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Pavol Kalinay
Diffusion of point-like particles driven by a constant longitudinal force in two-dimensional channels of periodically varying width is studied. The dynamics of such systems can be effectively described by the one-dimensional Smoluchowski(-Fick-Jacobs) equation in the longitudinal coordinate x, extended by a space dependent effective diffusion coefficient D(x). Our paper is focused on calculation of this function for an arbitrary channel shaping function h(x). Unlike the previous algorithms based on scaling of the transverse lengths, the method presented here uses periodicity of the channel...
October 2017: Physical Review. E
Kevin S King, Min Sheng, Peiying Liu, Christopher D Maroules, Craig D Rubin, Ron M Peshock, Roderick W McColl, Hanzhang Lu
Background and purpose Vascular risk factors have been associated with decreased cerebral blood flow (CBF) but this is etiologically nonspecific and may result from vascular insufficiency or a response to decreased brain metabolic activity. We apply new MRI techniques to measure oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen consumption (CMRO2), hypothesizing that decreased CBF related to these vascular risk factors will be associated with increased OEF, confirming a primary vascular insufficiency...
January 1, 2018: Neuroradiology Journal
Daniel M Hirai, Jesse C Craig, Trenton D Colburn, Hiroaki Eshima, Yutaka Kano, William L Sexton, Timothy I Musch, David C Poole
Oxygen pressure (PO2 ) gradients across the blood-myocyte interface are required for diffusive O2 transport thereby supporting oxidative metabolism. The greatest resistance to O2 flux into skeletal muscle is considered to reside between the erythrocyte surface and adjacent sarcolemma, although this has not been measured during contractions. We tested the hypothesis that O2 gradients between skeletal muscle microvascular (PO2 mv) and interstitial (PO2 is) spaces would be present at rest and maintained or increased during contractions...
December 30, 2017: Journal of Physiology
Justin L Grodin, Wilfried Mullens, Matthias Dupont, David O Taylor, Paul M McKie, Randall C Starling, Jeffrey M Testani, W H Wilson Tang
BACKGROUND: Lower serum chloride (Cl) is associated with mortality in heart failure patients and may be more prognostically relevant than sodium. However, the association of hemodynamics and Cl levels is unknown. METHODS: 438 sequential patients with advanced chronic heart failure (ACHF) underwent invasive hemodynamic assessment with measured serum Cl levels during an evaluation for ACHF. Patients were followed for death, heart transplant (HT), or ventricular assist device placement (VAD)...
February 1, 2018: International Journal of Cardiology
Kelly J Caverzagie, Susan W Lane, Niraj Sharma, John Donnelly, Jeffrey R Jaeger, Heather Laird-Fick, John P Moriarty, Darilyn V Moyer, Sara L Wallach, Richard M Wardrop, Alwin F Steinmann
Graduate medical education (GME) in the United States is financed by contributions from both federal and state entities that total over $15 billion annually. Within institutions, these funds are distributed with limited transparency to achieve ill-defined outcomes. To address this, the Institute of Medicine convened a committee on the governance and financing of GME to recommend finance reform that would promote a physician training system that meets society's current and future needs. The resulting report provided several recommendations regarding the oversight and mechanisms of GME funding, including implementation of performance-based GME payments, but did not provide specific details about the content and development of metrics for these payments...
December 12, 2017: Academic Medicine: Journal of the Association of American Medical Colleges
James R Ficke, Nathan M Moroski, Steven D Ross, Ranjan Gupta
Patients often seek nontraditional forms of treatment, including alternative/complementary medical options, such as chiropractic care and acupuncture, to meet their personal needs. In the United States, interest has grown in methods to reduce pain and improve function through Ayurvedic medicine, which uses plant-based supplements, such as turmeric. Traditional allopathic medicine attempts to provide patients with evidence-based therapeutic regimens for their musculoskeletal conditions. Integrative medicine often is used to prevent and manage the sequelae associated with injuries and illnesses; however, competitive athletes and military personnel use complementary medicine for performance enhancement...
January 15, 2018: Journal of the American Academy of Orthopaedic Surgeons
Andrés Vásquez-Rivera, Kim K Sommer, Harriëtte Oldenhof, Adam Z Higgins, Kelvin G M Brockbank, Andres Hilfiker, Willem F Wolkers
Cryopreservation can be used for long-term preservation of tissues and organs. It relies on using complex mixtures of cryoprotective agents (CPAs) to reduce the damaging effects of freezing, but care should be taken to avoid toxic effects of CPAs themselves. In order to rationally design cryopreservation strategies for tissues, it is important to precisely determine permeation kinetics of the protectants that are used to ensure maximum permeation, while minimizing the exposure time and toxicity effects. This is particularly challenging with protectant solutions consisting of multiple components each with different physical properties and diffusing at a different rate...
