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https://www.readbyqxmd.com/read/28432980/discovery-of-potential-inhibitor-against-human-acetylcholinesterase-a-molecular-docking-and-molecular-dynamics-investigation
#1
Surya Pratap Singh, Dwijendra Gupta
Alzheimer's disease (AD) is a progressive neurodegenerative disease of central nervous system among elderly people. Human acetylcholinesterase (hAChE), an important enzyme in neuronal signaling, is responsible for the degradation of acetylcholine which in turn prevents the post synaptic signal transmissions. hAChE has been an attractive target of drug discovery for the search of therapeutics against AD. In the recent past hAChE has become hot target for the investigation of new potential therapeutics. We performed virtual screening of entire database against hAChE...
April 12, 2017: Computational Biology and Chemistry
https://www.readbyqxmd.com/read/28432960/molecular-dynamic-simulations-on-tkx-50-rdx-cocrystal
#2
Shuling Xiong, Shusen Chen, Shaohua Jin
Dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (TKX-50) is a newly synthesized energetic material with excellent comprehensive properties. Cyclotrimethylenetrinitramine (RDX) is currently one of the most widely used energetic materials in the world. TKX-50 and RDX supercell models and TKX-50/RDX cocrystal model were constructed based on their crystal cell parameters and the formation mechanism of cocrystal, respectively, then they were simulated by molecular dynamics (MD) simulations. The maximum trigger bond (NNO2) length(Lmax), binding energy (Ebind), radial distribution function (RDF), cohesive energy density(CED) and mechanical properties were simulated at different temperatures based on the simulated equilibrium structures of the models...
March 19, 2017: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28432959/molecular-dynamics-simulation-studies-of-novel-%C3%AE-lactamase-inhibitor
#3
Farhan Ul Haq, Asma Abro, Saad Raza, Klaus R Liedl, Syed Sikander Azam
New Delhi Metallo-β-Lactamase-1 (NDM-1) has drawn great attention due to its diverse antibiotic resistant activity. It can hydrolyze almost all clinically available β-lactam antibiotics. To inhibit the activity of NDM-1 a new strategy is proposed using computational methods. Molecular dynamics (MD) simulations are used to analyze the molecular interactions between selected inhibitor candidates and NDM-1 structure. The enzyme-ligand complex is subject to binding free energy calculations using MM(PB/GB)SA methods...
April 4, 2017: Journal of Molecular Graphics & Modelling
https://www.readbyqxmd.com/read/28432953/new-and-practical-mathematical-model-of-membrane-fouling-in-an-aerobic-submerged-membrane-bioreactor
#4
Mst Fazana Rahman Zuthi, Wenshan Guo, Huu Hao Ngo, Duc Long Nghiem, Faisal I Hai, Siqing Xia, Jianxin Li, Jixiang Li, Yi Liu
This study aimed to develop a practical semi-empirical mathematical model of membrane fouling that accounts for cake formation on the membrane and its pore blocking as the major processes of membrane fouling. In the developed model, the concentration of mixed liquor suspended solid is used as a lumped parameter to describe the formation of cake layer including the biofilm. The new model considers the combined effect of aeration and backwash on the foulants' detachment from the membrane. New exponential coefficients are also included in the model to describe the exponential increase of transmembrane pressure that typically occurs after the initial stage of an MBR operation...
April 4, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28432952/removal-of-antibiotics-from-piggery-wastewater-by-biological-aerated-filter-system-treatment-efficiency-and-biodegradation-kinetics
#5
Jun Chen, You-Sheng Liu, Jin-Na Zhang, Yong-Qiang Yang, Li-Xin Hu, Yuan-Yuan Yang, Jian-Liang Zhao, Fan-Rong Chen, Guang-Guo Ying
This study aimed to investigate the removal efficiency and mechanism for antibiotics in swine wastewater by a biological aerated filter system (BAF system) in combination with laboratory aerobic and anaerobic incubation experiments. Nine antibiotics including sulfamonomethoxine, sulfachloropyridazine, sulfamethazine, trimethoprim, norfloxacin, ofloxacin, lincomycin, leucomycin and oxytetracycline were detected in the wastewater with concentrations up to 192,000ng/L. The results from this pilot study showed efficient removals (>82%) of the conventional wastewater pollutants (BOD5, COD, TN and NH3-N) and the detected nine antibiotics by the BAF system...
