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1.
J Mol Graph Model ; 128: 108704, 2024 05.
Article in English | MEDLINE | ID: mdl-38306789

ABSTRACT

The oxidation of CO has attracted great interest in recent years due to its important role in enhancing the catalyst durability in fuel cells and solving the growing environmental problems caused by CO emissions. Consequently, the catalytic oxidation of CO at double non-noble metal atoms anchored C2N is investigated using density functional theory (DFT) computations. All the screened Ti@C2N and Ti2@C2N are thermodynamically stable based on their binding energy calculations. The electronic characteristics, the natural bond orbital analyses (NBO), Frontier orbital, statistical thermodynamics, projected densities of states (PDOS) characteristics, non-covalent interactions (NCI), and quantum theory of atoms in molecules (QTAIM) descriptors of these systems have been examined to analyze the interaction process. Our comparative study suggested that the newly predicted double-atom catalyst (Ti2@C2N) is highly active for CO oxidation, which is a useful guideline for further development. The calculated static first-order hyperpolarizability (ßo) illustrated that the double-atom catalyst under investigation can be considered a potential candidate for non-linear optical behavior and could be used for NLO applications. CO oxidation on Ti2@C2N along the Eley-Rideal (ER) mechanism with a low energy barrier of 0.16 eV, which is smaller than the maximum energy barrier (0.73 eV) of CO oxidation along the Langmuir-Hinshelwood (LH) mechanism. Consequently, the ER mechanism is more favorable both thermodynamically and dynamically. This work can provide useful insights and guidelines for future theoretical and experimental investigations to promote the design and development of highly effective and low-cost non-precious-metal Ti2@C2N nanocatalysts towards CO oxidation at ambient temperature.


Subject(s)
Electronics , Transition Elements , Catalysis , Oxidation-Reduction , Quantum Theory , Thermodynamics
2.
J Funct Foods ; 1072023 08.
Article in English | MEDLINE | ID: mdl-37654434

ABSTRACT

Background: Humans have been consuming medicinal plants (as herbs/ spices) to combat illness for centuries while ascribing beneficial effects predominantly to the plant/phytochemical constituents, without recognizing the power of obligatory resident microorganism' communities (MOCs) (live/dead bacteria, fungus, yeast, molds etc.) which remain after industrial microbial reduction methods. Very little is known about the taxonomic identity of residual antigenic microbial associated molecular patterns (MAMPs) debris in our botanical over the counter (OTC) products, which if present would be recognized as foreign (non-self) antigenic matter by host pattern recognition receptors (PRRs) provoking a host immune response; this the basis of vaccine adjuvants. As of today, only few research groups have removed the herbal MAMP biomass from herbs, all suggesting that immune activation may not be from the plant but rather its microbial biomass; a hypothesis we corroborate. Purpose: The purpose of this work was to conduct a high through put screening (HTPS) of over 2500 natural plants, OTC botanical supplements and phytochemicals to elucidate those with pro-inflammatory; toll like receptor 4 (TLR4) activating properties in macrophages. Study Design: The HTPS was conducted on RAW 264.7 cells vs. lipopolysaccharide (LPS) E. coli 0111:B4, testing iNOS / nitric oxide production (NO2-) as a perimeter endpoint. The data show not a single drug/chemical/ phytochemical and approximately 98 % of botanicals to be immune idle (not effective) with only 65 pro-inflammatory (hits) in a potency range of LPS. Method validation studies eliminated the possibility of false artifact or contamination, and results were cross verified through multiple vendors/ manufacturers/lot numbers by botanical species. Lead botanicals were evaluated for plant concentration of LPS, 1,3:1,6-ß-glucan, 1,3:1,4-ß-D-glucan and α-glucans; where the former paralleled strength in vitro. LPS was then removed from plants using high-capacity endotoxin poly lysine columns, where bioactivity of LPS null "plant" extracts were lost. The stability of E.Coli 0111:B4 in an acid stomach mimetic model was confirmed. Last, we conducted a reverse culture on aerobic plate counts (APCs) from select hits, with subsequent isolation of gram-negative bacteria (MacConkey agar). Cultures were 1) heat destroyed (retested/ confirming bioactivity) and 2) subject to taxonomical identification by genetic sequencing 18S, ITS1, 5.8 s, ITS2 28S, and 16S. Conclusion: The data show significant gram negative MAMP biomass dominance in A) roots (e.g. echinacea, yucca, burdock, stinging nettle, sarsaparilla, hydrangea, poke, madder, calamus, rhaponticum, pleurisy, aconite etc.) and B) oceanic plants / algae's (e.g. bladderwrack, chlorella, spirulina, kelp, and "OTC Seamoss-blends" (irish moss, bladderwrack, burdock root etc), as well as other random herbs (eg. corn silk, cleavers, watercress, cardamom seed, tribulus, duckweed, puffball, hordeum and pollen). The results show a dominance of gram negative microbes (e.g. Klebsilla aerogenes, Pantoae agglomerans, Cronobacter sakazakii), fungus (Glomeracaea, Ascomycota, Irpex lacteus, Aureobasidium pullulans, Fibroporia albicans, Chlorociboria clavula, Aspergillus_sp JUC-2), with black walnut hull, echinacea and burdock root also containing gram positive microbial strains (Fontibacillus, Paenibacillus, Enterococcus gallinarum, Bromate-reducing bacterium B6 and various strains of Clostridium). Conclusion: This work brings attention to the existence of a functional immune bioactive herbal microbiome, independent from the plant. There is need to further this avenue of research, which should be carried out with consideration as to both positive or negative consequences arising from daily consumption of botanicals highly laden with bioactive MAMPS.

