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Results 201 - 250 of 1587
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Lucas Peter W - - 2012
Here, we show how the mechanical properties of a thick-shelled tropical seed are adapted to permit them to germinate while preventing their predation. The seed has evolved a complex heterogeneous microstructure resulting in hardness, stiffness and fracture toughness values that place the structure at the intersection of these competing selective ...
Wang Junrui - - 2011
BACKGROUND: Colonization pressure has been confirmed as an important risk factor for methicillin-resistant Staphylococcus aureus (MRSA) acquisition among inpatients, but their precise relationship has not been well investigated. Because MRSA carriers can disperse MRSA into their immediate environment with different abilities, the relationship among colonization pressure, the degree of MRSA ...
Holecki Michał - - 2011
Large clinical trials and experimental studies have indicated that not all of the beneficial properties of angiotensin-converting enzyme inhibitors (ACE-Is) can be attributed to the lowering of blood pressure. The aim of this study was to assess doctors' opinions about the importance of the cardioprotective effects of ACE-Is beyond lowering ...
Flevari A G - - 2011
The aim of the study was to calculate the in vitro inspiratory resistance (R(ETT)) of adult endotracheal tubes (ETT), via the end-inspiratory occlusion method, and to apply this method in vivo in order to estimate R(ETT) value in real time. By plotting R(ETT) over inspiratory flow (V) and calculating Rohrer's ...
Yang Qiang - - 2011
Objective  To determine the effect of intraocular pressure (IOP) on blood flow velocity and resistance in the rabbit ophthalmic artery. Animals  Ten adult New Zealand White rabbits were used. Procedures  Right eyes were cannulated and the IOP was raised in a stepwise manner from 20 to 70 mmHg. Peak systolic velocity ...
Korniewicz Denise M - - 2011
: This study was conducted to: (1) determine the clinical effectiveness of a low-air-loss surface, VersaCare P500, in the prevention of pressure ulcers in surgical patients; (2) determine differences in the adjusted Braden scores between those using VersaCare and VersaCare P500 mattress surfaces; and (3) explore the demographic and therapeutic ...
Nguyen Ba D - - 2011
Epidermolysis bullosa encompasses a group of inherited cutaneous disorders with characteristic blisters easily induced by minor mechanical injury from pressure or friction of the skin. The authors present a case of recessive dystrophic epidermolysis bullosa with positive PET finding from non-neoplastic skin lesion of the upper extremity caused by blood ...
Keller David Melvin - - 2011
Prolonged exposure to microgravity and its ground-based analog, head-down bed rest (HDBR), reduces orthostatic tolerance in humans. While skin surface cooling improves orthostatic tolerance, it remains unknown whether this could be an effective countermeasure to preserve post-HDBR orthostatic tolerance. We tested the hypothesis that skin surface cooling improves orthostatic tolerance ...
Sarafidis Pantelis A - - 2011
J Clin Hypertens (Greenwich). 2011;13:523-528. ©2011 Wiley Periodicals, Inc. Resistant hypertension is an entity that has gained a lot of attention in recent years. The prevalence and prognosis of resistant hypertension have not yet been examined by proper population studies, but data from several sources suggest that this entity is ...
Shi Yubing - - 2011
This study presents a numerical simulation of cardiovascular response in the heart failure condition under the support of a Berlin Heart INCOR impeller pump-type ventricular assist device (VAD). The model is implemented using the CellML modelling language. To investigate the potential of using the Berlin Heart INCOR impeller pump to ...
Forni Cristiana - - 2011
Aim.  The aim of this study was to test the effectiveness of polyurethane foam in contact with the heel inside a plaster cast to decrease the rate of pressure sores in the population at most risk. Background.  The rate of pressure sores caused by the plaster cast is reported to ...
Clarys Peter - - 2011
Background/purpose: The measuring probe of the electrical hydration instruments is equipped with a spring system to ensure a constant pressure of probe application on the skin surface. However, it is possible to trigger the measurement at, respectively, a low and a high force of probe application. It is the purpose ...
Manifold R N - - 2011
Topical 5-aminolevulinic acid (ALA) and methyl aminolevulinate (MAL) photodynamic therapy (PDT) of skin lesions is an accepted treatment for skin tumours but success rates need improvement. The effectiveness of PDT is influenced by availability of oxygen. The aim of this study was to demonstrate, in normal skin, whether a decrease ...
