In place of mercury, small-scale alluvial gold miners in Tadó, Dept. Chocó, Colombia produce “green gold” (oroverde) using locally available plant extracts. The leaves of Balso (Ochroma pyramidale) and Mal...In place of mercury, small-scale alluvial gold miners in Tadó, Dept. Chocó, Colombia produce “green gold” (oroverde) using locally available plant extracts. The leaves of Balso (Ochroma pyramidale) and Malva (Hibiscus furcellatus) are crushed by hand and are mixed with water to make a foamy liquid that is added to the gold pan (batea) instead of mercury. After the plant extract is added, the gold, magnetite, and other heavy minerals sink and the lighter minerals are floated out of the gold pan. For final clean-up, a combination of other methods may be used. However, ICP (Inductively Coupled Plasma) analyses indicate that even green gold contains 208 - 4530 ppm Hg—this mercury may have been released from dragas or other small-scale gold mining operations that continue to use mercury;coal burning;volcanism;or native mercury released from cinnabar occurrences. ICP also indicates 308 - 106,000 ppm Ag and 452 - 585 ppm Pt.展开更多
In the present research program, cost effective and environment friendly gold nanoparticless were synthesized using the onion (Allium cepa) extract as the reducing agent. The nanoparticless were characterized using UV...In the present research program, cost effective and environment friendly gold nanoparticless were synthesized using the onion (Allium cepa) extract as the reducing agent. The nanoparticless were characterized using UV-visble, XRD, and SEM, TEM methods. The absorption peak at 540 nm was found to be broaden with increase in time indicating the polydispersity nature of the nanoparticles. The XRD results suggested that the crystallization of the bio-organic phase occurs on the surface of the gold nanoparticles or vice versa. The broadening of peaks in the XRD patterns was attributed to particle size effects. The internalization of nanoparticles within cells could occur via processes including phagocytosis, fluid-phase endocytosis and receptor mediated endocytosis.展开更多
In this investigation, the anticancer potentiality and biological mechanism of gold nanoparticles (AuNPs) was studied in SUDHL-4 cell line. Metallic AuNPs were prepared and stabilized with ethanol clove (Syzygium arom...In this investigation, the anticancer potentiality and biological mechanism of gold nanoparticles (AuNPs) was studied in SUDHL-4 cell line. Metallic AuNPs were prepared and stabilized with ethanol clove (Syzygium aromaticum) extract. The green synthesis of AuNPs was characterized and evaluated by UV-Visible Spectroscopic, X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Transmission electron microscopy (TEM), Dynamic Light Scattering (DLS) and biological activities using various biochemical assays. Green synthesis of AuNPs was confirmed by instrument method. The TEM images show polydis-perse, mostly spherical AuNPs particles of 12 - 20 nm. AuNPs were decreased the growth and viability of SU-DHL-4 cell line and increased the apoptosis. The treatments of SU-DHL-4 cells with AuNPs resulted in a moderate considerably increase in Reactive oxygen species (ROS) production. We measured apoptosis by Annexin-V/propidium iodide (PI) in the existence and nonexistence of the antioxidant N-acetyl-L-cysteine (NAC), the glutathione-depleting agent buthionine sulfoximine (BSO), or caspase inhibitors to determine the mechanism of cell death. AuNPs are unique potential anticancer agents that cause ROS-dependent apoptosis in SUDHL-4 cell line which was improved by depletion of glutathione (GHS) and inhibited by N-acetyl-L-cysteine on Z-VAD-FMK.展开更多
The advantage of using plants in nanoparticles synthesis is that they are easily available, safe to handle and possess a broad variability of metabolites such as antioxidants, nucleotides and vitamins. The aim of this...The advantage of using plants in nanoparticles synthesis is that they are easily available, safe to handle and possess a broad variability of metabolites such as antioxidants, nucleotides and vitamins. The aim of this study was to investigate the effects of Green and Zimbro tea and also Green coconut water as a reducing and stabilizer agent in gold nanoparticle synthesis. The gold nanoparticles were characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Dynamic light scattering (DLS) and Transmission electron microscopy (TEM) analysis. Their physical stability was determined using a UV-Vis spectrophotometer over several days during storage at room temperature. We observed that green chemical process to obtain gold nanoparticles did not require any external chemicals reagent for stabilization of nanoparticulate. Absorption measurements indicated that the plasmon resonance wavelength appears around 530 nm. X-ray diffracto-grams of gold nanoparticles evidenced the presence of Au-rich (fcc) phases. TEM analysis showed a homogeneous dispersion of nanoparticles and some agglomerates. Differences in size and shape of the nanoparticles were observed. Zeta potential of AuNPs synthetized in presence of Green tea was -33 mV indicating stability of the synthesized nanoparticles.展开更多