3.
J Mol Model ; 29(5): 140, 2023 Apr 14.
Article in English | MEDLINE | ID: mdl-37059860

ABSTRACT

The adsorption of SO2, NO2, and NH3 toxic gases on Al24N24 and Al24N23C nanocages was investigated by using density functional theory (DFT) calculations. The adsorption energies, frontier orbitals, charge transfer using natural bonding orbital (NBO) analysis, dipole moment, the partial density of states (PDOS), thermodynamic relationships, non-covalent interaction (NCI), and quantum theory of atoms in molecules (QTAIM) were considered. The results reveal that carbon-doped Al24N24 nanocage increases the adsorption energies for SO2 and NO2 gases while decreasing the adsorption energy of NH3 gas. The ΔG for all configurations were negative except the configurations A1 and G2 confirming the weak adsorption of these two complexes. In conclusion, Al24N24 and Al24N23C nanocages are in general promising adsorbents for the removal of SO2, NO2, and NH3 toxic gases. The Al24N24 and Al24N23C nanocages are ideal electronic materials.

4.
RSC Adv ; 12(31): 20122-20137, 2022 Jul 06.
Article in English | MEDLINE | ID: mdl-35919590

ABSTRACT

The anticorrosion efficiency of two polymer compounds, namely polystyrene (PS), polybutylene terephthalate (PBT), against the corrosion of SABIC iron (S-Fe) in 1.0 M HCl solution was investigated. The anticorrosion efficiency was estimated by chemical and electrochemical measurements. The anticorrosion efficiency increased with the increase in the concentration of the polymer compounds and reduction in temperature. All the obtained corrosion data confirmed the anticorrosion strength in the presence of PS and PBT compounds, such as the decreasing values of the corrosion current density, capacity of the double layer, and weight reduction, while the values of the charge-transfer resistance increased. Also, the pitting potential values moved in the noble (+) direction. The anticorrosion efficiency of the PBT compound was higher than that of the PS compound, which was 95.98% at 500 ppm concentration for PBT while for PS it was 93.34% according to polarization measurements. The anticorrosion activity occurred by the adsorption of PS and PBT compounds on the surface of S-Fe according to the Langmuir isotherm. The polarization curves indicated that the PS and PBT compounds were mixed-type inhibitors. Density functional theory (DFT) and Monte Carlo simulation (MC) were performed for the two polymer compounds. The computational quantum functions were found to be in agreement with the experimental results.

