keyword
MENU ▼
Read by QxMD icon Read
search

Biological models

keyword
https://www.readbyqxmd.com/read/27923201/synthesis-and-biological-evaluation-of-a-new-class-of-benzothiazines-as-neuroprotective-agents
#1
Alessandra Mancini, Alessia Chelini, Angela Di Capua, Loretta Castelli, Simone Brogi, Marco Paolino, Germano Giuliani, Andrea Cappelli, Maria Frosini, Lorenzo Ricci, Erminia Leonelli, Gianluca Giorgi, Antonio Giordani, Jacopo Magistretti, Maurizio Anzini
Neurodegenerative diseases are disorders related to the degeneration of central neurons that gradually lead to various, severe alterations of cognitive and/or motor functions. Currently, for no such diseases does any pharmacological treatment exist able to arrest its progression. Riluzole (1) is a small molecule able to interfere with multiple cellular and molecular mechanisms of neurodegeneration, and is the only approved treatment of amyotrophic lateral sclerosis (ALS), the progression of which proved to significantly slow, thus increasing somewhat average survival...
November 27, 2016: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/27923154/socioeconomic-position-john-henryism-and-incidence-of-acute-myocardial-infarction-in-finnish-men
#2
Mahasin S Mujahid, Sherman A James, George A Kaplan, Jukka T Salonen
Previous cross-sectional studies examining whether John Henryism (JH), or high-effort coping with socioeconomic adversity, potentiates the inverse association between socioeconomic position (SEP) and cardiovascular health have focused mainly on hypertension in African Americans. We conducted the first longitudinal test of this hypothesis on incident acute myocardial infarction (AMI) using data from the Kuopio Ischemic Heart Disease Risk Factor Study in Finland (N = 1405 men, 42-60 years). We hypothesized that the expected inverse gradient between SEP and AMI risk would be stronger for men scoring high on JH than for those scoring low...
November 25, 2016: Social Science & Medicine
https://www.readbyqxmd.com/read/27923064/sparse-regression-based-structure-learning-of-stochastic-reaction-networks-from-single-cell-snapshot-time-series
#3
Anna Klimovskaia, Stefan Ganscha, Manfred Claassen
Stochastic chemical reaction networks constitute a model class to quantitatively describe dynamics and cell-to-cell variability in biological systems. The topology of these networks typically is only partially characterized due to experimental limitations. Current approaches for refining network topology are based on the explicit enumeration of alternative topologies and are therefore restricted to small problem instances with almost complete knowledge. We propose the reactionet lasso, a computational procedure that derives a stepwise sparse regression approach on the basis of the Chemical Master Equation, enabling large-scale structure learning for reaction networks by implicitly accounting for billions of topology variants...
December 2016: PLoS Computational Biology
https://www.readbyqxmd.com/read/27923062/the-kinematics-of-plant-nutation-reveals-a-simple-relation-between-curvature-and-the-orientation-of-differential-growth
#4
Renaud Bastien, Yasmine Meroz
Nutation is an oscillatory movement that plants display during their development. Despite its ubiquity among plants movements, the relation between the observed movement and the underlying biological mechanisms remains unclear. Here we show that the kinematics of the full organ in 3D give a simple picture of plant nutation, where the orientation of the curvature along the main axis of the organ aligns with the direction of maximal differential growth. Within this framework we reexamine the validity of widely used experimental measurements of the apical tip as markers of growth dynamics...
December 2016: PLoS Computational Biology
https://www.readbyqxmd.com/read/27923060/the-limitations-of-model-based-experimental-design-and-parameter-estimation-in-sloppy-systems
#5
Andrew White, Malachi Tolman, Howard D Thames, Hubert Rodney Withers, Kathy A Mason, Mark K Transtrum
We explore the relationship among experimental design, parameter estimation, and systematic error in sloppy models. We show that the approximate nature of mathematical models poses challenges for experimental design in sloppy models. In many models of complex biological processes it is unknown what are the relevant physical mechanisms that must be included to explain system behaviors. As a consequence, models are often overly complex, with many practically unidentifiable parameters. Furthermore, which mechanisms are relevant/irrelevant vary among experiments...
