Parametric investigation of W-EDM factors for machining AM60B conductive biomaterial.

Wire-electrical discharge machining (W-EDM) is a precise and efficient non-traditional technology employed to cut intricate shapes in conductive biomaterials. These biomaterials are challenging to machine using traditional methods. This present study delves into the impact of various process parameters, namely discharge duration (Ddur), spark gap time (Stime), discharge voltage (Dvolt), and wire advance rate rate (Wadv). This research evaluates the impact of several factors on response variables, namely the machining rate (MR) and surface irregularity (SR), during the machining process of the AM60B magnesium alloy. The confirmation of the material used in the machining process is achieved via the utilisation of a scanning electron microscopy (SEM) image in conjunction with an energy dispersive spectroscopic (EDS) image. The experiment is designed as L9 orthogonal array by using Taguchi's approach, taking into account 4 factors with 3 levels. The objective of this experiment is to ascertain the most favourable values for machining parameters while working with AM60B magnesium alloy using brass wire. Through analysis of variance (ANOVA), the study confirms that wire advance rate (43.10%) is the most influencing parameter for machining rate and surface irregularity followed by spark gap time (33.91%) and discharge duration (11.48%). Additionally, The TOPSIS-CRITIC and the desirability approach were used in order to determine the optimum parameter combinations that provide the most favourable combined output. Confirmatory testing is used to evaluate the efficiency of the stated ideal conditions. The maximum improvement in Desirability approach is obtained at 4.56% and 4.193% for MR and SR respectively. The maximum improvement in TOPSIS approach is obtained at 1.77% and 2.78% for MR and SR respectively.

Bottom-Up Growth of Monolayer Honeycomb SiC.

The long theorized two-dimensional allotrope of SiC has remained elusive amid the exploration of graphenelike honeycomb structured monolayers. It is anticipated to possess a large direct band gap (2.5 eV), ambient stability, and chemical versatility. While sp^{2} bonding between silicon and carbon is energetically favorable, only disordered nanoflakes have been reported to date. Here we demonstrate large-area, bottom-up synthesis of monocrystalline, epitaxial monolayer honeycomb SiC atop ultrathin transition metal carbide films on SiC substrates. We find the 2D phase of SiC to be almost planar and stable at high temperatures, up to 1200 °C in vacuum. Interactions between the 2D-SiC and the transition metal carbide surface result in a Dirac-like feature in the electronic band structure, which in the case of a TaC substrate is strongly spin-split. Our findings represent the first step towards routine and tailored synthesis of 2D-SiC monolayers, and this novel heteroepitaxial system may find diverse applications ranging from photovoltaics to topological superconductivity.

Clinicopathological profile and outcome of adult infection-related glomerulonephritis: A prospective follow-up study.

Background: . Infection-related glomerulonephritis (IRGN) in adults is witnessing a dramatic shift in its epidemiology and outcome. Adult IRGN studies are all retrospective in nature, and Indian studies are scarce. Methods: . We did this prospective study (September 2016-April 2018) on all patients with biopsy-proven IRGN and age ≥18 years satisfying three of five diagnostic criteria. Patients with persistent hypocomplementaemia (>3 months) were excluded. We did electron microscopy in those without a minimum of three diagnostic criteria and did an extensive search for any occult infection in every patient. Results: . Forty-five patients were studied with a mean (SD) follow-up of 45.7 (20) weeks. Their mean age was 41.5 years (18-70 years), with a female preponderance (1:1.25). At presentation, the majority had oedema (100%), oliguria (84.4%), hypertension (80%) and haematuria (77.8%). Of them, 86.7% had renal insufficiency and 35.6% required dialysis. Only 53.3% of them had evidence of antecedent/ current infection, with skin/subcutaneous focus being the most common site. Hypocomplementaemia was present in 82.2% of patients. Salient pathological features were endocapillary proliferation (93.3%), neutrophilic infiltration (88.9%), presence of crescents (17.8%), interstitial infiltration (24.4%), moderate-to-severe interstitial fibrosis with tubular atrophy (IFTA; 15.5%) and underlying diabetic glomerulosclerosis (8.9%). Only 66.7% of patients made complete renal recovery. By logistic regression analysis, the predictors of poor outcome were a requirement for dialysis at presentation (p=0.04) and presence of IFTA (p = 0.03). Conclusion: . A proportion of adult IRGN patients progress to chronic kidney disease.