5.
RSC Adv ; 12(5): 2959-2971, 2022 Jan 18.
Article in English | MEDLINE | ID: mdl-35425319

ABSTRACT

This work focuses on the use of natural parsley oil as a safe, eco-friendly and cost-effective inhibitor for dissolution of X80 carbon steel (X80CS) in 0.5 M H2SO4 solution. Electrochemical and chemical measurements and theoretical studies were utilized to determine the inhibitory vigor of parsley oil. The inhibition efficacy increases with an increase in the parsley oil concentration and a decrease in temperature. It reached 95.68% at 450 ppm of parsley oil. The inhibition process is explained by spontaneous adsorption of the oil on the X80CS. Adsorption is described by the Langmuir isotherm model. The polarization data demonstrate that parsley oil is categorized as a mixed inhibitor with a dominant control of the cathodic reaction. Parsley oil inhibits the pitting corrosion of X80CS in the presence of NaCl solution by moving the pitting potential to a more positive mode indicating protection against pitting attack. The thermodynamic parameters for activation and adsorption were computed and interpreted. The four chemical components in natural parsley oil were examined using density functional theory (DFT). Monte Carlo (MC) simulation was performed to study the adsorption of parsley oil on the X80CS surface. The outcomes confirmed that the Apiole molecule is the most effective in the inhibition process.

6.
RSC Adv ; 11(28): 17092-17107, 2021 May 06.
Article in English | MEDLINE | ID: mdl-35479718

ABSTRACT

The inhibition potency of expired thiamine or vitamin B1 (VB1) and riboflavin or vitamin B2 (VB2) against SABIC iron corrosion in 0.5 M H2SO4 solutions was investigated using chemical and electrochemical techniques. Theoretical studies such as DFT and MC simulations were performed on both VB1 and VB2 inhibitors to obtain information related to the experimental results. It has been found that the inhibition efficacy assigned from all measurements used increases with increasing concentration of the two expired vitamins and reduces at elevated temperatures. It reached 91.14% and 92.40% at 250 ppm of VB1 and VB2, respectively. The inhibition was explicated by the adsorption of the complex formed between expired vitamins and ferrous ions on the SABIC iron surface. The adsorption was found to obey the Langmuir isotherm model. Galvanostatic polarization demonstrated that the two expired vitamins act as an inhibitor of the mixed type. These expired vitamins have proven effective in inhibiting the pitting corrosion induced by the presence of Cl- ions. The pitting potential is transferred to the positive values showing resistance to pitting damage. The theoretical parameter values are consistent with experimental results.

7.
Article in English | MEDLINE | ID: mdl-29955238

ABSTRACT

Nerve growth factor (NGF) is an endogenously produced protein with the capacity to induce central nervous system (CNS) neuronal differentiation and repair. NGF signaling involves its binding to tropomyosin-related kinase (Trk) receptors, internalization, and initiation of phosphorylation cascades which cause microtubule reorganization and neuronal outgrowth. Because NGF cannot cross the blood-brain barrier, its therapeutic use is limited. Synthetic peptides that can act as NGF receptor agonists (NGF mimetics) are known to attenuate neurodegenerative pathologies in experimental models of Alzheimer's disease and Parkinson's disease; however, the existence of plant-based NGF mimetics is uncertain. For this reason, we recently completed a high throughput screening of over 1100 nutraceuticals (vitamins, herbal plant parts, polyphenolics, teas, fruits, and vegetables) to identify neuritogenic factor using a PC-12 cell model. Remarkably we found only one, commonly known as the seed of Gac plant (Momordica cochinchinensis) (MCS). In the current study, we further investigated this seed for its neuritogenic effect using bioactivity-guided chemical separations. The data show no biological neuritogenic activity in any chemical solvent fraction, where activity was exclusive to the crude protein. MSC crude proteins were then separated by 1D electrophoresis, where the active neuritogenic activity was confirmed to have a molecular mass of approximately 17 kDa. Subsequently, the 17kDa band was excised, digested, and run on a UPLC-MS/MS with a Q Exactive Hybrid Quadrupole-Orbitrap Mass Spectrometer with data evaluated diverse tools such as X! Tandem, OMS, and K-score algorithms. Proteomic evaluation of the 17kDa band confirmed evidence for 11S globulin subunit beta, napin, oleosin, Momordica trypsin inhibitors (TI) MCoTI-I /II, and many isoforms of Two Inhibitor Peptide Topologies (TIPTOPs). While all peptides identified correspond to the genus/species, Momordica cochinchinensis and Cucumis Sativus, a significant limitation of the analysis is the nonexistence of full annotation for the Momordica cochinchinensis proteome. In conclusion, these findings demonstrate that there is a stable protein within MCS having a mass of 17kDa with the capacity to induce neurite outgrowth. Future work will be required to establish the therapeutic value of the MCS for the treatment of neurodegenerative diseases.

