Joris Vėžys

This study evaluated infrared thermography (IRT) as a dual-purpose, non-invasive tool for detecting limb pathology and subclinical mastitis in dairy cows. Surface temperatures were measured at the coffin, pastern, and fetlock regions of all limbs and at the teat surface of all udder quarters. Limb health status was determined by orthopedic clinical examination, and mastitis status was assessed using the California Mastitis Test (CMT). Hindlimbs were significantly warmer than forelimbs in healthy cows (p < 0.001), with confirmed bilateral symmetry (r = 0.524–0.569). Limbs with pathology showed significantly higher temperatures at all anatomical sites, with particularly large effect sizes in the hindlimbs (r around 0.80). Additional lesion-specific analyses demonstrated that both infectious and claw horn lesions exhibited significantly higher temperatures than healthy limbs. In the hindlimbs, infectious lesions showed higher thermographic values than claw horn lesions. CMT-positive quarters showed teat temperatures of 30.0–30.2 °C compared with 25.2–25.8 °C in CMT-negative quarters (p < 0.001). Receiver operating characteristic (ROC) analysis demonstrated excellent diagnostic performance for teat surface temperature in identifying CMT-positive quarters, with an area under the ROC curve (AUC) of 0.956. The optimal threshold was 29.5 °C, corresponding to a sensitivity of 0.992 and a specificity of 0.838. Each 1 °C increase in teat temperature increased the odds of CMT positivity by 5.3-fold (p < 0.001). A practical three-zone thermographic framework was established: p ≤ 0.001). These findings demonstrate that IRT has strong potential as an integrated screening tool for dairy cow limb health and udder health monitoring.

The fundamental differences between high- and low-frequency ultrasound for medical purposes were demonstrated. A model describing the effect of ultrasound on erythrocyte aggregation was developed, and the rapid movement of erythrocytes toward the nodes of a standing acoustic wave was demonstrated, with its velocity compared to the rate of erythrocyte dissociation under the influence of shear forces. The t-test was used to assess the statistical significance of differences between two blood samples and confirmed the effect of low-frequency ultrasound intensity on erythrocyte aggregation. The study employed a patented low-frequency ultrasound transducer generating a traveling acoustic wave that produces shear forces capable of disrupting erythrocyte aggregates into individual erythrocytes. Since the developed technique is intended for human therapy, it is assumed that the proposed low-frequency ultrasound parameters are safe for flowing blood. Due to deeper and more precise penetration of the acoustic signal into tissues, this ultrasound transducer may be promising for improving microcirculation and alleviating patient condition without medication, as well as for reducing blood pressure and heart rate. The developed technique also enables more effective disruption of heart valve plaques and shows therapeutic potential for tumor treatment and in vivo drug encapsulation. Since erythrocytes in diabetic patients are stiffer than those in healthy individuals, their passage through capillaries is more difficult. Therefore, the developed and patented ultrasound-based sole stimulation technique may produce a positive physiological effect by stimulating blood flow in the capillaries of patients with foot ulcers.

Digital technologies that continuously quantify animal behavior, physiology, and production offer significant potential for the early identification of health and welfare disorders of dairy cows. In this study, a multimodal artificial intelligence (AI) framework is proposed for real-time health monitoring of dairy cows through the integration of physiological, behavioral, production, and thermal imaging data, targeting veterinarian-confirmed udder, leg, and hoof infections. Predictions are generated at the cow-day level by aggregating multimodal measurements collected during daily milking events. The dataset comprised 88 lactating cows, including veterinarian-confirmed udder, leg, and hoof infections grouped under a single ‘sick’ label. To prevent information leakage, model evaluation was performed using a cow-level data split, ensuring that data from the same animal did not appear in both training and testing sets. The system is designed to detect early deviations from normal health trajectories prior to the appearance of overt clinical symptoms. All measurements, with the exception of the intra-ruminal bolus sensor, were obtained non-invasively within a commercial dairy farm equipped with automated milking and monitoring infrastructure. A key novelty of this work is the simultaneous integration of data from three independent sources: an automated milking system, a thermal imaging camera, and an intra-ruminal bolus sensor. A hybrid deep learning architecture is introduced that combines the core components of established models, including U-Net, O-Net, and ResNet, to exploit their complementary strengths for the analysis of dairy cow health states. The proposed multimodal approach achieved an overall accuracy of 91.62% and an AUC of 0.94 and improved classification performance by up to 3% compared with single-modality models, demonstrating enhanced robustness and sensitivity to early-stage disease.