Evaluation of anti-urolithiatic potential of ethyl acetate extract of Pedalium murex L. on struvite crystal (kidney stone).

Pedalium murex (L.) is a traditional herb, commonly used for the treatment of kidney stone related problems. Struvite stone can swiftly grow and become 'staghorn calculi' in kidney and its associated areas, which is the most aching urological disorder. The present study investigated the anti-urolithiasis activities of ethyl acetate extract of P. murex L. (EAEP) against struvite crystal. The antibacterial activity of EAEP examined against several urease producing bacteria. It showed the minimum bactericidal concentration (MBC) against Escherichia coli and Staphylococcus aureus (>125). On the other hand, total mass, volume, number, growth rate and dissolution rate of synthesised struvite crystals were observed at different concentrations 0.5%, 0.75%, 1% of EAEP and without EAEP. In which, EAEP addition showed appreciably reduced struvite crystal. Alternatively, MgO (300 mg of EAEP/kg/body weight) induced urolithiasis of Wistar albino rat at the rate of 1 ml for 28 days. Various biochemical parameters in serum, urine and histological analysis of kidney were taken for evaluation. Significant results (p < 0.05) were observed in 1% EAEP (300 mg) treated group than cystone treated group. From the histological study, reduced renal damage and glomerular development were observed. Our experiment, P. murex L. enhances the reducing activity on struvite crystal and prevents the crystal formation both in-vitro and in-vivo. It can be suggesting that P. murex L. and its phyto-components could be used as remedy for the management of kidney stone by dissolving the struvite stone in kidney.

Genomic insights of Vibrio harveyi RT-6 strain, from infected "Whiteleg shrimp" (Litopenaeus vannamei) using Illumina platform.

The pathogenicity of "Vibriosis" in shrimps imposes prominent menace to the sustainable growth of mariculture economy. Often the disease outbreak is associated speciously with Vibrio harveyi and its closely related species. The present study investigated the complete genome of the strain V. harveyi RT-6 to explore the molecular mechanism of pathogenesis. The genome of V. harveyi possesses a single chromosome of 6,374,398 bp in size, G + C content (44.7%) and 5730 protein coding genes. The reads of 1.3 Gb were retained from Illumina Hiseq 2500 sequencing method, assembled into 5912 predicted genes, 114 tRNAs genes, and 11 rRNAs genes. Unigenes were annotated by matching against Clusters of Orthologous Groups of proteins (COG)-5730, Gene ontology (GO)-1088, and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases-3401. Furthermore, 13 insertion sequences-(IS), virulence factors and prophage regions were also identified. A total of 94 pathogenic genes and 36 virulence factor genes were mainly identified using Virulence Factors Database (VFDB). Out of the 36 virulence factors, 23 genes responsible for encoding flagella-based motility protein were exclusively predicted to take part in pathogenic mechanism. The Whole Genome Sequencing (WGS) of the strain RT-6 (accession number: SRR5410471) highlighted the underlying genes and specifically accountable functional genes that were responsible for pathogenic infections in shrimps.

Influence of Bicationic and Catanionic Surfactants Over the Morphology of Mesoporous Nanohydroxyapatite.

In the co-precipitation method, the morphology of nano Hydroxyapatite (HAp) is usually being controlled by parameters like pH, temperature, concentration, and the ratio of the mixed surfactants. In the present work, effective tailoring of morphology has been done by exploiting the electrostatic interaction between surfactants by grouping them as catanionic (Cetrimide and SDS) and bicationic (Cetrimide and CTAB), with weight ratio of 1:1 and total concentration of 0.28 g/100 ml. The prepared samples were subjected to various characterizations like FTIR, XRD, FESEM, HRTEM, TGA/DTA, and BET analysis. The results show that the samples are in HAp phase, nano size and mesoporous in nature. The FESEM images reveal the fact that the catanionic surfactant enhances the growth of particle from sphere to hexagonal rod whereas bicationic mixture suppresses the growth and results in a disk-like HAp. The samples were subjected to AAS test for finding the Ca2+ ion release rate in SBF and were compared with a commercial nanocrystalline HAp sample. The Ca2+ ion release test of the samples shows signs of better bioactivity of disk-like HAp than that of commercial one.

