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Find video protocols related to scientific articles indexed in Pubmed.
Micromixing visualization and quantification in a microscale multi-inlet vortex nanoprecipitation reactor using confocal-based reactive micro laser-induced fluorescence.
Biomicrofluidics
PUBLISHED: 07-01-2014
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A technique for visualizing and quantifying reactive mixing for laminar and turbulent flow in a microscale chemical reactor using confocal-based microscopic laser induced fluorescence (confocal ?-LIF) was demonstrated in a microscale multi-inlet vortex nanoprecipitation reactor. Unlike passive scalar ?-LIF, the reactive ?-LIF technique is able to visualize and quantify micromixing effects. The confocal imaging results indicated that the flow in the reactor was laminar and steady for inlet Reynolds numbers of 10, 53, and 93. Mixing and reaction were incomplete at each of these Reynolds numbers. The results also suggested that although mixing by diffusion was enhanced near the midplane of the reactor at Rej?=?53 and 93 due to very thin bands of acidic and basic fluid forming as the fluid spiraled towards the center of the reactor, near the top, and bottom walls of the reactor, the lower velocities due to fluid friction with the walls hindered the formation of these thin bands, and, thus, resulted in large regions of unmixed and unreacted fluid. At Rej?=?240, the flow was turbulent and unsteady. The mixing and reaction processes were still found to be incomplete even at this highest Reynolds number. At the reactor midplane, the flow images at Rej?=?240 showed unmixed base fluid near the center of the reactor, suggesting that just as in the Rej?=?53 and 93 cases, lower velocities near the top and bottom walls of the reactor hinder the mixing and rection of the acidic and basic streams. Ensemble averages of line-scan profiles for the Rej?=?240 were then calculated to provide statistical quantification of the microscale mixing in the reactor. These results further demonstrate that even at this highest Reynolds number investigated, mixing and reaction are incomplete. Visualization and quantification of micromixing using this reactive ?-LIF technique can prove useful in the validation of computational fluid dynamics models of micromixing within microscale chemical reactors.
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Soluble urokinase plasminogen activator receptor is in contrast to high-sensitive C-reactive-protein associated with coronary artery calcifications in healthy middle-aged subjects.
Atherosclerosis
PUBLISHED: 06-10-2014
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The main objective of this study was to investigate the association between two markers of low-grade inflammation; soluble urokinase plasminogen activator receptor (suPAR) and high-sensitive C-reactive protein (hs-CRP); and coronary artery calcification (CAC) score detected by cardiac computed tomography (CT) scan.
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Effect of changes in BMI and waist circumference on ambulatory blood pressure in obese children and adolescents.
J. Hypertens.
PUBLISHED: 04-16-2014
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Weight reduction has been accompanied with a reduction in clinic blood pressure (BP) in children and adolescents; however, the effect on ambulatory BP (ABP) is uncertain. The objective was to investigate the impact of weight changes on ABP in obese children and adolescents.
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Obese children and adolescents have elevated nighttime blood pressure independent of insulin resistance and arterial stiffness.
Am. J. Hypertens.
PUBLISHED: 04-09-2014
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Insulin resistance has been related to elevated blood pressure (BP) in obese children and may adversely affect the vasculature by arterial stiffening. The objective was to investigate whether daytime and nighttime BP were elevated and related to insulin resistance and arterial stiffness in obese children and adolescents.
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Eligibility for renal denervation: experience at 11 European expert centers.
Hypertension
PUBLISHED: 03-24-2014
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Based on the SYMPLICITY studies and CE (Conformité Européenne) certification, renal denervation is currently applied as a novel treatment of resistant hypertension in Europe. However, information on the proportion of patients with resistant hypertension qualifying for renal denervation after a thorough work-up and treatment adjustment remains scarce. The aim of this study was to investigate the proportion of patients eligible for renal denervation and the reasons for noneligibility at 11 expert centers participating in the European Network COordinating Research on renal Denervation in treatment-resistant hypertension (ENCOReD). The analysis included 731 patients. Age averaged 61.6 years, office blood pressure at screening was 177/96 mm Hg, and the number of blood pressure-lowering drugs taken was 4.1. Specialists referred 75.6% of patients. The proportion of patients eligible for renal denervation according to the SYMPLICITY HTN-2 criteria and each center's criteria was 42.5% (95% confidence interval, 38.0%-47.0%) and 39.7% (36.2%-43.2%), respectively. The main reasons of noneligibility were normalization of blood pressure after treatment adjustment (46.9%), unsuitable renal arterial anatomy (17.0%), and previously undetected secondary causes of hypertension (11.1%). In conclusion, after careful screening and treatment adjustment at hypertension expert centers, only ?40% of patients referred for renal denervation, mostly by specialists, were eligible for the procedure. The most frequent cause of ineligibility (approximately half of cases) was blood pressure normalization after treatment adjustment by a hypertension specialist. Our findings highlight that hypertension centers with a record in clinical experience and research should remain the gatekeepers before renal denervation is considered.
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Association between albuminuria, atherosclerotic plaques, elevated pulse wave velocity, age, risk category and prognosis in apparently healthy individuals.
J. Hypertens.
PUBLISHED: 03-14-2014
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Two thousand and fifty-nine healthy individuals aged 41, 51, 61 and 71 years examined in 1993, were divided in age, SCORE and Framingham risk score (FRS) groups. Subclinical vascular damage (SVD) was defined as carotid-femoral pulse wave velocity (cfPWV) at least 12?m/s, carotid atherosclerotic plaques or albuminuria defined as urine albumin/creatinine ratio at least 90th percentile of 0.73/1.06?mg/mmol men/women. In 2006, the composite endpoint (CEP) of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke and hospitalization for ischemic heart disease was recorded (n?=?229).
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Extracellular matrix biomarker, fibulin-1, is closely related to NT-proBNP and soluble urokinase plasminogen activator receptor in patients with aortic valve stenosis (the SEAS study).
PLoS ONE
PUBLISHED: 01-01-2014
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Fibulin-1, a circulating extracellular matrix glycoprotein, has been associated with arterial disease and elevated N-terminal prohormone B-type natriuretic peptide (NT-proBNP) in diabetes. Soluble urokinase plasminogen activator receptor (suPAR), a marker of inflammation, has been associated with subclinical atherosclerosis. Therefore, we aimed to explore the interplay between these biomarkers and mild to moderate aortic valve stenosis (AS).
