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11.
Navdeep Raghuwanshi Neha Arora Ritu Varshney Partha Roy Vikas Pruthi 《IET nanobiotechnology / IET》2017,11(7):827
This study for the first time reports on fresh water microalgae Chlorella minutissima aqueous extract (CmAe) which was utilized for the biogenic synthesis of silver nanoparticles and tested their antineoplastic potential against Liver Hepatocellular Carcinoma (HepG2) cell line. The characteristic colour change of the reaction mixture from greenish yellow to yellowish brown confirmed the synthesis of Chlorella minutissima silver nanoparticles (CmAgNPs). Microscopic analysis revealed CmAgNPs to be spherical‐shaped with particle size ranging from 10 to 30 nm. The carbohydrates and proteins distinctive peaks were observed in Fourier transform infrared spectroscopy (FTIR) spectra which suggested these biomolecules acted as reducing and capping agents. Further, the crystalline nature of CmAgNPs was confirmed by X‐ray diffraction (XRD) analysis. CmAgNPs showed maximum free radical scavenging proving it to be more potent antioxidant agent as compared to CmAe. The mortality rate of HepG2 cells treated with CmAgNPs was found to be 91.8 % at 120 μg/ml with IC50 value 12.42 ± 1.096 μg/ml after 48 h whereas no effect was observed on normal Human Embryonic Kidney (HEK 293) cells. Fluorescent images of the treated HepG2 cells revealed the formation of apoptotic bodies, condensed nuclei and cell shrinkage indicating their effectiveness against the cancer cells.Inspec keywords: silver, nanoparticles, nanomedicine, microorganisms, cellular biophysics, nanofabrication, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, proteins, Fourier transform infrared spectra, molecular biophysics, X‐ray chemical analysis, X‐ray diffraction, kidney, cancer, biomedical materialsOther keywords: antineoplastic potential, antioxidant potential, phycofabricated silver nanoparticle, Chlorella minutissima, freshwater microalgae, aqueous extract, liver hepatocellular carcinoma cell line, CmAgNP synthesis, field emission scanning electron microscopy, high‐resolution transmission electron microscopy, atomic force microscopy, dynamic light scattering, carbohydrate, protein, Fourier transform infrared spectroscopy, biomolecule, energy‐dispersive X‐ray spectroscopy, elemental silver signal, CmAgNP crystalline, X‐ray diffraction analysis, antioxidant agent, HepG2 cell mortality rate, human embryonic kidney, HEK 293 cell, fluorescent image, apoptotic body formation, condensed nuclei, cell shrinkage, cancer cell, antineoplastic agent, Ag 相似文献
12.
13.
This paper addresses the heterogeneous redundancy allocation problem in multi-state series-parallel reliability structures with the objective to minimize the total cost of system design satisfying the given reliability constraint and the consumer load demand. The demand distribution is presented as a piecewise cumulative load curve and each subsystem is allowed to consist of parallel redundant components of not more than three types. The system uses binary capacitated components chosen from a list of available products to provide redundancy so as to increase system performance and reliability. The components are characterized by their feeding capacity, reliability and cost. A system that consists of elements with different reliability and productivity parameters has the capacity strongly dependent upon the selection of constituent components. A binomial probability based method to compute exact system reliability index is suggested. To analyze the problem and suggest an optimal/near-optimal system structure, an ant colony optimization algorithm has been presented. The solution approach consists of a series of simple steps as used in early ant colony optimization algorithms dealing with other optimization problems and offers straightforward analysis. Four multi-state system design problems have been solved for illustration. Two problems are taken from the literature and solved to compare the algorithm with the other existing methods. The other two problems are based upon randomly generated data. The results show that the method can be appealing to many researchers with regard to the time efficiency and yet without compromising over the solution quality. 相似文献
14.
Mahendra Nath Roy Bhoj Bahadur Gurung Vikas Kumar Dakua 《International Journal of Thermophysics》2006,27(5):1539-1550
Electrolytic conductivities of potassium halides, KX (X = Cl−, Br−, I−) have been investigated in 10, 20, and 30 mass% glycerol + H2O mixtures at 298.0, 308.0, and 318.0 K. The conductance data have been analyzed by the Fuoss-conductance–concentration equation in terms of the limiting molar conductance (Λ0), the association constant (K
A
), and the distance of closest approach of ion (R). The association constant (K
A
) tends to increase in the order: 10 mass% < 20 mass% < 30 mass% glycerol + water mixtures, while it decreases with temperature. Thermodynamic parameters ΔH
0, ΔG
0, and ΔS
0 are obtained and discussed. Also, Walden products (Λ0η) are reported. The results have been interpreted in terms of ion–solvent interactions and structural changes in the mixed solvents. 相似文献
15.
