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https://www.readbyqxmd.com/read/28926951/insights-into-the-hexose-liver-metabolism-glucose-versus-fructose
#1
REVIEW
Bettina Geidl-Flueck, Philipp A Gerber
High-fructose intake in healthy men is associated with characteristics of metabolic syndrome. Extensive knowledge exists about the differences between hepatic fructose and glucose metabolism and fructose-specific mechanisms favoring the development of metabolic disturbances. Nevertheless, the causal relationship between fructose consumption and metabolic alterations is still debated. Multiple effects of fructose on hepatic metabolism are attributed to the fact that the liver represents the major sink of fructose...
September 16, 2017: Nutrients
https://www.readbyqxmd.com/read/28926847/probing-the-stochastic-property-of-endoreduplication-in-cell-size-determination-of-arabidopsis-thaliana-leaf-epidermal-tissue
#2
Kensuke Kawade, Hirokazu Tsukaya
Cell size distribution is highly reproducible, whereas the size of individual cells often varies greatly within a tissue. This is obvious in a population of Arabidopsis thaliana leaf epidermal cells, which ranged from 1,000 to 10,000 μm2 in size. Endoreduplication is a specialized cell cycle in which nuclear genome size (ploidy) is doubled in the absence of cell division. Although epidermal cells require endoreduplication to enhance cellular expansion, the issue of whether this mechanism is sufficient for explaining cell size distribution remains unclear due to a lack of quantitative understanding linking the occurrence of endoreduplication with cell size diversity...
2017: PloS One
https://www.readbyqxmd.com/read/28926135/a-spatial-approach-to-combatting-wildlife-crime
#3
Sally C Faulkner, Michael C A Stevens, Stephanie S Romañach, Peter A Lindsey, Steven C Le Comber
Poaching can have devastating impacts on animal and plant numbers, and in many countries has reached crisis levels, with illegal hunters employing increasingly sophisticated techniques. Here, we show how geographic profiling - a mathematical technique originally developed in criminology and recently applied to animal foraging and epidemiology - can be adapted for use in investigations of wildlife crime, using data from an eight-year study in Savé Valley Conservancy, Zimbabwe that in total includes more than 10,000 incidents of illegal hunting and the deaths of 6,454 wild animals...
September 19, 2017: Conservation Biology: the Journal of the Society for Conservation Biology
https://www.readbyqxmd.com/read/28925811/it-s-fun-to-transcribe-with-fun30-a-model-for-nucleosome-dynamics-during-rna-polymerase-ii-mediated-elongation
#4
Junwoo Lee, Eun Shik Choi, Daeyoup Lee
The ability of elongating RNA polymerase II (RNAPII) to regulate the nucleosome barrier is poorly understood because we do not know enough about the involved factors and we lack a conceptual framework to model this process. Our group recently identified the conserved Fun30/SMARCAD1 family chromatin-remodeling factor, Fun30(Fft3), as being critical for relieving the nucleosome barrier during RNAPII-mediated elongation, and proposed a model illustrating how Fun30(Fft3) may contribute to nucleosome disassembly during RNAPII-mediated elongation...
September 19, 2017: Transcription
https://www.readbyqxmd.com/read/28925006/evidence-based-source-modeling-of-nociceptive-cortical-responses-a-direct-comparison-of-scalp-and-intracranial-activity-in-humans
#5
Claire Bradley, Hélène Bastuji, Luis Garcia-Larrea
BACKGROUND: Source modeling of EEG traditionally relies on interplay between physiological hypotheses and mathematical estimates. We propose to optimize the process by using evidence gathered from brain imaging and intracortical recordings. METHODS: We recorded laser-evoked potentials in 18 healthy participants, using high-density EEG. Brain sources were modeled during the first second poststimulus, constraining their initial position to regions where nociceptive-related activity has been ascertained by intracranial EEG...