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Genetic deletion of transglutaminase 2 does not rescue the phenotypic deficits observed in R6/2 and zQ175 mouse models of Huntington's disease.
PLoS ONE
PUBLISHED: 01-01-2014
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Huntington's disease (HD) is an autosomal dominant, progressive neurodegenerative disorder caused by expansion of CAG repeats in the huntingtin gene. Tissue transglutaminase 2 (TG2), a multi-functional enzyme, was found to be increased both in HD patients and in mouse models of the disease. Furthermore, beneficial effects have been reported from the genetic ablation of TG2 in R6/2 and R6/1 mouse lines. To further evaluate the validity of this target for the treatment of HD, we examined the effects of TG2 deletion in two genetic mouse models of HD: R6/2 CAG 240 and zQ175 knock in (KI). Contrary to previous reports, under rigorous experimental conditions we found that TG2 ablation had no effect on either motor or cognitive deficits, or on the weight loss. In addition, under optimal husbandry conditions, TG2 ablation did not extend R6/2 lifespan. Moreover, TG2 deletion did not change the huntingtin aggregate load in cortex or striatum and did not decrease the brain atrophy observed in either mouse line. Finally, no amelioration of the dysregulation of striatal and cortical gene markers was detected. We conclude that TG2 is not a valid therapeutic target for the treatment of HD.
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Computer navigation experience in hip resurfacing improves femoral component alignment using a conventional jig.
Indian J Orthop
PUBLISHED: 06-27-2013
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The use of computer navigation has been shown to improve the accuracy of femoral component placement compared to conventional instrumentation in hip resurfacing. Whether exposure to computer navigation improves accuracy when the procedure is subsequently performed with conventional instrumentation without navigation has not been explored. We examined whether femoral component alignment utilizing a conventional jig improves following experience with the use of imageless computer navigation for hip resurfacing.
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Should we worry about periacetabular interference gaps in hip resurfacing?
Clin. Orthop. Relat. Res.
PUBLISHED: 05-29-2013
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Press-fit acetabular component seating in hip resurfacing can be challenging as a strong interference fit is required. It has not been established whether reducing the acetabular underream minimizes incomplete component seating or leads to increased acetabular loosening.
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Evaluation of a Patient Specific Femoral Alignment Guide for Hip Resurfacing.
J Arthroplasty
PUBLISHED: 05-09-2013
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A novel alternative to conventional instrumentation for femoral component insertion in hip resurfacing is a patient specific, computed tomography based femoral alignment guide. A benchside study using cadaveric femora was performed comparing a custom alignment guide to conventional instrumentation and computer navigation. A clinical series of twenty-five hip resurfacings utilizing a custom alignment guide was conducted by three surgeons experienced in hip resurfacing. Using cadaveric femora, the custom guide was comparable to conventional instrumentation with computer navigation proving superior to both. Clinical femoral component alignment accuracy was 3.7° and measured within ±5° of plan in 20 of 24 cases. Patient specific femoral alignment guides provide a satisfactory level of accuracy and may be a better alternative to conventional instrumentation for initial femoral guidewire placement in hip resurfacing.
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The biomechanical effect of notch size, notch location, and femur orientation on hip resurfacing failure.
IEEE Trans Biomed Eng
PUBLISHED: 03-07-2013
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For hip resurfacing, this is the first biomechanical study to assess anterior and posterior femoral neck notching and femur flexion and extension. Forty-seven artificial femurs were implanted with the Birmingham hip resurfacing (BHR) using a range of notch sizes (0, 2, and 5 mm), notch locations (superior, anterior, and posterior), and femur orientations (neutral stance, flexion, and extension). Implant preparation was done using imageless computer navigation, and mechanical tests measured stiffness and strength. For notch size and location, in neutral stance the unnotched group had 1.9 times greater strength than the 5-mm superior notch group (4539 N versus 2423 N, p=0.047), and the 5-mm anterior notch group had 1.6 times greater strength than the 5-mm superior notch group, yielding a borderline statistical difference (3988 N versus 2423 N, p = 0.056). For femur orientation, in the presence of a 5-mm anterior notch, femurs in neutral stance had 2.2 times greater stiffness than femurs in 25° flexion (1542 N/mm versus 696 N/mm, p = 0.000). Similarly, in the presence of a 5-mm posterior notch, femurs in neutral stance had 2.8 times greater stiffness than femurs in 25° extension (1637 N/mm versus 575 N/mm, p = 0.000). No other statistical differences were noted. All femurs failed through the neck. The results have implications for BHR surgical techniques and recommended patient activities.
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Coronary artery calcification and ECG pattern of left ventricular hypertrophy or strain identify different healthy individuals at risk.
J. Hypertens.
PUBLISHED: 03-07-2013
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To improve risk stratification for development of ischaemic heart disease, several markers have been proposed. Both the presence of coronary artery calcification (CAC) and ECG pattern of left ventricular hypertrophy/strain have been shown to provide independent prognostic information. In this study, we investigated the association between established risk factors, ECG measurements and the presence of coronary artery calcification.
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Mitral annular calcification and incident ischemic stroke in treated hypertensive patients: the LIFE study.
Am. J. Hypertens.
PUBLISHED: 02-07-2013
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Background Fibro-calcification of the mitral annulus (MAC) has been associated with increased risk of ischemic stroke in general populations. This study was performed to assess whether MAC predicts incidence of ischemic stroke in treated hypertensive patients with left ventricular hypertrophy (LVH). Methods Baseline and follow-up clinical and echocardiographic parameters were assessed in 939 hypertensive patients with electrocardiogram (ECG) LVH participating in the Losartan Intervention for Endpoint reduction in hypertension (LIFE) echocardiography substudy (66±7 years; 42% women; 11% with diabetes) who did not have aortic or mitral valve stenosis or prosthesis. Results MAC was found in 458 patients (49%). Patients with MAC were older (68±7 vs. 65±7 years); were more often women (47% vs. 37%); had higher baseline systolic blood pressure (BP) (175±14 vs. 172±15mm Hg), left atrial diameter (4.0±0.5 vs. 3.8±0.6cm), and left ventricular mass index (58±13 vs. 55±12g/m(2.7)) and included more patients with proteinuria (30% vs. 21%; all P < 0.01). During a mean follow-up of 4.8 years, 58 participants had an ischemic stroke. Risk of incident ischemic stroke was significantly related to presence of MAC (log rank = 9; P < 0.01). In multivariable Cox regression analysis models, MAC was associated with increased risk of ischemic stroke (hazard ratio = 1.78-2.35), independent of age, baseline or time-varying systolic BP, prevalence or incidence of atrial fibrillation, history of previous cerebrovascular disease, and other well-recognized confounders, such as sex, time-varying left ventricular mass, left atrial diameter, and urinary albumin/creatinine ratio (all P < 0.05). Conclusions MAC is common in treated hypertensive patients with ECG LVH and is an independent predictor of incident ischemic stroke.
