Metagenomic profiling of tomato rhizosphere delineates the diverse nature of uncultured microbes as influenced by Bacillus velezensis VB7 and Trichoderma koningiopsis TK towards the suppression of root-knot nematode under field conditions.

The plant-parasitic Root Knot Nematodes (Meloidogyne spp.,) play a pivotal role to devastate vegetable crops across the globe. Considering the significance of plant-microbe interaction in the suppression of Root Knot Nematode, we investigated the diversity of microbiome associated with bioagents-treated and nematode-infected rhizosphere soil samples through metagenomics approach. The wide variety of organisms spread across different ecosystems showed the highest average abundance within each taxonomic level. In the rhizosphere, Proteobacteria, Firmicutes, and Actinobacteria were the dominant bacterial taxa, while Ascomycota, Basidiomycota, and Mucoromycota were prevalent among the fungal taxa. Regardless of the specific treatments, bacterial genera like Bacillus, Sphingomonas, and Pseudomonas were consistently found in high abundance. Shannon diversity index vividly ensured that, bacterial communities were maximum in B. velezensis VB7-treated soil (1.4-2.4), followed by Root Knot Nematode-associated soils (1.3-2.2), whereas richness was higher with Trichoderma konigiopsis TK drenched soils (1.3-2.0). The predominant occurrence of fungal genera such as Aspergillus Epicoccum, Choanephora, Alternaria and Thanatephorus habituate rhizosphere soils. Shannon index expressed the abundant richness of fungal species in treated samples (1.04-0.90). Further, refraction and species diversity curve also depicted a significant increase with maximum diversity of fungal species in B. velezensis VB7-treated soil than T. koningiopsis and nematode-infested soil. In field trial, bioagents-treated tomato plant (60% reduction of Meloidogyne incognita infection) had reduced gall index along with enhanced plant growth and increased fruit yield in comparison with the untreated plant. Hence, B. velezensis VB7 and T. koingiopsis can be well explored as an antinemic bioagents against RKN. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03851-1.

Surface alloying of FeCoCrNiMn particles on Inconel-718 using plasma-transferred arc technique: microstructure and wear characteristics.

Inconel-718 (IN-718) is a commonly used nickel-based superalloy in various fields, such as gas turbine and power generation applications. However, the lower wear and oxidation resistance hinder their wide usage. In this work, FeCoCrNiMn particles were mechanically ball-milled and preplaced on the IN-718 substrate. Then, the preplaced FeCoCrNiMn particles were scanned by heat source using plasma-transferred arc (PTA) technique. The effect of PTA alloying on the phase changes, microstructure, nanohardness and wear resistance has been investigated. The result showed that the PTA region contained different phases, such as FCC, BCC and intermetallic. No cracks were observed in the PTA alloyed region. Moreover, the porous free structure was viewed in the alloyed region, which revealed that the PTA alloying process was effectively used to perform the alloying process. More hard phases, such as NiFe, CoMn, Cr9Mn25Ni21, MnNi, FeCo, FeMn and MnCo, were formed on the PTA-alloyed region. The obtained wear rate of the substrate specimen at 30 N applied load is 2.45 × 10-3 mm3 m-1 and 1.79 × 10-3 mm3 m-1 for the PTA specimen. Similarly, the wear rate of the substrate specimen at 50 N is 5.38 × 10-3 mm3 m-1 and for the PTA sample, it is 2.29 × 10-3 mm3 m-1. The PTA specimen showed lower CoF than the substrate specimen due to increased surface hardness and minimum deformation of asperities. The primary wear type was mildly abrasive, accompanied by slight oxidative wear. Oxygen reacted with the surface alloying elements and formed different oxides, such as CoO, Cr2O3, MnO2, Mn2O3, Mn3O4, FeO and Fe2O3. These dense oxidation films covered the working surface and enhanced the wear resistance. The worn-out PTA surface showed that the wear scar depths were shallow and lower than the substrate, and reduced the roughness.

Proximal row carpectomy for complex perilunate fracture dislocations with migration of proximal scaphoid bone into the forearm.