8.
Methods Mol Biol ; 1663: 253-259, 2017.
Article in English | MEDLINE | ID: mdl-28924673

ABSTRACT

Revealing the subcellular phenotypes at the molecular scale is critical to understand the mechanisms by which the cells function and respond to chemical treatments. Super-resolution microscopy and robust analysis tools enabled biologists to reveal and quantify phenotypes at unprecedented resolution. Developing automated imaging analysis solutions for super-resolution imaging will make high-content-screening (HCS) applicable for super-resolution microscopy, which will give access to new complex information. Here, I provide an instant automated analysis procedure for analyzing super-resolution images via CellProfiler ( www.cellprofiler.org ) platform.


Subject(s)
Microscopy, Fluorescence/methods , Image Processing, Computer-Assisted , Internet , Molecular Imaging , Normal Distribution , Phenotype
9.
Appl Opt ; 55(21): 5665, 2016 Jul 20.
Article in English | MEDLINE | ID: mdl-27463922

ABSTRACT

This note corrects an error in the math of [Appl. Opt.55, 838 (2016)APOPAI0003-693510.1364/AO.55.000838] and reports a deletion of text that should have occurred in production.

10.
Article in English | MEDLINE | ID: mdl-27158628

ABSTRACT

AIMS: In the presence of oxygen, most of the synthesized pyruvate during glycolysis in the cancer cell of solid tumors is released away from the mitochondria to form lactate (Warburg Effect). To maintain cell homeostasis, lactate is transported across the cell membrane by monocarboxylate transporters (MCTs). The major aim of the current investigation is to identify novel compounds that inhibit lactate efflux that may lead to identifying effective targets for cancer treatment. STUDY DESIGN: In this study, 900 ethanol plant extracts were screened for their lactate efflux inhibition using neuroblastoma (N2-A) cell line. Additionally, we investigated the mechanism of inhibition for the most potent plant extract regarding monocarboxylate transporters expression, and consequences effects on viability, growth, and apoptosis. METHODOLOGY: The potency of lactate efflux inhibition of ethanol plant extracts was evaluated in N2-A cells by measuring extracellular lactate levels. Caspase 3- activity and acridine orange/ethidium bromide staining were performed to assess the apoptotic effect. The antiproliferative effect was measured using WST assay. Western blotting was performed to quantify protein expression of MCTs and their chaperone CD147 in treated cells lysates. RESULTS: Terminalia chebula plant extract was the most potent lactate efflux inhibitor in N2-A cells among the 900 - tested plant extracts. The results obtained show that extract of Terminalia chebula fruits (TCE) significantly (P = 0.05) reduced the expression of the MCT1, MCT3, MCT4 and the chaperone CD147. The plant extract was more potent (IC50 of 3.59 ± 0.26 µg/ml) than the MCT standard inhibitor phloretin (IC50 76.54 ± 3.19 µg/ml). The extract also showed more potency and selective cytotoxicity in cancer cells than DI-TNC1 primary cell line (IC50 7.37 ± 0.28 vs. 17.35 ± 0.19 µg/ml). Moreover, TCE Inhibited N2-A cell growth (IG50 = 5.20 ± 0.30 µg/ml) and induced apoptosis at the 7.5 µg/ml concentration. CONCLUSION: Out of the 900 plant extracts screened, Terminalia chebula ethanol extract was found to be the most potent lactate efflux inhibitor with the ability to inhibit chaperone CD147 expression and impact the function of monocarboxylate transporters. Furthermore, TCE was found to have growth inhibition and apoptotic effects. The results obtained indicate that Terminalia chebula constituent(s) may contain promising compounds that can be useful in the management of neuroblastoma cancer.

