Abasaheb Garware College

The size and shape dependent electronic and chemical properties of metal nanoparticles has drawn the attention of chemists, physicists, biologists, and engineers who wish to use them for the development of new generation nanodevices. In this article, we report the synthesis of gold nanotriangles using tamarind leaf extract as the reducing agent. On treating aqueous chloroauric acid solution with tamarind leaf extract, rapid reduction of the chloroaurate ions is observed leading to the formation of flat and thin single crystalline gold nanotriangles. Atomic force microscopy analysis of the gold nanotriangles indicated that they ranged in thickness from 20 to 40 nm. These gold nanotriangles with unique and highly anisotropic planer shapes might find application in photonics, optoelectronics, and optical sensing. We investigated the effect of different organic solvent vapors like methanol, benzene and acetone on the conductivity of tamarind leaf extract reduced gold nanotriangles. I‐V characteristics measurement of these nanotriangles was done in presence of these organic solvent vapors. The observed characteristics suggest the application of gold nanotriangles to future chemical sensors.

BACKGROUND: Development of an environmentally benign process for the synthesis of silver nanomaterials is an important aspect of current nanotechnology research. Among the 600 species of the genus Dioscorea, Dioscorea bulbifera has profound therapeutic applications due to its unique phytochemistry. In this paper, we report on the rapid synthesis of silver nanoparticles by reduction of aqueous Ag(+) ions using D. bulbifera tuber extract. METHODS AND RESULTS: Phytochemical analysis revealed that D. bulbifera tuber extract is rich in flavonoid, phenolics, reducing sugars, starch, diosgenin, ascorbic acid, and citric acid. The biosynthesis process was quite fast, and silver nanoparticles were formed within 5 hours. Ultraviolet-visible absorption spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy dispersive spectroscopy, and x-ray diffraction confirmed reduction of the Ag(+) ions. Varied morphology of the bioreduced silver nanoparticles included spheres, triangles, and hexagons. Optimization studies revealed that the maximum rate of synthesis could be achieved with 0.7 mM AgNO(3) solution at 50°C in 5 hours. The resulting silver nanoparticles were found to possess potent antibacterial activity against both Gram-negative and Gram-positive bacteria. Beta-lactam (piperacillin) and macrolide (eryth-romycin) antibiotics showed a 3.6-fold and 3-fold increase, respectively, in combination with silver nanoparticles selectively against multidrug-resistant Acinetobacter baumannii. Notable synergy was seen between silver nanoparticles and chloramphenicol or vancomycin against Pseudomonas aeruginosa, and was supported by a 4.9-fold and 4.2-fold increase in zone diameter, respectively. Similarly, we found a maximum 11.8-fold increase in zone diameter of streptomycin when combined with silver nanoparticles against E. coli, providing strong evidence for the synergistic action of a combination of antibiotics and silver nanoparticles. CONCLUSION: This is the first report on the synthesis of silver nanoparticles using D. bulbifera tuber extract followed by an estimation of its synergistic potential for enhancement of the antibacterial activity of broad spectrum antimicrobial agents.

Landslide hazard assessment is an important step towards landslide hazard and risk management. There are several methods of Landslide Hazard Zonation (LHZ) viz. heuristic, semi quantitative, quantitative, probabilistic and multi-criteria decision making process. However, no one method is accepted universally for effective assessment of landslide hazards. In recent years, several attempts have been made to apply different methods of LHZ and to compare results in order to find the best suited model. This paper presents the review of researches on landslide hazard mapping published in recent years. The advanced multivariate techniques are proved to be effective in spatial prediction of landslides with high degree of accuracy. Physical process based models also perform well in LHZ mapping even in the areas with poor database. Multi-criteria decision making approach also play significant role in determining relative importance of landslide causative factors in slope instability process. Remote Sensing and Geographical Information System (GIS) are powerful tools to assess landslide hazards and are being used extensively in landslide researches since last decade. Aerial photographs and high resolution satellite data are useful in detection, mapping and monitoring landslide processes. GIS based LHZ models helps not only to map and monitor landslides but also to predict future slope failures. The advancements in Geo-spatial technologies have opened the doors for detailed and accurate assessment of landslide hazards.

Pancreatic cancer is considered to be the deadliest of all cancers due to its poor prognosis and resistance to conventional therapies.