Synergistic Role of Electrolyte and Binder for Enhanced Electrochemical Storage for Sodium-Ion Battery.

Sodium-ion batteries are promising futuristic large-scale energy-storage devices because of the abundance and low cost of sodium. However, the development and commercialization of the sodium-ion battery solely depends on the use of high-capacity electrode materials. Among the various metal oxides, SnO2 has a high theoretical specific capacity for sodium-ion battery. However, the enormous volume expansion and low electrical conductivity of SnO2 hinder its capability to reach the predicted theoretical value. Although different nanostructured designs of electrode materials like SnO2 nanocomposites have been studied, the effects of other cell components like electrolyte and binder on the specific capacity and cyclic stability are yet to be understood. In the present study, we have investigated the synergistic effect of electrolyte and binder on the performance enhancement of SnO2 supported on the intertwined network structure of reduced graphene oxide partially open multiwalled carbon nanotube hybrid as anode in sodium-ion battery. Our result shows that sodium carboxyl methyl cellulose and ethylene carbonate/diethyl carbonate as the electrolyte solvent offers a high specific capacity of 688 mAh g-1 and a satisfactory cyclic stability for 500 cycles. This is about 56% enhancement in specific capacity compared to the use of poly(vinylidene fluoride) binder and propylene carbonate as the electrolyte solvent. The present study provides a better understanding of the synergistic role of electrolyte and binder for the development of metal-oxide-based electrode materials for the advancement of the commercialization of sodium-ion battery.

Ubiquitous formation of bulk Dirac cones and topological surface states from a single orbital manifold in transition-metal dichalcogenides.

Transition-metal dichalcogenides (TMDs) are renowned for their rich and varied bulk properties, while their single-layer variants have become one of the most prominent examples of two-dimensional materials beyond graphene. Their disparate ground states largely depend on transition metal d-electron-derived electronic states, on which the vast majority of attention has been concentrated to date. Here, we focus on the chalcogen-derived states. From density-functional theory calculations together with spin- and angle-resolved photoemission, we find that these generically host a co-existence of type-I and type-II three-dimensional bulk Dirac fermions as well as ladders of topological surface states and surface resonances. We demonstrate how these naturally arise within a single p-orbital manifold as a general consequence of a trigonal crystal field, and as such can be expected across a large number of compounds. Already, we demonstrate their existence in six separate TMDs, opening routes to tune, and ultimately exploit, their topological physics.

De novo assembly and annotation of the whole genomic analysis of Vibrio campbellii RT-1 strain, from infected shrimp: Litopenaeus vannamei.

OBJECTIVES: This study aimed to sequence the whole genome of Vibrio campbellii RT-1 strain. METHODS: V. campbellii strain was isolated from an infected shrimp, Litopenaeus vannamei collected from aquaculture ponds, India (12.1899° N, 79.9249° E). The whole genome sequencing (WGS) was performed using the Illumina Hiseq 2500 platform and assembled de novo using SPAdes and Velvet optimiser. Furthermore, the gene prediction and annotation were performed by a rapid prokaryotic genome tool-Prokka. RESULTS: The genome of V. campbellii RT-1 strain has one circular chromosome with 6327218 bp long. V. campbellii RT-1 strain contains 5787 predicted genes with an average of 45% GC content. A total of 86 known genes associated with pathogenicity were identified and 28 genes were found to be responsible for virulence factors. Furthermore, 1112 unigenes were subjected to Gene Ontology (GO) terms, and 4895 predicted proteins were annotated with Clusters of orthologous (COGs) functional groups. CONCLUSIONS: The phylogenetic position of V. campbellii RT-1 strain was established through whole genome sequencing and genomic tools which provides a strong platform to further study on genomic alterations and phenotype of V. campbellii.

Strong Linear Dichroism in Spin-Polarized Photoemission from Spin-Orbit-Coupled Surface States.