Black Joyce M - - 2011
Although pressure ulcer (PrU) development is now generally considered an indicator for quality of care, questions and concerns about situations in which they are unavoidable remain. Considering the importance of this issue and the lack of available research data, in 2010 the National Pressure Ulcer Advisory Panel (NPUAP) hosted a ...
Andrews Samantha N SN Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, - - 2011
Microdermabrasion has been shown to increase skin permeability for transdermal drug delivery by damaging or removing skin's outer layer, stratum corneum. However, relationships between microdermabrasion parameters and effects on the stratum corneum barrier have not been developed. In this study, we determined the effect of microdermabrasion crystal flow rate, time, ...
Mohiuddin Mohammad - - 2011
Electrically conductive polymers reinforced with carbon nanotubes (CNTs) have generated a great deal of scientific and industrial interest in the last few years. Advanced thermoplastic composites made of three different weight percentages (8%, 9%, and 10%) of multiwalled CNTs and polyether ether ketone (PEEK) were prepared by shear mixing process. ...
Klein Ainat - - 2011
to compare the reproducibility of three portable instruments-the Tono-Pen tonometer (Reichert Ophthalmic Instruments, Depew, NY), the Phosphene tonometer (Bausch & Lomb, Rochester, NY), and the TERT (Through Eyelid Russian Tonometer; Rjazan State Instrument Making, Rjazan, Russia)-in the measurement of intraocular pressure (IOP) with and without soft contact lenses and in ...
Papademetriou Vasilios - - 2011
Despite the many therapeutic options available today for the treatment of hypertension, a sizable number of patients still remain resistant to treatment. The prevalence of resistant hypertension in the general population under optimal conditions is about 3-5%. Although several factors and conditions can be identified and corrected a percentage of ...
Hopps Eugenia - - 2011
Portopulmonary hypertension (PPHT) is a respiratory complication of portal hypertension, defined as an increase in mean pulmonary artery pressure (PAP) of > 25 mmHg with an increase in pulmonary vascular resistance of > 240 dyn.s/cm-5 and a normal pulmonary capillary wedge pressure ( < 15 mmHg), which often occurs in ...
Lim Liang - - 2011
Diffuse reflectance and fluorescence spectroscopy are popular research techniques for noninvasive disease diagnostics. Most systems include an optical fiber probe that transmits and collects optical spectra in contact with the suspected lesion. The purpose of this study is to investigate probe pressure effects on human skin spectroscopic measurements. We conduct ...
Jacobsen Jens Christian Brings - - 2011
Vascular flow reserve (VFR) is the relative increase in tissue perfusion from the resting state to a state with maximum vasodilatation. Longstanding hypertension reduces the VFR, which in turn reduces the maximum working capacity of the tissue. In principle, both inward arteriolar remodelling and rarefaction of the microvascular network may ...
Gefen Amit - - 2011
In this study, a mathematical model is developed for analyzing the effects of the microclimate on skin tolerance to superficial pressure ulcers (SPUs). The modeling identified the following factors as such that decrease the tolerance of skin to SPUs: (i) increase in the skin temperature, (ii) increase in the ambient ...
Capelli Claudio - - 2010
To investigate the impact of balloon inflation pressure and balloon diameter on the expansion forces exerted in a stenosed vessel (congenital heart disease applications) using computational models. A simplified three-dimensional model of a vessel with a cylindrical stenosis was created. Two low-compliance balloons with different inflation diameters (10 vs. 16 ...
Beiderman Yevgeny - - 2010
We present a novel technique for remote noncontact blood pulse pressure measurement. It is based on tracking both temporal and amplitude changes of reflected secondary speckle produced in human skin when illuminated by a laser beam. The implemented technique extracts the difference between the systolic and the diastolic blood pressure. ...
Shafer Ilari - - 2011
Vascular adaptation-or structural changes of microvessels in response to physical and metabolic stresses-can influence physiological processes like angiogenesis and hypertension. To better understand the influence of these stresses on adaptation, Pries et al. (1998, 2001a,b, 2005) have developed a computational model for microvascular adaptation. Here, we reformulate this model in ...
Ramirez Rolando J J RJ University of Akron, Department of Biology & Integrative Biology Program, Akron, OH 44325, - - 2011
A central component of preeclampsia is a reduction in utero-placental perfusion. We tested the hypothesis that vascular reactivity of second - order mesenteric arteries would be increased in a pregnant rat with reduced uterine perfusion pressure (RUPP). Pregnant 10-12 week old Sprague-Dawley rats underwent RUPP surgery on gestational day 14, ...
