keyword
MENU ▼
Read by QxMD icon Read
search

mathematical modeling

keyword
https://www.readbyqxmd.com/read/28087782/mutation-supply-and-relative-fitness-shape-the-genotypes-of-ciprofloxacin-resistant-escherichia-coli
#1
Douglas L Huseby, Franziska Pietsch, Gerrit Brandis, Linnéa Garoff, Angelica Tegehall, Diarmaid Hughes
Ciprofloxacin is an important antibacterial drug targeting Type II topoisomerases, highly active against Gram-negatives including Escherichia coli The evolution of resistance to ciprofloxacin in E. coli always requires multiple genetic changes, usually including mutations affecting two different drug target genes, gyrA and parC Resistant mutants selected in vitro or in vivo can have many different mutations in target genes and efflux regulator genes that contribute to resistance. Among resistant clinical isolates the genotype, gyrA S83L D87N, parC S80I is significantly overrepresented suggesting that it has a selective advantage...
January 12, 2017: Molecular Biology and Evolution
https://www.readbyqxmd.com/read/28087422/nano-qsar-in-cell-biology-model-of-cell-viability-as-a-mathematical-function-of-available-eclectic-data
#2
Alla P Toropova, Andrey A Toropov
The prediction of biochemical endpoints is an important task of the modern medicinal chemistry, cell biology, and nanotechnology. Simplified molecular input-line entry system (SMILES) is a tool for representation of the molecular structure. In particular, SMILES can be used to build up the quantitative structure - property / activity relationships (QSPRs/QSARs). The QSPR/QSAR is a tool to predict an endpoint for a new substance, which has not been examined in experiment. Quasi-SMILES are representation of eclectic data related to an endpoint...
January 10, 2017: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/28087352/engineering-hot-melt-extruded-solid-dispersion-for-controlled-release-of-hydrophilic-drugs
#3
Shuli Zhang, Xuan Meng, Zheng Wang, Aiping Fan, Guocheng Wang, Yanjun Zhao, Yu Tang
It is often challenging to precisely manipulate the release behavior of hydrophilic drugs that is believed to be crucial for a satisfactory therapeutic outcome. The aim of this work was to regulate the dissolution of hydrophilic drug from hot-melt extruded solid dispersion via rational screening of the pore-forming agents. Venlafaxine hydrochloride and Compritol® 888 ATO was selected as the model drug and carrier excipient, respectively. Hydrophilic polyethylene glycol (PEG 6000) and polyvinylpyrolidone (PVP K30) were chosen as the transient pore-forming agents...
January 10, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28086846/stochastic-agent-based-modeling-of-tuberculosis-in-canadian-indigenous-communities
#4
Ashleigh R Tuite, Victor Gallant, Elaine Randell, Annie-Claude Bourgeois, Amy L Greer
BACKGROUND: In Canada, active tuberculosis (TB) disease rates remain disproportionately higher among the Indigenous population, especially among the Inuit in the north. We used mathematical modeling to evaluate how interventions might enhance existing TB control efforts in a region of Nunavut. METHODS: We developed a stochastic, agent-based model of TB transmission that captured the unique household and community structure. Evaluated interventions included: (i) rapid treatment of active cases; (ii) rapid contact tracing; (iii) expanded screening programs for latent TB infection (LTBI); and (iv) reduced household density...
January 13, 2017: BMC Public Health
https://www.readbyqxmd.com/read/28081545/mathematical-optimisation-of-the-cisplatin-plus-etoposide-combination-for-managing-extensive-stage-small-cell-lung-cancer-patients
#5
C Faivre, R El Cheikh, D Barbolosi, F Barlesi
BACKGROUND: Small-cell lung cancer (SCLC) represents one of the most aggressive forms of lung cancer. Despite the fair sensitivity of SCLC to chemotherapy and radiotherapy, the current standard treatment regimens have modest survival rates and are associated with potential life-threatening adverse events. Therefore, research into new optimised regimens that increase drug efficacy while respecting toxicity constraints is of primary importance. METHODS: A PK/PD model for the combination of cisplatin and etoposide to treat extensive-stage SCLC patients was generated...
