Search Results (128)

This study investigates the complex dynamic behavior of three-tailed helical microrobots operating in confined spaces. A stochastic dynamic model has been developed to analyze the effects of input angular velocity, current, fluid viscosity, and channel width on their motion trajectories, velocity, mean squared displacement (MSD), and wobbling rate. The results indicate that Gaussian white noise exerts a dispersive driving effect on the motion characteristics of the microrobots, leading to a 49% reduction in their velocity compared to deterministic conditions. Additionally, the time required for microrobots to traverse from the initial position to the bifurcation point decreases by 65% when the current is increased and by 39% when the fluid viscosity is reduced. These findings underscore the importance of optimizing control parameters to effectively mitigate noise impacts, enhancing the practical performance of the microrobots in real-world applications. This research offers solid theoretical support and guidance for the deployment of microrobots in complex environments. Full article

Background/Objectives: The origin of genes and genetics is the story of the coevolution of translation systems and the genetic code. Remarkably, the history of the origin of life on Earth was inscribed and preserved in the sequences of tRNAs. Methods: Sequence logos demonstrate the patterning of pre-life tRNA sequences. Results: The pre-life type I and type II tRNA sequences are known to the last nucleotide with only a few ambiguities. Type I and type II tRNAs evolved from ligation of three 31 nt minihelices of highly patterned and known sequence followed by closely related 9 nt internal deletion(s) within ligated acceptor stems. The D loop 17 nt core was a truncated UAGCC repeat. The anticodon and T 17 nt stem-loop-stems are homologous sequences with 5 nt stems and 7 nt U-turn loops that were selected in pre-life to resist ribozyme nucleases and to present a 3 nt anticodon with a single wobble position. The 7 nt T loop in tRNA was selected to interact with the D loop at the “elbow”. The 5′-acceptor stem was based on a 7 nt truncated GCG repeat. The 3′-acceptor stem was based on a complementary 7 nt CGC repeat. In pre-life, ACCA-Gly was a primitive adapter molecule ligated to many RNAs, including tRNAs, to synthesize polyglycine. Conclusions: Analysis of sequence logos of tRNAs from an ancient Archaeon substantiates how the pre-life to life transition occurred on Earth. Polyglycine is posited to have aggregated complex molecular assemblies, including minihelices, tRNAs, cooperating molecules, and protocells, leading to the first life on Earth. Full article

This paper investigates Ring Beam Modulation-assisted Laser (RBML) welding as a novel approach for joining dissimilar materials, specifically aluminum and copper, which are essential in high-performance applications such as electric vehicle batteries and aerospace components. The study aims to address challenges such as thermal mismatches, brittle intermetallic compounds, and structural defects that hinder traditional welding methods. The research combines experimental and computational analyses to evaluate the impact of heat input distributions and laser modulation parameters on weld quality and strength. Three welding cases are compared: fixed center beam with variable ring beam outputs, variable center beam with fixed ring outputs, and a wobble-mode beam to enhance interfacial bonding. Computational modeling supports the optimization process by simulating heat flows and material responses, exploring various shape factors, and guiding parameter selection. Key findings include a nonlinear relationship between heat input and welding strength across the cases. Case 1 demonstrates improved weld strength with higher ring beam input, while Case 2 achieves excellent reliability with relatively lower inputs. Case 3 introduces wobble welding, yielding superior resolution and consistent weld quality. These results confirm that precise ring beam modulation enhances weld reliability, minimizes thermal distortions, and optimizes energy consumption. The manuscript advances the state of knowledge in laser welding technology by demonstrating a scalable, energy-efficient method for joining dissimilar materials. This contribution supports the fabrication of lightweight, high-reliability assemblies, paving the way for innovative applications in the automotive, medical, aerospace, and shipbuilding industries. Full article

