An Evaluation of Optimal Friction Stir Welding Factors (FSWF) For Yellow Brass 405-20

Friction stir welding (FSW) is a green, environmentally amicable, and solid-state joining technology. FSW can successfully weld a wide range of materials (similar/dissimilar parent materials) including aluminum, copper, steel, different alloys from these materials, plastics, composites. FSW of brass has already been accomplished by fewer researchers. In this research, yellow brass 405-20 is, therefore, welded with FSW that was never welded before. In this study, tool material utilized was M2 HSS that was also novel. Effect of two friction stir weld factors (FSWF), rotational speed (RS) and traverse speed (TS), was found on three output parameters i.e., weld temperature, weld strength and weld hardness. Weld temperature developed, was found to be 63.72% of melting point of base metal. A significant improvement in friction stir weld strength (FSWS) was also measured that was found to be 106.37% of the base brass strength. Finally, weld hardness was measured which was found to be 87.80% of original brass hardness. Based on main effects, optimal FSW factors were found to be 1450 rpm and 60 mm/min resulting interestingly in optimal temperature, optimal weld strength, and optimal hardness. Rotational speed (RS) was found to be significant to affect the weld temperature only at the friction stir weld zone (FSWZ) with the highest percent contribution (PCR) of 65.69%. However, PCR of transverse speed was found to be maximum for affecting weld strength as compared to its PCR towards both weld temperature and weld hardness. Current study was also deepened by microscopic investigation.

Cytological, Biochemical, and Transcriptomic Analyses of a Novel Yellow Leaf Variation in a Paphiopedilum (Orchidaceae) SCBG COP15

The genus Paphiopedilum, belonging to the Orchidaceae, has high ornamental value. Leaf variations can considerably improve the economic and horticultural value of the orchids. In the study, a yellow leaf mutant of a Paphiopedilum hybrid named P. SCBG COP15 was identified during the in vitro plant culture process; however, little is known about their molecular mechanisms. For this, RNA-seq libraries were created and used for the transcriptomic profiling of P. SCBG COP15 and the yellow mutant. The Chl a, Chl b, and carotenoid contents in the yellow leaves decreased by approximately 75.99%, 76.92%, and 56.83%, respectively, relative to the green leaves. Decreased chloroplasts per cell and abnormal chloroplast ultrastructure were observed by electron microscopic investigation in yellowing leaves; photosynthetic characteristics and Chl fluorescence parameters were also decreased in the mutant. Altogether, 34,492 unigenes were annotated by BLASTX; 1,835 DEGs were identified, consisting of 697 upregulated and 1138 downregulated DEGs. HEMA, CRD, CAO, and CHLE, involved in Chl biosynthesis, were predicted to be key genes responsible for leaf yellow coloration. Our findings provide an essential genetic resource for understanding the molecular mechanism of leaf color variation and breeding new varieties of Paphiopedilum with increased horticultural value.

Experience Professional dermatomycosis of the face, neck and upper part of chest caused by T. mentagrophytes

A 43-year-old female zoologist has an occupational dermatomycosis of the face, neck and upper part of chest caused by T. mentagrophytes. It was mistakenly diagnosed and treated as "Rosacea, papulopustular subtype, ocular rosacea" for 1.5 years. Symmetrical, atypical clinical manifestations with recurrent blepharoconjunctivitis developed as a result of self-treatment using a topical steroid. The detection of cicatrizing folliculitis in the eyebrow area and an arcual peripheral edge in fresh foci on the chest helped to suspect dermatomycosis. The definitive diagnosis was made after the detection of abundant coarse septate mycelium during microscopic investigation of skin scales from foci on the face and chest with 30% KOH and an abundant growth of Trichophyton mentagrophytes during a cultural research study of skin scales, eyebrow hair and eyelashes from lesions. The use of terbinafine for 4 weeks led to the recovery of the patient.

Phenotypical and Myopathological Consequences of Compound Heterozygous Missense and Nonsense Variants in SLC18A3

Background: Presynaptic forms of congenital myasthenic syndromes (CMS) due to pathogenic variants in SLC18A3 impairing the synthesis and recycling of acetylcholine (ACh) have recently been described. SLC18A3 encodes the vesicular ACh transporter (VAChT), modulating the active transport of ACh at the neuromuscular junction, and homozygous loss of VAChT leads to lethality. Methods: Exome sequencing (ES) was carried out to identify the molecular genetic cause of the disease in a 5-year-old male patient and histological, immunofluorescence as well as electron- and CARS-microscopic studies were performed to delineate the muscle pathology, which has so far only been studied in VAChT-deficient animal models. Results: ES unraveled compound heterozygous missense and nonsense variants (c.315G>A, p.Trp105* and c.1192G>C, p.Asp398His) in SLC18A3. Comparison with already-published cases suggests a more severe phenotype including impaired motor and cognitive development, possibly related to a more severe effect of the nonsense variant. Therapy with pyridostigmine was only partially effective while 3,4 diaminopyridine showed no effect. Microscopic investigation of the muscle biopsy revealed reduced fibre size and a significant accumulation of lipid droplets. Conclusions: We suggest that nonsense variants have a more detrimental impact on the clinical manifestation of SLC18A3-associated CMS. The impact of pathogenic SLC18A3 variants on muscle fibre integrity beyond the effect of denervation is suggested by the build-up of lipid aggregates. This in turn implicates the importance of proper VAChT-mediated synthesis and recycling of ACh for lipid homeostasis in muscle cells. This hypothesis is further supported by the pathological observations obtained in previously published VAChT-animal models.