A look under the hood of the IETF's file transfer protocol, including a summary of the commands in the FTP standard. Today, FTP is used primarily for maintaining archives of public files, and is losing ground to HTTP even there. FTP simply doesn't maintain as much metadata: not creation date, not original location, not application data type. Its addressing structure is an opaque pathname at a host. Consider that in the context of mirroring or relocating information: FTP mirrors are an ad hoc, user driven abstraction; HTTP can send automatable redirection messages. Per-site metadata is also provided manually as OOindex files, compared to automatable Web spiders 相似文献
16.
Cross Virtual Concatenation is the new technique proposed for bandwidth efficient transmission of data over SDH networks.
SDH networks came into existence for reliable voice transmission. As the demand of data traffic grew in wide area networks,
new technologies were developed and standardized for data transmission over SDH networks. The technologies used namely, GFP
(generic framing procedure), VCAT (virtual concatenation) and LCAS (link capacity adjustment scheme) enable network operator
to provide integrated voice and data services over their legacy SDH infrastructure. Data packets are encapsulated using framing
protocols GFP. VCAT is a process of distributing the GFP framed data payload in number of virtual channels of same capacity
forming a Virtually Concatenated Group (VCG). LCAS is used for dynamic bandwidth allocation. LCAS enhances the VCAT scheme
with hitless in service addition and removal of VC’s to/from the VCG.VCAT combines homogeneous virtual channels together which
in some cases limits the performance of VCAT. This paper describes the implementation of new concatenation technology named
cross virtual concatenation (CVC), which combines heterogeneous VC’s together to utilize the SDH bandwidth more efficiently.
CVC implementation requires only end node equipments to be upgraded as VCG members travel through the link similar to the
conventional VCAT. This paper proposes FPGA implementation of transmitter and receiver circuits for 100 Mbps Ethernet data
transmission over next Generation SDH systems using CVC, where two types of VC’s namely VC-3 and VC-12 are used for data transmission.
Total Transmission delay is calculated as 125 μs. There is no complexity added at the receiver side due to this delay. The
receiver is designed for 32 ms differential delay compensation which can be increased up to maximum 256 ms by increasing the
buffer size at the receiver. 相似文献
17.
Particle swarm optimization is a stochastic optimization, evolutionary and simulating algorithm derived from human behaviour and animal behaviour as well. Special property of particle swarm optimization is that it can be operated in continuous real number space directly, does not use gradient of an objective function similar to other algorithms. Particle swarm optimization has few parameters to adjust, is easy to implement and has special characteristic of memory. Paper presents extensive review of literature available on concept, development and modification of Particle swarm optimization. This paper is structured as first concept and development of PSO is discussed then modification with inertia weight and constriction factor is discussed. Issues related to parameter tuning, dynamic environments, stagnation, and hybridization are also discussed, including a brief review of selected works on particle swarm optimization, followed by application of PSO in Solar Photovoltaics. 相似文献
18.
Alok K. Jha Neeraj Khare R. Pinto 《Journal of Superconductivity and Novel Magnetism》2012,25(2):377-380
Thin films of YBCO and YBCO:BaZrO3 (BZO) nanocomposite have been deposited using the pulsed laser deposition technique. Substantial increase in critical current
density (J
C
) and pinning force density (F
p
) of the nanocomposite thin films was observed. The possible pinning mechanism in YBCO:BZO nanocomposite thin films has been
explored and compared with the pinning mechanism in pure YBCO thin film by studying the variation of J
C
with magnetic field (B) and temperature. In the intermediate field regime (0.1–1 T), J
C
follows B
−α
with nearly similar values of α for YBCO and YBCO:BZO nanocomposite thin films indicating similar pinning mechanism in both thin films. The variation of
J
C
with reduced temperature (t=T/T
C
) has been studied for both the films and it was observed that the mechanism of pinning in both YBCO and YBCO:BZO thin films
is similar (δT
C
pinning). The observed enhanced values of J
C
and F
p
of the nanocomposite thin film is attributed to the presence of BZO nanoparticles, which induces more defects due to lattice
mismatch between YBCO and BZO leading to improved flux pinning properties of the nanocomposite thin film. 相似文献
19.
20.
Machine Learning - Covariance estimation for high-dimensional datasets is a fundamental problem in machine learning, and has numerous applications. In these high-dimensional settings the number of... 相似文献