Complex perilunate dislocations include scaphoid, triquetrum, radial styloid fractures, and associated ligamentous injuries. The purpose of the study is to assess the role of proximal row carpectomy (PRC) in such complex injuries involving the proximal scaphoid migration and analyze the outcome. We operated on eighteen patients with complex perilunate dislocations and extreme proximal migration of proximal scaphoid by PRC between 2012 and 2018. We analyzed the postoperative radiographs, VAS pain score, range of motion, return to work, Quick DASH and Mayo wrist scores and assessed the overall functional outcome. The average follow-up was 46 months. The mean range of wrist flexion was 65%, extension 70 %, pronation 88%, supination 90%, and grip strength 70% of the opposite side. The median VAS pain score was 0.1 (range, 0-3). Median Quick DASH score was 4.4 (range, 3.3-6.7), and Mayo wrist score 70 (range, 65-75). The age, gender, side of injury, dominant hand, fracture displacement or type, osteochondral fracture of the capitate head, and treatment delay had no significant impact on the functional outcome. The presence of degenerative changes had no significant association with age, grip strength, range of movements, pain, and outcome scores. All patients had good subjective satisfaction with the surgery and functional outcome. PRC is a reliable option for complex perilunate fracture-dislocations with extended proximal migration of the scaphoid proximal pole. The degenerative changes after PRC may progress with time, mostly when done for young patients. Outcomes of salvage procedure in the long-term follow-up need to be taken into account when counselling patients on the treatment of these injuries.

A Novel Profiled Multi-Pin Electrospinning System for Nanofiber Production and Encapsulation of Nanoparticles into Nanofibers.

Electrospinning with various machine configurations is being used to produce polymer nanofibers with different rates of output. The use of polymers with high viscosity and the encapsulation of nanoparticles for achieving functionalities are some of the limitations of the existing methods. A profiled multi-pin electrospinning (PMES) setup is demonstrated in this work that overcomes the limitations in the needle and needleless electrospinning like needle clogging, particle settling, and uncontrolled/uneven Taylor cone formation, the requirement of very high voltage and uncontrolled distribution of nanoparticles in nanofibers. The key feature of the current setup is the use of profiled pin arrangement that aids in the formation of spherical shape polymer droplet and hence ensures uniform Taylor cone formation throughout the fiber production process. With a 10 wt% of Polyvinyl Alcohol (PVA) polymer solution and at an applied voltage of 30 kV, the production rate was observed as 1.690 g/h and average fiber diameter obtained was 160.5 ± 48.9 nm for PVA and 124.9 ± 49.8 nm for Cellulose acetate (CA) respectively. Moreover, the setup also provides the added advantage of using high viscosity polymer solutions in electrospinning. This approach is expected to increase the range of multifunctional electrospun nanofiber applications.

Computational identification of miRNAs and their target genes from expressed sequence tags of tea (Camellia sinensis).

MicroRNAs (miRNAs) are a newly identified class of small non-protein-coding post-transcriptional regulatory RNA in both plants and animals. The use of computational homology based search for expressed sequence tags (ESTs) with the Ambros empirical formula and other structural feature criteria filter is a suitable combination towards the discovery and isolation of conserved miRNAs from tea and other plant species whose genomes are not yet sequenced. In the present study, we blasted the database of tea (Camellia sinensis) ESTs to search for potential miRNAs, using previously known plant miRNAs. For the first time, four candidate miRNAs from four families were identified in tea. Using the newly identified miRNA sequences, a total of 30 potential target genes were identified for 11 miRNA families; 6 of these predicted target genes encode transcription factors (20%), 16 target genes appear to play roles in diverse physiological processes (53%) and 8 target genes have hypothetical or unknown functions (27%). These findings considerably broaden the scope of understanding the functions of miRNA in tea.

Guaijaverin -- a plant flavonoid as potential antiplaque agent against Streptococcus mutans.

AIMS: The aim of the present study was to investigate the anti-Streptococcus mutans activity and the in vitro effects of subminimal inhibitory concentrations of guaijaverin isolated from Psidium guajava Linn. on cariogenic properties of Strep. mutans. METHODS AND RESULTS: Bioautography-directed chromatographic fractionation, yield biologically active compound, quercetin-3-O-alpha-l-arabinopyranoside (guaijaverin), from crude methanol extract of P. guajava. Growth-inhibitory activity of the compound against Strep. mutans of both clinical and type strain cultures was evaluated. The anti-Strep. mutans activity of the guaijaverin was found to be bacteriostatic, both heat and acid stable and alkali labile with the minimum inhibitory concentration (MIC) of 4 mg ml(-1) for MTCC 1943 and 2 mg ml(-1) for CLSM 001. The sub-MIC concentrations (0.0078-2 mg ml(-1)) of the guaijaverin were evaluated for its cariogenic properties such as acid production, cell-surface hydrophobicity, sucrose-dependent adherence to glass surface and sucrose-induced aggregation of Strep. mutans. CONCLUSIONS: The active flavonoid compound, quercetin-3-O-alpha-l-arabinopyranoside (guaijaverin) demonstrated high potential antiplaque agent by inhibiting the growth of the Strep. mutans. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrated the new growth-inhibitory compound guaijaverin against Strep. mutans and led to the acceptance of traditional medicine and natural products as an alternative form of health care.