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https://www.readbyqxmd.com/read/29164050/colorectal-stenting-for-obstruction-due-to-retrorectal-tumor-in-a-patient-unsuitable-for-surgery
#1
Veysel Ersan, Ramazan Kutlu, Ceyhun Erdem, Servet Karagul, Cuneyt Kayaalp
Fund of knowledge on palliative treatment of unresectable retrorectal tumors is scare. Here, we reported a non-surgical treatment of a huge retrorectal malignant tumor in an aged and debilitated patient complicated with colorectal obstruction. An 86-year-old male with severe comorbidities was admitted with acute colorectal obstruction owing to an untreated retrorectal malign epithelial tumor. There was a lobulated retrorectal mass, 20 cm × 15 cm at largest size, extending to the superior iliac bifurcation level, caused an obstruction of the rectal lumen...
September 2017: Journal of Translational Internal Medicine
https://www.readbyqxmd.com/read/29163747/endovascular-stenting-of-tandem-carotid-artery-origin-and-bifurcation-stenotic-lesions-using-flow-reversal
#2
Andrew A Fanous, Parham Yashar, Ashish Sonig, Amanda Zakeri, Kenneth V Snyder, Elad I Levy, Jason M Davies, Adnan H Siddiqui
Background: The treatment of tandem lesions involving severe stenosis of the internal carotid artery with concomitant stenosis of the ipsilateral common carotid artery (CCA) origin represents an ongoing challenge. Current options for the treatment of tandem carotid artery origin and bifurcation stenotic lesions include open surgical endarterectomy, endovascular stenting, balloon angioplasty, and hybrid procedures combining both modalities. However, these options are either associated with high peri-operative risks or not always anatomically feasible...
October 2017: Journal of Vascular and Interventional Neurology
https://www.readbyqxmd.com/read/29163276/a-joint-prosodic-origin-of-language-and-music
#3
Steven Brown
Vocal theories of the origin of language rarely make a case for the precursor functions that underlay the evolution of speech. The vocal expression of emotion is unquestionably the best candidate for such a precursor, although most evolutionary models of both language and speech ignore emotion and prosody altogether. I present here a model for a joint prosodic precursor of language and music in which ritualized group-level vocalizations served as the ancestral state. This precursor combined not only affective and intonational aspects of prosody, but also holistic and combinatorial mechanisms of phrase generation...
2017: Frontiers in Psychology
https://www.readbyqxmd.com/read/29161874/onset-and-termination-of-oscillation-of-disease-spread-through-contaminated-environment
#4
Xue Zhang, Shuni Song, Jianhong Wu
We consider a reaction diffusion equation with a delayed nonlocal nonlinearity and subject to Dirichlet boundary condition. The model equation is motivated by infection dynamics of disease spread (avian influenza, for example) through environment contamination, and the nonlinearity takes into account of distribution of limited resources for rapid and slow interventions to clean contaminated environment. We determine conditions under which an equilibrium with positive value in the interior of the domain (disease equilibrium) emerges and determine conditions under which Hope bifurcation occurs...
October 2017: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/29161873/bogdanov-takens-bifurcations-in-the-enzyme-catalyzed-reaction-comprising-a-branched-network
#5
Qiuyan Zhang, Lingling Liu, Weinian Zhang
There have been some results on bifurcations of codimension one (such as saddle-node, transcritical, pitchfork) and degenerate Hopf bifurcations for an enzyme-catalyzed reaction system comprising a branched network but no further discussion for bifurcations at its cusp. In this paper we give conditions for the existence of a cusp and compute the parameter curves for the Bogdanov-Takens bifurcation, which induces the appearance of homoclinic orbits and periodic orbits, indicating the tendency to steady-states or a rise of periodic oscillations for the concentrations of the substrate and the product...
October 2017: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/29161871/transition-of-interaction-outcomes-in-a-facilitation-competition-system-of-two-species
#6
Yuanshi Wang, Hong Wu
A facilitation-competition system of two species is considered, where one species has a facilitation effect on the other but there is spatial competition between them. Our aim is to show mechanism by which the facilitation promotes coexistence of the species. A lattice gas model describing the facilitation-competition system is analyzed, in which nonexistence of periodic solution is shown and previous results are extended. Global dynamics of the model demonstrate essential features of the facilitation-competition system...
October 2017: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/29161870/modeling-transcriptional-co-regulation-of-mammalian-circadian-clock
#7
Yanqin Wang, Xin Ni, Jie Yan, Ling Yang
The circadian clock is a self-sustaining oscillator that has a period of about 24 hours at the molecular level. The oscillator is a transcription-translation feedback loop system composed of several genes. In this paper, a scalar nonlinear differential equation with two delays, modeling the transcriptional co-regulation in mammalian circadian clock, is proposed and analyzed. Sufficient conditions are established for the asymptotic stability of the unique nontrivial positive equilibrium point of the model by studying an exponential polynomial characteristic equation with delay-dependent coefficients...