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NT-proBNP, C-reactive protein and soluble uPAR in a bi-ethnic male population: the SAfrEIC study.
PLoS ONE
PUBLISHED: 02-05-2013
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This cross-sectional study aimed to investigate associations between a marker of cardiac strain, the N-terminal prohormone B-type natriuretic peptide (NT-proBNP), and inflammation as reflected by either a conventional or novel inflammatory marker in a bi-ethnic South African cohort.
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The biomechanical effect of artificial and human bone density on stopping and stripping torque during screw insertion.
J Mech Behav Biomed Mater
PUBLISHED: 01-19-2013
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Orthopedic surgeons apply torque to metal screws manually by "subjective feel" to obtain adequate fracture fixation, i.e. stopping torque, and attempt to avoid accidental over-tightening that leads to screw-bone interface failure, i.e. stripping torque. Few studies have quantified stripping torque in human bone, and only one older study from 1980 reported stopping/ stripping torque ratio. The present aim was to measure stopping and stripping torque of cortical and cancellous screws in artificial and human bone over a wide range of densities. Sawbone blocks were obtained having densities from 0.08 to 0.80g/cm(3). Sixteen fresh-frozen human femurs of known standardized bone mineral density (sBMD) were also used. Using a torque screwdriver, 3.5-mm diameter cortical screws and 6.5-mm diameter cancellous screws were inserted for adequate tightening as determined subjectively by an orthopedic surgeon, i.e. stopping torque, and then further tightened until failure of the screw-bone interface, i.e. stripping torque. There were weak (R=0.25) to strong (R=0.99) linear correlations of absolute and normalized torque vs. density or sBMD. Maximum stopping torques normalized by screw thread area engaged by the host material were 15.2N/mm (cortical screws) and 13.4N/mm (cancellous screws) in sawbone blocks and 20.9N/mm (cortical screws) and 6.1N/mm (cancellous screws) in human femurs. Maximum stripping torques normalized by screw thread area engaged by the host material were 23.4N/mm (cortical screws) and 16.8N/mm (cancellous screws) in sawbone blocks and 29.3N/mm (cortical screws) and 8.3N/mm (cancellous screws) in human femurs. Combined average stopping/ stripping torque ratios were 80.8% (cortical screws) and 76.8% (cancellous screws) in sawbone blocks, as well as 66.6% (cortical screws) and 84.5% (cancellous screws) in human femurs. Surgeons should be aware of stripping torque limits for human femurs and monitor stopping torque during surgery. This is the first study of the effect of sawbone density or human bone sBMD on stopping and stripping torque.
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Impact of alcohol habits and smoking on the risk of new-onset atrial fibrillation in hypertensive patients with ECG left ventricular hypertrophy: the LIFE study.
Blood Press.
PUBLISHED: 11-10-2011
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The incidence of new-onset atrial fibrillation (AF) is increased by uncontrolled hypertension, and antihypertensive treatment reduces new-onset AF. However, it is unclear whether alcohol intake and smoking influence the risk of new-onset AF during antihypertensive treatment.
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Hip resurfacing versus metal-on-metal total hip arthroplasty - are metal ion levels different?
Bull NYU Hosp Jt Dis
PUBLISHED: 11-01-2011
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A systematic review and meta-analysis of trials comparing hip resurfacing to metal-on-metal total hip arthroplasty was conducted to determine if there is a difference in serum metal ion levels in patients receiving these implants. EMBASE and MEDLINE databases were searched from inception to December 2010 for all trials involving the use of these devices. Eligibility for inclusion in the review were studies with 1. comparative trials that were both retrospective and prospective; 2. inclusion of a treatment arm receiving hip resurfacing; 3. inclusion of a treatment arm receiving metal-on-metal total hip arthroplasty; and 4. analysis of chromium and cobalt ions, or either, in patient serum or whole blood at a minimum of 1 year after implantation. The literature search identified 87 potential studies, of which 10 met the inclusion criteria. Pooled mean differences were calculated for serum cobalt and chromium ion levels. Mean differences for serum cobalt and chromium metal ions were not significantly different between hip resurfacing and metal-on-metal total hip arthroplasty patients, although there was a tendency for lower serum cobalt ion levels in patients receiving hip resurfacing. Larger prospective randomized trials are required to better substantiate a difference in metal ion levels occurring between these implants.
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N-terminal prohormone B-type natriuretic peptide and cardiovascular function in Africans and Caucasians: the SAfrEIC study.
Heart Lung Circ
PUBLISHED: 08-18-2011
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This study compared NT-proBNP levels and the association with cardiovascular markers between Africans and Caucasians from South Africa.
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Exploring soluble urokinase plasminogen activator receptor and its relationship with arterial stiffness in a bi-ethnic population: the SAfrEIC-study.
Thromb. Res.
PUBLISHED: 08-10-2011
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Elevated soluble urokinase-type plasminogen activator receptor (suPAR) indicates an inflammatory state caused by conditions such as HIV and cancer. Recently suPAR was identified as an indicator of cardiovascular disease (CVD). CVD is highly prevalent in black South Africans, but the potential role of suPAR is unknown. We investigated suPAR as a possible marker of arterial stiffness in Africans and Caucasians.
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Avoiding short-term femoral neck fracture with imageless computer navigation for hip resurfacing.
Clin. Orthop. Relat. Res.
PUBLISHED: 07-22-2011
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Femoral neck fracture in hip resurfacing has been attributed to technical error during femoral head preparation. In the absence of fracture, several radiographic findings have been speculated to increase the risk of femoral component failure.
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A biomechanical comparison of epiphyseal versus metaphyseal fixed bone-conserving hip arthroplasty.
J Bone Joint Surg Am
PUBLISHED: 05-06-2011
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The Birmingham Mid-Head Resection (BMHR) is a bone-conserving, short-stem alternative to hip resurfacing for patients with abnormal femoral head anatomy.
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Stroke mortality and trends from 1990 to 2006 in 39 countries from Europe and Central Asia: implications for control of high blood pressure.
Eur. Heart J.