Abstract Aim To study (1) the large‐scale distribution patterns of freshwater fishes in the Western Ghats of India; (2) the endemism and uniqueness of the fishes in various zones; and (3) the threat status of fishes by categorizing them under low risk (LR), vulnerable (VU), endangered (EN) and critically endangered (CR). Location The Western Ghats of India. Methods The scientific literature describing the freshwater fishes of the Western Ghats was reviewed. Data describing the lists of the species were extracted and complied. The species accumulation curve was plotted using Michaelis–Menten‐like equation. The Western Ghats was divided into six zones and similarity of the species was calculated using Jacquard's index. Results Literature to date records 288 species belonging to 12 orders, 41 families and 109 genera, of which 118 species are endemic and 51 are unique. However, the species accumulation curve shows that there might be 345 species in this region, indicating that 16% species have not been recorded to date. An analysis of the distribution pattern of fishes in the Western Ghats suggests that the southern region is more diverse than the northern and central regions. The southern region shows high endemism and high uniqueness while the northern region shows high endemism but less uniqueness. The similarity index between the zones indicates that as the distance between the zones increases similarity decreases. The status of 105 of 288 species was not known due to data deficiency but among the remaining 183 species, 58 species were categorized as LR, 41 as VU, 54 as EN, 24 as CR while the remaining six species were introduced. Conclusions The distribution patterns of fishes in the Western Ghats are discussed in accordance with the geography of Western Ghats, its climatic conditions and ‘Satpura Hypothesis’. The threat status of fishes found in Western Ghats suggests that at least 41% of fish fauna is threatened by either being VU, EN or CR. Implication of potent conservation measures is necessary to conserve the fish fauna of Western Ghats.

The degradation of Orange G, a monoazo dye, in aqueous solutions was investigated using as-synthesized and stored Fe-Ni bimetallic nanoparticles. Batch experiments with a nanocatalyst loading of 3 g/L showed complete dye degradation (150 mg/L) after 10 min of reaction time. HPLC-MS analysis of the degradation products showed that as-synthesized nanoparticles reductively cleaved the azo linkage to produce aniline as the major degradation product. However, 1-year-stored nanoparticles showed an oxidative degradation of Orange G through a hydroxyl-radical induced coupling of parent and/or product molecules. XPS analysis in corroboration with HPLC-MS data showed that the surface chemistry between Fe and Ni in as-synthesized and stored nanoparticles play a crucial role in directing the mode of degradation. Reductive dye degradation using as-synthesized nanoparticles proceeded through hydride transfer from nickel, whereas formation of a Fe2+ -Ni(0) galvanic cell in stored nanoparticles generated hydroxyl radicals from water in a nonFenton type reaction. The latter were responsible for the generation of radical centers on the dye molecule, which led to a coupling-mediated oxidative degradation of Orange G. The generation of hydroxyl radicals is further substantiated with radical quenching experiments using ascorbic acid indicating that stored nanoparticles degrade Orange G through a predominantly oxidative mechanism. HPLC-MS and XPS analysis of dye degradation using as-synthesized nanoparticles exposed to air and water confirmed that the reductive or oxidative degradation capability of Fe-Ni nanoparticles is decided by the time and type of catalyst aging process.

Aging is known in all organisms that have different somatic and reproductive cells or in unicellular organisms that divide asymmetrically. Bacteria that divide symmetrically were believed to be immune to natural aging. The demonstration of functionally asymmetric division and aging in Escherichia coli recently has challenged this belief and led to the suggestion that aging might be inevitable for all life forms. We modeled the effects of symmetric and asymmetric division in bacteria to examine selective advantages of the alternative strategies of division. Aging of cell components was modeled by using a modified Leslie matrix framework. The model suggests that asymmetric division accompanied by aging and death of some cells results in a higher growth rate but a reduced growth yield. Symmetric division with or without gradual replacement of the old components, on the other hand, slows down the growth rate but may increase growth yield over a wide range of conditions. Thus, aging and immortality can be selected under different sets of conditions, and this selection may also lead to a tradeoff between growth rate and growth yield.

Various iridium supported carbon catalysts were prepared and screened for the direct hydrogenation of furfural (FFR) to 2-methyl furan (2-MF).