January 12, 2017: British Journal of Cancer
https://www.readbyqxmd.com/read/28081004/reverberant-shear-wave-fields-and-estimation-of-tissue-properties
#6
Kevin J Parker, Juvenal Ormachea, Fernando Zvietcovich, Benjamin Castaneda
The determination of shear wave speed is an important subject in the field of elastography, since elevated shear wave speeds can be directly linked to increased stiffness of tissues. MRI and ultrasound scanners are frequently used to detect shear waves and a variety of estimators are applied to calculate the underlying shear wave speed. The estimators can be relatively simple if plane wave behavior is assumed with a known direction of propagation. However, multiple reflections from organ boundaries and internal inhomogeneities and mode conversions can create a complicated field in time and space...
January 12, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28079924/optimized-microwave-assistant-extraction-combined-ultrasonic-pretreatment-of-flavonoids-from-periploca-forrestii-schltr-and-evaluation-of-its-anti-allergic-activity
#7
Qian Liang, Huaguo Chen, Xin Zhou, Qingfang Deng, Enming Hu, Chao Zhao, Xiaojian Gong
Microwave extraction combined ultrasonic pretreatment of flavonoids from Periploca forrestii Schltr. was investigated in this study, extraction process was firstly performed in an ultrasonic cleaner, then treated by microwave irradiation. The optimum ultrasonic time of 25 min was selected by single-factor experiments. A response surface methodology (RSM) has been used to obtain a mathematical model that describes the process and analyzes the significant parameters ethanol concentration 59.92%, liquid to raw materials ratio 21...
January 12, 2017: Electrophoresis
https://www.readbyqxmd.com/read/28077763/a-simplified-mathematical-model-of-directional-dna-site-specific-recombination-by-serine-integrases
#8
Alexandra Pokhilko, Jia Zhao, W Marshall Stark, Sean D Colloms, Oliver Ebenhöh
Serine integrases catalyse site-specific recombination to integrate and excise bacteriophage genomes into and out of their host's genome. These enzymes exhibit remarkable directionality; in the presence of the integrase alone, recombination between attP and attB DNA sites is efficient and irreversible, giving attL and attR products which do not recombine further. However, in the presence of the bacteriophage-encoded recombination directionality factor (RDF), integrase efficiently promotes recombination between attL and attR to re-form attP and attB The DNA substrates and products of both reactions are approximately isoenergetic, and no cofactors (such as adenosine triphosphate) are required for recombination...
January 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/28077441/predicting-ifn-%C3%AE-responses-after-bcg-vaccination-in-humans-from-macaques-a-proof-of-concept-study-of-immunostimulation-immunodynamic-modelling-methods
#9
Sophie J Rhodes, Charlotte Sarfas, Gwenan M Knight, Andrew White, Ansar A Pathan, Helen McShane, Thomas G Evans, Helen Fletcher, Sally Sharpe, Richard G White
INTRODUCTION: Macaques play a central role in human tuberculosis(TB) vaccine development. Immune and challenge responses differ across macaque and human subpopulations. We determined which macaque subpopulations best predicted immune responses in different human subpopulations, using novel immunostimulation/immunodynamic modelling methods in a proof of concept study. METHODS: Data on IFN-γ secreting CD4+ T cells over time after recent BCG vaccination were available for 55 humans and 81 macaques...
January 11, 2017: Clinical and Vaccine Immunology: CVI
https://www.readbyqxmd.com/read/28077304/drosophila-dorsal-closure-an-orchestra-of-forces-to-zip-shut-the-embryo
#10
REVIEW
Peran Hayes, Jérôme Solon
Dorsal closure, a late-embryogenesis process, consists in the sealing of an epidermal gap on the dorsal side of the Drosophila embryo. Because of its similarities with wound healing and neural tube closure in humans, it has been extensively studied in the last twenty years. The process requires the coordination of several force generating mechanisms, that together will zip shut the epidermis. Recent works have provided a precise description of the cellular behavior at the origin of these forces and proposed quantitative models of the process...