PUBLISHED: 04-12-2011
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The aim of the present study was to extend our understanding of international trends in stroke and major sequelae in Europe and countries peripheral to Europe by assessing: (1) current mortality rates, (2) the most recent 15-year prevalence trends, and (3) the relationship between systolic blood pressure in community surveys and national stroke mortality.
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Changes in subclinical organ damage vs. in Framingham risk score for assessing cardiovascular risk reduction during continued antihypertensive treatment: a LIFE substudy.
J. Hypertens.
PUBLISHED: 03-02-2011
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To investigate whether in-treatment measurements of subclinical organ damage (SOD) assessed by elevated urine albumin/creatinine ratio (UACR) or electrocardiographic left ventricular hypertrophy improved the prediction of the composite cardiovascular endpoint of cardiovascular death, nonfatal myocardial infarction and stroke beyond in-treatment Framingham risk score (FRS).
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Mechanism of action of stinging nettles.
Wilderness Environ Med
PUBLISHED: 01-06-2011
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Inadvertent exposure to the ubiquitous weed, Urtica dioica, called "stinging nettles" produces an immediate stinging and burning sensation on the skin. This investigation evaluates the structural effect that stinging nettle spicules may have on the clinical manifestation of these symptoms. This hypothesis was investigated by exposing murine skin to stinging nettles and then evaluating the skin using electron microscopy. It was hypothesized that the mechanism of action of stinging nettles is both biochemical and mechanical, which may have clinical significance regarding treatment for acute exposure.
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3-(Pyridin-2-yl-ethynyl)benzamide metabotropic glutamate receptor 5 negative allosteric modulators: hit to lead studies.
Bioorg. Med. Chem. Lett.
PUBLISHED: 10-04-2010
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A series of 3-(pyridin-2-yl-ethynyl)benzamide negative allosteric modulators of the metabotropic glutamate receptor 5 (mGluR5 NAMs) have been prepared. Starting from HTS hit 1 (IC(50): 926 nM), potent mGluR5 NAMs showing excellent potencies (IC(50)s<50 nM) and good physicochemical profiles were prepared by monitoring LipE values. One compound 26 showed excellent mGluR5 binding (K(i): 21 nM) and antagonism (IC(50): 8 nM), an excellent rat PK profile (CL: 12 mL/min/kg, %F: 85) and showed oral activity in a mouse 4-Plate Behavioral model of anxiety (MED: 30 mpk) and a mouse Stress Induced Hyperthermia model of anxiety (MED 17.8 mpk).
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A comparison of conventional guidewire alignment jigs with imageless computer navigation in hip resurfacing arthroplasty.
J Bone Joint Surg Am
PUBLISHED: 08-06-2010
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Correct positioning of the initial femoral guidewire is vital in order to prepare the femoral head properly for hip resurfacing. The purpose of the present investigation was to determine the accuracy and precision of the placement of the initial femoral guidewire with use of conventional alignment jigs and to compare the results with those of imageless computer navigation.
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The biomechanical consequence of insufficient femoral component lateralization and exposed cancellous bone in hip resurfacing arthroplasty.
J Biomech Eng
PUBLISHED: 07-31-2010
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Insufficient lateralization of the femoral component coupled with exposed reamed cancellous bone has been speculated to predispose to femoral neck fracture. The current study examined the effect of mediolateral implant position and exposed cancellous bone on the strength of the resurfaced proximal femur. Composite femurs were prepared in three configurations: (1) partial, with the implant placed at the native femoral head offset of the femur, partially exposing reamed cancellous bone; (2) proud, with a medialized implant exposing a circumferential ring of cancellous bone; and (3) complete, with a lateralized implant covering all reamed cancellous bone. Specimens were loaded to failure in axial compression. A finite element model was used to further explore the effect of exposed cancellous bone, cement mantle thickness, and relative valgus orientation on the strain distributions in the resurfaced femur. The proud group (2063 N) was significantly weaker than both the partial (2974 N, p=0.004) and complete groups (5899 N, p=0.001) when tested to failure. The partial group was also significantly weaker than the complete group when tested to failure (p=0.001). The finite element model demonstrated increasing levels of strain in the superior reamed cortical-cancellous bone interface with increasing degree of exposed cancellous bone. The condition of the femoral component medialized as the result of a thick cement mantle had the greatest detrimental impact on strain level in the superior reamed cancellous bone while a valgus oriented implant provided a protective effect. This study provides biomechanical evidence that exposed reamed cancellous bone significantly reduces the load-to-failure and increases maximum strains in the resurfaced proximal femur. The perceived benefit of reconstructing the femur to its native geometry may inherently weaken the proximal femur and increase femoral neck fracture risk if the femoral component is not sufficiently lateralized to cover all unsupported reamed cancellous bone. Relative valgus orientation of the implant may help to minimize the risk of neck fracture if reamed cancellous bone remains exposed following implant impaction.
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A biomechanical investigation of implant alignment and femoral neck notching with the Birmingham Mid-Head Resection.
J Arthroplasty
PUBLISHED: 05-17-2010
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The Birmingham Mid-Head Resection (BMHR) is a bone-conserving, short-stem alternative to hip resurfacing for patients with compromised femoral head anatomy. The current study examined the effect of coronal implant alignment and femoral neck notching on proximal femoral strength with the BMHR. Neither relative valgus nor varus implant alignment had a significant impact on femoral strength compared to neutrally aligned, matched, paired cadaveric specimens. A 5-mm superior neck notch significantly weakened BMHR-implanted synthetic femurs compared to unnotched controls, whereas a 2-mm notch did not significantly affect ultimate failure load. Relative valgus alignment had a protective effect on a full-cortical-thickness superior neck notch. Mid-head resection arthroplasty may be more forgiving to minor preparatory errors than a typical hip resurfacing.
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In-treatment reduced left atrial diameter during antihypertensive treatment is associated with reduced new-onset atrial fibrillation in hypertensive patients with left ventricular hypertrophy: The LIFE Study.
Blood Press.
PUBLISHED: 05-05-2010
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It is unclear whether improvement of left atrial (LA) and ventricular (LV) structure results in reduction in new-onset atrial fibrillation (AF). The aim of the present study was to examine whether changes in-treatment LA diameter were related to changes in risk of new-onset AF.
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Subclinical organ damage and cardiovascular risk prediction.
Blood Press.