11.
Appl Opt ; 55(4): 838-45, 2016 Feb 01.
Article in English | MEDLINE | ID: mdl-26836089

ABSTRACT

This work presents an experimental and theoretical study of cyanidin natural dye as a sensitizer for ZnO dye-sensitized solar cells. ZnO nanoparticles were prepared using ammonia and oxalic acid as a capping agent. The calculated average size of the synthesized ZnO with different capping agents was found to be 32.1 nm. Electronic properties of cyanidin and delphinidin dye were studied using density functional theory (DFT) and time-dependent DFT with a B3LYP/6-31G(d,p) level. By comparing the theoretical results with the experimental data, the cyanidin dye can be used as a sensitizer in dye-sensitized solar cells. An efficiency of 0.006% under an AM-1.5 illumination at 100 mW/cm(2) was attained. The influence of dye adsorption time on the solar cell performance is discussed.


Subject(s)
Coloring Agents/isolation & purification , Hibiscus/chemistry , Models, Theoretical , Quantum Theory , Solar Energy , Adsorption , Anthocyanins/chemistry , Coloring Agents/chemistry , Computer Simulation , Electricity , Models, Molecular , Molecular Conformation , Spectrophotometry, Ultraviolet , Thermodynamics , X-Ray Diffraction
12.
Cytokine ; 75(1): 117-26, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26100848

ABSTRACT

TNFα receptors are constitutively overexpressed in tumor cells, correlating to sustain elevated NFκB and monocyte chemotactic protein-1 (MCP-1/CCL2) expression. The elevation of CCL2 evokes aggressive forms of malignant tumors marked by tumor associated macrophage (TAM) recruitment, cell proliferation, invasion and angiogenesis. Previously, we have shown that the organo-sulfur compound diallyl disulfide (DADS) found in garlic (Allium sativum) attenuates TNFα induced CCL2 production in MDA-MB-231 cells. In the current study, we explored the signaling pathways responsible for DADS suppressive effect on TNFα mediated CCL2 release using PCR Arrays, RT-PCR and western blots. The data in this study show that TNFα initiates a rise in NFκB mRNA, which is not reversed by DADS. However, TNFα induced heightened expression of IKKε and phosphorylated ERK. The expression of these proteins corresponds to increased CCL2 release that can be attenuated by DADS. CCL2 induction by TNFα was also lessened by inhibitors of p38 (SB202190) and MEK (U0126) but not JNK (SP 600125), all of which were suppressed by DADS. In conclusion, the obtained results indicate that DADS down regulates TNFα invoked CCL2 production primarily through reduction of IKKε and phosphorylated-ERK, thereby impairing MAPK/ERK, and NFκB pathway signaling. Future research will be required to evaluate the effects of DADS on the function and expression of TNFα surface receptors.


Subject(s)
Allyl Compounds/chemistry , Chemokine CCL2/metabolism , Disulfides/chemistry , Gene Expression Regulation, Neoplastic , MAP Kinase Signaling System , NF-kappa B p50 Subunit/metabolism , Tumor Necrosis Factor-alpha/metabolism , Anthracenes/chemistry , Anticarcinogenic Agents/chemistry , Butadienes/chemistry , Cell Line, Tumor , Garlic/chemistry , Humans , Imidazoles/chemistry , MAP Kinase Kinase 4/antagonists & inhibitors , MAP Kinase Kinase Kinases/antagonists & inhibitors , Macrophages/metabolism , Nitriles/chemistry , Phosphorylation , Pyridines/chemistry , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors
13.
Radiat Prot Dosimetry ; 165(1-4): 373-5, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25852183

ABSTRACT

Based on manufacturer specifications, radiochromic films are sensitive enough to be used for dosimetry in digital mammography (DM). The aim of this work was to study the feasibility of measuring entrance surface dose (ESD) distribution using Gafchromic XR-QA2 films. The films were irradiated following a standard clinical two-view screening mammography protocol using a full-field digital mammography (FFDM) imaging system. The films were then digitised using a flatbed scanner. The calibration curve relating the readings from a calibrated ionisation chamber and the films' net optical density (NOD) could not be obtained. The examination of the calibration data revealed non-sensitivity of the films to resolve dose differences below 20 mGy at 28 kVp. Therefore, radiochromic films were found not to be suitable for measuring ESD profiles in DM. A 2D map of the NOD of the irradiated films obtained using in-house developed MATLAB computer program is presented.


