Read by QxMD icon Read


Johannes A Eble
The dissociation constant describes the interaction between two partners in the binding equilibrium and is a measure of their affinity. It is a crucial parameter to compare different ligands, e.g., competitive inhibitors, protein isoforms and mutants, for their binding strength to a binding partner. Dissociation constants are determined by plotting concentrations of bound versus free ligand as binding curves. In contrast, titration curves, in which a signal that is proportional to the concentration of bound ligand is plotted against the total concentration of added ligand, are much easier to record...
February 15, 2018: Journal of Visualized Experiments: JoVE
Federica Cavalera, Mario Zanoni, Valeria Merico, Thi Thu Hien Bui, Martina Belli, Lorenzo Fassina, Silvia Garagna, Maurizio Zuccotti
Infertility clinics would benefit from the ability to select developmentally competent vs. incompetent oocytes using non-invasive procedures, thus improving the overall pregnancy outcome. We recently developed a classification method based on microscopic live observations of mouse oocytes during their in vitro maturation from the germinal vesicle (GV) to the metaphase II stage, followed by the analysis of the cytoplasmic movements occurring during this time-lapse period. Here, we present detailed protocols of this procedure...
March 3, 2018: Journal of Visualized Experiments: JoVE
Soroush Safaei, Pablo J Blanco, Lucas O Müller, Leif R Hellevik, Peter J Hunter
We propose a detailed CellML model of the human cerebral circulation that runs faster than real time on a desktop computer and is designed for use in clinical settings when the speed of response is important. A lumped parameter mathematical model, which is based on a one-dimensional formulation of the flow of an incompressible fluid in distensible vessels, is constructed using a bond graph formulation to ensure mass conservation and energy conservation. The model includes arterial vessels with geometric and anatomical data based on the ADAN circulation model...
2018: Frontiers in Physiology
Mariétou F Paye, Harrison B Rose, John M Robbins, Diana A Yunda, Seonggeon Cho, Andreas S Bommarius
Research involving α/β hydrolases, including α-amino acid ester hydrolase and cocaine esterase, has been limited by the lack of an online high throughput screening assay. The development of a high throughput screening assay capable of detecting α/β hydrolase activity toward specific substrates and/or chemical reactions (e.g., hydrolysis in lieu of amidase activity and/or synthesis instead of thioesterase activity) is of interest in a broad set of scientific questions and applications. Here we present a general framework for pH-based colorimetric assays, as well as the mathematical considerations necessary to estimate de novo the experimental response required to assign a 'hit' or a 'miss,' in the absence of experimental standard curves...
March 15, 2018: Analytical Biochemistry
Yu Xia, Xianghua Wen, Bing Zhang, Yunfeng Yang
Understanding diversity and assembly patterns of microbial communities in activated sludge (AS) is pivotal for addressing fundamental ecological questions and wastewater treatment engineering. Recent applications of molecular methods especially next generation sequencing (NGS) have led to the explosion of information about AS community diversity, including the identification of uncultured taxa, and characterization of low-abundance but environmentally important populations such as antibiotic resistant bacteria and pathogens...
March 15, 2018: Biotechnology Advances
Guantian Li, Fan Zhu
Quinoa starch granules are small (~0.5 to 3 μm) with potential for some food and other applications. To better exploit it as a new starch resource, this study reports the steady shear and dynamic oscillatory properties of 9 quinoa starches varying in composition and structure. Steady shear analysis shows that the flow curves could be well described by 4 selected mathematic models. Temperature sweep analysis reveals that the quinoa starch encounters a 4-stage process including 2 phase transitions. Structure-function relationship analysis showed that composition, and unit and internal chain length distribution of amylopectin have significant impact on the rheological properties (e...
March 15, 2018: International Journal of Biological Macromolecules
Chenju Yi, Jérémy Theillon, Annette Koulakoff, Hugues Berry, Christian Giaume
Intercellular communication through gap junction channels plays a key role in cellular homeostasis and in synchronizing physiological functions, a feature that is modified in number of pathological situations. In the brain, astrocytes are the cell population that expresses the highest amount of gap junction proteins, named connexins. Several techniques have been used to assess the level of gap junctional communication in astrocytes, but so far they remain very difficult to apply in adult brain tissue. Here, using specific loading of astrocytes with sulforhodamine 101, we adapted the gap-FRAP (Fluorescence Recovery After Photobleaching) to acute hippocampal slices from 9 month-old adult mice...