December 2016: PLoS Computational Biology
https://www.readbyqxmd.com/read/27923035/biomarkers-in-anal-cancer-from-biological-understanding-to-stratified-treatment
#6
Christopher M Jones, Vicky Goh, David Sebag-Montefiore, Duncan C Gilbert
Squamous cell carcinomas of the anus and anal canal represent a model of a cancer and perhaps the first where level 1 evidence supported primary chemoradiotherapy (CRT) in treating locoregional disease with curative intent. The majority of tumours are associated with infection with oncogenic subtypes of human papilloma virus and this plays a significant role in their sensitivity to treatment. However, not all tumours are cured with CRT and there remain opportunities to improve outcomes in terms of oncological control and also reducing late toxicities...
December 6, 2016: British Journal of Cancer
https://www.readbyqxmd.com/read/27923015/project-shikamana-baseline-findings-from-a-community-empowerment-based-combination-hiv-prevention-trial-among-female-sex-workers-in-iringa-tanzania
#7
Deanna Kerrigan, Jessie Mbwambo, Samuel Likindikoki, Sarah Beckham, Ard Mwampashi, Catherine Shembilu, Andrea Mantsios, Anna Leddy, Wendy Davis, Noya Galai
BACKGROUND: Community empowerment approaches have been found to be effective in responding to HIV among female sex workers (FSWs) in South Asia and Latin America. To date, limited rigorous evaluations of these approaches have been conducted in sub-Saharan Africa. METHODS: A phase II community randomized controlled trial is being conducted in Iringa, Tanzania, to evaluate the effectiveness of a community empowerment-based combination HIV prevention model (Project Shikamana) among a stratified sample of HIV-infected and HIV-uninfected FSWs...
January 1, 2017: Journal of Acquired Immune Deficiency Syndromes: JAIDS
https://www.readbyqxmd.com/read/27922979/a-comparison-of-thermal-plasma-energy-versus-argon-beam-coagulator-induced-intestinal-injury-after-vaporization-in-a-porcine-model
#8
Edward J Tanner, Erica Dun, Yukio Sonoda, Alexander B Olawaiye, Dennis S Chi
OBJECTIVES: Complete cytoreduction of ovarian cancer often requires excision or ablation of bowel serosa implants. Both argon beam coagulator (ABC) and thermal plasma energy (TPE) (PlasmaJet; PlasmaSurgical, Roswell, Ga) have been used to ablate bowel serosa implants. Our objective was to identify comparable power settings as well as determine the rate of bowel perforation, depth of thermal injury, and extent of inflammatory response with ABC versus TPE in a porcine model. MATERIALS AND METHODS: Nine pigs underwent vaporization of small bowel and colon serosa according to assigned treatment group (TPE vs ABC) and settings (ABC: 30, 50, and 70 W; TPE: Cut 10U, 20U, and 30U and Coagulation 10U, 20U, and 30U)...
December 3, 2016: International Journal of Gynecological Cancer
https://www.readbyqxmd.com/read/27922834/complexity-of-generic-biochemical-circuits-topology-versus-strength-of-interactions
#9
Mikhail Tikhonov, William Bialek
The historical focus on network topology as a determinant of biological function is still largely maintained today, illustrated by the rise of structure-only approaches to network analysis. However, biochemical circuits and genetic regulatory networks are defined both by their topology and by a multitude of continuously adjustable parameters, such as the strength of interactions between nodes, also recognized as important. Here we present a class of simple perceptron-based Boolean models within which comparing the relative importance of topology versus interaction strengths becomes a quantitatively well-posed problem...
December 6, 2016: Physical Biology
https://www.readbyqxmd.com/read/27922726/bichromophoric-compounds-with-orthogonally-and-parallelly-arranged-chromophores-separated-by-rigid-spacers
#10
Dirk N H Meineke, Mariano L Bossi, Haisen Ta, Vladimir N Belov, Stefan W Hell
Electronic energy transfer (EET) between chromophores is of fundamental importance for many biological processes and optoelectronic devices. However, common models fall short in fully describing the process, especially in bichromophoric model systems with a donor and acceptor connected by a rigid linker providing perpendicular geometries. Herein, we report a novel strategy to prepare bichromophores containing adamantane or 2-(2-adamantylidene)-adamantane as rigid spacers, providing a fixed distance between chromophores, and their parallel or perpendicular arrangement without chromophore rotation...