A comprehensive understanding of spin-polarized photoemission is crucial for accessing the electronic structure of spin-orbit coupled materials. Yet, the impact of the final state in the photoemission process on the photoelectron spin has been difficult to assess in these systems. We present experiments for the spin-orbit split states in a Bi-Ag surface alloy showing that the alteration of the final state with energy may cause a complete reversal of the photoelectron spin polarization. We explain the effect on the basis of ab initio one-step photoemission theory and describe how it originates from linear dichroism in the angular distribution of photoelectrons. Our analysis shows that the modulated photoelectron spin polarization reflects the intrinsic spin density of the surface state being sampled differently depending on the final state, and it indicates linear dichroism as a natural probe of spin-orbit coupling at surfaces.

Antidiabetic and Antioxidant Potentials of Amaranthus hybridus in Streptozotocin-Induced Diabetic Rats.

CONTEXT: Amaranthus hybridus (Amaranthaceae) has been used as a folk medicine in southern parts of India for the treatment of diabetes. OBJECTIVE: This research evaluates the antidiabetic and antioxidant effects of Amaranthus hybridus ethanol leaf extract (AHELE) in streptozotocin-induced diabetic rats. METHODS: Blood glucose levels of diabetic rats were measured on days 1, 4, 7, and 15 after oral administration of AHELE at doses of 200 and 400 mg/kg for 14 days. The effects of extract were observed on serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, serum alkaline phosphatase, cholesterol, high- and low-density lipoprotein, antioxidant potential, and histopathological changes. RESULT: AHELE (200 and 400 mg/kg) caused a significant (p < 0.001) reduction in blood glucose levels on day 15 (152.2 and 181.2 mg/dL, respectively versus diabetic control 287.0 mg/dL). The extract also improved serum biochemical parameters associated with diabetes. A significant (p < 0.001) decrease in malondialdehyde protein (liver: 15.92, 12.29 nmol/mg, and kidney: 13.92, 10.29 nmol/mg vs. diabetic control 25.49, 24.49 nmol/mg), increase in superoxide dismutase protein (14.01; 17.47 IU/mg, and 25.01; 37.47 IU/mg vs. diabetic control 9.65; 15.65 IU/mg), catalase protein (35.80, 44.49, and 39.80, 49.69 nmol/min/mg vs. diabetic control 18.45, 20.85 nmol/min/mg) and reduced glutathione protein (44.77, 55.08 and 40.77, 51.08 µM/gm vs. diabetic control 29.81, 26.50 µM/gm) were observed. CONCLUSIONS: The study reveals that treatment of diabetic rats with AHELE significantly reduced hyperglycemia-associated oxidative damage. This could provide a rationale for the use of the plant to treat diabetes in folk medicine.

Observation of a topologically non-trivial surface state in half-Heusler PtLuSb (001) thin films.

The discovery of topological insulators, materials with bulk band gaps and protected cross-gap surface states in compounds such as Bi2Se3, has generated much interest in identifying topological surface states (TSSs) in other classes of materials. In particular, recent theoretical calculations suggest that TSSs may be found in half-Heusler ternary compounds. If experimentally realizable, this would provide a materials platform for entirely new heterostructure spintronic devices that make use of the structurally identical but electronically varied nature of Heusler compounds. Here we show the presence of a TSS in epitaxially grown thin films of the half-Heusler compound PtLuSb. Spin- and angle-resolved photoemission spectroscopy, complemented by theoretical calculations, reveals a surface state with linear dispersion and a helical tangential spin texture consistent with previous predictions. This experimental verification of topological behaviour is a significant step forward in establishing half-Heusler compounds as a viable material system for future spintronic devices.

Spin-valley locking in the normal state of a transition-metal dichalcogenide superconductor.

Metallic transition-metal dichalcogenides (TMDCs) are benchmark systems for studying and controlling intertwined electronic orders in solids, with superconductivity developing from a charge-density wave state. The interplay between such phases is thought to play a critical role in the unconventional superconductivity of cuprates, Fe-based and heavy-fermion systems, yet even for the more moderately-correlated TMDCs, their nature and origins have proved controversial. Here, we study a prototypical example, 2H-NbSe2, by spin- and angle-resolved photoemission and first-principles theory. We find that the normal state, from which its hallmark collective phases emerge, is characterized by quasiparticles whose spin is locked to their valley pseudospin. This results from a combination of strong spin-orbit interactions and local inversion symmetry breaking, while interlayer coupling further drives a rich three-dimensional momentum dependence of the underlying Fermi-surface spin texture. These findings necessitate a re-investigation of the nature of charge order and superconducting pairing in NbSe2 and related TMDCs.