January 7, 2017: Mechanisms of Development
https://www.readbyqxmd.com/read/28077161/mathematical-modelling-of-echinococcus-multilocularis-abundance-in-foxes-in-zurich-switzerland
#11
Belen Otero-Abad, Simon R Rüegg, Daniel Hegglin, Peter Deplazes, Paul R Torgerson
BACKGROUND: In Europe, the red fox (Vulpes vulpes) is the main definitive host of Echinococcus multilocularis, the aetiological agent of a severe disease in humans called alveolar echinococcosis. The distribution of this zoonotic parasite among the fox population is remarkably aggregated with few heavily infected animals harbouring much of the parasite burdens and being responsible for most of the environmental parasitic egg contamination. Important research questions explored were: (i) spatial differences in parasite infection pressure related to the level of urbanization; (ii) temporal differences in parasite infection pressure in relation to time of the year; (iii) is herd immunity or an age-dependent infection pressure responsible for the observed parasite abundance; (iv) assuming E...
January 11, 2017: Parasites & Vectors
https://www.readbyqxmd.com/read/28076811/modeling-the-effect-of-curvature-on-the-collective-behavior-of-cells-growing-new-tissue
#12
Mohd Almie Alias, Pascal R Buenzli
The growth of several biological tissues is known to be controlled in part by local geometrical features, such as the curvature of the tissue interface. This control leads to changes in tissue shape that in turn can affect the tissue's evolution. Understanding the cellular basis of this control is highly significant for bioscaffold tissue engineering, the evolution of bone microarchitecture, wound healing, and tumor growth. Although previous models have proposed geometrical relationships between tissue growth and curvature, the role of cell density and cell vigor remains poorly understood...
January 10, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28076810/dna-occupancy-of-polymerizing-transcription-factors-a-chemical-model-of-the-ets-family-factor-yan
#13
C Matthew Hope, Ilaria Rebay, John Reinitz
Transcription factors use both protein-DNA and protein-protein interactions to assemble appropriate complexes to regulate gene expression. Although most transcription factors operate as monomers or dimers, a few, including the E26 transformation-specific family repressors Drosophila melanogaster Yan and its human homolog TEL/ETV6, can polymerize. Although polymerization is required for both the normal and oncogenic function of Yan and TEL/ETV6, the mechanisms by which it influences the recruitment, organization, and stability of transcriptional complexes remain poorly understood...
January 10, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28076681/computational-modeling-of-neurotransmitter-release-evoked-by-electrical-stimulation-non-linear-approaches-to-predicting-stimulation-evoked-dopamine-release
#14
James K Trevathan, Ali Yousefi, Hyung Ook Park, John J Bartoletta, Kip A Ludwig, Kendall H Lee, J Luis Lujan
Neurochemical changes evoked by electrical stimulation of the nervous system have been linked to both therapeutic and undesired effects of neuromodulation therapies used to treat obsessive-compulsive disorder, depression, epilepsy, Parkinson's disease, stroke, hypertension, tinnitus, and many other indications. In fact, interest in better understanding the role of neurochemical signaling in neuromodulation therapies has been a focus of recent government- and industry-sponsored programs whose ultimate goal is to usher in an era of personalized medicine by creating neuromodulation therapies that respond to real-time changes in patient status...
January 11, 2017: ACS Chemical Neuroscience
https://www.readbyqxmd.com/read/28075184/elucidation-of-formulation-and-delivery-device-related-effects-on-in-vitro-performance-of-nasal-spray-with-implication-to-rational-product-specification-identification
#15
Jernej Grmaš, Katarina Stare, Dane Božič, Rade Injac, Rok Dreu
BACKGROUND: The aim of this work is to use an experimental design approach to identify and study influential formulation and delivery device properties, which can be controlled by final product manufacturer, to establish design space, within which desired in vitro performance can be reached. METHODS: Combining three factors, viscosity of suspension, nozzle orifice diameter (OD), and shot weight (SW), at three levels resulted in D-optimal experimental design with 20 runs...