PUBLISHED: 05-01-2010
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Traditional cardiovascular risk factors have poor prognostic value for individuals and screening for subclinical organ damage has been recommended in hypertension in recent guidelines. The aim of this review was to investigate the clinical impact of the additive prognostic information provided by measuring subclinical organ damage. We have (i) reviewed recent studies linking markers of subclinical organ damage in the heart, blood vessels and kidney to cardiovascular risk; (ii) discussed the evidence for improvement in cardiovascular risk prediction using markers of subclinical organ damage; (iii) investigated which and how many markers to measure and (iv) finally discussed whether measuring subclinical organ damage provided benefits beyond risk prediction. In conclusion, more studies and if possible randomized studies are needed to investigate (i) the importance of markers of subclinical organ damage for risk discrimination, calibration and reclassification; and (ii) the economic costs and health benefits associated with measuring markers of subclinical organ damage.
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Lack of regression of left ventricular hypertrophy is associated with higher incidence of revascularization in hypertension: The LIFE Study.
Blood Press.
PUBLISHED: 05-01-2010
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Regression of left ventricular (LV) hypertrophy and albuminuria in hypertension has previously been shown to reduce clinical cardiovascular events and death. We aimed to investigate the associations of regression of electrocardiographic (ECG) LV hypertrophy and albuminuria with the incidence of revascularization.
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Serum uric acid is associated with new-onset diabetes in hypertensive patients with left ventricular hypertrophy: The LIFE Study.
Am. J. Hypertens.
PUBLISHED: 04-29-2010
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It is unclear whether serum uric acid (SUA) is associated with development of new-onset diabetes (NOD) in patients with hypertension and left ventricular hypertrophy (LVH). The aim of the present investigation was to test the hypothesis that SUA predicts development of NOD in these patients.
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In-treatment midwall and endocardial fractional shortening predict cardiovascular outcome in hypertensive patients with preserved baseline systolic ventricular function: the Losartan Intervention For Endpoint reduction study.
J. Hypertens.
PUBLISHED: 04-23-2010
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Endocardial fractional shortening (EFS) and midwall shortening (MWS) are impaired in patients with left ventricular hypertrophy. However, it remains unknown whether improvement of left ventricular systolic function during treatment reduces cardiovascular morbidity and mortality in hypertensive patients with preserved left ventricular function.
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Measures of overweight and obesity and risk of cardiovascular disease: a population-based study.
Eur J Cardiovasc Prev Rehabil
PUBLISHED: 02-06-2010
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Although overweight and obesity are associated with cardiovascular disease (CVD), it is unclear which clinical measure of overweight and obesity is the strongest predictor of CVD, and it is unclear whether the various measures of overweight and obesity are indeed independent predictors of CVD.
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Risk prediction is improved by adding markers of subclinical organ damage to SCORE.
Eur. Heart J.
PUBLISHED: 12-23-2009
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It is unclear whether subclinical vascular damage adds significantly to Systemic Coronary Risk Evaluation (SCORE) risk stratification in healthy subjects.
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Risk stratification with the risk chart from the European Society of Hypertension compared with SCORE in the general population.
J. Hypertens.
PUBLISHED: 11-17-2009
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The risk chart from the European Society of Hypertension (ESH) and Systemic Coronary Risk Evaluation (SCORE) from the European Society of Cardiology (ESC) are equally recommended tools for risk stratification. However, ESH risk chart recommends measuring subclinical organ damage, whereas SCORE is based on traditional risk factors. We wanted to compare the predictive performance of the two charts.
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Cortical screw purchase in synthetic and human femurs.
J Biomech Eng
PUBLISHED: 09-04-2009
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Biomechanical investigations of orthopedic fracture fixation constructs increasingly use analogs like the third and fourth generation composite femurs. However, no study has directly compared cortical screw purchase between these surrogates and human femurs, which was the present aim. Synthetic and human femurs had bicortical orthopedic screws (diameter=3.5 mm and length=50 mm) inserted in three locations along the anterior length. The screws were extracted to obtain pullout force, shear stress, and energy-to-pullout. The four study groups (n=6 femurs each) assessed were the fourth generation composite femur with both 16 mm and 20 mm diameter canals, the third generation composite femur with a 16 mm canal, and the human femur. For a given femur type, there was no statistical difference between the proximal, center, or distal screw sites for virtually all comparisons. The fourth generation composite femur with a 20 mm canal was closest to the human femur for the outcome measures considered. Synthetic femurs showed a range of average measures (2948.54-5286.30 N, 27.30-35.60 MPa, and 3.63-9.95 J) above that for human femurs (1645.92-3084.95 N, 17.86-24.64 MPa, and 1.82-3.27 J). Shear stress and energy-to-pullout were useful supplemental evaluators of screw purchase, since they account for material properties and screw motion. Although synthetic femurs approximated human femurs with respect to screw extraction behavior, ongoing research is required to definitively determine which type of synthetic femur most closely resembles normal, osteopenic, or osteoporotic human bone at the screw-bone interface.
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[Hypertension and the metabolic syndrome].
Ugeskr. Laeg.
PUBLISHED: 08-13-2009
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The metabolic syndrome is a relatively prevalent condition characterized by co-existence of several metabolic and cardiovascular risk factors including hypertension. Patients with hypertension have an increased risk of developing the metabolic syndrome which, in turn, increases the cardiovascular risk associated with increased blood pressure. As the definition of the metabolic syndrome is based on dichotomization of cardiovascular risk factors with a continuously increasing risk, it cannot match risk stratification tools like the HeartScore for calculation of prognosis. However, the metabolic syndrome is of clinical importance as it makes the treating physician test for other elements of the syndrome in patients with one of the elements, e.g. hypertension.
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[Microalbuminuria].
Ugeskr. Laeg.
PUBLISHED: 08-13-2009
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Microalbuminuria is common in patients with hypertension and even lower levels of albuminuria reflect subclinical cardiovascular damage which is associated with increased cardiovascular risk. Reduction of albuminuria is associated with improved prognosis independently of reduction of blood pressure and regression of left ventricular hypertrophy. Accordingly, albuminuria--an integrated measure of cardiovascular risk--should be monitored and reduced through intensified antihypertensive treatment in combination with careful correction of other cardiovascular risk factors.
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Computer navigated hip resurfacing for patients with abnormal femoral anatomy.