Background: Use of novel microorganisms for beneficial purposes is still remaining a challenging job. This study was designed to isolate, characterize and use of a novel hot spring bacterial strain from a virgin hot s...Background: Use of novel microorganisms for beneficial purposes is still remaining a challenging job. This study was designed to isolate, characterize and use of a novel hot spring bacterial strain from a virgin hot spring of Metaldanga, Birbhum, West Bengal, India. Methods: A pure bacterial strain (MDH1) was identified by growing the enrichment culture isolated from Metaldanga hot spring through serial dilution process in a semi-synthetic medium at pH 8.0 and 42°C temperature. The novelty of the strain was characterized by 16S-rRNA gene sequence analysis. The bacterium acted as template to synthesize spherical gold nanoparticles (GNPs). GNPs were characterized by using UV-Vis spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS) and Fourier transform infra-red spectroscopy (FTIR). Results: The phylogenetic analysis suggested that MDH1 strain (GenBank accession number: KT600031) was affiliated to the family “Pseudomonadaceae” with 99% homologous to Pseudomonas putida H8234. The coccoid shaped bacterium was gram-negative and facultative-anaerobic which acted as a template to synthesize spherical GNPs with an average size of 12 ± 3 nm when examined under transmission electron microscopy (TEM). FT-IR studies revealed the presence of bioactive functional groups which acted as capping and stabilizing agents of the GNPs. XRD pattern confirmed the amorphous nature of GNPs. The Zeta potential (ζ) concluded the adequate stability of GNPs in an aqueous environment. Conclusions: The present investigation explores the microbial diversity of a virgin hot spring of Metaldanga for its beneficial applications in industry, particularly in the synthesis of the gold nanoparticles.展开更多
With regard to the rapid growth of China’s building area and the increasing energy consumption of buildings, green buildings have become an important issue for balancing economic development and environmental impact....With regard to the rapid growth of China’s building area and the increasing energy consumption of buildings, green buildings have become an important issue for balancing economic development and environmental impact. However, the current evaluation systems for various types of green buildings are often unable to achieve a set of standards in practice due to the distinct regional characteristics of each region. Therefore, in view of the regional characteristics of the climate, terrain, ecology, and economic development in the cold regions of Sichuan, it is important to study the evaluation system of green residential buildings suitable for the cold regions of Sichuan. This article focuses on the regional characteristics of climate, topography, ecology, and economic development in the cold regions of Sichuan, and discusses the limitations of the current standards on the practice of green building in cold regions of Sichuan through a sociological questionnaire survey on the comfort of living in the local population. Then from the two dimensions of the advantages of traditional houses and the particularity of national culture, the strategies for the optimization and improvement of the evaluation index system for green residential buildings in the cold regions of Sichuan were proposed. After comprehensively considering the factors that affect the green residential buildings, including the regional characteristics of the cold regions of Sichuan, and the green performance of buildings, local characteristics and ethnic features were included in the evaluation system. The evaluation index system of green residential buildings in the cold regions of Sichuan, consists of 92 three-level indicators. A professional hierarchical analysis software yaahp was used to establish a multi-level hierarchical model between the indicators, and the indicators were compared with each other layer by layer to clarify the importance of the indicators. Based on this, a judgment matrix for each layer was constructed and obtained. The weight of each indicator is accurate, and the scoring mechanism and grading standards are constructed according to it. Through the calculation, the consistency test of the entire model was passed, thereby confirming the scientificity and rationality of the entire evaluation system.展开更多