Diabetes mellitus is a multifactorial metabolic disease characterized by post-prandial hyperglycemia (PPHG). α-amylase and α-glucosidase inhibitors aim to explore novel therapeutic agents. Herein we report the promises of Dioscorea bulbifera and its bioactive principle, diosgenin as novel α-amylase and α-glucosidase inhibitor. Among petroleum ether, ethyl acetate, methanol and 70% ethanol (v/v) extracts of bulbs of D. bulbifera, ethyl acetate extract showed highest inhibition upto 72.06 ± 0.51% and 82.64 ± 2.32% against α-amylase and α-glucosidase respectively. GC-TOF-MS analysis of ethyl acetate extract indicated presence of high diosgenin content. Diosgenin was isolated and identified by FTIR, 1H NMR and 13C NMR and confirmed by HPLC which showed an α-amylase and α-glucosidase inhibition upto 70.94 ± 1.24% and 81.71 ± 3.39%, respectively. Kinetic studies confirmed the uncompetitive mode of binding of diosgenin to α-amylase indicated by lowering of both Km and Vm. Interaction studies revealed the quenching of intrinsic fluorescence of α-amylase in presence of diosgenin. Similarly, circular dichroism spectrometry showed diminished negative humped peaks at 208 nm and 222 nm. Molecular docking indicated hydrogen bonding between carboxyl group of Asp300, while hydrophobic interactions between Tyr62, Trp58, Trp59, Val163, His305 and Gln63 residues of α-amylase. Diosgenin interacted with two catalytic residues (Asp352 and Glu411) from α-glucosidase. This is the first report of its kind that provides an intense scientific rationale for use of diosgenin as novel drug candidate for type II diabetes mellitus.

Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as sources of natural antioxidants. Herein we report the phytochemical analysis and free radical scavenging activity of their sequential extracts. Phenolic and flavonoid content were determined. Scavenging activity was checked against pulse radiolysis generated ABTS(•+) and OH radical, in addition to DPPH, superoxide and hydroxyl radicals by biochemical methods followed by principal component analysis. G. glauca leaf extracts were rich in phenolic and flavonoid content. Ethyl acetate extract of D. bulbifera bulbs and methanol extract of G. glauca stem exhibited excellent scavenging of pulse radiolysis generated ABTS(•+) radical with a second order rate constant of 2.33 × 10(6) and 1.72 × 10(6), respectively. Similarly, methanol extract of G. glauca flower and ethyl acetate extract of D. bulbifera bulb with second order rate constants of 4.48 × 10(6) and 4.46 × 10(6) were found to be potent scavengers of pulse radiolysis generated OH radical. G. glauca leaf and stem showed excellent reducing activity and free radical scavenging activity. HPTLC fingerprinting, carried out in mobile phase, chloroform: toluene: ethanol (4: 4: 1, v/v) showed presence of florescent compound at 366 nm as well as UV active compound at 254 nm. GC-TOF-MS analysis revealed the predominance of diphenyl sulfone as major compound in G. glauca. Significant levels of n-hexadecanoic acid and octadecanoic acid were also present. Diosgenin (C₂₇H₄₂O₃) and diosgenin (3á,25R) acetate were present as major phytoconstituents in the extracts of D. bulbifera. G. glauca and D. bulbifera contain significant amounts of phytochemicals with antioxidative properties that can be exploited as a potential source for herbal remedy for oxidative stress induced diseases. These results rationalize further investigation in the potential discovery of new natural bioactive principles from these two important medicinal plants.

Diabetes is a metabolic disorder affecting about 220 million people worldwide. One of the most critical complications of diabetes is post-prandial hyper-glycemia (PPHG). Glucosidase inhibitor and α-amylase inhibitors are class of compounds that help in managing PPHG. Low-cost herbal treatment is recommended due to their lesser side effect for treatment of diabetes. Two plants with significant traditional therapeutic potential, namely, Gnidia glauca and Dioscorea bulbifera, were tested for their efficiency to inhibit α-amylase and α-glucosidase. Stem, leaf, and flower of G. glauca and bulb of D. bulbifera were sequentially extracted with petroleum ether, ethyl acetate, and methanol as well as separately with 70% ethanol. Petroleum ether extract of flower of G. glauca was found to inhibit α-amylase significantly (78.56%). Extracts were further tested against crude murine pancreatic, small intestinal, and liver glucosidase enzyme which revealed excellent inhibitory properties. α-glucosidase inhibition provided a strong in vitro evidence for confirmation of both G. glauca and D. bulbifera as excellent antidiabetic remedy. This is the first report of its kind that provides a strong biochemical basis for management of type II diabetes using G. glauca and D. bulbifera. These results provide intense rationale for further in vivo and clinical study.