December 6, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27922614/molecular-mechanisms-at-the-core-of-the-plant-circadian-oscillator
#11
REVIEW
Maria A Nohales, Steve A Kay
Circadian clocks are endogenous timekeeping networks that allow organisms to align their physiology with their changing environment and to perform biological processes at the most relevant times of the day and year. Initial feedback-loop models of the oscillator have been enriched by emerging evidence highlighting the increasing variety of factors and mechanisms that contribute to the generation of rhythms. In this Review, we consider the two major input pathways that connect the circadian clock of the model plant Arabidopsis thaliana to its environment and discuss recent advances in understanding of how transcriptional, post-translational and post-transcriptional mechanisms contribute to clock function...
December 2016: Nature Structural & Molecular Biology
https://www.readbyqxmd.com/read/27922606/otto-a-new-strategy-to-extract-mental-disease-relevant-combinations-of-gwas-hits-from-individuals
#12
H Ehrenreich, M Mitjans, S Van der Auwera, T P Centeno, M Begemann, H J Grabe, S Bonn, K-A Nave
Despite high heritability of schizophrenia, genome-wide association studies (GWAS) have not yet revealed distinct combinations of single-nucleotide polymorphisms (SNPs), relevant for mental disease-related, quantifiable behavioral phenotypes. Here we propose an individual-based model to use genome-wide significant markers for extracting first genetic signatures of such behavioral continua. 'OTTO' (old Germanic=heritage) marks an individual characterized by a prominent phenotype and a particular load of phenotype-associated risk SNPs derived from GWAS that likely contributed to the development of his personal mental illness...
December 6, 2016: Molecular Psychiatry
https://www.readbyqxmd.com/read/27922463/the-dangers-of-estimating-v%C3%AB-o2max-using-linear-nonexercise-prediction-models
#13
Alan M Nevill, Carlton B Cooke
PURPOSE: To compare the accuracy and goodness-of-fit of two competing models (linear versus allometric) when estimating V˙O2max (ml.kg.min) using non-exercise prediction models. METHODS: The two competing models were fitted to the V˙O2max (ml.kg.min) data taken from two previously published studies. Study 1 (the Allied Dunbar National Fitness Survey, ADNFS), recruited 1732 randomly selected healthy participants, aged 16 years and over, from thirty English parliamentary constituencies...
December 1, 2016: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/27922333/environmentally-relevant-chronic-low-dose-tritium-and-gamma-exposures-do-not-increase-somatic-intrachromosomal-recombination-in-pkz1-mouse-spleen
#14
Laura Bannister, Mandy Serran, Lindsey Bertrand, Dmitry Klokov, Heather Wyatt, Melinda Blimkie, Yann Gueguen, Nicholas Priest, Jean-René Jourdain, Pamela Sykes
The toxicity of tritium is a public health concern given its presence and mobility in the environment. For risk predictions using radiological protection models, it is essential to allocate an appropriate radiation weighting factor (WR). This in turn should be consistent with the observed relative biological effectiveness (RBE) of tritium beta radiation. Although the International Commission on Radiological Protection (ICRP) currently recommends a WR of 1 for the calculation of committed effective dose for X rays, gamma rays and electrons of all energies, including tritium energies, there are concerns that tritium health risks are underestimated and that current regulatory tritium drinking water standards need revision...
December 6, 2016: Radiation Research
https://www.readbyqxmd.com/read/27922124/convex-analysis-of-mixtures-for-separating-non-negative-well-grounded-sources
#15
Yitan Zhu, Niya Wang, David J Miller, Yue Wang
Blind Source Separation (BSS) is a powerful tool for analyzing composite data patterns in many areas, such as computational biology. We introduce a novel BSS method, Convex Analysis of Mixtures (CAM), for separating non-negative well-grounded sources, which learns the mixing matrix by identifying the lateral edges of the convex data scatter plot. We propose and prove a sufficient and necessary condition for identifying the mixing matrix through edge detection in the noise-free case, which enables CAM to identify the mixing matrix not only in the exact-determined and over-determined scenarios, but also in the under-determined scenario...