January 11, 2017: Journal of Aerosol Medicine and Pulmonary Drug Delivery
https://www.readbyqxmd.com/read/28075046/a-standardized-fluoroscopy-based-technique-to-measure-intraoperative-cup-anteversion
#16
Matthieu Zingg, Sana Boudabbous, Didier Hannouche, Xavier Montet, Friedrich Boettner
Direct anterior approach (DAA) with the patient lying supine has facilitated the use of intraoperative fluoroscopy and allows for standardized positioning of the patient. The current study presents a new technique to measure acetabular component anteversion using intraoperative fluoroscopy. The current paper describes a mathematical formula to calculate true acetabular component anteversion based on the acetabular component abduction angle and the c-arm tilt angle (CaT). The CaT is determined by tilting the c-arm until an external pelvic oblique radiograph with the equatorial plane of the acetabular component perpendicular to the fluoroscopy receptor is obtained...
January 11, 2017: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
https://www.readbyqxmd.com/read/28074874/modeling-confirmation-bias-and-polarization
#17
Michela Del Vicario, Antonio Scala, Guido Caldarelli, H Eugene Stanley, Walter Quattrociocchi
Online users tend to select claims that adhere to their system of beliefs and to ignore dissenting information. Confirmation bias, indeed, plays a pivotal role in viral phenomena. Furthermore, the wide availability of content on the web fosters the aggregation of likeminded people where debates tend to enforce group polarization. Such a configuration might alter the public debate and thus the formation of the public opinion. In this paper we provide a mathematical model to study online social debates and the related polarization dynamics...
January 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28074564/sustaining-sbirt-in-the-wild-simulating-revenues-and-costs-for-screening-brief-intervention-and-referral-to-treatment-programs
#18
Alexander J Cowell, William N Dowd, Michael J Mills, Jesse M Hinde, Jeremy W Bray
AIMS: To examine the conditions under which Screening, Brief Intervention and Referral to Treatment (SBIRT) programs can be sustained by health insurance payments. DESIGN: A mathematical model was used to estimate the number of patients needed for revenues to exceed costs. SETTING: Three medical settings in the United States were examined: in-patient, out-patient and emergency department. Components of SBIRT were delivered by combinations of health-care practitioners (generalists) and behavioral health specialists...
February 2017: Addiction
https://www.readbyqxmd.com/read/28074526/risk-factors-for-nonmelanoma-skin-cancer-in-renal-transplant-recipients-a-case-control-study-from-a-reference-outpatient-clinic-in-southeast-brazil
#19
Flávia R Ferreira, Marilia M Ogawa, Luiz F C Nascimento, Jane Tomimori
BACKGROUND: Nonmelanoma skin cancer (NMSC) is the most common tumor in humans, and its incidence increases among renal transplant recipients (RTRs). The aims of this study were to characterize the RTRs with NMSC, to identify risk factors, and to calculate the probability of this tumor in this population. METHODS: This was a hospital-based case-control study. Epidemiological and clinical variables were evaluated. Hierarchical logistic regression was used, and a mathematical model was built...
February 2017: International Journal of Dermatology
https://www.readbyqxmd.com/read/28074473/predicting-cd4-t-cell-reconstitution-following-paediatric-haematopoietic-stem-cell-transplantation
#20
Rollo L Hoare, Paul Veys, Nigel Klein, Robin Callard, Joseph F Standing
Haematopoietic stem cell transplantation is an increasingly common treatment for children with a range of haematological disorders. Conditioning with cytotoxic chemotherapy and total body irradiation leaves patients severely immunocompromised. T-cell reconstitution can take several years due to delayed restoration of thymic output. Understanding T-cell reconstitution in children is complicated by normal immune system maturation, heterogeneous diagnoses, and sparse uneven sampling due to the long time spans involved...
January 11, 2017: Clinical Pharmacology and Therapeutics
keyword
keyword
8568
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"