In the present study, zinc oxide nanoparticles (ZnO NPs) were synthesized using leaf extract of
(
) under different physical parameters. Biosynthesis of ZnO NPs was confirmed by UV-Visible ...spectrophotometer and further, characterized by X-Ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy-Dispersive X-ray spectroscopy (EDX), Atomic Force Microscopy (AFM), Photoluminescence study and Dynamic Light Scattering (DLS). We have also confirmed that several physical parameters such as pH, temperature, concentration of metal ions and reaction time were able to regulate shape and size of synthesized ZnO NPs. XRD and TEM analysis provided the information about the average size and hexagonal morphology of ZnO NPs. FTIR spectra analysis suggested that phenolic compounds played crucial role in the biosynthesis of ZnO NPs. The significant antibacterial activity of ZnO NPs was observed against
MTCC 9760 (
),
MTCC 1926 (
),
MTCC 430 (
),
MTCC 424
,
MTCC 3310
and
MTCC 40 (
). The synthesized ZnO NPs have shown antibacterial efficacy against both Gram-positive and Gram-negative pathogens. Synergistic effects of ZnO NPs and streptomycin showed increased efficacy as indicated by the increased zone of clearance in comparison to their individual effects (either ZnO NPs or streptomycin). Overall, the results elucidated a rapid, cost-effective, environmentally friendly and convenient method for ZnO NPs synthesis, which could be used as a potential antimicrobial agent against drug resistant microbes.
Cellulose, a linear biopolymer, is present naturally in all plants. Apart from being the planet’s predominant natural polymer, it also offers a variety of features including excellent ...biocompatibility, lower density, substantial strength and the most beneficial mechanical characteristics, inexpensive in cost. Applying the mechanical or chemical techniques, cellulosic materials are transformed into cellulose nanofibres (CNFs) and even cellulose nanocrystals (CNCs). These CNFs and CNCs exhibit excellent capabilities in comparison with native cellulose fibre. Nowadays, nanocellulose is being used in a variety of practical applications such as product packaging, papers as well as paperboard, food sector, healthcare, hygiene products, paints, skin care products and sensors. The current review article summarizes the cellulose, processing methods for nanocellulose, techniques used for chemical modification of cellulose surface and consequently its application as reinforcement in polymeric materials. This article also provides a comprehensive discussion of the historical development in the area of nanocellulose.
Abiotic stresses such as heat, drought, and salinity are major environmental constraints that limit potato (Solanum tuberosum L.) production worldwide. Previously, we found a potential ...thermo-tolerance gene, named StnsLTP1 from potato using yeast functional screening. Here, we report the functional characterization of StnsLTP1 and its role in multiple abiotic stresses in potato plants. Computational analysis of StnsLTP1 with other plant LTPs showed eight conserved cysteine residues, and four α-helices stabilized by four disulfide bridges. Expression analysis of StnsLTP1 gene showed differential expression under heat, water-deficit and salt stresses. Transgenic potato lines over-expressing StnsLTP1 gene displayed enhanced cell membrane integrity under stress conditions, as indicated by reduced membrane lipid per-oxidation, and hydrogen peroxide content relative to untransformed (UT) control plants. In addition, transgenic lines over-expressing StLTP1 also exhibited increased antioxidant enzyme activity with enhanced accumulation of ascorbates, and up-regulation of stress-related genes including StAPX, StCAT, StSOD, StHsfA3, StHSP70, and StsHSP20 compared with the UT plants. These results suggests that StnsLTP1 transgenic plants acquired improved tolerance to multiple abiotic stresses through enhanced activation of antioxidative defense mechanisms via cyclic scavenging of reactive oxygen species and regulated expression of stress-related genes.