March 15, 2018: Journal of Neuroscience Methods
D Cingolani, F Fatone, N Frison, M Spinelli, A L Eusebi
Recovery of high quality water from municipal landfill leachate was studied by three-stage disc tube reverse osmosis optimized in pilot-scale. Following UF-membrane-assisted activated sludge plant, overall 46.5 tons of leachate were post-treated in real environment and analyzed for conventional contaminants and hazardous compounds (e.g. heavy metals, boron, selenium) throughout operation of membrane system. Operating pressure ranged from 21 to 76 bar, while permeate flux varied in the range 7.1-32.5 L m-2  h-1 ...
March 15, 2018: Waste Management
Mehran Mazandarani, Naser Pariz
This paper deals with sub-optimal control of a fuzzy linear dynamical system. The aim is to keep the state variables of the fuzzy linear dynamical system close to zero in an optimal manner. In the fuzzy dynamical system, the fuzzy derivative is considered as the granular derivative; and all the coefficients and initial conditions can be uncertain. The criterion for assessing the optimality is regarded as a granular integral whose integrand is a quadratic function of the state variables and control inputs. Using the relative-distance-measure (RDM) fuzzy interval arithmetic and calculus of variations, the optimal control law is presented as the fuzzy state variables feedback...
March 16, 2018: ISA Transactions
Yao Li, Zhiqiang Yue, Hua Yu, Xiaojian Liu, Li Tao, Zhijie Zhu, Fangtian Fan, Cunsi Shen, Aiyun Wang, Wenxing Chen, Yin Lu
PURPOSE: A computational model based on clinical data from pancreatic cancer patients has been successfully created and used for predicting tumor sizes in primary and metastasis sites and survival time from kinetics of tumor cells, such as growth rate, metastasis rate and mutation rate, etc. Whether this computational model could be fitted or necessary modification of some parameters for fitting in mice is unknown. Here, we developed a computational model in mice for spontaneous metastasis to simulate the process of tumor metastasis based on the mathematical frameworks...
March 14, 2018: Journal of Pharmacological and Toxicological Methods
Clement Aldebert, Bob W Kooi, David Nerini, Jean-Christophe Poggiale
Many current issues in ecology require predictions made by mathematical models, which are built on somewhat arbitrary choices. Their consequences are quantified by sensitivity analysis to quantify how changes in model parameters propagate into an uncertainty in model predictions. An extension called structural sensitivity analysis deals with changes in the mathematical description of complex processes like predation. Such processes are described at the population scale by a specific mathematical function taken among similar ones, a choice that can strongly drive model predictions...
March 14, 2018: Journal of Theoretical Biology
Tanja Stadler, Alexandra Gavryushkina, Rachel C M Warnock, Alexei J Drummond, Tracy A Heath
A birth-death-sampling model gives rise to phylogenetic trees with samples from the past and the present. Interpreting "birth" as branching speciation, "death" as extinction, and "sampling" as fossil preservation and recovery, this model - also referred to as the fossilized birth-death (FBD) model - gives rise to phylogenetic trees on extant and fossil samples. The model has been mathematically analyzed and successfully applied to a range of datasets on different taxonomic levels, such as penguins, plants, and insects...
March 14, 2018: Journal of Theoretical Biology
María Del Mar Sáez Freire, Adrián Blanco Gómez, Sonia Castillo Lluva, Aurora Gómez Vecino, Julie Milena Galvis Jiménez, Carmen Martín Seisdedos, María Isidoro García, Lourdes Hontecillas Prieto, María Begoña García-Cenador, Francisco Javier García Criado, María Carmen Patino Alonso, Purificación Galindo Villardón, Jian-Hua Mao, Carlos Prieto, Andrés Castellanos Martín, Lars Kaderali, Jesús Pérez Losada
The incidence of breast cancer increases with age until menopause, and breast cancer is more aggressive in younger women. The existence of epidemiological links between breast cancer and aging indicates that both processes share some common mechanisms of development. Oxidative stress is associated with both cancer susceptibility and aging. Here we observed that ERBB2-positive breast cancer, which developed in genetically heterogeneous ERBB2-positive transgenic mice generated by a backcross, is more aggressive in chronologically younger than in older mice (differentiated by the median survival of the cohort that was 79 weeks), similar to what occurs in humans...
March 14, 2018: Free Radical Biology & Medicine
Gosse Overal, Bas Teusink, Frank J Bruggeman, Josephus Hulshof, Robert Planqué
Yeast glycolysis has been the focus of research for decades, yet a number of dynamical aspects of yeast glycolysis remain poorly understood at present. If nutrients are scarce, yeast will provide its catabolic and energetic needs with other pathways, but the enzymes catalysing upper glycolytic fluxes are still expressed. We conjecture that this overexpression facilitates the rapid transition to glycolysis in case of a sudden increase in nutrient concentration. However, if starved yeast is presented with abundant glucose, it can enter into an imbalanced state where glycolytic intermediates keep accumulating, leading to arrested growth and cell death...