Background: Ischemic heart disease remains the leading cause of death worldwide, with coronary microvascular dysfunction (CMD) as a key complication after ST-elevation myocardial infarction (STEMI). Endothelial dysfunction contributes to CMD, impairing vascular tone and increasing inflammation. While angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) aid vascular health, their efficacy may improve with therapeutic ultrasound, which enhances drug delivery and endothelial response. This study explores the combined effects of ultrasound and pharmacological treatment on the ACE axis and inflammation in endothelial and renal cells. Methods: Human umbilical vein endothelial cells (HUVECs) and human renal proximal tubular epithelial cell line RPTEC/TERT1 were treated with captopril, losartan, and dexamethasone, alone or combined with low-frequency ultrasound (LFU). Cell viability and wound-healing assays assessed cellular function, while nitric oxide (NO) and reactive oxygen species (ROS) assays were used to evaluate redox signaling. Gene expression related to the ACE axis, inflammation, and vascular and renal cell function was analyzed via qPCR. Results: Captopril and losartan combined with LFU improved endothelial cell viability, wound healing, and NO production at various concentrations, whereas only losartan with LFU enhanced cell viability and wound healing in renal cells. Dexamethasone with LFU increased ROS levels and had variable effects on RPTEC/TERT1 cell survival. Gene expression analysis showed that LFU alone reduced pro-inflammatory markers VCAM-1, ICAM-1, and PTGS2 in captopril-treated HUVECs and similarly affected CYP4F2 in losartan-treated HUVECs. LFU also decreased PTGS2 expression at higher dexamethasone concentrations. In RPTEC/TERT1 cells, LFU alone did not impact SGLT2 or GGT1 expression, but captopril with LFU downregulated GGT1, and dexamethasone with LFU upregulated SGLT2 at higher concentrations. Conclusions: This study demonstrates that LFU enhances the effects of RAS inhibitors by promoting NO synthesis and reducing oxidative stress, while its combination with dexamethasone may have variable, potentially cytotoxic effects on renal cells. Gene expression patterns suggest LFU’s anti-inflammatory potential and its role in modulating drug efficacy.

Manipulators of this type can be used as constituent parts of robots of several dimensions. Vibration drive based on centrifugal forces is often used in elements of manipulators and robots. In this paper manipulator with vibration drive based on centrifugal forces and with the self-stopping mechanism is investigated. The model of the investigated manipulator is described and equations determining the motion of the manipulator are obtained. The conservative system is investigated. Then the full dynamic model is investigated. Also, the model with excitation of unlimited power is investigated. Numerical solution of the obtained equations is performed. First the results for the conservative system are described and investigated. Then the full dynamic model is investigated in detail. Also, the model with excitation of unlimited power is described and investigated. Various typical graphical relationships determining the dynamic behavior of the investigated manipulator with vibration drive based on centrifugal forces in steady state regimes of motion are presented. Experimental investigations are performed. The obtained results are used in the process of design of manipulators with vibration drive based on centrifugal forces.

Typically, polymer composites and ceramics are used to create biosensors. Materials with properties that are ideal for biosensors and chemical sensors include AgNO₃ (silver nitrate), PVDF (polyvinylidene fluoride), and HA (hydroxyapatite). Polyvinylidene fluoride (PVDF) polymer has been widely used in several applications because of its well-known superior ferroelectric characteristics and biocompatibility. The brittleness and low bending strength of hydroxyapatite limit its applicability. Several HA and polymer composite formulations have been developed to compensate for HA’s mechanical weakness. The final product contains a significant amount of HA, making HA/polymer composites highly biocompatible. When the right amount of silver is deposited, the maximum piezoelectric activity is generated, and silver nitrate has antimicrobial properties. The non-toxic solvent DMSO (dimethyl sulfoxide) and the solvent casting method were chosen for the preparation of the film. Surface roughness was chosen to measure the Str and Sdr properties of the thin film. For liquid preparation, the multifractal spectra analysis was chosen for each sample. SEM was used to examine the samples morphologically. EDX and mapping analyses were presented for chemistry distribution in the samples.

The safety of ultrasound exposure is very important for a patient’s well-being. High-frequency (1–10 MHz) ultrasound waves are highly absorbed by biological tissue and have limited therapeutic effects on internal organs. This article presents the results of the development and application of a low-frequency (20–100 kHz) ultrasonic transducer for sonication of biological tissues. Using the methodology of digital twins, consisting of virtual and physical twins, an ultrasonic transducer has been developed that emits a focused ultrasound signal that penetrates into deeper biological tissues. For this purpose, the ring-shaped end surface of this transducer is excited not only by the main longitudinal vibrational mode, which is typical of the flat end surface transducers used to date, but also by higher mode radial vibrations. The virtual twin simulation shows that the acoustic signal emitted by the ring-shaped transducer, which is excited by a higher vibrational mode, is concentrated into a narrower and more precise acoustic wave that penetrates deeper into the biological tissue and affects only the part of the body to be treated, but not the whole body.

Sheet metal forming is one of the most popular technologies for obtaining finished products in automotive industries. The main techniques of sheet metal forming: sheet microforming, warm/hot forming, incremental sheet forming, flexible-die forming, Electromagnetic sheet forming, Electrohydraulic forming, Spinning and Shear Spinning, Shear Spinning and Flow Forming and cold sheet forming. One most popular cold stamping process. In the production line of Ravne VPS400 1992, we take twenty details for looking quality review, looking for surface damage reasons - a little changing tonnage and speed. The biggest deformation, when velocity is the slowest the tonnage don’t have an impact on this radius deformation. Firstly, we measured the surface for all twenty details with Contourograph CV-2100 M4. In one measurement point we have ten points which is the biggest or slowest tolerance, these results can be the reason why the detail is damage. These details make one tact process. We can say the recommendation – if the detail will be making for one more tact process, detail not be damage, but this extra process is a very grown the price. Second, we see metal steel chemistry alloy elements, and we can be looking which elements have some reason mechanical properties of steels. Our samples have not enough elasticity, and in steel structure we can recommend taking more carbon C, Silicon Si and Vanadium V. Silicon Si, is important for a machinability and tensile properties as well and this element is essential in steel structure. Thirsty, we used the 3D coordinate measuring machine Mitutoyo SurfaceMeasure 606T, looking for tolerances differences. And we see in detail which places will have a damage, we have the results lowest from the layout, we see the blue color. If we made detail not one tact process, but more tact’s making detail the thickness would be evenly gradually. The crystalline structure of the metal broke due to excessive thinning.