Isolation and structural elucidation of antioxidant peptides from oyster (Saccostrea cucullata) protein hydrolysate.

Protein derived from the oyster (Saccostrea cucullata) was hydrolyzed using protease from Bacillus cereus SU12 for isolation of antioxidant peptides. The oyster hydrolysate exhibited a strong antioxidant potential in DPPH (85.7±0.37%) followed by Hydrogen peroxide radical scavenging activity (81.6±0.3%), Hydroxyl radical-scavenging activity (79.32±0.6%), Reducing power assay (2.63±0.2 OD at 700nm). Due to the high antioxidant potential, hydrolysate was fractionated in Sephadex G-25 gel filtration chromatography. The active peptide fraction was further purified by UPLC-MS. Totally 7 antioxidant peptides were collected. Among 7 peptides (SCAP 1-7), 3 peptides (SCAP 1, 3 and 7) had highest scavenging ability on DPPH radicals. The amino acid sequence and molecular mass of purified antioxidant peptides (SCAP1, SCAP3 and SCAP7) were determined by Q-TOF ESI mass spectroscopy and structures of the peptides were Leu-Ala-Asn-Ala-Lys (MW=515.29Da), Pro-Ser-Leu-Val-Gly-Arg-Pro-Pro-Val-Gly-Lys-Leu-Thr-Leu (MW=1432.89Da) and Val-Lys-Val-Leu-Leu-Glu-His-Pro-Val-Leu (MW=1145.75Da), respectively. The unique amino acid composition and sequence in the peptides might play an important role in expression of their antioxidant activity. The results of this study suggest that oyster protein hydrolysate is good source of natural antioxidants.

Hahn Sequence Space of Modals.

The history of modal intervals goes back to the very first publications on the topic of interval calculus. The modal interval analysis is used in Computer graphics and Computer Aided Design (CAD), namely, the computation of narrow bounds on Bezier and B-Spline curves. Since modal intervals are used in many fields, we introduce a new sequence space h(gI) called the Hahn sequence space of modal intervals. We have given some new definitions and theorems. Some inclusion relation and some topological properties of this space are investigated. Also dual spaces of this space are computed.

Kinks in the σ band of graphene induced by electron-phonon coupling.

Angle-resolved photoemission spectroscopy reveals pronounced kinks in the dispersion of the σ band of graphene. Such kinks are usually caused by the combination of a strong electron-boson interaction and the cutoff in the Fermi-Dirac distribution. They are therefore not expected for the σ band of graphene that has a binding energy of more than ≈3.5 eV. We argue that the observed kinks are indeed caused by the electron-phonon interaction, but the role of the Fermi-Dirac distribution cutoff is assumed by a cutoff in the density of σ states. The existence of the effect suggests a very weak coupling of holes in the σ band not only to the π electrons of graphene but also to the substrate electronic states. This is confirmed by the presence of such kinks for graphene on several different substrates that all show a strong coupling constant of λ≈1.

Modulating effect of d-carvone on 1,2-dimethylhydrazine-induced pre-neoplastic lesions, oxidative stress and biotransforming enzymes, in an experimental model of rat colon carcinogenesis.