September 18, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28923471/accurately-diagnosing-uric-acid-stones-from-conventional-ct-imaging-development-and-preliminary-assessment-of-a-pixel-mapping-software
#6
Vishnu Ganesan, Shubha De, Nicholas Shkumat, Giovanni Marchini, Manoj Monga
PURPOSE: Preoperative determination of uric acid stones from computed tomography (CT) imaging would be of tremendous clinical utility. We proposed to design a software algorithm that can utilize data from non-contrast CT to predict the presence of uric acid stones. MATERIALS AND METHODS: Patients with pure uric acid (UA) and calcium oxalate (CaOx) stones were identified from our stone registry. Only stones >4 mm and clearly traceable from initial CT to final composition were included...
September 15, 2017: Journal of Urology
https://www.readbyqxmd.com/read/28922946/temperature-simulation-of-microwave-ablation-based-on-improved-specific-absorption-rate-method-compared-to-phantom-measurements
#7
Hongjian Gao, Shuicai Wu, Xiaoru Wang, Rui Hu, Zhuhuang Zhou, Xuecong Sun
PURPOSE: To propose an improved specific absorption rate (SAR) computation method by incorporating a thermal conductivity item, develop mathematical simulation models based on the SAR, and enhance the accuracy of temperature simulation for 2450-MHz microwave fields. MATERIALS AND METHODS: Experimental data of 2450-MHz microwave antenna were obtained with a phantom and then new SAR equations were calculated according to Pennes bio-heat transfer equation. Next, the SAR equations were regarded as heating sources and SAR-derived temperature changes were simulated numerically; Finally, temperature measurement results were compared with simulation data to validate the accuracy of the new SAR method...
September 18, 2017: Computer Assisted Surgery (Abingdon, England)
https://www.readbyqxmd.com/read/28922811/a-programme-to-create-short-course-chemotherapy-for-pulmonary-mycobacterium-avium-disease-based-on-pharmacokinetics-pharmacodynamics-and-mathematical-forecasting
#8
Devyani Deshpande, Shashikant Srivastava, Tawanda Gumbo
Objectives: Pulmonary Mycobacterium avium complex (MAC) prevalence is on the rise worldwide. The average therapy duration is 1.5 years, which is associated with poor cure rates. Our objective was to develop a programme to design a combination therapy regimen for pulmonary MAC to be administered for 6 months or less with efficacy in > 90% of patients. Methods: We performed a literature search for the following MeSH headings 'Mycobacterium avium' AND 'pharmacokinetics/pharmacodynamics' in PubMed up to 2016...
September 1, 2017: Journal of Antimicrobial Chemotherapy
https://www.readbyqxmd.com/read/28922358/quantifying-the-effects-of-antiangiogenic-and-chemotherapy-drug-combinations-on-drug-delivery-and-treatment-efficacy
#9
Sirin Yonucu, Defne Yιlmaz, Colin Phipps, Mehmet Burcin Unlu, Mohammad Kohandel
Tumor-induced angiogenesis leads to the development of leaky tumor vessels devoid of structural and morphological integrity. Due to angiogenesis, elevated interstitial fluid pressure (IFP) and low blood perfusion emerge as common properties of the tumor microenvironment that act as barriers for drug delivery. In order to overcome these barriers, normalization of vasculature is considered to be a viable option. However, insight is needed into the phenomenon of normalization and in which conditions it can realize its promise...
September 18, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28922356/mathematical-modeling-and-quantitative-analysis-of-hiv-1-gag-trafficking-and-polymerization
#10
Yuewu Liu, Xiufen Zou
Gag, as the major structural protein of HIV-1, is necessary for the assembly of the HIV-1 sphere shell. An in-depth understanding of its trafficking and polymerization is important for gaining further insights into the mechanisms of HIV-1 replication and the design of antiviral drugs. We developed a mathematical model to simulate two biophysical processes, specifically Gag monomer and dimer transport in the cytoplasm and the polymerization of monomers to form a hexamer underneath the plasma membrane. Using experimental data, an optimization approach was utilized to identify the model parameters, and the identifiability and sensitivity of these parameters were then analyzed...