Kieć-Wilk Beata - - 2010
Remodelling process is associated with activity of such substances as transforming growth factor β1 (TGFβ1), basic fibroblast growth factor (bFGF, FGF2), or insulin like growth factor-1 (IGF-1). In the course of hypertension the remodelling of blood vessels and heart muscle takes place. Studies performed on animal models as well as ...
Kumar V Suresh - - 2010
The design and development of a novel supercritical extraction experimental facility adapted for safe operation in a glove box for the recovery of radioactive elements from waste is described. The apparatus incorporates a high pressure extraction vessel, reciprocating pumps for delivering supercritical fluid and reagent, a back pressure regulator, and ...
Suzuki Yoshihisa - - 2010
A standalone-type beryllium (Be) high-pressure crystallography vessel has been developed. Using a coupler-joint unit and a pressure valve, we could keep the pressure in the vessel constant at 100+/-1 MPa for more than 24 h without connecting to a pressure-generating apparatus. Diffraction spots of a glucose isomerase (GI) crystal under ...
Grinberg L - - 2011
We compare results from numerical simulations of pulsatile blood flow in two patient-specific intracranial arterial networks using one-dimensional (1D) and three-dimensional (3D) models. Specifically, we focus on the pressure and flowrate distribution at different segments of the network computed by the two models. Results obtained with 1D and 3D models ...
Steelman Samantha M SM Department of Systems Biology and Translational Medicine, Texas A&M Health Science Center, College Station, TX, - - 2010
Recent studies have renewed interest in the effects of perivascular tethering on vascular mechanics, particularly growth and remodeling. We quantified effects of axial and circumferential tethering on rabbit pial arterioles from the ventral occipital lobe of the brain. The homeostatic axial pre-stretch, which is influenced by perivascular tethering, was measured ...
Günther Axel - - 2010
Although pathologic changes to the structure and function of small blood vessels are hallmarks of various cardiovascular diseases, limitations of conventional investigation methods (i.e. pressure myography) have prohibited a comprehensive understanding of the underlying mechanisms. We developed a microfluidic device to facilitate assessment of resistance artery structure and function under ...
Pires Paulo Wagner PW Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA. - - 2010
Increased reactive oxygen species (ROS) production is involved in the pathogenesis of hypertension and stroke. The effects of ROS on cerebral vessels from hypertensive rats have not been studied. We hypothesized that tempol, a superoxide dismutase mimetic, would prevent middle cerebral artery (MCA) remodeling in stroke-prone spontaneously hypertensive rats (SHRSP). ...
Telinius Niklas - - 2010
The current study characterizes the mechanical properties of the human thoracic duct and demonstrates a role for adrenoceptors, thromboxane, and endothelin receptors in human lymph vessel function. With ethical permission and informed consent, portions of the thoracic duct (2-5 cm) were resected and retrieved at T(7)-T(9) during esophageal and cardia ...
Ring Andrej - - 2010
The effect of cold low-pressure plasma treatment on neovascularization of a dermis substitute was evaluated in a mouse model. Collagen-elastin matrices (Matriderm(®)) were used as scaffolds. Low-pressure argon/hydrogene plasma-treated scaffolds were transplanted into the dorsal skinfold chambers of balb/c mice (group 1, n=10). Untreated scaffolds served as controls (group 2, ...
Ler A S H - - 2010
The state-dependent portion of cardio-vagal baroreflex control is called baroreflex hyteresis: we observe hysteresis when RR interval and carotid diameter depend on both the direction and value of arterial pressure. The elasticity of arterial walls, as well as the responsiveness of central command reset controls the real-time pattern of neural ...
Wagenseil Jessica E JE Dept. of Biomedical Engineering, Saint Louis Univ., 3507 Lindell Blvd., St. Louis, MO 63103, USA. - - 2010
Elastin is an essential component of vertebrate arteries that provides elasticity and stores energy during the cardiac cycle. Elastin production in the arterial wall begins midgestation but increases rapidly during the last third of human and mouse development, just as blood pressure and cardiac output increase sharply. The aim of ...
Marelli Benedetto - - 2010
Processing silk fibroin (SF) by electrospinning offers a very attractive opportunity for producing three-dimensional nanofibrillar matrices in tubular form, which may be useful for a biomimetic approach to small calibre vessel regeneration. Bypass grafting of small calibre vessels, with a diameter less than 6mm, is performed mainly using autografts, like ...