The stability of time-dependent compressible linear flows, which are characterized by periodic variations in either their shape or their shear, is investigated. Two novel parametric instabilities are found: an instability that occurs for periodically wobbling elliptic vortices at a number of discrete oscillation frequencies that are proportional to the Mach number and an instability that occurs for all linear flows at various frequencies of the shear oscillation that depend on the Mach number. In addition, the physical mechanism underlying the instabilities is explained in terms of the linear interaction of three waves with time-varying wavevectors that describe the evolution of perturbations: a vorticity wave representing the evolution of incompressible perturbations and two counter-propagating acoustic waves. Elliptical instability occurs because the scale of the acoustic waves decreases exponentially and their wave action is conserved, leading to an exponential increase in the acoustic waves’ energies. The instability in shear-varying flows is driven by the interaction between vorticity and the acoustic waves, which couple through the shear and for specific frequencies resonate parametrically, leading to exponential or linear growth. Full article

Introduction: Hyperuricemia is characterized by increased uric acid (UA) in the body. The ability to block xanthine oxidase (XO) is a useful way to check how different bioactive molecules affect hyperuricemia. Previous reports showed the significant effect of corn against hyperuricemia disorder with its anti-XO activity. The identification of stable Zea mays miRNA (zma-miR) in humans has opened up a new avenue for speculation about its part in regulating novel human gene targets. Aims: The aim of this study was to investigate the prospects of zma-miRs in XO gene regulation, the possible mechanism, and the interaction analysis of the zma-miR-XO mRNA transcript. Method: Significant features of miRNA-mRNA interaction were revealed using two popular miRNA target prediction software—intaRNA (version 3.3.1) and RNA hybrid (version 2.2.1) Results: Only 12 zma-miR-156 variants, out of the 325 zma-miR’s sequences reported in the miRNA database, efficiently interact with the 3′UTR of the XO gene. Characteristics of miRNA-mRNA interaction were as follows: the positioning of zma-miR-156 variants shows that they all have the same 11-mer binding sites, guanine (G), and uracil (U) loops at the 13th and 14th positions from the 5′ end, and no G: U wobble pairing. These factors are related to the inhibition of functional mRNA expression. Additionally, the zma-miR-156 variants exhibit a single-base variation (SBV), which leads to distinct yet highly effective alterations in their interaction pattern with the XO mRNA transcript and the corresponding free energy values. Conclusion: Therefore, we propose that zma-miR-156 variants may be a promising new bioactive compound against hyperuricemia and related diseases. Full article

A 3D-printed guide is an effective method for accurately placing pedicle screws in dog vertebrae. While a conventional drill guide allows precise pilot hole formation, it can lead to potential screw wobbling during insertion. In this study, we applied a technique that assists with both drilling and screw insertion, and we compared the accuracy of screw placement using this approach with that achieved by the conventional drill guide. The screws were divided into three groups: Group A (drill guide), Group B (cannulated guide), and Group C (screw guide). The accuracy of screw placement was assessed by comparing preoperative and postoperative CT images. Group A exhibited the largest angular deviation. Group C exhibited significantly smaller deviations in entry point, exit point, angle α, and angular deviation than Group A. In Group B, only the exit-point deviation was significantly smaller than that in Group A. Furthermore, the angular deviation in Group C was significantly smaller than that in Group B. In conclusion, 3D-printed screw-guiding techniques improved the accuracy of pedicle screw placement, with screw guides outperforming cannulated guides, making them a viable option for small breed dogs. Full article

We have previously shown that 2-thiouridine (S2U), either as a single nucleoside or as an element of RNA chain, is effectively desulfurized under applied in vitro oxidative conditions. The chemically induced desulfuration of S2U resulted in two products: 4-pyrimidinone nucleoside (H2U) and uridine (U). Recently, we investigated whether the desulfuration of S2U is a natural process that also occurs in the cells exposed to oxidative stress or whether it only occurs in the test tube during chemical reactions with oxidants at high concentrations. Using different types of eukaryotic cells, such as baker’s yeast, human cancer cells, or modified HEK293 cells with an impaired antioxidant system, we confirmed that 5-substituted 2-thiouridines are oxidatively desulfurized in the wobble position of the anticodon of some tRNAs. The quantitative LC-MS/MS-MRMhr analysis of the nucleoside mixtures obtained from the hydrolyzed tRNA revealed the presence of the desulfuration products of mcm5S2U: mcm5H2U and mcm5U modifications. We also observed some amounts of immature cm5S2U, cm5H2U and cm5U products, which may have indicated a disruption of the enzymatic modification pathway at the C5 position of 2-thiouridine. The observed process, which was triggered by oxidative stress in the living cells, could impair the function of 2-thiouridine-containing tRNAs and alter the translation of genetic information. Full article