This report provides for the first time rapid novel environment friendly cell surface based synthesis of stable gold nanoprisms at room temperature using Penicillium citrinum MTCC9999 biomass. The UV-Visible spectral ...This report provides for the first time rapid novel environment friendly cell surface based synthesis of stable gold nanoprisms at room temperature using Penicillium citrinum MTCC9999 biomass. The UV-Visible spectral scan of dispersed gold nanoparticles (GNPs) solution showed absorption maxima at 540 nm due to surface plasma resonance (SPR) of gold nanoparticles. Typical Transmission Electron Microscopic (TEM) images showed that most of them were prism (55%) shaped with a diameter ranging from 20 - 40 nm. These results obtained from TEM correlated well with the data obtained from Dynamic Light Scattering (DLS) experiment. Average zeta potential of GNPs was -20 mV suggesting some biomolecules capped the nanoparticles imparting a net negative charge over it. FTIR analysis also showed that protein molecules were involved in stabilization.展开更多
文摘In place of mercury, small-scale alluvial gold miners in Tadó, Dept. Chocó, Colombia produce “green gold” (oroverde) using locally available plant extracts. The leaves of Balso (Ochroma pyramidale) and Malva (Hibiscus furcellatus) are crushed by hand and are mixed with water to make a foamy liquid that is added to the gold pan (batea) instead of mercury. After the plant extract is added, the gold, magnetite, and other heavy minerals sink and the lighter minerals are floated out of the gold pan. For final clean-up, a combination of other methods may be used. However, ICP (Inductively Coupled Plasma) analyses indicate that even green gold contains 208 - 4530 ppm Hg—this mercury may have been released from dragas or other small-scale gold mining operations that continue to use mercury;coal burning;volcanism;or native mercury released from cinnabar occurrences. ICP also indicates 308 - 106,000 ppm Ag and 452 - 585 ppm Pt.
文摘In the present research program, cost effective and environment friendly gold nanoparticless were synthesized using the onion (Allium cepa) extract as the reducing agent. The nanoparticless were characterized using UV-visble, XRD, and SEM, TEM methods. The absorption peak at 540 nm was found to be broaden with increase in time indicating the polydispersity nature of the nanoparticles. The XRD results suggested that the crystallization of the bio-organic phase occurs on the surface of the gold nanoparticles or vice versa. The broadening of peaks in the XRD patterns was attributed to particle size effects. The internalization of nanoparticles within cells could occur via processes including phagocytosis, fluid-phase endocytosis and receptor mediated endocytosis.
文摘In this investigation, the anticancer potentiality and biological mechanism of gold nanoparticles (AuNPs) was studied in SUDHL-4 cell line. Metallic AuNPs were prepared and stabilized with ethanol clove (Syzygium aromaticum) extract. The green synthesis of AuNPs was characterized and evaluated by UV-Visible Spectroscopic, X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Transmission electron microscopy (TEM), Dynamic Light Scattering (DLS) and biological activities using various biochemical assays. Green synthesis of AuNPs was confirmed by instrument method. The TEM images show polydis-perse, mostly spherical AuNPs particles of 12 - 20 nm. AuNPs were decreased the growth and viability of SU-DHL-4 cell line and increased the apoptosis. The treatments of SU-DHL-4 cells with AuNPs resulted in a moderate considerably increase in Reactive oxygen species (ROS) production. We measured apoptosis by Annexin-V/propidium iodide (PI) in the existence and nonexistence of the antioxidant N-acetyl-L-cysteine (NAC), the glutathione-depleting agent buthionine sulfoximine (BSO), or caspase inhibitors to determine the mechanism of cell death. AuNPs are unique potential anticancer agents that cause ROS-dependent apoptosis in SUDHL-4 cell line which was improved by depletion of glutathione (GHS) and inhibited by N-acetyl-L-cysteine on Z-VAD-FMK.
文摘The advantage of using plants in nanoparticles synthesis is that they are easily available, safe to handle and possess a broad variability of metabolites such as antioxidants, nucleotides and vitamins. The aim of this study was to investigate the effects of Green and Zimbro tea and also Green coconut water as a reducing and stabilizer agent in gold nanoparticle synthesis. The gold nanoparticles were characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Dynamic light scattering (DLS) and Transmission electron microscopy (TEM) analysis. Their physical stability was determined using a UV-Vis spectrophotometer over several days during storage at room temperature. We observed that green chemical process to obtain gold nanoparticles did not require any external chemicals reagent for stabilization of nanoparticulate. Absorption measurements indicated that the plasmon resonance wavelength appears around 530 nm. X-ray diffracto-grams of gold nanoparticles evidenced the presence of Au-rich (fcc) phases. TEM analysis showed a homogeneous dispersion of nanoparticles and some agglomerates. Differences in size and shape of the nanoparticles were observed. Zeta potential of AuNPs synthetized in presence of Green tea was -33 mV indicating stability of the synthesized nanoparticles.
