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排序方式: 共有135条查询结果,搜索用时 62 毫秒
91.
Cervical cancer ranks seventh overall among all types of cancer in women. Although several treatments, including radiation, surgery and chemotherapy, are available to eradicate or reduce the size of cancer, many cancers eventually relapse. Thus, it is essential to identify possible alternative therapeutic approaches for cancer. We sought to identify alternative and effective therapeutic approaches, by first synthesizing palladium nanoparticles (PdNPs), using a novel biomolecule called saponin. The synthesized PdNPs were characterized by several analytical techniques. They were significantly spherical in shape, with an average size of 5 nm. Recently, PdNPs gained much interest in various therapies of cancer cells. Similarly, histone deacetylase inhibitors are known to play a vital role in anti-proliferative activity, gene expression, cell cycle arrest, differentiation and apoptosis in various cancer cells. Therefore, we selected trichostatin A (TSA) and PdNPs and studied their combined effect on apoptosis in cervical cancer cells. Cells treated with either TSA or PdNPs showed a dose-dependent effect on cell viability. The combinatorial effect, tested with 50 nM TSA and 50 nMPdNPs, had a more dramatic inhibitory effect on cell viability, than either TSA or PdNPs alone. The combination of TSA and PdNPs had a more pronounced effect on cytotoxicity, oxidative stress, mitochondrial membrane potential (MMP), caspase-3/9 activity and expression of pro- and anti-apoptotic genes. Our data show a strong synergistic interaction between TSA and PdNPs in cervical cancer cells. The combinatorial treatment increased the therapeutic potential and demonstrated relevant targeted therapy for cervical cancer. Furthermore, we provide the first evidence for the combinatory effect and cytotoxicity mechanism of TSA and PdNPs in cervical cancer cells.  相似文献   
92.
93.
A sequential one‐pot synthesis of Michael adducts of aroylmethylidenemalonates with activated aromatics is described. The method involves treatment of trans‐2‐aryl‐3‐nitro‐cyclopropane‐1,1‐dicarboxylates with boron trifluoride etherate to form aroylmethylidenemalonates in situ and then addition of activated aromatics such as indoles, carbazole, pyrrole, thiophenes, methoxybenzenes and benzodioxole followed by a catalytic amount of indium(III) triflate to the same reaction vessel. To prove the synthetic potential of the resulting Michael adducts, one of the adducts was transformed into a pharmaceutically interesting dihydropyridazinone derivative.

  相似文献   

94.
Silver nanoparticles (AgNPs) have been used as antibacterial, antifungal, antiviral, anti-inflammtory, and antiangiogenic due to its unique properties such as physical, chemical, and biological properties. The present study was aimed to investigate antibacterial and anti-biofilm activities of silver nanoparticles alone and in combination with conventional antibiotics against various human pathogenic bacteria. Here, we show that a simple, reliable, cost effective and green method for the synthesis of AgNPs by treating silver ions with leaf extract of Allophylus cobbe. The A. cobbe-mediated synthesis of AgNPs (AgNPs) was characterized by ultraviolet-visible absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Furthermore, the antibacterial and anti-biofilm activity of antibiotics or AgNPs, or combinations of AgNPs with an antibiotic was evaluated using a series of assays: such as in vitro killing assay, disc diffusion assay, biofilm inhibition, and reactive oxygen species generation in Pseudomonas aeruginosa, Shigella flexneri, Staphylococcus aureus, and Streptococcus pneumonia. The results suggest that, in combination with antibiotics, there were significant antimicrobial and anti-biofilm effects at lowest concentration of AgNPs using a novel plant extract of A. cobbe, otherwise sublethal concentrations of the antibiotics. The significant enhancing effects were observed for ampicillin and vancomycin against Gram-negative and Gram-positive bacteria, respectively. These data suggest that combining antibiotics and biogenic AgNPs can be used therapeutically for the treatment of infectious diseases caused by bacteria. This study presented evidence of antibacterial and anti-biofilm effects of A. cobbe-mediated synthesis of AgNPs and their enhanced capacity against various human pathogenic bacteria. These results suggest that AgNPs could be used as an adjuvant for the treatment of infectious diseases.  相似文献   
95.
96.
Thevar T  Barnes NP 《Applied optics》2006,45(14):3352-3355
A continuous-wave, diode-pumped, room-temperature Tm:YAlO3 laser was built, characterized, and compared with a theoretical model. Spectroscopic parameters of the laser crystal, such as the pump band ((3)H4 manifold) lifetime, the upper laser level ((3)F4 manifold) lifetime, and the absorption coefficient were measured. The experimental data were used to calculate the quantum efficiency of Tm self-quenching of the (3)H4 manifold.  相似文献   
97.
Acrylamide in foods is declared as carcinogen. In the present work, the effect of enzymatic pretreatment and other parameters like enzyme concentration, frying conditions with respect to temperature and time, size of potato chips, and effect of sodium chloride and citric acid on mitigation of acrylamide were studied. The concentration of acrylamide in fried potatoes after the pretreatment was found to be 815.63 μg kg?1. The optimised asparaginase concentration for the mitigation of acrylamide was calibrated as 4 U mL?1, and optimised frying time and temperature were 15 min and 170 °C, respectively. An in‐depth kinetic relationship for the effect of asparaginase on the mitigation of acrylamide was studied. The prime novelty of the project is focused on the immobilisation of asparaginase to nanomagnetic particles for redundant usage with stabilised enzyme activity. The work projected three stables cycles of asparaginase activity and on further usage of the immobilised enzyme resulted in decreased activity. The repeated use of immobilised asparaginase provides the advantage of decreasing cost in processing.  相似文献   
98.
This paper describes the effect of annealing on PbS and Cd-doped PbS thin films prepared by chemical bath deposition at different bath temperatures (Tb). The X-ray diffraction (XRD), optical absorption, scanning electron microscopy, and energy dispersive X-ray (EDX) analyses have been performed to explore the properties of PbS and PbCdS films. From the XRD measurements, the particle size (D) of as-deposited PbS and PbCdS films is estimated to be 22 (27) and 12 (9) nm, respectively, for a Tb of 75 (85) °C. A reduction in D was noticed upon annealing the films at 200 °C, irrespective of the Tb and the doping. The optical band gap energy (Eg) of as-deposited PbS films grown at different Tb is found to be in the range of 1.22-1.42 eV. Doping of PbS with Cd and annealing have led to increase in Eg up to 2.61 (2.66) eV. Optical studies revealed prominent blue shifts in the Eg of as-deposited and annealed films due to quantum confinement effect. The addition of Cd into PbS was confirmed by EDX analysis.  相似文献   
99.
A new learning algorithm is proposed for training single hidden layer feedforward neural network. In each epoch, the connection weights are updated by simultaneous perturbation. Tunneling using perturbation technique is applied to detrap the local minima. The proposed technique is shown to give better convergence results for the selected problems, namely neuro-controller, XOR, L-T character recognition, two spirals, simple interaction function, harmonic function and complicated interaction function. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
100.
Journal of Materials Science - Using total energy calculations, we thoroughly looked into the two-dimensional (2D) ternary Mo1?xWxS2 monolayers by exploring their electronic band structures...  相似文献   
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