Common microscopic origin of the phase transitions in Ta2NiS5 and the excitonic insulator candidate Ta2NiSe5

The structural phase transition in Ta2NiSe5 has been envisioned as driven by the formation of an excitonic insulating phase. However, the role of structural and electronic instabilities on crystal symmetry breaking has yet to be disentangled. Meanwhile, the phase transition in its complementary material Ta2NiS5 does not show any experimental hints of an excitonic insulating phase. We present a microscopic investigation of the electronic and phononic effects involved in the structural phase transition in Ta2NiSe5 and Ta2NiS5 using extensive first-principles calculations. In both materials the crystal symmetries are broken by phonon instabilities, which in turn lead to changes in the electronic bandstructure also observed in the experiment. A total energy landscape analysis shows no tendency towards a purely electronic instability and we find that a sizeable lattice distortion is needed to open a bandgap. We conclude that an excitonic instability is not needed to explain the phase transition in both Ta2NiSe5 and Ta2NiS5.

A Comprehensive Investigation on Development of Lightweight Aluminium Miniature Gears by Thermoelectric Erosion Machining Process

Nowadays, size, weight, and durability are crucial factors in product development that draw the attention of many researchers and engineers towards research and innovation in the micromanufacturing area. This paper reports on the development of a lightweight aluminium gear of miniature size with a bore and hub using wire-assisted thermoelectric erosion machining (WTEM). The external spur gear was cut from 7075 aluminium alloy round stepped gear blank by WTEM using 0.25 mm brass wire. Further, the miniature gear was tested for various manufacturing quality parameters such as microgeometry, surface roughness, and microstructure, along with evaluating process productivity in terms of volumetric gear cutting speed To understand the mechanism of development of aluminium miniature gear, an investigation on the influence of WTEM parameters namely servo-voltage, pulse-on time, pulse-off time, and wire speed on surface roughness was conducted. A total of 18 gears were fabricated following Taguchi L9 (34) orthogonal array approach of design of experiments considering the randomization and replication. A typical average surface roughness value of 1.58 μm and manufacturing quality of DIN standard number 7 based on gear microgeometry were successfully achieved. Microscopic investigation revealed uniform and accurate tooth profiles, flank surfaces free from burrs and contaminants, and uniform microstructure that confirm the good performance characteristics of the developed lightweight miniature gear of aluminium. This investigation will add new results in the field as regards the development of lightweight microparts.

Bacterial endosymbionts protect beneficial soil fungus from nematode attack

Fungi of the genus Mortierella occur ubiquitously in soils where they play pivotal roles in carbon cycling, xenobiont degradation, and promoting plant growth. These important fungi are, however, threatened by micropredators such as fungivorous nematodes, and yet little is known about their protective tactics. We report that Mortierella verticillata NRRL 6337 harbors a bacterial endosymbiont that efficiently shields its host from nematode attacks with anthelmintic metabolites. Microscopic investigation and 16S ribosomal DNA analysis revealed that a previously overlooked bacterial symbiont belonging to the genus Mycoavidus dwells in M. verticillata hyphae. Metabolic profiling of the wild-type fungus and a symbiont-free strain obtained by antibiotic treatment as well as genome analyses revealed that highly cytotoxic macrolactones (CJ-12,950 and CJ-13,357, syn. necroxime C and D), initially thought to be metabolites of the soil-inhabiting fungus, are actually biosynthesized by the endosymbiont. According to comparative genomics, the symbiont belongs to a new species (Candidatus Mycoavidus necroximicus) with 12% of its 2.2 Mb genome dedicated to natural product biosynthesis, including the modular polyketide-nonribosomal peptide synthetase for necroxime assembly. Using Caenorhabditis elegans and the fungivorous nematode Aphelenchus avenae as test strains, we show that necroximes exert highly potent anthelmintic activities. Effective host protection was demonstrated in cocultures of nematodes with symbiotic and chemically complemented aposymbiotic fungal strains. Image analysis and mathematical quantification of nematode movement enabled evaluation of the potency. Our work describes a relevant role for endofungal bacteria in protecting fungi against mycophagous nematodes.

HUMAN URINARY BLADDER GLANDS AND THERE MACRO-MICROSCOPIC PECULIARITIES

Purpose of the investigation is to learn the morphological peculiarities (quantity parameters, age, individual and regional characteristics) of the glands of urinary bladder in the different age stages of the postnatal ontogenesis in the norm. A macro-microscopy method on total preparations of a wall of the bladder 54 received from corpses. Victims from the casual reasons at the age from the period newborn to senile age and we investigated variants of the form of a bladder glands, feature of its change in different sites of a wall of organ (proximal, average, distal thirds), taking into account age. Glands have preliminary been painted 0.05 % by a solution methylene dark blue with Sinelnicov’s method. The glands were investigated with the application of stereomicroscopic-binocular microscope MBS-9. Statistical data processing included calculation of arithmeticmean values, their errors, confidential intervals (excel). In quantity of the parameters of the urinary bladder, glands have individual changeability in the investigation. The boundary of variation of the parameters of the urinary bladder glands is rather wider in the maturity and senile stages. Connected with biological activity of the people in the definite degree, the quantity of the glands does not change in comparison with elderly period in old stage. In the stages of the first maturity and majority, the parameters of the measure and quantity of the urinary bladder glands in the women have difference from men. In this microscopic investigation, there is very important anatomical scientific information about the human urinary bladder glands that in the different stages, their quantity, age, form and regional changeability, proximal-distal gradient as well as other anatomical facts were established.