Subject(s)
Film Dosimetry/instrumentation , Film Dosimetry/methods , Mammography/methods , Radiographic Image Enhancement/methods , Skin/radiation effects , Breast/pathology , Calibration , Female , Humans , Phantoms, Imaging , Radiation Dosage , Radiographic Image Enhancement/instrumentation , Reference Standards , Software
14.
Ann ICRP ; 44(1 Suppl): 259-75, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25915553

ABSTRACT

Over the past decade, the number of positron emission tomography/computed tomography (PET/CT) imaging procedures has increased substantially. This imaging technique provides accurate functional and anatomical information, particularly for oncological applications. Separately, both PET and CT are considered as high-dose imaging modalities. With the increased use of PET/CT, one could expect an increase in radiation doses to staff and patients. As such, major efforts have been made to reduce radiation dose in PET/CT facilities. Variations in working techniques have made it difficult to compare published results. This study aimed to review the literature on proposed methods to reduce patient and staff dose in clinical PET/CT imaging. A brief overview of some published information on staff and patient doses will be analysed and presented. Recent trends regarding radiation protection in PET/CT imaging will be discussed, and practical recommendations for reducing radiation doses to staff and patients will be discussed and summarised. Generally, the CT dose component is often higher in magnitude than the dose from PET alone; as such, focusing on CT dose reduction will decrease the overall patient dose in PET/CT imaging studies. The following factors should be considered in order to reduce the patient's dose from CT alone: proper justification for ordering contrast-enhanced CT; use of automatic exposure control features; use of adaptive statistical iterative reconstruction algorithms; and optimisation of scan parameters, especially scan length. The PET dose component can be reduced by administration of lower activity to the patient, optimisation of the workflow, and appropriate use of protective devices and engineered systems. At the international level, there is wide variation in work practices among institutions. The current observed trends are such that the annual dose limits for radiation workers in PET/CT imaging are unlikely to be exceeded.


Subject(s)
Multimodal Imaging , Positron-Emission Tomography , Radiation Protection , Tomography, X-Ray Computed , Humans , Multimodal Imaging/trends , Positron-Emission Tomography/trends , Tomography, X-Ray Computed/trends
15.
Radiat Prot Dosimetry ; 165(1-4): 448-51, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25862533

ABSTRACT

The calculated dose rate from the radioiodine therapy patient should normally include a factor accounting for the attenuation and scatter of patient body tissues. The attenuation factor is currently neglected, and not applied in operational radiation protection. Realistic estimation of radiation dose rate levels from radioiodine therapy patients when properly performed will reduce operational cost and optimise institutional radiation protection practice. In this work, the existence of a patient body tissue attenuation factor is verified by comparing the dose rates measured from the radioiodine capsules immediately before administration with those measured from the patient immediately after administration. The correlation between the factors suspected to influence the patient body tissue attenuation and the measured dose rates from the patient normalised per unit activity is statistically analysed. The calculated attenuation correction factor based on authors' measurements was (0.55 ± 0.17). The measured dose rate per unit of radioactivity from the patient showed a negative correlation with their body mass index.


Subject(s)
Iodine Radioisotopes/analysis , Iodine Radioisotopes/therapeutic use , Radiation Dosage , Radiometry/methods , Adolescent , Adult , Aged , Aged, 80 and over , Body Mass Index , Gamma Rays , Hospitalization , Humans , Middle Aged , Radiation Protection , Radiotherapy Dosage , Reproducibility of Results , Risk Assessment , Thyroid Diseases/radiotherapy , Whole Body Imaging , Young Adult
16.
Phys Chem Chem Phys ; 16(36): 19333-9, 2014 Sep 28.
Article in English | MEDLINE | ID: mdl-25099825