December 13, 2017: Analyst
Narendra B Dahotre, Soundarapandian Santhanakrishnan, Sameehan S Joshi, Riaz J K Khan, Daniel P Fick, William B Robertson, Raymond K Sheh, Charlie N Ironside
This study describes the fundamentals of laser-bone interaction during bone machining through an integrated experimental-computational approach. Two groups of laser machining parameters identified the effects of process thermodynamics and kinetics on machining attributes at micro to macro. A continuous wave Yb-fiber Nd:YAG laser (wavelength 1070 nm) with fluences in the range of 3.18 J/mm2-8.48 J/mm2 in combination of laser power (300 W-700 W) and machining speed (110 mm/s-250 mm/s) were considered for machining trials...
December 8, 2017: Medical Engineering & Physics
Alexander C Egbe, Heidi M Connolly, Nathaniel W Taggart, Mohamad Al-Otaibi, Barry A Borlaug
BACKGROUND/OBJECTIVES: Although echocardiographic-Doppler cardiac index (CI) assessment is widely used to guide heart failure management in patients with biventricular circulation, this application has not been studied in the Fontan population. The objective of this study was to: (1) determine the correlation between Doppler and cardiac catheterization CI calculation; (2) determine the association between Doppler CI and the occurrence of Fontan failure. METHODS: Retrospective review of adult Fontan patients followed at Mayo Clinic Adult Congenital Heart Disease program, 1994-2015...
December 5, 2017: International Journal of Cardiology
Asma Chebil, Michèle Léonard, Jean-Luc Six, Cécile Nouvel, Alain Durand
PLA nanoparticles loaded with n-alkyl gallates (AGs) were prepared either by nanoprecipitation (NP) or by O/W emulsion/solvent evaporation (E/SE). A nonionic hydrophobically modified polysaccharide was used for surface coverage and for ensuring colloidal stability. Different parameters were systematically assessed to enhance the drug incorporation, with the aim of obtaining monomodal and narrow particle size distributions. The nanoparticles were characterized by 1H NMR, transmission electron microscopy (TEM) and laser light scattering granulometry...
November 27, 2017: Colloids and Surfaces. B, Biointerfaces
Mira D Liu, Elliot A Warner, Charlotte E Morrissey, Caitlyn W Fick, Taia S Wu, Marya Y Ornelas, Gabriela V Ochoa, Brendan Zhang, Colin M Rathbun, William B Porterfield, Jennifer A Prescher, Aaron Morgan Leconte
Directed evolution has proven to be an invaluable tool for protein engineering; however, there is still a need for developing new approaches to continue to improve the efficiency and efficacy of these methods. Here, we demonstrate a new method for library design that applies a previously developed bioinformatic method, Statistical Coupling Analysis (SCA). SCA uses homologous enzymes to identify amino acid positions that are mutable, functionally important, and engage in synergistic interactions between amino acids...
December 11, 2017: Biochemistry
L W Schelke, M Fick, L J van Rijn, T Decates, P J Velthuis, F Niessen
BACKGROUND: A rare but known adverse event following a cosmetic filler treatment is unilateral blindness. In the Netherlands, this complication has not been reported in a patient before. CASE DESCRIPTION: A 26-year-old woman developed unilateral blindness after undergoing a cosmetic treatment of the dorsum nasi in which hyaluronic acid was used as filler. The blindness was caused by backflow of the filler via the ophthalmic artery into the carotid internal artery...
2017: Nederlands Tijdschrift Voor Geneeskunde
Vamshi Vishnu Yamsani, Madan Kumar Mudulaghar, Safoora Afreen, Syed Wajid, Shiva Kumar Ravula, Salmeen D Babelghaith
The aim of this study was to develop a Transdermal patch containing Cinnarizine using different ratios of hydrophilic and hydrophobic polymeric systems by solvent evaporation technique employing Polyethylene glycol (PEG 400) as plasticizer. The physicochemical compatibility of the drug and the polymers were studied by performing FT-IR spectroscopic analysis. Formulated patches were evaluated for physicochemical properties, skin irritation, in vitro drug release, ex-vivo permeation studies across rat abdominal skin and stability studies...
November 2017: Pakistan Journal of Pharmaceutical Sciences
Tatjana Janzen, Shi Zhang, Aliaksandr Mialdun, Gabriela Guevara-Carrion, Jadran Vrabec, Maogang He, Valentina Shevtsova
To gain an understanding of the transport and thermodynamic behavior of the highly non-ideal mixture methanol + cyclohexane, three complementary approaches, i.e. experiment, molecular simulation and predictive equations, are employed. The temperature and composition dependence of different diffusion coefficients is studied around the miscibility gap at ambient pressure. On the one hand Fick diffusion coefficients are measured experimentally by interferometric probing and on the other hand Maxwell-Stefan diffusion coefficients and intradiffusion coefficients are sampled by equilibrium molecular dynamics simulation at five temperatures below the upper critical temperature of ∼319 K...