Rahmouni Kamal - - 2010
Obesity increases cardiovascular morbidity and mortality in part by inducing hypertension. One factor linking excess fat mass to cardiovascular diseases may be the sympathetic cardiovascular actions of leptin. Initial studies of leptin showed it regulates appetite and enhances energy expenditure by activating sympathetic nerve activity (SNA) to thermogenic brown adipose ...
Heagerty Anthony M - - 2010
It has been known for some considerable time that sustained hypertension changes the circulatory architecture both in the heart and blood vessels. The histopathological alterations are of considerable interest because once they have developed they appear to carry an adverse prognostic risk. In the heart it is apparent that there ...
Alessandri N - - 2010
The hysto-morfological composition of the ascending aorta wall gives to the vessel its characteristic elasticity/distensibility, which is deteriorated due to both physiological (age) and pathological events (hypertension, diabetes, dyslipidemia). This contributes to reduce the wall elasticity and to occurrence of cardiovascular events. Thirty young healthy subjects (20 males, 10 females, ...
Heitmar Rebekka - - 2010
To establish an alternative method, sequential and diameter response analysis (SDRA), to determine dynamic retinal vessel responses and their time course in serial stimulation compared with the established method of averaged diameter responses and standard static assessment. SDRA focuses on individual time and diameter responses, taking into account the fluctuation ...
Lillie M A - - 2010
Uniaxial and biaxial mechanical properties of purified elastic tissue from the proximal thoracic aorta were studied to understand physiological load distributions within the arterial wall. Stress-strain behaviour was non-linear in uniaxial and inflation tests. Elastic tissue was 40% stiffer in the circumferential direction compared to axial in uniaxial tests and ...
Hassona Mohamed D H - - 2010
Increased mechanical stress/hypertension in the vessel wall triggers the hypertrophic signaling pathway, resulting in structural remodeling of vasculature. Vascular hypertrophy of resistance vessels leads to reduced compliance and elevation of blood pressure. We showed before that increased expression of profilin1 protein in the medial layer of the aorta induces stress ...
Aladin Darwesh M K - - 2010
Collagen fibrils are the main structural components of the nucleus pulposus tissue in the intervertebral discs. The structure-property relationship of the nucleus pulposus (NP) tissues is still unclear. We investigated the structure of individual collagen fibrils of the NP and evaluated its correlation with the bulk mechanical properties of the ...
Pressler Axel - - 2010
Patients after coarctation repair still have an increased risk of cardiovascular or cerebrovascular events. This has been explained by the persisting hypertension and alterations in the peripheral vessels. However, involvement of the central vessels such as the retinal arteries is virtually unknown. A total of 34 patients after coarctation repair ...
Matrai M - - 2010
Hypertension causes small vessel remodeling, vasomotor alterations. We investigated diameter, tone and mechanics of intramural small coronaries of female rats that received chronic angiotensin treatment to induce hypertension.Angiotensin II infusion (AII, 100 ng/bwkg/min, sc.) was used to establish hypertension in 10 female rats. Other 10 rats served as controls. Following ...
Wang Yutang Y Centre for Vascular Research, School of Medical Sciences (Pathology) and Bosch Institute, Faculty of Medicine, University of Sydney, Sydney, - - 2010
Control of blood vessel tone is central to vascular homeostasis. Here we show that metabolism of tryptophan to kynurenine by indoleamine 2,3-dioxygenase (Ido) expressed in endothelial cells contributes to arterial vessel relaxation and the control of blood pressure. Infection of mice with malarial parasites (Plasmodium berghei) or induction of endotoxemia ...
Baek Eun Bok - - 2010
Mechanosensitive nonselective cation channels (NSC(ms)), protein kinase C (PKC), and Rho kinase (ROCK) are suggested as underlying mechanisms for the myogenic contractile response (MR) to luminal pressure (P(lum)). Here we compared relative contributions from these mechanisms using pharmacological inhibitors in rabbit middle cerebral (RbCA), rat middle cerebral (RtCA), rat femoral ...
Funamoto Seiichi - - 2010
A decellularization method using high-hydrostatic pressure (HHP) technology (>600MPa) is described. The HHP disrupts the cells inside the tissue. The cell debris can be eliminated with a simple washing process, producing clean, decellularized tissue. In this study, porcine aortic blood vessel was decellularized by HHP. The mechanical properties and in ...
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