Bull NYU Hosp Jt Dis
PUBLISHED: 07-09-2009
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Hip resurfacing is a technically demanding alternative to total hip arthroplasty. The use of traditional jigs for placement of the femoral guidewire can lead to preparatory errors that may predispose the resurfacing construct to premature failure. Computer navigation is a tool that can be used to minimize the incidence of inadequate to detrimental preparation of the femoral head and improve the accuracy of component placement. Computer navigation not only shows promise in routine cases of hip resurfacing but also in those cases that are technically challenging. The current study demonstrated the utility of imageless computer navigation in placement of the femoral component for patients presenting with abnormal femoral anatomy.
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The reliability of radiographic assessment of femoral neck-shaft and implant angulation in hip resurfacing arthroplasty.
J Arthroplasty
PUBLISHED: 06-26-2009
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Fifteen sets of patient radiographs were analyzed by 3 different observers on 2 occasions. Each observer measured the femoral neck-shaft angles (NSAs) of the preoperative digital radiographs and stem-shaft angles (SSAs) of the postoperative radiographs. The effect of femur position on SSA measured by digital radiographs was also investigated using a resurfaced synthetic femur. Radiographs were taken with the synthetic specimen positioned in 10 degrees increments of either flexion or rotation. Measurement by digital radiographs proved less than optimal in assessing preoperative NSA but was better in assessing the postoperative component SSA. External rotation of 30 degrees and flexion of 40 degrees resulted in a clinically significant disparity in SSA measurements. Patient malposition during radiographic imaging can contribute to erroneous NSA and SSA results.
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[Cardiovascular risk profile and anti-hypertensive treatment].
Ugeskr. Laeg.
PUBLISHED: 06-16-2009
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Estimation of absolute cardiovascular risk is important for choice of primary as well as secondary cardiovascular prevention. In general, physicians are advised to use SCORE in apparently healthy subjects with optimal or normal blood pressure, the ESH risk stratification chart in patients with hypertension and either one or even better a combination of the two instruments in apparently healthy subjects with a high normal blood pressure.
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Which markers of subclinical organ damage to measure in individuals with high normal blood pressure?
J. Hypertens.
PUBLISHED: 04-24-2009
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Medical treatment of healthy individuals with high normal blood pressure (BP) is recommended if there is subclinical organ damage (SOD). We examined which markers of SOD to use based on their supplementary prognostic value.
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Linear and torsional mechanical characteristics of intact and reconstructed scapholunate ligaments.
J Biomech Eng
PUBLISHED: 03-12-2009
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The mechanical behavior of human scapholunate ligaments is not well understood. Presently, intact scapholunate specimens were mechanically tested in linear distraction and torsion. Fresh bovine tendon grafts were used to reconstruct the scapholunate interval and the tests repeated. Tests yielded the following average values for intact specimens: linear stiffness (48.9 Nmm), linear load retained at 100 s (44%), torsional stiffness (19.5 N mmdeg), torque remaining at 100 seconds (66%), torque-to-failure (1253.9 N mm), and angle-to-failure (50.4 deg). Tests showed the following average values for reconstructed specimens: linear stiffness (5.4 Nmm), linear load retained at 100 s (49%), torsional stiffness (12.6 N mmdeg), torque remaining at 100 s (71%), torque-to-failure (936.8 N mm), and angle-to-failure (54.5 deg). There were no statistically significant differences between the intact and reconstructed specimens, with the exception of linear stiffness. Biomechanically, this is the first study in the literature to quantify torsional stress relaxation, failure torque, and failure angle for the intact and repaired human scapholunate ligament. Surgically, reconstruction with bovine tendon may warrant further investigation as a method to potentially retain function and strength after scapholunate injury.
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A biomechanical and finite element analysis of femoral neck notching during hip resurfacing.
J Biomech Eng
PUBLISHED: 03-12-2009
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Hip resurfacing is an alternative to total hip arthroplasty in which the femoral head surface is replaced with a metallic shell, thus preserving most of the proximal femoral bone stock. Accidental notching of the femoral neck during the procedure may predispose it to fracture. We examined the effect of neck notching on the strength of the proximal femur. Six composite femurs were prepared without a superior femoral neck notch, six were prepared in an inferiorly translated position to create a 2 mm notch, and six were prepared with a 5 mm notch. Six intact synthetic femurs were also tested. The samples were loaded to failure axially. A finite element model of a composite femur with increasing superior notch depths computed maximum equivalent stress and strain distributions. Experimental results showed that resurfaced synthetic femurs were significantly weaker than intact femurs (mean failure of 7034 N, p<0.001). The 2 mm notched group (mean failure of 4034 N) was significantly weaker than the un-notched group (mean failure of 5302 N, p=0.018). The 5 mm notched group (mean failure of 2808 N) was also significantly weaker than both the un-notched and the 2 mm notched groups (p<0.001, p=0.023, respectively). The finite element model showed the maximum equivalent strain in the superior reamed cancellous bone increasing with corresponding notch size. Fracture patterns inferred from equivalent stress distributions were consistent with those obtained from mechanical testing. A superior notch of 2 mm weakened the proximal femur by 24%, and a 5 mm notch weakened it by 47%. The finite element analysis substantiates this showing increasing stress and strain distributions within the prepared femoral neck with increasing notch depth.
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Assessment of accuracy and reliability in preoperative templating for hip resurfacing arthroplasty.
J Arthroplasty
PUBLISHED: 01-30-2009
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The current study investigated the accuracy and reliability of hip resurfacing component selection based on digital preoperative templating. Four surgeons made a template of preoperative radiographs on 2 occasions for acetabular and femoral components in 50 randomly selected hip resurfacing patients. Component selection reliability was variable among surgeons (kappa = 0.16-0.73) and fair between surgeons (kappa = 0.23-0.32). The average percentage of agreement for the acetabular component was 47% (range, 32%-64%) and for the femoral component was 54% (range, 38%-70%). Surgeons tended to underestimate implant size if the correct implant was not chosen (acetabular, 29%; femoral, 32%). Selection of an undersized femoral component may lead to femoral neck notching or varus implant alignment. This study emphasizes the need for intraoperative verification of preoperative templating results to ensure optimal implant selection in hip resurfacing.
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Turbulence in a microscale planar confined impinging-jets reactor.