Several challenges arise during edge trimming of carbon fibre-reinforced polymer (CFRP) composites, such as the formation of machining-induced burrs and delamination. In a recent development, appropriate-quality geometric features in CFRPs can be machined using special cutting tools and optimised machining parameters. However, these suitable technologies quickly become inappropriate due to the accelerated tool wear. Therefore, the main aim of our research was to find a novel solution for maintaining the machined edge quality even if the tool condition changed significantly. We developed a novel mechanical edge-trimming technology inspired by wobble milling, i.e., the composite plate compression is governed by the proper tool tilting. The effectiveness of the novel technology was tested through mechanical machining experiments and compared with that of conventional edge-trimming technology. Furthermore, the influences of the tool tilting angle and the permanent chamfer size on the burr characteristics were also investigated. A one-fluted solid carbide end mill with a helix angle of 0° was applied for the experiments. The machined edges were examined trough stereomicroscopy and scanning electron microscopy. The images were evaluated through digital image processing. Our results show that multi-axis edge-trimming technology produces less extensive machining-induced burrs than conventional edge trimming by an average of 50%. Furthermore, we found that the tool tilting angle has a significant impact on burr size, while permanent chamfer does not influence it. These findings suggest that multi-axis edge trimming offers a strong alternative to conventional methods, especially when using end-of-life cutting tools, and highlight the importance of selecting the optimal tool tilting angle to minimize machining-induced burrs. Full article

Codon bias analysis of SARS-CoV-2 reveals suboptimal adaptation for translation in human cells it infects. The detailed examination of the codons preferentially used by SARS-CoV-2 shows a strong preference for Lys^AAA, Gln^CAA, Glu^GAA, and Arg^AGA, which are infrequently used in human genes. In the absence of an adapted tRNA pool, efficient decoding of these codons requires a 5-methoxycarbonylmethyl-2-thiouridine (mcm⁵s²) modification at the U₃₄ wobble position of the corresponding tRNAs (tLys^UUU; tGln^UUG; tGlu^UUC; tArg^UCU). The optimal translation of SARS-CoV-2 open reading frames (ORFs) may therefore require several adjustments to the host’s translation machinery, enabling the highly biased viral genome to achieve a more favorable “Ready-to-Translate” state in human cells. Experimental approaches based on LC-MS/MS quantification of tRNA modifications and on alteration of enzymatic tRNA modification pathways provide strong evidence to support the hypothesis that SARS-CoV-2 induces U₃₄ tRNA modifications and relies on these modifications for its lifecycle. The conclusions emphasize the need for future studies on the evolution of SARS-CoV-2 codon bias and its ability to alter the host tRNA pool through the manipulation of RNA modifications. Full article

Neuron-specific Enolase 2 (Eno2) is an isozyme primarily distributed in the central and peripheral nervous systems and neuroendocrine cells. It promotes neuronal survival, differentiation, and axonal regeneration. Recent studies have shown that Eno2 localized on the cell membrane of motor neurons acts as a receptor for extracellular phosphoglycerate kinase 1 (ePgk1), which is secreted by muscle cells and promotes the neurite outgrowth of motor neurons (NOMN). However, interaction between Eno1, another isozyme of Enolase, and ePgk1 failed to return the same result. To account for the difference, we constructed seven point-mutations of Eno2, corresponding to those of Eno1, and verified their effects on NOMN. Among the seven Eno2 mutants, eno2-siRNA-knockdown NSC34 cells transfected with plasmid encoding the 419th aspartic acid mutated into serine (Eno2-[D419S]) or Eno2-[E420K] showed a significant reduction in neurite length. Moreover, the Eno2-ePgk1-interacted synergic effect on NOMN driven by Eno2-[D419S] was more profoundly reduced than that driven by Eno2-[E420K], suggesting that D419 was the more essential residue involved in NOMN mediated by Eno2-ePgk1 interaction. Eno2-ePgk1-mediated NOMN appeared to increase the level of p-Cofilin, a growth cone collapse marker, in NSC34 cells transfected with Eno2-[D419S] and incubated with ePgk1, thereby inhibiting NOMN. Furthermore, we conducted in vivo experiments using zebrafish transgenic line Tg(mnx1:GFP), in which GFP is tagged in motor neurons. In the presence of ePgk1, the retarded growth of axons in embryos injected with eno2-specific antisense morpholino oligonucleotides (MO) could be rescued by wobble-eno2-mRNA. However, despite the addition of ePgk1, the decreased defective axons and the increased branched neurons were not significantly improved in the eno2-[D419S]-mRNA-injected embryos. Collectively, these results lead us to suggest that the 419th aspartic acid of mouse Eno2 is likely a crucial site affecting motor neuron development mediated by Eno2-ePgk1 interaction, and, hence, mutations result in a significant reduction in the degree of NOMN in vitro and axonal growth in vivo. Full article