The present article reports a facile approach to fabrication of mesoporous octahedron-shaped tricobalt tetroxide nanoparticles (Co3O4 NPs) with a very narrow size distribution for eco-friendly ...remediation of toxic dyes. Co3O4 NPs were fabricated by a sol–gel process using cobalt chloride hexahydrate (CoCl2·6H2O) and monosodium succinate (C4H5O4Na) as a chelating/structure-directing agent and sodium dodecyl sulfate as a surfactant. Moreover, the phase structure, elemental composition, and thermal and morphological facets of Co3O4 NPs were investigated using XRD, FT-IR, EDS, Raman, XPS, TGA, SEM, and TEM techniques. The face-centered cubic spinel crystalline structure of the Co3O4 NPs was confirmed by XRD and SEM, and TEM analysis revealed their octahedron morphology with a smooth surface. Moreover, the narrow pore size distribution and the mesoporous nature of the Co3O4 NPs were confirmed by Brunauer–Emmett–Teller measurements. The photocatalytic activity of Co3O4 NPs for degradation of methyl red (MR), Eriochrome Black-T (EBT), bromophenol blue (BPB), and malachite green (MG) was examined under visible light irradiation, and the kinetics of the dye degradation was pseudo-zero-order with the rate constant in the order of MR > EBT > MG > BPB. Furthermore, the mechanism of photo-disintegration mechanism of the dye was examined by a scavenging test using liquid chromatography–mass chromatography, and its excellent photodegradation activities were attributed to the photogenerated holes (h+), superoxide (O2 –) anions, and hydroxyl (·OH) radicals. Finally, the synergistic effect of the nano-interconnected channels with octahedron geometry, mesoporous nature, and charge transfer properties along with photogenerated charge separations leads to an enhanced Co3O4 photocatalytic activity.
Background & objectives: Methicillin resistant Staphylococcus aureus (MRSA) are the commonest cause of osteomyelitis. The aim of this study was to evaluate the role of an alternative therapy i.e. ...application of S. aureus specific bacteriophages in cases of osteomyelitis caused by MRSA in animal model.
Methods: Twenty two rabbits were included in this study. The first two rabbits were used to test the safety of phage cocktail while the remaining 20 rabbits were divided into three groups; group A (n=4) to assess the establishment of osteomyelitis; group B (n=4) osteomyelitis developed but therapy started only after six weeks; and group C (n=12) osteomyelitis developed and therapy started after three weeks. Groups B and C rabbits were treated with four doses of cocktail of seven virulent bacteriophages at the interval of 48 h. Comparison between three groups was made on the basis of observation of clinical, radiological, microbiological, and histopathological examinations.
Results: Experimental group rabbits recovered from the illness in the subsequent two weeks of the therapy. Appetite and activity of the rabbits improved, local oedema, erythema and induration subsided. There were minimal changes associated with osteomyelitis in X-ray and histopathology also showed no signs of infection with new bone formation. Control B group rabbits also recovered well from the infection.
Interpretation & conclusions: The present study shows a potential of phage therapy to treat difficult infections caused by multidrug resistant bacteria.
Magnesium is one of the largely available elements in the earth's crust. It has a low structural density with high specific strength. This unique material property has forced an increase in the use ...of magnesium and its alloys in various applications pertaining to industrial sector, automobiles, aerospace and biomedical. Since magnesium is a highly reactive metal, it is prone to higher rate of corrosion as compared to its counterparts. Thus, it is essential to analyze the corrosion behavior of magnesium and its alloys in its applications. An appropriate process is to be followed in the design and development of magnesium alloys which overcome the limitations of magnesium and enhance the desired material properties in accordance to their applications. This review paper summarizes the importance of magnesium and its material properties. The influence of various alloying elements on the mechanical properties of magnesium is reviewed. The broad classification of Mg alloys and their behavioral trends are detailed. The corrosion behavior of magnesium and the influence of corrosion products on the material characteristics of magnesium, in aqueous medium, are discussed. The manufacturing techniques of magnesium alloys along with the secondary techniques are also covered. The various applications and the limitations of magnesium in these applications are covered. A complete section is dedicated towards detailing the recent trends of magnesium (Mg) alloys, i.e., the biodegradable nature and applications of Mg alloys. The influence of biocorrosion on Mg alloys and techniques to overcome it have been deliberated. This paper provides a thorough review on recent developments of magnesium with respect to engineering applications.
