The Effect of Non-Thermal Plasma on the Structural and Functional Characteristics of Human Spermatozoa

Significant antibacterial properties of non-thermal plasma (NTP) have converted this technology into a promising alternative to the widespread use of antibiotics in assisted reproduction. As substantial data available on the specific in vitro effects of NTP on male reproductive cells are currently missing, this study was designed to investigate selected quality parameters of human spermatozoa (n = 51) exposed to diffuse coplanar surface barrier discharge NTP for 0 s, 15 s, 30 s, 60 s and 90 s. Sperm motility characteristics, membrane integrity, mitochondrial activity, production of reactive oxygen species (ROS), DNA fragmentation and lipid peroxidation (LPO) were investigated immediately following exposure to NTP and 2 h post-NTP treatment. Exposure to NTP with a power input of 40 W for 15 s or 30 s was found to have no negative effects on the sperm structure or function. However, a prolonged NTP treatment impaired all the sperm quality markers in a time- and dose-dependent manner. The most likely mechanism of action of high NTP doses may be connected to ROS overproduction, leading to plasma membrane destabilization, LPO, mitochondrial failure and a subsequent loss of motility as well as DNA integrity. As such, our findings indicate that appropriate plasma exposure conditions need to be carefully selected in order to preserve the sperm vitality, should NTP be used in the practical management of bacteriospermia in the future.     

Preparation,structure and microwave dielectric properties of novel La2MgGeO6 ceramics with hexagonal structure and adjustment of its τf value

A novel La₂MgGeO₆ ceramic was synthesized through a solid-state reaction process within a sintering temperature range of 1450–1550 °C. By a combination of X-ray diffraction and Rietveld refinement analyses, the ceramics were found to have a pure hexagonal phase structure belonging to space group R3/146. The scanning electron microscopy images revealed that the ceramic grains were closely connected. The effects of internal (lattice energy, valence bond, and fraction packing) and external factors (density) on the microwave properties of ceramics were also studied. The ceramic exhibited excellent microwave dielectric performances, with a relative permittivity (?_r) of 21.2, a quality factor (Q × f) of 52 360 GHz, and a temperature coefficient of resonant frequency (τ_f) of ?44.2 ppm/°C, when sintered at 1500 °C for 4 h. The τ_f value of the La₂MgGeO₆ ceramic doped with CaTiO₃ could be adjusted to zero. Particularly, 0.2La₂MgGeO₆-0.8CaTiO₃ ceramics have good microwave dielectric properties with τ_f = +2.1 ppm/°C, Q × f = 15 610 GHz, and ?_r = 40.3.     

Influence of Wheel Blunting on the Machining Precision in CNC Plunge Grinding: Digital Twin Analysis

Russian Engineering Research - The machining precision in grinding a flexible shaft by sharp and blunt wheels is compared for a CNC system with a specified cycle of radial supply velocities. To...     

Energy Conservation at High-Tech Enterprises by Means of Automated Energy Management

Russian Engineering Research - Practical approaches are described for introducing an energy management system at a high-tech enterprise so as to centralize and automate the regulation of energy...     

Short-Term Creep of St3 Steel Under Low-Frequency Cyclic Loading

Strength of Materials - Creep constitutive equations have been derived for the materials that exhibit the properties of orthotropy (transversal isotropy) and transient creep under cyclic loading. A...     

Study of the Effect of Composition and Thermal Deformation Treatment on Properties of Ferritic Steels Microalloyed with Titanium and Niobium. Part 2. Phase Precipitate Characteristics*

Metallurgist - The effect of composition and thermal deformation treatment parameters (temperature for the end of rolling and strip winding on a coil, cooling rate after rolling) on mechanical...     

Dictionary-based classifiers for exploiting feature sequence information and their application to hyperspectral remotely sensed data

The problem of classification is shared across various disciplines. Designing even less computationally demanding and more effective classifiers has been a key challenge for researchers for many years. No single classifier can be highly effective for all types of datasets and thus, depending on the data distribution, various classifiers have been proposed in the literature. To our knowledge, feature values have been vastly exploited as the base for discriminating classes, while feature sequence information has been somehow under-exploited so far. In the proposed approach normalised features are sorted and ranked, creating a sequence of finite numbers. The associated rank of the created sequence is used as an additional feature, which in a way defines the sample-specific intra-feature relationship. Three novel dictionary-based approaches such as Sequence Classifier (SC), Sequence-dictionary-based k-Nearest Neighbours Classifier (SDk-NN) and Combined-dictionary-based k-Nearest Neighbours Classifier (CDk-NN) are proposed in this paper.

In the case of remotely sensed data, and specifically in Hyper-Spectral Images (HSI), the spectral features (Spectral signatures) represent a strong, object-specific spectral relationship, which is a key point in our proposed approach. In this case, indeed, the proposed classifiers were tested over various (five) HS datasets and found to be effective. Based on the classifiers features, two derived distance measures are proposed and validated for the HS dataset, namely: the Normalised Sequence Distance (NSD) measure and Combined Distance (CD) measure. These measures appear to overperform the conventional Normalised Euclidean Distance (NED) in this context. Also, validation for both binary and multi-class datasets are experimented and their performances are evaluated in terms of accuracy and other standard measures. Experimental results over 21 datasets revealed that the proposed approaches perform comparably, and in some cases even better than other classifiers. Stack-operated, class-specific sparse dictionaries are also introduced in order to reduce the computational complexity, which can be used as an active learning-based approach for optimal training sample selection. Additional tests were performed with variable levels of dictionary sparsity for assessing its impact on accuracy.     

Strategic environmental assessment in Romania: between benefits and constraints

This paper offers an overall picture of the importance of Strategic Environmental Assessment (SEA) in Romania and its opportunities and constraints. The role, scope and effectiveness of SEA in Romania are presented in two good practice examples and examined in order to highlight the strengths and weaknesses of the procedure at national and local scale. In practice, the number of SEA procedures is very high due to the legislation in force, and it is increasingly effective in decision-making about programmes and plans. SEA can be viewed as a great opportunity for the implementation of sustainable development in practice. It also continues to be an important procedural and decisional instrument for management and monitoring of socioeconomic development, spatial planning and environmental protection in Romania.     

Effect of Chemical Composition and Microstructure Parameters on Carbon and Low-Alloy Steel Corrosion Resistance Under Oil Industry Pipeline Operation Conditions

Metallurgist - The effect of chemical composition and microstructure parameters on corrosion resistance of carbon and low-alloy steels in neutral aqueous media, typical for oil-field pipeline...     

Thermal Stability of Nitric Acid Solutions of Hydrazine Nitrate

Radiochemistry - Thermal stability of hydrazine nitrate (HN) in solutions in 4–12 M HNO3 in the temperature interval 70–150°C was studied. Exothermic reactions accompanied by gas...