文摘Background: Use of novel microorganisms for beneficial purposes is still remaining a challenging job. This study was designed to isolate, characterize and use of a novel hot spring bacterial strain from a virgin hot spring of Metaldanga, Birbhum, West Bengal, India. Methods: A pure bacterial strain (MDH1) was identified by growing the enrichment culture isolated from Metaldanga hot spring through serial dilution process in a semi-synthetic medium at pH 8.0 and 42°C temperature. The novelty of the strain was characterized by 16S-rRNA gene sequence analysis. The bacterium acted as template to synthesize spherical gold nanoparticles (GNPs). GNPs were characterized by using UV-Vis spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS) and Fourier transform infra-red spectroscopy (FTIR). Results: The phylogenetic analysis suggested that MDH1 strain (GenBank accession number: KT600031) was affiliated to the family “Pseudomonadaceae” with 99% homologous to Pseudomonas putida H8234. The coccoid shaped bacterium was gram-negative and facultative-anaerobic which acted as a template to synthesize spherical GNPs with an average size of 12 ± 3 nm when examined under transmission electron microscopy (TEM). FT-IR studies revealed the presence of bioactive functional groups which acted as capping and stabilizing agents of the GNPs. XRD pattern confirmed the amorphous nature of GNPs. The Zeta potential (ζ) concluded the adequate stability of GNPs in an aqueous environment. Conclusions: The present investigation explores the microbial diversity of a virgin hot spring of Metaldanga for its beneficial applications in industry, particularly in the synthesis of the gold nanoparticles.
文摘With regard to the rapid growth of China’s building area and the increasing energy consumption of buildings, green buildings have become an important issue for balancing economic development and environmental impact. However, the current evaluation systems for various types of green buildings are often unable to achieve a set of standards in practice due to the distinct regional characteristics of each region. Therefore, in view of the regional characteristics of the climate, terrain, ecology, and economic development in the cold regions of Sichuan, it is important to study the evaluation system of green residential buildings suitable for the cold regions of Sichuan. This article focuses on the regional characteristics of climate, topography, ecology, and economic development in the cold regions of Sichuan, and discusses the limitations of the current standards on the practice of green building in cold regions of Sichuan through a sociological questionnaire survey on the comfort of living in the local population. Then from the two dimensions of the advantages of traditional houses and the particularity of national culture, the strategies for the optimization and improvement of the evaluation index system for green residential buildings in the cold regions of Sichuan were proposed. After comprehensively considering the factors that affect the green residential buildings, including the regional characteristics of the cold regions of Sichuan, and the green performance of buildings, local characteristics and ethnic features were included in the evaluation system. The evaluation index system of green residential buildings in the cold regions of Sichuan, consists of 92 three-level indicators. A professional hierarchical analysis software yaahp was used to establish a multi-level hierarchical model between the indicators, and the indicators were compared with each other layer by layer to clarify the importance of the indicators. Based on this, a judgment matrix for each layer was constructed and obtained. The weight of each indicator is accurate, and the scoring mechanism and grading standards are constructed according to it. Through the calculation, the consistency test of the entire model was passed, thereby confirming the scientificity and rationality of the entire evaluation system.
文摘This report provides for the first time rapid novel environment friendly cell surface based synthesis of stable gold nanoprisms at room temperature using Penicillium citrinum MTCC9999 biomass. The UV-Visible spectral scan of dispersed gold nanoparticles (GNPs) solution showed absorption maxima at 540 nm due to surface plasma resonance (SPR) of gold nanoparticles. Typical Transmission Electron Microscopic (TEM) images showed that most of them were prism (55%) shaped with a diameter ranging from 20 - 40 nm. These results obtained from TEM correlated well with the data obtained from Dynamic Light Scattering (DLS) experiment. Average zeta potential of GNPs was -20 mV suggesting some biomolecules capped the nanoparticles imparting a net negative charge over it. FTIR analysis also showed that protein molecules were involved in stabilization.