April 9, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28432909/source-receptor-relationships-for-pm2-5-during-typical-pollution-episodes-in-the-pearl-river-delta-city-cluster-china
#6
Yiming Liu, Yingying Hong, Qi Fan, Xuemei Wang, Pakwai Chan, Xiaoyang Chen, Anqi Lai, Mingjie Wang, Xunlai Chen
Located in the Southern China monsoon region, pollution days in Pearl River Delta (PRD) were classified into "Western type", "Central type" or "Eastern type", with a relative percentage of 67%, 24% and 9%, respectively. Using this classification system, three typical pollution events were selected for numerical simulations using the WRF-Chem model. The source sensitivity method for anthropogenic emissions of PM2.5 and its precursors was applied to identify the source-receptor relationships for PM2.5 among 9 cities in PRD...
April 19, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28432889/reducing-domestic-heating-demand-managing-the-impact-of-behavior-changing-feedback-devices-via-marketing
#7
Thorben Jensen, Émile J L Chappin
Feedback devices can be used to inform households about their energy-consumption behavior. This may persuade them to practice energy conservation. The use of feedback devices can also-via word of mouth-spread among households and thereby support the spread of the incentivized behavior, e.g. energy-efficient heating behavior. This study investigates how to manage the impact of these environmental innovations via marketing. Marketing activities can support the diffusion of devices. This study aims to identify the most effective strategies of marketing feedback devices...
April 19, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28432828/quantitative-contrast-enhanced-spectral-mammography-based-on-photon-counting-detectors-a-feasibility-study
#8
Huanjun Ding, Sabee Molloi
PURPOSE: To investigate the feasibility of accurate quantification of iodine mass thickness in contrast-enhanced spectral mammography. MATERIALS AND METHODS: A computer simulation model was developed to evaluate the performance of a photon-counting spectral mammography system in the application of contrast-enhanced spectral mammography. A figure-of-merit (FOM), which was defined as the decomposed iodine signal-to-noise ratio (SNR) with respect to the square root of the mean glandular dose (MGD), was chosen to optimize the imaging parameters, in terms of beam energy, splitting energy, and pre-filtrations for breasts of various thicknesses and densities...
April 22, 2017: Medical Physics
https://www.readbyqxmd.com/read/28432821/addition-of-hydrogen-peroxide-to-groundwater-with-natural-iron-induces-water-disinfection-by-photo-fenton-at-circumneutral-ph-and-other-photochemical-events
#9
Héctor Mario Gutiérrez-Zapata, John Jairo Alvear-Daza, Julián Andrés Rengifo-Herrera, Janeth Sanabria
Samples of natural groundwater (with low turbidity, neutral pH and 0.3 mg L(-1) iron concentration) inoculated with Escherichia coli K-12, were exposed to simulated solar light both in the presence and absence 10 mg L(-1) of H2 O2. Results demonstrated that the viability of E. coli (by DVC-FISH) was grounded to zero after 360 min of irradiation. This abatement could be caused by the oxidative stress induced by •OH radicals or another photo-induced reactive oxygen species. Two 2(3) factorial experimental designs enabled the evaluation of the effects of chemical factors on the inactivation of E...
April 22, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28432820/the-impact-of-small-motion-on-the-visualization-of-coronary-vessels-and-lesions-in-cardiac-ct-a-simulation-study
#10
Francisco Contijoch, J Webster Stayman, Elliot R McVeigh
PURPOSE: Coronary x-ray computed tomography angiography (CCTA) is used to non-invasively assess coronary artery geometry and has, combined with computational modeling, demonstrated the potential to identify physiologically significant lesions. These measurements require robust and accurate coronary imaging and delineation of vessels in the presence of small motion. This simulation study characterizes the impact of small, uncorrected vessel drifts during data acquisition on the assessment of vessel intensity, diameter, and shape...