Lab Chip
PUBLISHED: 01-29-2009
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Confined impinging-jets reactors (CIJR) offer many advantages for rapid chemical processing at the microscale in applications such as precipitation and the production of organic nanoparticles. It has been demonstrated that computational fluid dynamics (CFD) is a promising tool for "experiment-free" design and scale-up of such reactors. However, validation of the CFD model used for the microscale turbulence applications requires detailed experimental data on the unsteady flow, the availability of which has until now been very limited. In this work, microscopic particle-image velocimetry (microPIV) techniques were employed to measure the instantaneous velocity field for various Reynolds numbers in a planar CIJR. In order to illustrate the validation procedure, the performance of a particular CFD model, the two-layer k-epsilon model, was evaluated by comparing the predicted flow field with the experimental data. To our knowledge, this study represents the first attempt to directly measure and quantify velocity and turbulence in a microreactor and to use the results to validate a CFD model for microscale turbulent flows.
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Prospective randomized trial comparing alumina ceramic-on-ceramic with ceramic-on-conventional polyethylene bearings in total hip arthroplasty.
J Arthroplasty
PUBLISHED: 01-11-2009
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This prospective randomized study aims to compare the outcome between an alumina ceramic-on-ceramic (CC) articulation with a ceramic on ultra-high-molecular-weight polyethylene articulation (CP). Fifty-six hips in 55 patients with mean age 42.2 (range, 19-56) each received uncemented components, a 28-mm alumina head with randomization of acetabular liner. Mean St Michaels outcome score for each group with up to 10 years follow-up (median, 8 years; range, 1-10) was 22.8 and 22.9, respectively (P = .819). Wear was identified in all but 1 CP replacement, but only 12 of the 23 CC. Mean wear in the CP group was 0.11 mm/y and 0.02 mm/yr in the CC group (P < .001). Other than significantly greater wear in the polyethylene group, there was no significant difference in midterm outcome between the 2 groups.
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Biomechanical measurements of surgical drilling force and torque in human versus artificial femurs.
J Biomech Eng
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Few experimental studies have examined surgical drilling in human bone, and no studies have inquired into this aspect for a popular commercially-available artificial bone used in biomechanical studies. Sixteen fresh-frozen human femurs and five artificial femurs were obtained. Cortical specimens were mounted into a clamping system equipped with a thrust force and torque transducer. Using a CNC machine, unicortical holes were drilled in each specimen at 1000?rpm, 1250?rpm, and 1500?rpm with a 3.2?mm diameter surgical drill bit. Feed rate was 120?mm/min. Statistical significance was set at p?
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Combustion resistance of the 129Xe hyperpolarized nuclear spin state.
Phys Chem Chem Phys
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Using a methane-xenon mixture for spin exchange optical pumping, MRI of combustion was enabled. The (129)Xe hyperpolarized nuclear spin state was found to sufficiently survive the complete passage through the harsh environment of the reaction zone. A velocity profile (V(z)(z)) of a flame was recorded to demonstrate the feasibility of MRI velocimetry of transport processes in combustors.
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NT-proBNP and potential vascular calcification in Black and Caucasian African men: the SAfrEIC study.
Ethn Dis
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The N-terminal prohormone B-type natriuretic peptide (NT-proBNP) is a reliable marker of cardiac strain. In hypertensive heart disease, NT-proBNP levels increase and may lose its protective function. Simultaneously, the vasculature is also subject to hemodynamic stress, resulting in vascular matrix remodeling and stiffening which contribute to further cardiac alterations. Alkaline phosphatase (ALP) is a marker of osteoblast activity and is involved in vascular calcification. We explored the link between NT-proBNP and ALP in Black and Caucasian African men.
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Biomechanical measurements of cortical screw stripping torque in human versus artificial femurs.
Proc Inst Mech Eng H
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Femur fracture plates are applied using cortical bone screws. Surgeons do this manually by subjective feel without monitoring torque. Few studies have quantified stripping torque in human bone. No studies have measured stripping torque in the artificial bones from Sawbones (Vashon, WA, USA) that are frequently used in biomechanical studies. The present aim was to measure stripping torque of cortical screws in human versus artificial femurs. Sixteen fresh-frozen human femurs and eight artificial femurs were used. Using a digital torque screwdriver, each femur had a 3.5-mm diameter uni-cortical screw manually inserted into the anterior midshaft until failure of the screw-bone interface. Results were normalized by cortical thickness and the screw-bone interfacial area. There were no statistical differences in human versus artificial data, respectively, for stripping torque (1741 +/- 442 N.mm, 2012 +/- 176 N.mm, p = 0.11), stripping torque/thickness (313 +/- 59 N, 305 +/- 30 N, p = 0.74), and stripping torque area (28.5 +/- 5.3 N/mm, 27.8 +/- 2.8 N/mm, p = 0.74). Artificial unicortical thickness (6.6 + 0.3 mm) was greater than human thickness (5.6 +/- 1.1 mm) (p = 0.02). For human specimens, there was a moderate linear correlation of absolute and normalized stripping torque versus standardized bone mineral density (R > or = 0.32) and clinical T-score (R = 0.29), but not with age (R < or = 0.29). Surgeons should be aware of the stripping torque limits for human femurs and potentially take steps to monitor these values during surgery. The artificial femurs being increasingly used in research accurately replicate human cortical properties during screw insertion. To date, this is the first series of human femurs evaluated for cortical screw stripping.
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Impact of age on the importance of systolic and diastolic blood pressures for stroke risk: the MOnica, Risk, Genetics, Archiving, and Monograph (MORGAM) Project.
Hypertension
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This study investigates age-related shifts in the relative importance of systolic (SBP) and diastolic (DBP) blood pressures as predictors of stroke and whether these relations are influenced by other cardiovascular risk factors. Using 34 European cohorts from the MOnica, Risk, Genetics, Archiving, and Monograph (MORGAM) Project with baseline between 1982 and 1997, 68 551 subjects aged 19 to 78 years, without cardiovascular disease and not receiving antihypertensive treatment, were included. During a mean of 13.2 years of follow-up, stroke incidence was 2.8%. Stroke risk was analyzed using hazard ratios per 10-mm Hg/5-mm Hg increase in SBP/DBP by multivariate-adjusted Cox regressions, including SBP and DBP simultaneously. Because of nonlinearity, DBP was analyzed separately for DBP ? 71 mm Hg and DBP <71 mm Hg. Stroke risk was associated positively with SBP and DBP ? 71 mm Hg (SBP/DBP ? 71 mm Hg; hazard ratios: 1.15/1.06 [95% CI: 1.12-1.18/1.03-1.09]) and negatively with DBP <71 mm Hg (0.88[0.79-0.98]). The hazard ratio for DBP decreased with age (P<0.001) and was not influenced by other cardiovascular risk factors. Taking into account the age × DBP interaction, both SBP and DBP ? 71 mm Hg were significantly associated with stroke risk until age 62 years, but in subjects older than 46 years the superiority of SBP for stroke risk exceeded that of DBP ? 71 mm Hg and remained significant until age 78 years. DBP <71 mm Hg became significant at age 50 years with an inverse relation to stroke risk. In Europeans, stroke risk should be assessed by both SBP and DBP until age 62 years with increased focus on SBP from age 47 years. From age 62 years, emphasis should be on SBP without neglecting the potential harm of very low DBP.
