as a negative regulator of neurotrophic factor release. These findings underscore the need for further investigation into the role of Piezo2 in SC function and neurotrophic regulation.

Hierarchical Composites Patterned via 3D Printed Cellular Fluidics

AbstractAdditive manufacturing of freeform structures containing multiple materials with deterministic spatial arrangement and interactions remains a challenge for most 3D printing processes, due to complex fabrication tool requirements and limitations in printability of some material classes. Here, a versatile method is reported to produce architected composites using the concept of cellular fluidics, in which lattices of unit cells are used as templating scaffolds to guide flowable infill materials in a programmed spatial pattern, upon which they are cured in place to produce a deterministically ordered multimaterial solid. The lattice design relies on the unit cell size, type, strut diameter, surface wetting, and distribution of cellular structures to control liquid flow and retention. Individual unit cells are tuned to achieve reliable infilling and combined into higher‐order architectures to achieve multiscale composite materials with disparate mechanical properties, including those considered non‐printable. Lattice design considerations for leveraging capillary phenomena and demonstrate several methods of patterning polymers in 3D‐printed cellular fluidic structures are presented. The concept of tuning the compressive response of an architected composite using a flexible‐elastomer as the lattice and a stiff‐epoxy as the infill material is illustrated.

Experimental investigation of porous gyroid structure: Effect of cell size and porosity on performance

This paper presents an experimental investigation of three triply periodic minimal surface based gyroid sheet samples with varying cell size and porosity. The thermal and hydraulic performances of the samples were analyzed and compared under different design parameters (cell size and porosity). The experimental results revealed that the gyroid structures achieved uniform temperature distribution, allowing for the disruption of the thermal boundary layer and enhancing heat transfer. The gyroid structure characterised by small cell size and low porosity (Gyroid-A: 15 mm/0.75) dissipates more heat from its surface compared to the structure with large cell size and high porosity (Gyroid-C: 32 mm/0.9). Gyroid-A also exhibits higher Nusselt number and convection heat transfer coefficient with 51.5 % increase as compared to Gyroid-C. In addition, Gyroid-A has the lowest thermal resistance (with maximum of 45.4 % reduction) and the highest specific pressure drop as compared to the other gyroid structures. Moreover, Gyroid-A exhibits lower total entropy generation (75.9 % reduction) and higher overall performance evaluation criteria, PEC (more efficient heat transfer in relation to flow resistance) as compared to Gyroid-C. The experimental results of this work is important for the design and optimization of heat transfer applications utilizing gyroid sheet structures for effective heat dissipation.

IN-STORAGE WEIGHT LOSS BY TABLE BEETROOTS DEPENDING ON THE ROOT PULP STRUCTURE

Purpose - to determine the in-storage weight loss by table beetroots depending on the root pulp structure. Methods. 1. General scientific: hypotheses – drawing up designs of experiments; experiments - conducting laboratory tests; analysis and synthesis – summarizing and concluding. 2. Computantional and analytical. Results. Beetroots naturally lose their weight during storage and this process is uneven. At the beginning, it is quite rapid, then it gradually slows down, accelerating in spring. Of the studied beet cultivars, the greatest losses of weight during storage were registered for cvs. 'Renova' and 'Tsylindra'. The weight loss by beetroots was correlated with a decrease in the dry matter content, which was spent on the respiration of beetroots to support their vital activity. In beet cvs. 'Renova' and 'Opolskyi', the decrease in the dry matter during storage was greater, amounting to 5.6 and 4.5%, respectively. There was a relationship between cell area and in-storage water evaporation. It was revealed that in cells with the largest area of 140.04·103 μm, the evaporation-caused losses amounted to 77.7% (cv. 'Karilon'), while in cells with the smallest area of 62.89·103 μm, this parameter was only 10.5% (cv. 'Opolskyi'). Conclusions. There was a direct strong correlation between water evaporation and cell size (r = 0.791). There was a significant second-order curvilinear dependence of beetroot weight loss on cultivars' features (R2 = 0.6041–0.9910).

Autophagy in the corpus luteum correlates with tissue growth in pregnant rats.

The developmental activation of the corpus luteum (CL) structurally and functionally is critical for the temporally regulated establishment, maintenance, and termination of pregnancy in rats. In this study, we have investigated the possible involvement of autophagy in the regulation of the CL during pregnancy in rats. The expression ratio of microtubule-associated protein light chain 3 (LC3)-II/-I, a widely used indicator of autophagic activity, in the CL remained relatively stable until day 15 of pregnancy. Subsequently, it progressively increased until day 21, and then declined until day 3 postpartum. This fluctuation was closely associated with the tissue weight of the CL rather than progesterone (P4) production activity. Light and electron microscopy revealed the presence of immunoreactive LC3 aggregates and irregularly shaped autolysosome-like microstructures in the cytoplasm of luteal cells during late pregnancy. Notably, a bolus intrabursal injection of the autophagy inhibitor bafilomycin A1 on day 15 of pregnancy resulted in a significant reduction in luteal cell size and disrupted the normal alteration of circulating P4 levels. Consequently, treatment with this inhibitor increased the likelihood of the varied timing (both advanced and delayed) of delivery and led to reduced body weight in neonates when compared with the vehicle-treated control group. Our findings suggest that autophagy in the rat CL contributes to luteal tissue growth, influences P4 production, and thereby fine-tunes the regulation of gestation length in rats.