October 2017: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/29161865/a-bacteriophage-model-based-on-crispr-cas-immune-system-in-a-chemostat
#8
Mengshi Shu, Rui Fu, Wendi Wang
Clustered regularly interspaced short palindromic repeats(CRISPRs) along with Cas proteins are a widespread immune system across bacteria and archaea. In this paper, a mathematical model in a chemostat is proposed to investigate the effect of CRISPR/Cas on the bacteriophage dynamics. It is shown that the introduction of CRISPR/Cas can induce a backward bifurcation and transcritical bifurcation. Numerical simulations reveal the coexistence of a stable infection-free equilibrium with an infection equilibrium, or a stable infection-free equilibrium with a stable periodic solution...
October 2017: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/29161863/an-sei-infection-model-incorporating-media-impact
#9
Xuejuan Lu, Shaokai Wang, Shengqiang Liu, Jia Li
To study the impact of media coverage on spread and control of infectious diseases, we use a susceptible-exposed-infective (SEI) model, including individuals' behavior changes in their contacts due to the influences of media coverage, and fully investigate the model dynamics. We define the basic reproductive number ?0 for the model, and show that the modeled disease dies out regardless of initial infections when ?0< 1, and becomes uniformly persistently endemic if ?0>1. When the disease is endemic and the influence of the media coverage is less than or equal to a critical number, there exists a unique endemic equilibrium which is asymptotical stable provided ?0 is greater than and near one...
October 2017: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/29161844/a-network-model-for-control-of-dengue-epidemic-using-sterile-insect-technique
#10
Arti Mishra, Benjamin Ambrosio, Sunita Gakkhar, M A Aziz-Alaoui
In this paper, a network model has been proposed to control dengue disease transmission considering host-vector dynamics in n patches. The control of mosquitoes is performed by SIT. In SIT, the male insects are sterilized in the laboratory and released into the environment to control the number of offsprings. The basic reproduction number has been computed. The existence and stability of various states have been discussed. The bifurcation diagram has been plotted to show the existence and stability regions of disease-free and endemic states for an isolated patch...
April 1, 2018: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/29161843/mathematical-analysis-and-modeling-of-dna-segregation-mechanisms
#11
Bashar Ibrahim
The precise regulation of cell life division is indispensable to the reliable inheritance of genetic material, i.e. DNA, in successive generations of cells. This is governed by dedicated biochemical networks which ensure that all requirements are met before transition from one phase to the next. The Spindle Assembly Checkpoint (SAC) is an evolutionarily mechanism that delays mitotic progression until all chromosomes are properly linked to the mitotic spindle. During some asymmetric cell divisions, such as those observed in budding yeast, an additional mechanism, the Spindle Position Checkpoint (SPOC), is required to delay exit from mitosis until the mitotic spindle is correctly aligned...
April 1, 2018: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/29161842/mathematical-model-for-the-growth-of-mycobacterium-tuberculosis-in-the-granuloma
#12
Eduardo Ibarguen-Mondragon, Lourdes Esteva, Edith Mariela Burbano-Rosero
In this work we formulate a model for the population dynamics of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB). Our main interest is to assess the impact of the competition among bacteria on the infection prevalence. For this end, we assume that Mtb population has two types of growth. The first one is due to bacteria produced in the interior of each infected macrophage, and it is assumed that is proportional to the number of infected macrophages. The second one is of logistic type due to the competition among free bacteria released by the same infected macrophages...
April 1, 2018: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/29161834/a-tb-model-is-disease-eradication-possible-in-india
#13
Surabhi Pandey, Ezio Venturino
Tuberculosis (TB) is returning to be a worldwide global public health threat. It is estimated that 9.6 million cases occurred in 2014, of which just two-thirds notified to public health authorities. The "missing cases" constitute a severe challenge for TB transmission control. TB is a severe disease in India, while, worldwide, the WHO estimates that one third of the entire world population is infected. Nowadays, incidence estimation relies increasingly more on notifications of new cases from routine surveillance...
February 1, 2018: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/29161827/mathematical-analysis-of-a-weather-driven-model-for-the-population-ecology-of-mosquitoes
#14
Kamaldeen Okuneye, Ahmed Abdelrazec, Abba B Gumel
A new deterministic model for the population biology of immature and mature mosquitoes is designed and used to assess the impact of temperature and rainfall on the abundance of mosquitoes in a community. The trivial equilibrium of the model is globally-asymptotically stable when the associated vectorial reproduction number (R0) is less than unity. In the absence of density-dependence mortality in the larval stage, the autonomous version of the model has a unique and globally-asymptotically stable non-trivial equilibrium whenever 1 andlt;R0 andlt;RC0 (this equilibrium bifurcates into a limit cycle, via a Hopf bifurcation at R0=RC0)...