April 22, 2017: Medical Physics
https://www.readbyqxmd.com/read/28432792/monte-carlo-study-of-the-chamber-phantom-air-gap-effect-in-a-magnetic-field
#11
Daniel J O'Brien, Gabriel O Sawakuchi
PURPOSE: The aim of this study was to examine the effect of sub-millimeter air gaps that may exist between an ionization chamber and solid phantoms when measurements are performed in a magnetic field. METHODS: Geant4 Monte Carlo simulations were performed using a model of a PTW 30013 Farmer chamber in a water phantom. Symmetrical and asymmetrical air gaps of various thicknesses were modeled surrounding the chamber, and the dose to the air cavity of the chamber was scored in each case...
April 22, 2017: Medical Physics
https://www.readbyqxmd.com/read/28432786/the-comprehensive-connectome-of-a-neural-substrate-for-on-motion-detection-in-drosophila
#12
Shin-Ya Takemura, Aljoscha Nern, Dmitri B Chklovskii, Louis K Scheffer, Gerald M Rubin, Ian A Meinertzhagen
Analysing computations in neural circuits often uses simplified models because the actual neuronal implementation is not known. For example, a problem in vision, how the eye detects image motion, has long been analysed using Hassenstein-Reichardt (HR) detector or Barlow-Levick (BL) models. These both simulate motion detection well, but the exact neuronal circuits undertaking these tasks remain elusive. We reconstructed a comprehensive connectome of the circuits of Drosophila's motion-sensing T4 cells using a novel EM technique...
April 22, 2017: ELife
https://www.readbyqxmd.com/read/28432784/contributions-of-imprecision-in-pet-mri-rigid-registration-to-imprecision-in-amyloid-pet-suvr-measurements
#13
Christopher G Schwarz, David T Jones, Jeffrey L Gunter, Val J Lowe, Prashanthi Vemuri, Matthew L Senjem, Ronald C Petersen, David S Knopman, Clifford R Jack
Quantitative measurement of β-amyloid from amyloid PET scans typically relies on localizing target and reference regions by image registration to MRI. In this work, we present a series of simulations where 50 small random perturbations of starting location and orientation were applied to each subject's PET scan, and rigid registration using spm_coreg was performed between each perturbed PET scan and its corresponding MRI. We then measured variation in the output PET-MRI registrations and how this variation affected the resulting SUVR measurements...
April 22, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28432677/development-of-yoghurt-with-ju%C3%A3-ara-pulp-euterpe-edulis-m-and-the-probiotic-lactobacillus-acidophilus-la5
#14
Marina V Geraldi, Fabricio L Tulini, Vanessa M Souza, Elaine C P De Martinis
Yoghurts are dairy products consumed worldwide and can be supplemented with substances that provide extra health benefits as well as probiotic strains. In this context, the present study aimed to prepare a yoghurt added of juçara (Euterpe edulis M.) pulp and the commercial probiotic strain Lactobacillus acidophilus La5. Moreover, the probiotic survival during storage and after in vitro exposure to simulated gastric and enteric conditions was evaluated. Four formulations of yoghurt were prepared: (a) natural yoghurt, (b) yoghurt added of probiotic, (c) yoghurt added of juçara pulp, and (d) yoghurt added of probiotic culture and juçara pulp...
April 21, 2017: Probiotics and Antimicrobial Proteins
https://www.readbyqxmd.com/read/28432656/collisional-cross-sections-with-t-wave-ion-mobility-spectrometry-without-experimental-calibration
#15
Daniel N Mortensen, Anna C Susa, Evan R Williams
A method for relating traveling-wave ion mobility spectrometry (TWIMS) drift times with collisional cross-sections using computational simulations is presented. This method is developed using SIMION modeling of the TWIMS potential wave and equations that describe the velocity of ions in gases induced by electric fields. The accuracy of this method is assessed by comparing the collisional cross-sections of 70 different reference ions obtained using this method with those obtained from static drift tube ion mobility measurements...