ABSTRACT

The hydrogen storage of Ti functionalized carbon nanocones and carbon nanocone sheets is investigated by using the state-of-the-art density functional theory calculations. The Ti atom prefers to bind at the hollow site of the hexagonal ring. The average adsorption energies corrected for dispersion forces are -0.54 and -0.39 eV per hydrogen molecule. With no metal clustering, the system gravimetric capacities are expected to be as large as 9.31 and 11.01 wt%. The hydrogen storage reactions are characterized in terms of simulated infrared spectra, projected densities of states, kinetics, and statistical thermodynamics. The free energies and enthalpies of the Ti functionalized carbon nanocone meet the ultimate targets of the Department of Energy for all temperatures and pressures. The closest reactions to zero free energy occur at 378.15 K/2.961 atm for carbon nanocones and 233.15 K/2.961 atm for carbon nanocone sheets. The translational component is found to exert a dominant effect on the total entropy change with temperature. More promising thermodynamics are assigned to the hydrogenation of Ti functionalized carbon nanocone sheets at 233.15 K. As the temperature is increased, the lifetimes of the hydrogen molecules adsorbed at the surface drop and the rate constants increase. At fixed pressure, the rate constants of hydrogenation of Ti functionalized carbon nanocones are smaller than those of Ti functionalized carbon nanocone sheets, while the lifetimes are greater.

17.
Radiat Prot Dosimetry ; 158(2): 170-4, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24084519

ABSTRACT

The aim of this study was to test the feasibility of using Gafchromic XR-QA2 films in the measurements of patient entrance surface dose (ESD) during the micturating cystourethrogram (MCUG) examination in paediatric patients. Radiochromic films were used to map the entrance dose and to identify the location of peak surface dose (PSD). Direct in vivo measurements of entrance dose were conducted by placing a radiochromic film between the patient and the examination table. The measured ESD values for the commonly performed MCUG fluoroscopic examinations at the authors' institution was in the range of 1.2-7.8 mGy and the PSD in the range of 1.2-8.5 mGy per MCUG procedure for patients with age ranging from 1 to 12 y old. Gafchromic films (XR-QA2) were found to be an efficient and practical dosimetry method that can be easily used to measure clinical patient entrance doses during fluoroscopically guided procedures and potentially in other diagnostic investigations.


Subject(s)
Film Dosimetry/methods , Fluoroscopy/methods , Urethra/diagnostic imaging , Urinary Bladder/diagnostic imaging , Urination , Urography/standards , X-Ray Film , Air , Calibration , Humans , Radiation Dosage , Skin/radiation effects , Urography/methods
18.
Phytother Res ; 28(6): 856-67, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24105850

ABSTRACT

Some of the most effective anti-mitotic microtubule-binding agents, such as paclitaxel (Taxus brevifolia) were originally discovered through robust National Cancer Institute botanical screenings. In this study, a high-through put microarray format was utilized to screen 897 aqueous extracts of commonly used natural products (0.00015-0.5 mg/mL) relative to paclitaxel for anti-mitotic effects (independent of toxicity) on proliferation of MDA-MB-231 cells. The data obtained showed that less than 1.34 % of the extracts tested showed inhibitory growth (IG50 ) properties <0.0183 mg/mL. The most potent anti-mitotics (independent of toxicity) were Mandrake root (Podophyllum peltatum), Truja twigs (Thuja occidentalis), Colorado desert mistletoe (Phoradendron flavescens), Tou Gu Cao [symbol: see text] Speranskia herb (Speranskia tuberculata), Bentonite clay, Bunge root (Pulsatilla chinensis), Brucea fruit (Brucea javanica), Madder root (Rubia tinctorum), Gallnut of Chinese Sumac (Melaphis chinensis), Elecampane root (Inula Helenium), Yuan Zhi [symbol: see text] root (Polygala tenuifolia), Pagoda Tree fruit (Melia Toosendan), Stone root (Collinsonia Canadensis), and others such as American Witchhazel, Arjun, and Bladderwrack. The strongest tumoricidal herbs identified from amongst the subset evaluated for anti-mitotic properties were wild yam (Dioscorea villosa), beth root (Trillium Pendulum), and alkanet root (Lithospermum canescens). Additional data was obtained on a lesser-recognized herb: (S. tuberculata), which showed growth inhibition on BT-474 (human ductal breast carcinoma) and Ishikawa (human endometrial adenocarcinoma) cells with ability to block replicative DNA synthesis, leading to G2 arrest in MDA-MB-231 cells. In conclusion, these findings present relative potency of anti-mitotic natural plants that are effective against human breast carcinoma MDA-MB-231 cell division.