November 24, 2017: Physical Chemistry Chemical Physics: PCCP
Kristen M Tecson, Anupama Vasudevan, Amarinder Bindra, Susan M Joseph, Joost Felius, Shelley A Hall, Parag Kale
The pulmonary artery catheter (PAC) remains the gold standard to calculate Fick cardiac outputs (FCOs) in patients with heart failure admitted to the intensive care unit (ICU). The peripherally inserted central catheter (PICC) provides long-term intravenous access and is used outside the ICU; however, there is scant literature validating venous oxygen saturations (VOSs) from PICC lines. Heart failure patients in the ICU with an existing PAC requiring a PICC line to transition were enrolled. Three blood samples were taken per person (1 at PICC, 1 at central venous pressure [CVP], and 1 at distal PAC)...
October 10, 2017: American Journal of Cardiology
Hanqiu Chen, Wen Zhang, Ning Yang, Chongmin Chen, Mingliang Zhang
The surface molecular imprinting technique has been proposed as a prospective strategy for template molecule recognition and separation by devising the recognition sites on the surface of imprinted materials. The purpose of this study was to establish a novel drug delivery system which was developed by surface molecular imprinting method using β-cyclodextrin (β-CD)-grafted chitosan (CS) (CS-g-β-CD) microspheres as matrix and sinomenine hydrochloride (SM) as the template molecule. By adjusting the amount of functional monomer and cross-linking agent, we got the more excellent adsorption of CS-g-β-CD molecularly imprinted polymers (MIPs-CS-g-β-CD)...
November 20, 2017: Applied Biochemistry and Biotechnology
Kevser Sevim, Jingzhe Pan
For aliphatic polyesters such as PLAs and PGAs, there is a strong interplay between the hydrolytic degradation and erosion - degradation leads to a critically low molecular weight at which erosion starts. This paper considers the underlying physical and chemical processes of hydrolytic degradation and erosion. Several kinetic mechanisms are incorporated into a mathematical model in an attempt to explain different behaviours of mass loss observed in experiments. In the combined model, autocatalytic hydrolysis, oligomer production and their diffusion are considered together with surface and interior erosion using a set of differential equations and Monte Carlo technique...
November 8, 2017: Acta Biomaterialia
Ahmad Alsarah, Osama Alsara, Heather S Laird-Fick
Familial Mediterranean fever (FMF) is autoinflammatory disorder characterized by sporadic attacks of fever, peritonitis, pleuritis, and arthritis. It is mainly seen in patients from Mediterranean origins, but it is now reported more frequently in Europe and North America due to immigration. To analyze the data on the cardiovascular manifestations in FMF patients, we searched PubMed using the terms "Familial Mediterranean Fever" or "FMF" in combination with other key words including "cardiovascular diseases" "pericardial diseases" "atherosclerosis" "coronary artery diseases" "cardiomyopathy" "pulmonary hypertension" or "valvular diseases...
October 2017: Avicenna Journal of Medicine
Menghua Li, Guilin Shan, Haiyang Zhou, Wolfgang Buescher, Christian Maack, Kerstin H Jungbluth, André Lipski, David A Grantz, Youheng Fan, Daokun Ma, Zhongyi Wang, Qiang Cheng, Yurui Sun
Silage is a critical global feedstock, but is prone to aerobic deterioration. The dominant mechanism of O2 transport into silage remains unresolved. Here, multiple sensors tracked O2 and CO2, gas pressure (ΔP) between internal silage and ambient air, pH and silage temperature (Tsi) during the ensilage of maize and ryegrass. We report the first observation that CO2 produced from microbial respiration was partially dissolved in silage water, with evidence of negative or positive ΔP depending on the changing balance between CO2 production and dissolution...
November 7, 2017: Scientific Reports
Nikki L Hill, Jacqueline Mogle, Rachel Wion, Ann M Kolanowski, Donna Fick, Liza Behrens, Paula Muhall, Jane McDowell
BACKGROUND: Research assistants (RAs) are critical members of all research teams. When a study involves vulnerable populations, it is particularly important to have the right team members. AIM: To describe the motivations, personal characteristics and team characteristics that promoted the job satisfaction of RAs who worked on two multi-year, randomised clinical trials involving older adults with dementia. DISCUSSION: A survey was conducted with 41 community members who worked as RAs for up to five years...
September 19, 2017: Nurse Researcher
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