February 1, 2018: Mathematical Biosciences and Engineering: MBE
https://www.readbyqxmd.com/read/29161412/fluid-dynamics-in-heart-development-effects-of-hematocrit-and-trabeculation
#15
Nicholas A Battista, Andrea N Lane, Jiandong Liu, Laura A Miller
Recent in vivo experiments have illustrated the importance of understanding the haemodynamics of heart morphogenesis. In particular, ventricular trabeculation is governed by a delicate interaction between haemodynamic forces, myocardial activity, and morphogen gradients, all of which are coupled to genetic regulatory networks. The underlying haemodynamics at the stage of development in which the trabeculae form is particularly complex, given the balance between inertial and viscous forces. Small perturbations in the geometry, scale, and steadiness of the flow can lead to changes in the overall flow structures and chemical morphogen gradients, including the local direction of flow, the transport of morphogens, and the formation of vortices...
November 16, 2017: Mathematical Medicine and Biology: a Journal of the IMA
https://www.readbyqxmd.com/read/29160072/solvent-controlled-branching-of-localized-versus-delocalized-singlet-exciton-states-and-equilibration-with-charge-transfer-in-a-structurally-well-defined-tetracene-dimer
#16
Jasper D Cook, Thomas J Carey, Dylan H Arias, Justin C Johnson, Niels H Damrauer
A detailed photophysical picture is elaborated for a structurally well-defined and symmetrical bis-tetracene dimer in solution. The molecule was designed for interrogation of the initial photophysical steps (S1 → (1)TT) in intramolecular singlet fission (SF). (Triisopropylsilyl)acetylene substituents on the dimer TIPS-BT1 as well as a monomer model TIPS-Tc enable a comparison of photophysical properties, including transient absorption dynamics, as solvent polarity is varied. In nonpolar toluene solutions, TIPS-BT1 decays via radiative and nonradiative pathways to the ground state with no evidence for dynamics related to the initial stages of SF...
November 21, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/29159805/the-anatomy-of-the-infrarenal-lumbar-splanchnic-nerves-in-human-cadavers-implications-for-retroperitoneal-nerve-sparing-surgery
#17
Tyler S Beveridge, Dale E Fournier, Adam M R Groh, Marjorie Johnson, Nicholas E Power, Brian L Allman
Injury to the nerves of the aortic- and superior hypogastric plexuses during retroperitoneal surgery often results in significant post-operative complications, including retrograde ejaculation and/or loss of seminal emission in males. Although previous characterizations of these plexuses have done well to provide a basis for understanding the typical anatomy, additional research into the common variations of these plexuses could further optimize nerve-sparing techniques for retroperitoneal surgery. To achieve this, the present study aimed to document the prevalence and positional variability of the infrarenal lumbar splanchnic nerves (LSNs) through gross dissection of 26 human cadavers...
November 21, 2017: Journal of Anatomy
https://www.readbyqxmd.com/read/29155702/using-the-sleeve-technique-in-a-mouse-model-of-aortic-transplantation-an-instructional-video
#18
Zuzanna Rowinska, Simone Gorressen, Marc W Merx, Thomas A Koeppel, Alma Zernecke, Elisa A Liehn
Orthotopic aortic transplantation using the sleeve technique reduces injury to the aorta with failure rate of only 10-20%. The time to anastomose the aorta in mice using the sleeve method was short and easy averaging 20 min, permitting studies of iso/allo grafts. The following article describes the aortic transplantation procedure used in our laboratory. The mice were anesthetized with a mixture of 1.5% volume isoflurane and 100% oxygen through a face mask. At this point, the segment of the aorta between the renal arteries and its bifurcation was separated from the vena cava, freely prepared and clampedat the proximal and distal segments with a single silk suture...
October 22, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/29155064/enterprise-deployment-through-a-pulserider-to-treat-an-anterior-communicating-artery-aneurysm-recurrence
#19
Iacopo Valente, Nicola Limbucci, Sergio Nappini, Andrea Rosi, Antonio Laiso, Salvatore Mangiafico
BACKGROUND: PulseRider (Pulsar Vascular, Los Gatos, CA, USA) is a new endovascular device designed to treat wide neck bifurcation intracranial aneurysms. Deployment of a stent through a PulseRider to treat an aneurysm's recurrence has never been described before. CASE DESCRIPTION: We report the case of a 55-year-old man who underwent coiling of a 8 mm anterior communicating artery aneurysm with assistance of a PulseRider neck reconstruction device. The 6-month digital subtraction angiography control showed aneurysm recurrence, so we deployed an Enterprise 2 closed-cell stent (Codman, Miami Lakes, FL, USA) in the A1-A2 segment passing across the previously implanted PulseRider...
November 14, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/29155006/retroperitoneoscopic-para-aortic-lymphadenectomy-with-high-level-vena-cava-bifurcation
#20
Kiyoshi Kanno, Masaaki Andou, Shiori Yanai, Akira Shirane, Saori Nakajima, Keiko Ebisawa, Tomonori Hada, Yoshiaki Ota
No abstract text is available yet for this article.
November 15, 2017: Journal of Minimally Invasive Gynecology
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