Subject(s)
Breast Neoplasms/pathology , Magnoliopsida/chemistry , Mitosis/drug effects , Plant Extracts/pharmacology , Cell Line, Tumor , Drug Evaluation, Preclinical , Female , High-Throughput Screening Assays , Humans , Plant Extracts/chemistry , Plants, Medicinal/chemistry
19.
Phytother Res ; 27(6): 818-28, 2013 Jun.
Article in English | MEDLINE | ID: mdl-22887993

ABSTRACT

Age-related increase in monoamine oxidase B (MAO-B) may contribute to CNS neurodegenerative diseases. Moreover, MAO-B inhibitors are used in the treatment of idiopathic Parkinson disease as preliminary monotherapy or adjunct therapy with L-dopa. To date, meager natural sources of MAO-B inhibitors have been identified, and the relative strength, potency and rank of many plants relative to standard drugs such as Selegiline (L-deprenyl,Eldepryl) are not known. In this work, we developed and utilized a high throughput enzyme microarray format to screen and evaluate 905 natural product extracts (0.025-.7 mg/ml) to inhibit human MAO-B derived from BTI-TN-5B1-4 cells infected with recombinant baculovirus. The protein sequence of purified enzyme was confirmed using 1D gel electrophoresis-matrix assisted laser desorption ionization -time-of-flight-tandem mass spectroscopy, and enzyme activity was confirmed by [1] substrate conversion (3-mM benzylamine) to H202 and [2] benzaldehyde. Of the 905 natural extracts tested, the lowest IC50s [<0.07 mg/ml] were obtained with extracts of Amur Corktree (Phellodendron amurense), Bakuchi Seed(Cyamopsis psoralioides), Licorice Root (Glycyrrhiza glabra/uralensis), Babchi (Psoralea corylifolia seed). The data also show, albeit to a lesser extent, inhibitory properties of herbs originating from the mint family (Lamiaceae) and Turmeric, Comfrey, Bringraj, Skullcap, Kava-kava, Wild Indigo, Gentian and Green Tea. In conclusion, the data reflect relative potency information by rank of commonly used herbs and plants that contain human MAO-B inhibitory properties in their natural form.


Subject(s)
Monoamine Oxidase Inhibitors/pharmacology , Monoamine Oxidase/metabolism , Plant Extracts/pharmacology , High-Throughput Screening Assays , Humans , Monoamine Oxidase Inhibitors/isolation & purification , Plant Extracts/isolation & purification , Plants, Medicinal/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Tandem Mass Spectrometry
20.
European J Med Plants ; 3(4): 603-615, 2013.
Article in English | MEDLINE | ID: mdl-24478981

ABSTRACT

AIMS: Lactate dehydrogenase (LDH)-A is highly expressed in diverse human malignant tumors, parallel to aggressive metastatic disease, resistance to radiation/chemotherapy and clinically poor outcome. Although this enzyme constitutes a plausible target in treatment of advanced cancer, there are few known LDH-A inhibitors. STUDY DESIGN: In this work, we utilized a high-throughput enzyme micro-array format to screen and evaluate > 900 commonly used medicinal plant extracts (0.00001-.5 mg/ml) for capacity to inhibit activity of recombinant full length human LDHA; EC .1.1.1.27. METHODOLOGY: The protein sequence of purified enzyme was confirmed using 1D gel electrophoresis- MALDI-TOF-MS/MS, enzyme activity was validated by oxidation of NADH (500µM) and kinetic inhibition established in the presence of a known inhibitor (Oxalic Acid). RESULTS: Of the natural extracts tested, the lowest IC50s [<0.001 mg/ml] were obtained by: Chinese Gallnut (Melaphis chinensis gallnut), Bladderwrack (Fucus vesiculosus), Kelp (Laminaria Japonica) and Babul (Acacia Arabica). Forty-six additional herbs contained significant LDH-A inhibitory properties with IC50s [<0.07 mg/ml], some of which have common names of Arjun, Pipsissewa, Cinnamon, Pink Rose Buds/Petals, Wintergreen, Cat's Claw, Witch Hazel Root and Rhodiola Root. CONCLUSION: These findings reflect relative potency by rank of commonly used herbs and plants that contain human LDH-A inhibitory properties. Future research will be required to isolate chemical constituents within these plants responsible for LDH-A inhibition and investigate potential therapeutic application.

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