The morphogenesis and histogenesis of an experimental malignant fibrous histiocytoma]

Light and electron microscopy, histochemistry, histoautoradiography and vital staining were used to assess changes occurring in subcutaneous connective tissue surrounding a DMBA-containing pill in rats, samples being obtained at 2-week intervals until malignant fibrous histiocytoma became apparent. Initial tumor lesions developing against the background of alterative-inflammatory and reparative changes included apparently atypical pleomorphic cells showing cytologic signs of malignant transformation which remained virtually unchanged in developed sarcoma. The study, therefore, failed to identify the stage of "presarcoma". A complex of morphologic and functional characteristics of the atypical cells revealed their fibroblastic nature. Progression of tumor was associated with appearance of cells of histiocytic pattern (as evidenced by high activity of acid phosphatase and non-specific esterases, thin villus-like outgrowths of cellular membrane and well-developed Golgi complex) which pointed to pronounced structural and functional variability of poorly-differentiated neoplastic fibroblasts. Tumor revealed xanthomatous and multinuclear giant cells, too. Malignant fibrous histiocytoma is, therefore, poorly-differentiated polymorphocellular sarcoma of fibroblastic origin.     

The rapid determination of the hemagglutinating and the blood coagulating activity of staphylococci]

A solid-phase preparation, designated by the authors "plasma pencil", has been developed for rapid measurements of plasma-agglutinating and plasma-coagulating activities of microorganisms. Plasma pencil employed instead of liquid plasma is economic, ready-to-use, may be stored for a long time, makes the procedure more rapid and simple. Measurements of the aforesaid activities in 388 staphylococcal clinical strains, carried out with the use of this pencil, have demonstrated a high efficacy of the preparation; the results coincided with those obtained by the routine methods.     

A Feasibility Study of High-Entropy Alloy Coating Deposition by Detonation Spraying Combined with Laser Melting

In this work, a new two-stage approach to the deposition of high-entropy alloy coatings is proposed. At the first stage, a composite precursor coating is formed by detonation spraying of the metal powder mixtures. At the second stage, the precursor coating is re-melted by a laser, and the formation of multi-component solid solution phases can be expected upon solidification. The feasibility of the proposed approach was validated using three different mixtures of Fe, Ni, Cu, Co and Al powders. It was shown that detonation spraying allows forming composite coatings with a uniform distribution of the lamellae of different metals. The results of the structural analysis of the laser-treated coatings suggest that complete alloying occurred in the melt and face-centered cubic solid solutions formed in the coatings upon cooling.     

Transmission of Diverse Variants of Strawberry Viruses Is Governed by a Vector Species

Advances in high-throughput sequencing methods have boosted the discovery of multistrain viral infections in diverse plant systems. This phenomenon appears to be pervasive for certain viral species. However, our knowledge of the transmission aspects leading to the establishment of such mixed infections is limited. Recently, we reported a mixed infection of a single strawberry plant with strawberry mottle virus (SMoV), strawberry crinkle virus (SCV) and strawberry virus 1 (StrV-1). While SCV and StrV-1 are represented by two and three molecular variants, respectively, SmoV has three different RNA1 and RNA2 segments. In this study, we focus on virus acquisition by individual adult aphids of the Aphis gossypii, Aphis forbesi and Chaetosiphon fragaefolii species. Single-aphid transmission trials are performed under experimental conditions. Both different viruses and individual virus strains show varying performances in single aphid acquisition. The obtained data suggests that numerous individual transmission events lead to the establishment of multistrain infections. These data will be important for the development of epidemiological models in plant virology.     

A Novel Model of Ultrasonic Fatigue Test in Pure Bending

The very high cycle fatigue (VHCF) failure of in-service components is mainly caused by the vibration of thin-wall elements at a high frequency. In this work, a novel model of ultrasonic fatigue test was developed to test thin-wall material in bending up to VHCF with an accelerated frequency. The theoretical principle and finite element analysis were introduced for designing a sample that resonated at the frequency of 20 kHz in flexural vibration. In the advantage of the second-order flexural vibration, the gauge section of the sample was in the pure bending condition which prevented the intricate stress condition for thin-wall material as in the root of cantilever or the contact point of three points bending. Moreover, combining the constraint and the loading contact in one small section significantly reduced heating that originated from the friction at an ultrasonic frequency. Both strain gauge and deflection angle methods were applied to verify the controlling of stress amplitude. The fractography observation on Ti6Al4V samples indicated that the characterized fracture obtained from the novel model was the same as that from the conventional bending test.