Plant base cellulose nanofibers with diameter 20–50 nm are obtained by Agave gigantea through the steam explosion method. These nanofibers used as a reinforcement to making composites at different ...percentages (10%, 15%, and 20%) with epoxy LY556 & hardener HY951 used as a matrix at a 10:1 ratio. Thermoset polymer is used as a matrix although it has a great strength-to-weight ratio, and performance, and good thermal properties. Preparation of composite used hand-lay-up method with random orientation of fibers, examining the mechanical properties of nanofiber-reinforced polymer matrix composites like tensile testing, impact testing, and hardness of the composites. The percentage of nanofibers has greatly influenced the mechanical properties of the material. The significant enhancement of mechanical characteristics was observed as the result of addition of nanofibers as a reinforcement in composites. Finding the percentage of absorption of moisture for the different samples at the same period and the rate of water absorption depend on the percentage of fiber used in the composite. It is directly proportional to the percentage of fibers and is the only the demerit when using plant base nanofiber as reinforcement.
Electrolytes with high Li
+
transference number and good electrochemical stability are urgently needed for high-energy-density Li battery. In this paper, we present newly synthesized ionic liquid ...(IL)-based polymer electrolyte using polymer poly(ethylene oxide) (PEO), salt lithium
bis
(fluorosulfonly)imide (LiFSI), and IL 1-butyl-3-methylpyridinium
bis
(trifluoromethylsulfonyl)imide (BMPyTFSI) by solution cast technique. They show high Li
+
transference number and good electrochemical and thermal stability. Also, nickel-rich layered cathode material LiNi
0.90
Co
0.05
Al
0.05
O
2
(NCA) with good electrochemical performance for lithium secondary battery is successfully synthesized by Co-precipitation method. Using the optimized polymer electrolyte and NCA cathode, Li cell is prepared which shows initial discharge capacity of ~ 137 mAh g
−1
at 0.1 C-rate and good Coulombic efficiency ~96.0% upto 125 cycles.
Activating point mutations in codons 12, 13, and 61 of the KRAS gene and loss of p16 expression, a tumor suppressor gene, are common genetic alterations in periampullary cancer (PAC). The present ...study explores expression profile of KRAS and p16 genes in PAC and its prognostic relevance. A total of 50 patients with PAC who underwent potentially curative pancreaticoduodenectomy were included in the study. Formalin-fixed, paraffin-embedded tissue samples were analyzed for point mutations in codons 12 and 13 of KRAS and codon 9 of p16 using polymerase chain reaction. KRAS mutation in codon 12/13 was found in 32 (64%) and loss of p16 expression in 36 (72%) cases. KRAS mutation was significantly associated with higher grade, higher pathological tumor (pT) stage, lymphovascular invasion (LVI), perineural invasion (PNI), and pathological lymph nodes (pN) involvement on univariate analysis. On multivariate analysis, significant association of KRAS remained with higher grade (
p
= 0.031), pT stage (
p
= 0.09), and LVI (
p
= 0.028). On univariate analysis, loss of p16 expression was significantly associated with higher grade, pN involvement, LVI, PNI, and pT stage whereas on multivariate analysis, statistical significant association of p16 was found with higher grade of tumor only (
p
= 0.04). Patients with KRAS mutation had significantly (
p
= 0.018) worse disease-free survival (DFS) whereas no significant association was found in overall survival (OS). Loss of p16 expression had no association with either DFS or OS. The presence of p16 and KRAS alterations in patients with PAC suggests aggressive tumor biology. KRAS mutations confer a significantly poor DFS in PAC.
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