This investigation aimed to analyze the effect that thawing time and temperature in combination with a termo-resistance test had on straws from dairy bulls used for artificial insemination (AI) on semen motility and kinematic variables measured with CASA systems. Eight animals of Holstein and Jersey breeds were used, and nine frozen-thawed semen doses per animal were analyzed for each breed. Three temperatures (35, 37, and 40 °C) and three thawing times (35, 40, and 45 s) were evaluated using a factorial design. Motility and kinematic patterns were analyzed using CASA-mot (Computer-Assisted Semen Analysis of motility) technology at different post-thawing times (0.5, 1, and 2 h). Sperm motility in Jersey bulls was higher (p < 0.05) than in Holstein ones (64.52 ± 1.45% and 53.10 ± 1.40%, respectively). The same effect was seen with progressive motility among the two breeds (Jersey: 45.29 ± 1.00%; Holstein: 36.30 ± 0.98%, p < 0.05). The Jersey breed presented higher values (p < 0.05) of curvilinear velocity (VCL), rectilinear velocity (VSL), average velocity (VAP), linearity on forward progression (LIN), and wobble (WOB). The Holstein breed showed a lower mean value (p < 0.05) of the beat-cross frequency (BCF) compared to the Jersey breed, thus suggesting an effect on VCL and VAP. During the post-thaw period, a gradual increase in VCL was observed at 2 h. VSL and VAP showed a decrease (p < 0.05) as the post-thaw period was prolonged. The study showed differences in sperm quality between Holstein and Jersey breeds, influenced by cryopreservation, thawing, and post-thawing incubation. Thawing at 37 °C for 30 s was considered optimal in relation to sperm motility. In addition, a decrease in sperm quality was observed as post-thawing time increased. Full article

Until now, research has not taken into consideration the physicochemical purine–pyrimidine symmetries of the genetic code in the transcription and translation processes of proteinogenesis. Our Supersymmetry Genetic Code table, developed in 2022, is common and unique for all RNA and DNA living species. Its basic structure is a purine–pyrimidine symmetry net with double mirror symmetry. Accordingly, the symmetry of the genetic code directly shows its organisation based on the principle of nucleotide Watson–Crick and codon–anticodon pairing. The maximal purine–pyrimidine symmetries of codons show that each codon has a strictly defined and unchangeable position within the genetic code. We discovered that the physicochemical symmetries of the genetic code play a fundamental role in recognising and differentiating codons from mRNA and the anticodon tRNA and aminoacyl-tRNA synthetases in the transcription and translation processes. These symmetries also support the wobble hypothesis with non-Watson–Crick pairing interactions between the translation process from mRNA to tRNA. The Supersymmetry Genetic Code table shows a specific arrangement of the second base of codons, according to which it is possible that an anticodon from tRNA recognises whether a codon from mRNA belongs to an amino acid with two or four codons, which is very important in the purposeful use of the wobble pairing process. Therefore, we show that canonical and wobble pairings essentially do not lead to misreading and errors during translation, and we point out the role of physicochemical purine–pyrimidine symmetries in decreasing disorder according to error minimisation and preserving the integrity of biological processes during proteinogenesis. Full article