December 6, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27922024/improvements-in-the-long-term-outcome-of-crohn-s-disease-over-the-past-two-decades-and-the-relation-to-changes-in-medical-management-results-from-the-population-based-ibdsl-cohort
#16
Steven F G Jeuring, Tim R A van den Heuvel, Limmie Y L Liu, Maurice P Zeegers, Wim H Hameeteman, Mariëlle J L Romberg-Camps, Liekele E Oostenbrug, Ad A M Masclee, Daisy M A E Jonkers, Marieke J Pierik
OBJECTIVES: Medical treatment options and strategies for Crohn's disease (CD) have changed over the past decades. To assess its impact, we studied the evolution of the long-term disease outcome in the Dutch Inflammatory Bowel Disease South Limburg (IBDSL) cohort. METHODS: In total, 1,162 CD patients were included. Three eras were distinguished: 1991-1998 (n=316), 1999-2005 (n=387), and 2006-2011 (n=459), and patients were followed until 2014. Medication exposure and the rates of hospitalization, surgery, and phenotype progression were estimated using Kaplan-Meier survival analyses and compared between eras by multivariable Cox regression models...
December 6, 2016: American Journal of Gastroenterology
https://www.readbyqxmd.com/read/27921363/morphomechanics-and-developmental-constraints-in-the-evolution-of-ammonites-shell-form
#17
Alexander Erlich, Derek E Moulton, Alain Goriely, Regis Chirat
The idea that physical processes involved in biological development underlie morphogenetic rules and channel morphological evolution has been central to the rise of evolutionary developmental biology. Here, we explore this idea in the context of seashell morphogenesis. We show that a morphomechanical model predicts the effects of variations in shell shape on the ornamental pattern in ammonites, a now extinct group of cephalopods with external chambered shell. Our model shows that several seemingly unrelated characteristics of synchronous, ontogenetic, intraspecific, and evolutionary variations in ornamental patterns among various ammonite species may all be understood from the fact that the mechanical forces underlying the oscillatory behavior of the shell secreting system scale with the cross-sectional curvature of the shell aperture...
December 6, 2016: Journal of Experimental Zoology. Part B, Molecular and Developmental Evolution
https://www.readbyqxmd.com/read/27921334/synacton-and-individual-activity-of-synthetic-and-natural-corticotropins
#18
T V Vyunova, L A Andreeva, K V Shevchenko, N F Myasoedov
Short endogenous peptides represent one of the most important constituents of the mammalian body's general regulatory system. Some synthesized analogs and modified natural peptides (eg, corticotropins) also show high biological activity. Nevertheless, the mechanism of action of regulatory peptides remains unclear. To explain the effects of peptides of intermolecular processes, the hypothesis that a synactonal mechanism underlies the action of regulatory peptides, exemplified by the heptapeptide Semax, has been proposed...
December 6, 2016: Journal of Molecular Recognition: JMR
https://www.readbyqxmd.com/read/27921292/cranial-joint-histology-in-the-mallard-duck-anas-platyrhynchos-new-insights-on-avian-cranial-kinesis
#19
Alida M Bailleul, Lawrence M Witmer, Casey M Holliday
The evolution of avian cranial kinesis is a phenomenon in part responsible for the remarkable diversity of avian feeding adaptations observable today. Although osteological, developmental and behavioral features of the feeding system are frequently studied, comparatively little is known about cranial joint skeletal tissue composition and morphology from a microscopic perspective. These data are key to understanding the developmental, biomechanical and evolutionary underpinnings of kinesis. Therefore, here we investigated joint microstructure in juvenile and adult mallard ducks (Anas platyrhynchos; Anseriformes)...
December 6, 2016: Journal of Anatomy
https://www.readbyqxmd.com/read/27921232/biological-function-and-mechanism-of-mir-33a-in-prostate-cancer-survival-and-metastasis-via-downregulating-engrailed-2
#20
Q Li, S Lu, X Li, G Hou, L Yan, W Zhang, B Qiao
OBJECTIVE: Recent studies have identified Engrailed-2 (EN-2), a homeobox-containing transcription factor, as a candidate oncogene in prostate cancer (PC). Therapeutic targeting on EN-2, however, is limited because the mechanism underlying EN-2 overexpression in prostatic cancer cells is unknown. This study was to investigate the potential regulatory role of miR-33a on EN-2 expression and explore this signaling axis in ability of prostate cancer survival and metastasis. METHODS: The relative expression of miR-33a and EN-2 in paired prostate cancer tissue and adjacent normal tissue as well as in prostate cancer cell lines, PC3 and DU145, was determined using quantitative real-time PCR or western blot, respectively...
December 5, 2016: Clinical & Translational Oncology
keyword
keyword
15173
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"