OBJECTIVES: The present study has aimed to evaluate chemopreventive potential of d-carvone on oxidative stress markers, biotransforming enzymes, incidence of colonic polyps and aberrant crypt foci (ACF) in 1,2-dimethylhydrazine (DMH)-induced experimental colon carcinogenesis. MATERIALS AND METHODS: Rats were randomly divided into six groups, with group I serving as control. Group II animals received d-carvone every day orally (20 mg/kg body weight) for 16 weeks; groups III-VI received subcutaneous injections of DMH (20 mg/kg body weight) once a week, for the first 4 weeks. In addition, groups IV-VI received different doses of d-carvone (5, 10 and 20 mg/kg body weight everyday orally) along with DMH injections. RESULTS: Our results revealed that supplementation with d-carvone significantly reduced incidence of polyps/ACF and ACF multiplicity in DMH-exposed rats compared to DMH-alone-exposed rats. Moreover, our results showed reduced activities of liver and circulatory antioxidants and increased levels of lipid peroxidation by products in DMH-exposed animals, which were significantly reversed on supplementation with d-carvone. In addition, colonic antioxidants and lipid peroxidation were significantly diminished in DMH-exposed rats, which were significantly elevated on supplementation with d-carvone. Furthermore, we also determined activities of biotransforming enzymes, which were found to be altered in DMH-exposed rats, but reversed on d-carvone supplementation. All these observations of changes were supported by histochemical findings. CONCLUSION: Overall, results obtained from this study suggest that d-carvone at 10 mg/kg body weight provided optimum protection and could be used as an effective chemopreventive agent against colon carcinogenesis induced by DMH.

Influence of host anemone (Stichodactyla haddoni, saville-kent, 1893) locomotion on its resident anemonefish reproduction.

Anemonefish are found commonly in reef habitats and they select only limited anemone species to exist their life. This study describes the movement of anemone, Stichodactyla haddoni and its impact on the reproduction of anemonefishes in captivity. The anemone movement was found to be creeping and in straight-line between successive positions (based on overlay mapping). The distance traveled by the host with (60%) and without substrate (20%) varied significantly (P<0.05) at a random direction. Spawning interval of the resident fish (3-4 days) increased significantly to 8-12 days (P<0.001) because of anemone mobility. Furthermore, host locomotion affected the embryonic development of harbored fish clutches. Percentage of egg maturity (3.5-35.3%) showed an exponential decrease with increase in the distance of substrate from the clutches, from 98 to 100% in the absence of host mobility to 3.5-35% with movement of >60cm. This study concludes that the sedentary habitat would enhance the reproduction value of the harbored fish. Further, in captivity providing with a substrate, supplying regular feed and good light intensity could prevent anemone migration and its implications on the reproductive success of the anemonefish.

Hatchery production of the clownfish Amphiprion nigripes at Agatti Island, Lakshadweep, India.

Healthy individuals of matured clownfish, Amphiprion nigripes and sea anemone, Heteractis magnifica were collected from the Agatti island lagoon by snorkeling. During 'conditioning' for 3 months, pair formation occurred and the same were transferred to rectangular fiber glass spawning tanks of 10001 capacity. Suitable water quality parameters were maintained. The fishes were fed with tuna eggs, boiled clam meat, squid, octopus and trash fish thrice in a day. Reproductive behaviour and embryonic development were documented. Spawning took place in between 0900 - 1100 hr and hatched-out occurs, after sunset following an incubation period of 8-9 days. Size of the newly laid egg was 2.0-2.2 mm in length and 1.0-1.2 mm in width. The larval rearing tanks were maintained with UV-treated water and followed the optimal physico-chemical parameters as in the parent tanks. The different light regimes and diets were used for the successful larval rearing. The maximum larval survival (61%) was achieved at the photoperiod of 24 L/0D. Within 15-17 days, the larvae metamorphosed and took up parent colouration and comparatively high growth rate was observed when fed on algae enriched rotifer than those with poly unsaturated fatty acid (PUFA).

Topological crystalline insulator states in Pb(1-x)Sn(x)Se.

Topological insulators are a class of quantum materials in which time-reversal symmetry, relativistic effects and an inverted band structure result in the occurrence of electronic metallic states on the surfaces of insulating bulk crystals. These helical states exhibit a Dirac-like energy dispersion across the bulk bandgap, and they are topologically protected. Recent theoretical results have suggested the existence of topological crystalline insulators (TCIs), a class of topological insulators in which crystalline symmetry replaces the role of time-reversal symmetry in ensuring topological protection. In this study we show that the narrow-gap semiconductor Pb(1-x)Sn(x)Se is a TCI for x = 0.23. Temperature-dependent angle-resolved photoelectron spectroscopy demonstrates that the material undergoes a temperature-driven topological phase transition from a trivial insulator to a TCI. These experimental findings add a new class to the family of topological insulators, and we anticipate that they will lead to a considerable body of further research as well as detailed studies of topological phase transitions.