September 18, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28922354/reconstructing-promoter-activity-from-lux-bioluminescent-reporters
#11
Mudassar Iqbal, Neil Doherty, Anna M L Page, Saara N A Qazi, Ishan Ajmera, Peter A Lund, Theodore Kypraios, David J Scott, Philip J Hill, Dov J Stekel
The bacterial Lux system is used as a gene expression reporter. It is fast, sensitive and non-destructive, enabling high frequency measurements. Originally developed for bacterial cells, it has also been adapted for eukaryotic cells, and can be used for whole cell biosensors, or in real time with live animals without the need for euthanasia. However, correct interpretation of bioluminescent data is limited: the bioluminescence is different from gene expression because of nonlinear molecular and enzyme dynamics of the Lux system...
September 18, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28921699/morphological-determinants-of-carrier-frequency-signal-in-katydids-orthoptera-a-comparative-analysis-using-biophysical-evidence
#12
Fernando Montealegre-Z, Jessica Ogden, Thorin Jonsson, Carl D Soulsbury
Male katydids produce mating calls by stridulation using specialized structures on the forewings. The right wing (RW) bears a scraper connected to a drum-like cell known as the mirror and a left wing (LW) that overlaps the RW and bears a serrated vein on the ventral side, the stridulatory file. Sound is generated with the scraper sweeping across the file, producing vibrations that are amplified by the mirror. Using this sound generator, katydids exploit a range of song carrier frequencies (CF) unsurpassed by any other insect group, with species singing as low as 600 Hz and others as high as 150 kHz...
September 16, 2017: Journal of Evolutionary Biology
https://www.readbyqxmd.com/read/28921508/selection-on-skewed-characters-and-the-paradox-of-stasis
#13
Suzanne Bonamour, Céline Teplitsky, Anne Charmantier, Pierre-André Crochet, Luis-Miguel Chevin
Observed phenotypic responses to selection in the wild often differ from predictions based on measurements of selection and genetic variance. An overlooked hypothesis to explain this paradox of stasis is that a skewed phenotypic distribution affects natural selection and evolution. We show through mathematical modelling that, when a trait selected for an optimum phenotype has a skewed distribution, directional selection is detected even at evolutionary equilibrium, where it causes no change in the mean phenotype...
September 18, 2017: Evolution; International Journal of Organic Evolution
https://www.readbyqxmd.com/read/28919900/preliminary-studies-to-characterize-the-temporal-variation-of-micronutrient-composition-of-the-above-ground-organs-of-maize-and-correlated-uptake-rates
#14
Karla Vilaça Martins, Durval Dourado-Neto, Klaus Reichardt, Quirijn de Jong van Lier, José Laércio Favarin, Felipe Fadel Sartori, Guilherme Felisberto, Simone da Costa Mello
The improvement of agronomic practices and the use of high technology in field crops contributes for significant increases in maize productivity, and may have altered the dynamics of nutrient uptake and partition by the plant. Official recommendations for fertilizer applications to the maize crop in Brazil and in many countries are based on critical soil nutrient contents and are relatively outdated. Since the factors that interact in an agricultural production system are dynamic, mathematical modeling of the growth process turns out to be an appropriate tool for these studies...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28919649/expanding-stem-opportunities-through-inclusive-stem-focused-high-schools
#15
Barbara Means, Haiwen Wang, Xin Wei, Sharon Lynch, Vanessa Peters, Viki Young, Carrie Allen
Inclusive STEM high schools (ISHSs) (where STEM is science, technology, engineering, and mathematics) admit students on the basis of interest rather than competitive examination. This study examines the central assumption behind these schools-that they provide students from subgroups underrepresented in STEM with experiences that equip them academically and attitudinally to enter and stay in the STEM pipeline. Hierarchical modeling was applied to data from student surveys and state longitudinal data records for 5113 students graduating from 39 ISHSs and 22 comprehensive high schools in North Carolina and Texas...