April 21, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28432614/dual-activity-of-hydroxypropyl-%C3%AE-cyclodextrin-and-water-soluble-carriers-on-the-solubility-of-carvedilol
#16
Abdelmoumin Zoghbi, Tianjiao Geng, Bo Wang
Carvedilol (CAR) is a non-selective α and β blocker categorized as class II drug with low water solubility. Several recent studies have investigated ways to overcome this problem. The aim of the present study was to combine two of these methods: the inclusion complex using hydroxypropyl-β-cyclodextrin (HPβCD) with solid dispersion using two carriers: Poloxamer 188 (PLX) and Polyvinylpyrrolidone K-30 (PVP) to enhance the solubility, bioavailability, and the stability of CAR. Kneading method was used to prepare CAR-HPβCD inclusion complex (KD)...
April 21, 2017: AAPS PharmSciTech
https://www.readbyqxmd.com/read/28432561/predicting-fluid-responsiveness-in-whom-a-simulated-example-of-patient-spectrum-influencing-the-receiver-operating-characteristics-curve
#17
Lars Øivind Høiseth, Jostein S Hagemo
The influence of patient spectrum on the sensitivities and specificities of diagnostic methods has been termed spectrum bias or spectrum effect. Receiver operating characteristics curves are often used to assess the ability of diagnostic methods to predict fluid responsiveness. As a receiver operating characteristics curve is a presentation of sensitivity and specificity, the purpose of the present manuscript was to explore if patient spectrum could affect areas under receiver operating characteristics curves and their gray zones...
April 21, 2017: Journal of Clinical Monitoring and Computing
https://www.readbyqxmd.com/read/28432535/exploring-the-carbamazepine-interaction-with-human-pregnane-x-receptor-and-effect-on-abcc2-using-in-vitro-and-in-silico-approach
#18
Gurpreet K Grewal, Khuraijam D Singh, Neha Kanojia, Chitra Rawat, Samiksha Kukal, Ajay Jajodia, Anshika Singhal, Richa Misra, Selvaraman Nagamani, Karthikeyan Muthusamy, Ritushree Kukreti
PURPOSE: Over expression of ATP-binding cassette transporters is considered one of the major reasons for non-responsiveness to antiepileptic drugs. Carbamazepine (CBZ), one of first line antiepileptic drug is known to influence ABCC2 expression but its exact molecular mechanism is unknown. METHODS: We investigated the effect of CBZ on expression of ABCC2 and pregnane X receptor (PXR) in HepG2 cell line and compared with hyperforin (agonist of PXR) and ketoconazole (antagonist of PXR) through realtime PCR and western blot assay...
April 21, 2017: Pharmaceutical Research
https://www.readbyqxmd.com/read/28432531/effectiveness-of-nanoencapsulated-methotrexate-against-osteosarcoma-cells-in-vitro-cytotoxicity-under-dynamic-conditions
#19
O Mitxelena-Iribarren, C L Hisey, M Errazquin-Irigoyen, Y González-Fernández, E Imbuluzqueta, M Mujika, M J Blanco-Prieto, S Arana
Cancer is a leading cause of mortality in the world, with osteosarcoma being one of the most common types among children between 1 and 14 years old. Current treatments including preoperative chemotherapy, surgery and postoperative chemotherapy produce several side effects with limited effectiveness. The use of lipid nanoparticles as biodegradable shells for controlled drug delivery shows promise as a more effective and targeted tumor treatment. However, in vitro validation of these vehicles is limited due to fluid stagnation in current techniques, in which nanoparticles sediment onto the bottom of the wells killing the cells by asphyxiation...
June 2017: Biomedical Microdevices
https://www.readbyqxmd.com/read/28432507/study-of-the-potential-of-barnyard-grass-for-the-remediation-of-cd-and-pb-contaminated-soil
#20
Jianling Xu, Qiongyao Cai, Hanxi Wang, Xuejun Liu, Jing Lv, Difu Yao, Yue Lu, Wei Li, Yuanyuan Liu
In this study, the microwave digestion method was used to determine total cadmium (Cd) and lead (Pb) concentrations, the BCR method was used to determine different states of Cd and Pb, and atomic absorption spectroscopy (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES) were used to determine Cd and Pb concentrations in simulated soil and barnyard grass before and after planting barnyard grass to provide a theoretical basis for the remediation of Cd- and Pb-contaminated soil. The results showed that the bioconcentration factor changes with different Cd concentrations are relatively complex and that the removal rate increases regularly...
May 2017: Environmental Monitoring and Assessment
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