Balance is integral in ankle injury prevention and therapy, especially in high-risk sports like volleyball. For balance assessment, the recommended wobble board (WB) performance (i.e., time at equilibrium) has never been compared with the gold standard. The objective was to investigate the relationships of force-plate-derived center of pressure (CoP) with WB performance and the accuracy of WB-derived CoP estimates. Twelve high-level volleyball players completed six unipedal standing trials on a computerized WB. WB tilt angles and CoP were obtained simultaneously via tri-axis accelerometers on the WB (200 Hz) and a force plate (1000 Hz), respectively. WB performance, polynomial-transformed CoP estimates, and CoP fractal sway, sway area, and mean sway velocity were assessed via Pearson and concordance correlation, root mean square errors, and dependent t-tests. WB performance was related with CoP sway and sway area (|r_linear| = 0.714–0.842, |r_nonlinear| = 0.833–0.910, p < 0.01). The strongest concordance (0.878–0.893, p < 0.001) and smallest errors (6.5–10.7%) were reported for anterior–posterior sway and sway area. Moderate to excellent relationships between the WB performance and force plate CoP variables supported the usefulness of WB performance and estimates (especially sway area) in balance assessment. Furthermore, this study presents recommendations for future analyses and modeling approaches to reflect the complexity of postural control. Full article

The purpose of this study was to investigate the effects of different diluents and freezing methods on the quality of thawed sperm after cryopreservation and find an inexpensive and practical method for freezing Hu ram semen for use in inseminations under farm conditions. Ejaculates were collected from five Hu rams. In experiment I, ejaculates were diluted with eight different freezing diluents (basic diluents A, B, C, D, E, F, G, and H). After dilution and cooling, the samples were loaded into 0.25 mL straws and frozen using the liquid nitrogen fumigation method. In experiment II, diluent C was used as the basic diluent and the semen was frozen using liquid nitrogen fumigation and two program-controlled cooling methods. For analysis, frozen samples were evaluated in terms of motility parameters (total motility (TM), progressive motility (PM)), biokinetic characteristics (straight-line velocity (VSL), average path velocity (VAP), curvilinear velocity (VCL), amplitude of lateral head displacement (ALH), wobble movement coefficient (WOB), average motion degree (MAD)), reactive oxygen species (ROS) level, and membrane and acrosome integrity. In experiment I, diluent C had higher TM, PM, and acrosome and membrane integrity and lower ROS compared to other extenders (p < 0.05) except diluent A. Diluent C exhibited higher (p < 0.05) VCL, VAP, ALH, WOB, and MAD compared to diluents B, D, E, and F. In experiment II, TM and all biokinetic characteristics did not show significant differences (p > 0.05) amongst the three freezing methods. Liquid nitrogen fumigation resulted in higher (p < 0.05) PM, membrane integrity, acrosome integrity, and lower ROS level compared to the program. In conclusion, the thawed semen diluted with diluent C had higher quality compared to other diluents. The liquid nitrogen fumigation demonstrated superior semen cryopreservation effects compared to the program-controlled cooling method using diluent C. Full article

Wobble-plate axial piston pumps, characterized by the lack of a slipper mechanism, experience reduced leakage in comparison to their swash-plate counterparts, which contributes to their higher volumetric efficiency. Presently, the primary focus of the research conducted by scholars both domestically and internationally is concentrated on wobble-plate axial piston pumps. The performance studies within this field are predominantly focused on investigating flow pulsation. They also investigate pressure pulsation. Additionally, they investigate cavitation phenomena. Research on inclined-axis axial piston pumps has been limited. This study focused on analyzing the operational form of the piston within an inclined-axis axial piston pump. A correction factor k was introduced based on the motion characteristics of the piston. The application of this factor significantly improved the accuracy of the simulations when compared to the experimental results. Specifically, at a load pressure of 10 MPa, the discrepancy between the simulation and the experimental data was reduced from 8.95% to 0.23%. Similarly, at a load pressure of 20 MPa, the error rate was minimized. It was reduced from 9.15% to 0.35%. This demonstrates the effectiveness of the proposed correction factor. The correction factor enhances the predictive accuracy of the pump’s performance. This enhancement is observed under varying load conditions. Full article