Abstract Meckel syndrome (MKS) is a pre‐ or perinatal multisystemic ciliopathic lethal disorder with an autosomal recessive mode of inheritance. Meckel syndrome is usually manifested with meningo‐occipital encephalocele, polycystic kidney dysplasia, postaxial polydactyly and hepatobiliary ductal plate malformation. Germline variants in CEP290 cause MKS4. In this study, we investigated a 35‐years‐old Chinese female who was 17+1 weeks pregnant. She had a history of adverse pregnancy of having foetus with multiple malformations. We performed ultrasonography and identified the foetus with occipital meningoencephalocele and enlarged cystic dysplastic kidneys. So, she decided to terminate her pregnancy and further genetic molecular analysis was performed. We identified the aborted foetus without postaxial polydactyly. Histological examination of foetal kidney showed cysts in kidney and thinning of the renal cortex with glomerular atrophy. Whole exome sequencing identified a novel homozygous variant (c.2144T>G; p.L715 * ) in exon 21 of the CEP290 in the foetus. Sanger sequencing confirmed that both the parents of the foetus were carrying this variant in a heterozygous state. This variant was not identified in two elder sisters of the foetus as well as in the 100 healthy individuals. Western blot analysis showed that this variant leads to the formation of truncated CEP290 protein with the molecular weight of 84 KD compared with the wild‐type CEP290 protein of 290 KD. Hence, it is a loss‐of‐function variant. We also found that the mutant cilium appears longer in length than the wild‐type cilium. Our present study reported the first variant of CEP290 associated with MKS4 in Chinese population.

A bifunctional Ni/MMT catalyst for catalytic transfer hydrogenation of levulinic acid to γ-valerolactone with complete conversion and selectivity.

Abstract We report the phonon and magnetic properties of various well-stabilized Co 3 O 4 nanoparticles. The net valence in cobalt (II)/(III) cation can be obtained by subtracting the Co 2+ ions in tetrahedral interstices and Co 3+ ions in the octahedral interstices, respectively, which will possess spatial inhomogeneity of its magnetic moment via Co 2+ in tetrahedra and Co 3+ in octahedral configurations in the normal spinel structure. Furthermore, the distribution of Co 2+ /Co 3+ governed by various external (magnetic field and temperature) and internal (particle size and slightly distorted CoO 6 octahedra) sources, have led to phenomena such as a large redshift of phonon-phonon interaction and short-range magnetic correlation in the inverse spinel structure. The outcome of our study is important in terms of the future development of magnetic semiconductor spintronic devices of Co 3 O 4 .

Room-temperature confocal Raman scattering was used to probe the antiferromagnetic exchange energy J2 between the next-nearest-neighboring Ni ions in different sized NiO nanoparticles. NiO nanoparticles were synthesized using the sol–gel method and annealed at various temperatures ranging from 300 to 800 °C. The morphology and crystal structure of the prepared samples were characterized using SEM and XRD, revealing the uniformity and development of short-range crystallinity of NiO nanoparticles. This study shows that short spin correlation leads to an exponential dependency of particle size and the existence of Ni vacancies in two-magnon excitation. The Ni vacancy concentration plays an important role in lattice expansion, along with the size reduction effect. A direct comparison between short-range magnon excitation related to the Ni vacancy concentration and NiO nonstoichiometry has been made.

Abstract Asymmetric supercapacitor was fabricated successfully using cerium (Ce) doped NiO as positive electrode and reduced graphene oxide (rGO) as negative electrode in aqueous KOH electrolyte. Initially, Ce doped nickel oxide nanostructures were synthesized by simple Sol‐Gel method. To investigate the effect of Ce doping in nickel oxide, different molar percentages of cerium with respect to nickel were incorporated. Among the different compositions, 1%Ce:NiO exhibits high specific capacitance and excellent electrochemical activities. Further, asymmetric supercapacitor based on 1%Ce:NiO and rGO was fabricated which could be cycled reversibly in the high‐voltage range of 0 to 1.4 V and displays intriguing performances with a specific capacitance of 110 F/g at a scan rate of 5 mV/s with a maximum energy density of 26.27 Wh/kg (based on the total mass of active materials, 0.78 mg). Importantly, this asymmetric device exhibits an excellent electrochemical stability of 91.6 % over 1000 cycles.

Members of the genus Nocardiopsis are an ecologically versatile and biotechnologically important group of Actinomycetes. Most of the isolates are halotolerant or halophilic and they prevail in soils, marine environments or hypersaline locations. To aid their survival under these conditions, they mainly produce extremozymes, compatible solutes, surfactants and bioactive compounds. The current review details the bioactive compounds obtained for this genus. Important antimicrobial agents obtained from this genus include polyketides, phenzines, quinoline alkaloids, terphenyls, proteins, thiopeptides and amines. Polyketides and peptides displaying potent anticancer activities are also significant. Tumour promoting agents, P-glycoprotein (P-gp) inhibitors, immunomodulators and protein kinase inhibitors are other relevant products obtained from Nocardiopsis species. Structurally, polyketides (synthesized by polyketide synthases) and peptides (made by nonribosomal peptide synthetases or cyclodipeptide synthases) are important compounds. Considered here are also toxins, anti photoaging and adipogenic agents produced by this genus. The gene clusters mediating the synthesis of bioactive compounds have been described. Commercially available products (Apoptolidins and K-252a) derived from this genus have also been described. This review highlights the significance of a single genus in producing an assortment of compounds with varied biological activities. On account of these features, the members of this genus have established a place for themselves and are of considerable value in producing compounds with profound bio-medical applications.