September 2017: Science Education
https://www.readbyqxmd.com/read/28919576/simulation-of-the-effects-of-oxygen-carriers-and-scaffold-geometry-on-oxygen-distribution-and-cell-growth-in-a-channeled-scaffold-for-engineering-myocardium
#16
Alireza Zehi Mofrad, Shohreh Mashayekhan, Dariush Bastani
This study proposes a mathematical model to evaluate the impact of oxygen carriers and scaffold geometry on oxygen distribution and cell growth in a 3D cardiac construct using computational fluid dynamics (CFD). Flow equations, oxygen balance equation and cell balance equation were solved using special initial and boundary conditions. The modeling results revealed that 55% increase in cardiac cell density occurred by using 6.4% perfluorocarbon oxygen carrier (PFC) compared to pure culture medium without PFC supplementation...
September 14, 2017: Mathematical Biosciences
https://www.readbyqxmd.com/read/28919575/an-integrative-model-of-prostate-cancer-interaction-with-the-bone-microenvironment
#17
A Farhat, D Jiang, D Cui, E T Keller, Trachette L Jackson
Despite advanced efforts in early diagnosis, aggressive surgical treatment, and use of targeted chemotherapies, the prognosis for many cancers is still dismal. This emphasizes the necessity to develop new strategies for understanding tumor growth and metastasis. Here we use a systems approach that combines mathematical modeling and numerical simulation to develop a predictive computational model for prostate cancer and its subversion of the bone microenvironment. This model simulates metastatic prostate cancer evolution, progressing from normal bone and hormone levels to quantifiable diseased states...
September 14, 2017: Mathematical Biosciences
https://www.readbyqxmd.com/read/28919166/kinetic-analysis-of-oxygen-dynamics-under-a-variable-work-rate
#18
Alexander Artiga Gonzalez, Raphael Bertschinger, Fabian Brosda, Thorsten Dahmen, Patrick Thumm, Dietmar Saupe
Measurements of oxygen uptake are central to methods for the assessment of physical fitness and endurance capabilities in athletes. Two important parameters extracted from such data of incremental exercise tests are the maximal oxygen uptake and the critical power. A commonly accepted model of the dynamics of oxygen uptake during exercise at a constant work rate comprises a constant baseline oxygen uptake, an exponential fast component, and another exponential slow component for heavy and severe work rates...
September 14, 2017: Human Movement Science
https://www.readbyqxmd.com/read/28919099/development-of-an-abiraterone-acetate-formulation-with-improved-oral-bioavailability-guided-by-absorption-modeling-based-on-in-vitro-dissolution-and-permeability-measurements
#19
Tamás Solymosi, Zsolt Ötvös, Réka Angi, Betti Ordasi, Tamás Jordán, Sándor Semsey, László Molnár, Soma Ránky, Genovéva Filipcsei, Gábor Heltovics, Hristos Glavinas
Particle size reduction of drug crystals in the presence of surfactants (often called "top-down" production methods) is a standard approach used in the pharmaceutical industry to improve bioavailability of poorly soluble drugs. Based on the mathematical model used to predict the fraction dose absorbed this formulation approach is successful when dissolution rate is the main rate limiting factor of oral absorption. In case compound solubility is also a major factor this approach might not result in an adequate improvement in bioavailability...
September 15, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28918570/mathematical-description-of-drug-target-interactions-application-to-biologics-that-bind-to-targets-with-two-binding-sites
#20
Leonid Gibiansky, Ekaterina Gibiansky
The emerging discipline of mathematical pharmacology occupies the space between advanced pharmacometrics and systems biology. A characteristic feature of the approach is application of advance mathematical methods to study the behavior of biological systems as described by mathematical (most often differential) equations. One of the early application of mathematical pharmacology (that was not called this name at the time) was formulation and investigation of the target-mediated drug disposition (TMDD) model and its approximations...
September 16, 2017: Journal of Pharmacokinetics and Pharmacodynamics
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