March 14, 2018: Mathematical Biosciences
A V Belyaev, J L Dunster, J M Gibbins, M A Panteleev, V Volpert
Hemostasis is a complex physiological mechanism that functions to maintain vascular integrity under any conditions. Its primary components are blood platelets and a coagulation network that interact to form the hemostatic plug, a combination of cell aggregate and gelatinous fibrin clot that stops bleeding upon vascular injury. Disorders of hemostasis result in bleeding or thrombosis, and are the major immediate cause of mortality and morbidity in the world. Regulation of hemostasis and thrombosis is immensely complex, as it depends on blood cell adhesion and mechanics, hydrodynamics and mass transport of various species, huge signal transduction networks in platelets, as well as spatiotemporal regulation of the blood coagulation network...
March 5, 2018: Physics of Life Reviews
C Deffrennes, M De Clercq, L Vallée, M-P Lemaître
Problems in mathematics are a frequent major complaint in neuropediatric departments, for which there are two explanatory theoretical models: the hypothesis of a genetic and modular origin (with a number sense deficit) and a multidetermined origin. The purpose of this paper is to review the mathematical difficulties described in Turner syndrome and Fragile X syndrome, because a specific mathematical disorder is usually reported in these populations, supporting the existence of a number sense. Analysis of the literature reveals highly variable cognitive phenotypes in these populations, especially regarding mathematical abilities...
March 14, 2018: Archives de Pédiatrie: Organe Officiel de la Sociéte Française de Pédiatrie
Marianne Dieterich, Stefan Glasauer, Thomas Brandt
A retrospective clinical study focused on the frequency of rotational vertigo in 63 patients with acute unilateral midbrain strokes involving the vestibular and ocular motor systems. In contrast to unilateral pontomedullary brainstem lesions, rotational vertigo in midbrain lesions occurred with a low frequency (14%) and transient (< 1 day) course. Swaying vertigo or unspecific dizziness (22%) and postural imbalance (31%) were more frequent. Midbrain strokes with transient rotational vertigo manifested with lesions chiefly in the caudal midbrain tegmentum, while manifestations with swaying, unspecific, or no vertigo chiefly occurred in rostral mesencephalic or meso-diencephalic lesions...
March 16, 2018: Journal of Neurology
Christian Hove Rasmussen, Mike K Smith, Kaori Ito, Vijayakumar Sundararajan, Mats O Magnusson, E Niclas Jonsson, Luke Fostvedt, Paula Burger, Lynn McFadyen, Thomas G Tensfeldt, Timothy Nicholas
Every year, the pharmaceutical industry generates a large number of scientific reports related to drug research, development, and regulatory submissions. Many of these reports are created using text processing tools such as Microsoft Word. Given the large number of figures, tables, references, and other elements, this is often a tedious task involving hours of copying and pasting and substantial efforts in quality control (QC). In the present article, we present the LaTeX-based open-source reporting platform, PharmTeX, a community-based effort to make reporting simple, reproducible, and user-friendly...
March 16, 2018: AAPS Journal
Delia Bucher, Felix Frey, Kem A Sochacki, Susann Kummer, Jan-Philip Bergeest, William J Godinez, Hans-Georg Kräusslich, Karl Rohr, Justin W Taraska, Ulrich S Schwarz, Steeve Boulant
Although essential for many cellular processes, the sequence of structural and molecular events during clathrin-mediated endocytosis remains elusive. While it was long believed that clathrin-coated pits grow with a constant curvature, it was recently suggested that clathrin first assembles to form flat structures that then bend while maintaining a constant surface area. Here, we combine correlative electron and light microscopy and mathematical growth laws to study the ultrastructural rearrangements of the clathrin coat during endocytosis in BSC-1 mammalian cells...
March 16, 2018: Nature Communications
Elena Piretto, Marcello Delitala, Mario Ferraro
Drug resistance is one of the major obstacles to a successful treatment of cancer and, in turn, has been recognized to be linked to intratumoral heterogeneity, which increases the probability of the emergence of a cancer clones refractory to treatment. Combination therapies have been introduced to overcome resistance, but the design of successful combined protocols is still an open problem. In order to provide some indications on the effectiveness of medical treatments, a mathematical model is proposed, comprising two cancer populations competing for resources and with different susceptibilities to the action of immune system cells and therapies: the focus is on the effects of chemotherapy and immunotherapy, used singularly or in combination...
March 13, 2018: Journal of Theoretical Biology
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"