Green synthesis of nanoparticles is regarded as a safe and non-toxic process whereas conventional synthesis using chemical methods produces toxic substance. This study provides a novel insight for enzymatic synthesis method of silver nanoparticles using purple acid phosphatase, isolated from <i>Limonia acidissima</i> (wood apple) as a new source and used in the synthesis of silver nanoparticles. Stable silver nanoparticles were produced by sonochemical method using apoenzyme as a stabilising and capping agent and were characterised by various physicochemical techniques like UV–Visible spectroscopy, Fourier-transform infrared, X-ray diffraction and transmission electron microscopy. X-ray study shows that nanoparticles are composed of silver and silver oxide. The synthesised nanoparticles exhibited excellent antimicrobial activity against <i>Escherichia coli</i>, <i>Pseudomonas aeruginosa</i> and <i>Staphylococcus aureus</i>.

Biosynthesis of metal nanoparticles employing plant extracts and thereby development of an environmentally benign process is an important branch of nanotechnology. Here, the synthesis of gold nanoparticles using Dioscorea bulbifera tuber extract (DBTE) as the reducing agent is reported. Field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDX), X-ray diffraction (XRD), and UV-visible absorption spectroscopy confirmed the reduction of gold ions to AuNPs. The anisotropic nanoparticles consist of a mixture of gold nanotriangles, nanoprisms, nanotrapezoid, and spheres. The kinetics of particle formation was time dependent and was enhanced by the increase of temperature from 6°C to 50°C, the optimum being 50°C. The optimum concentration of chloroauric acid was found to be 1 mM. Complete reduction of the metal ions within 5 hours by DBTE highlights the development of a novel ecofriendly route of biological synthesis of gold nanoparticles. This is the first paper on synthesis of gold nanoparticles using DBTE.

CONTEXT: Acetaminophen (APAP) leads to severe hepatic and renal necrosis and thus causes significant clinical problems. Artemisia pallens Walls ex D.C. (Asteraceae) possesses various pharmacological properties such as antidiabetic, antioxidant, analgesic, and anti-inflammatory activity. OBJECTIVE: The objective was to evaluate the protective effects of Artemisia pallens methanol extract (APME) in APAP-induced hepatic and nephro-toxicity. MATERIALS AND METHODS: The methanolic extract of aerial parts of Artemisia pallens (APME) was prepared. Toxicity was induced in male Wistar rats (180-220 g) by administration of APAP (700 mg/kg, p.o., 14 d). APME (100, 200, and 400 mg/kg, p.o.) was administered to rats 2 h before APAP oral administration. Various biochemical and molecular parameters along with histopathological aberration were studied in the kidney and liver of rats. RESULTS: Pretreatment with APME (200 and 400 mg/kg, p.o.) significantly (p < 0.01 and p < 0.001) decreased aspartate transaminase (AST), alanine transaminase (ALT), bilirubin, blood urea nitrogen (BUN), and serum creatinine as compared with APAP-treated rat. Decreased level of serum albumin, serum uric acid, and HDL were significantly (p < 0.01 and p < 0.001) restored by APME (200 and 400 mg/kg, p.o.) pre-treatment. Administration of APME (200 and 400 mg/kg, p.o.) significantly (p < 0.01 and p < 0.001) reduced the elevated level of cholesterol, LDL, LDH, triglyceride, and VLDL. It also significantly (p < 0.01 and p < 0.001) restored the altered level of hepatic and renal antioxidant enzymes (superoxide dismutase (SOD) and glutathione (GSH)). The increased level of malondialdehyde (MDA) and nitric oxide (NO) in hepatic as well as renal tissue was significantly (p < 0.01 and p < 0.001) decreased by APME (200 and 400 mg/kg, p.o.) administration. Histological alternation induced by APAP in liver and kidney was also reduced by the APME (200 and 400 mg/kg, p.o.) pre-treatment. CONCLUSION: It is concluded that the methanol extract of Artemisia pallens alleviates APAP induced in rats toxicity through its antioxidative and anti-inflammatory actions.