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[The initial experience in supervised injecting facilities in Denmark].
Ugeskr. Laeg.
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Intravenous drug abuse is a major health concern. The National Board of Health estimates the number of injecting drug users (IDUs) in Denmark to be 13,000. Supervised injecting facilities (SIF) reduce the risk behaviour and bacterial infections and also increase the rate of detoxification and access to health care. The first SIF in Denmark is driven by volunteers and it opened in September 2011. In the first six months there were 1,139 visits. As in earlier studies the IDUs were mainly males with a long history of drug use. Unlike in previously published studies cocaine was the most commonly injected drug.
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Cardiovascular risk prediction in the general population with use of suPAR, CRP, and Framingham Risk Score.
Int. J. Cardiol.
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The inflammatory biomarkers soluble urokinase plasminogen activator receptor (suPAR) and C-reactive protein (CRP) independently predict cardiovascular disease (CVD). The prognostic implications of suPAR and CRP combined with Framingham Risk Score (FRS) have not been determined.
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Thresholds for pulse wave velocity, urine albumin creatinine ratio and left ventricular mass index using SCORE, Framingham and ESH/ESC risk charts.
J. Hypertens.
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Markers of subclinical target organ damage (TOD) increase cardiovascular (CV) risk prediction beyond traditional risk factors. We wanted to establish thresholds for three markers of TOD based on absolute CV risk in different risk chart categories.
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Genetic variation in the natriuretic peptide system, circulating natriuretic peptide levels, and blood pressure: an ambulatory blood pressure study.
Am. J. Hypertens.
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In a large collaborative study (n > 50,000), common variants in the natriuretic peptide (NP) genes were found to be associated with circulating NP levels and also with blood pressure (BP) levels based on office BP measurements (OBPMs). It is unknown if determining an individuals BP by 24-h ambulatory BP measurements (ABPMs) will influence the effect of NP gene variations on BP levels.
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Predictors of femoral neck fracture following hip resurfacing: a cadaveric study.
J Arthroplasty
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We aimed to establish if radiological parameters, dual energy x-ray absorptiometry (DEXA) and quantitative CT (qCT) could predict the risk of sustaining a femoral neck fracture following hip resurfacing. Twenty-one unilateral fresh frozen femurs were used. Each femur had a plain digital anteroposterior radiograph, DEXA scan and qCT scan. Femurs were then prepared for a Birmingham Hip Resurfacing femoral component and loaded to failure. Results demonstrated that gender and qCT measurements showed strong correlation with failure load. QCT could be used as an individual measure to predict risk of post-operative femoral neck fracture. However, when qCT is unavailable; gender, pre-operative DEXA scan and Neck Width measurements can be used together to assess risk of post-operative femoral neck fracture in patients due to undergo hip resurfacing.
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Association of pulse pressure with new-onset atrial fibrillation in patients with hypertension and left ventricular hypertrophy: the Losartan Intervention For Endpoint (LIFE) reduction in hypertension study.
Hypertension
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Previous studies have found pulse pressure (PP), a marker of arterial stiffness, to be an independent predictor of atrial fibrillation (AF) in general and hypertensive populations. We examined whether PP predicted new-onset AF in comparison with other blood pressure components in the Losartan Intervention For Endpoint reduction in hypertension study, a double-blind, randomized (losartan versus atenolol), parallel-group study, including 9193 patients with hypertension and electrocardiographic left ventricular hypertrophy. In 8810 patients with neither a history of AF nor AF at baseline, Minnesota coding of electrocardiograms confirmed new-onset AF in 353 patients (4.0%) during mean 4.9 years of follow-up. In multivariate Cox regression analyses, baseline and in-treatment PP and baseline and in-treatment systolic blood pressure predicted new-onset AF, independent of baseline age, height, weight, and Framingham Risk Score; sex, race, and treatment allocation; and in-treatment heart rate and Cornell product. PP was the strongest single blood pressure predictor of new-onset AF determined by the decrease in the -2 Log likelihood statistic, in comparison with systolic blood pressure, diastolic blood pressure, and mean arterial pressure. When evaluated in the same model, the predictive effect of systolic and diastolic blood pressures together was similar to that of PP. In this population of patients with hypertension and left ventricular hypertrophy, PP was the strongest single blood pressure predictor of new-onset AF, independent of other risk factors.
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Regression of ECG-LVH is associated with lower risk of new-onset heart failure and mortality in patients with isolated systolic hypertension; The LIFE study.
Am. J. Hypertens.
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Hypertension and electrocardiographic left ventricular hypertrophy (ECG-LVH) are strong predictors of heart failure (HF). It is unclear whether regression of ECG-LVH during treatment predicts less new-onset HF in patients with isolated systolic hypertension (ISH).
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Contrasting hemodynamic mechanisms of losartan- vs. atenolol-based antihypertensive treatment: a LIFE study.
Am. J. Hypertens.
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Pharmaceutical differences in central hemodynamics might influence cardiac response to antihypertensive treatment despite similar lowering of brachial blood pressure (BP).
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Biomechanical measurements of axial crush injury to the distal condyles of human and synthetic femurs.
Proc Inst Mech Eng H
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Few studies have evaluated the bulk mechanical properties of human longbones and even fewer have compared human tissue to the synthetic longbones increasingly being used by researchers. Distal femur fractures, for example, comprise about 6% of all femur fractures, but the mechanical properties of the distal condyles of intact human and synthetic femurs have not been well quantified in the literature. To this end, the distal portions of a series of 16 human fresh-frozen femurs and six synthetic femurs were prepared identically for mechanical testing. Using a flat metal plate, an axial crush force was applied in-line with the long axis of the femurs. The two femur groups were statistically compared and values correlated to age, size, and bone quality. Results yielded the following: crush stiffness (human, 1545 +/- 728 N/mm; synthetic, 3063 +/- 1243 N/mm; p = 0.002); crush strength (human, 10.3 +/- 3.1 kN; synthetic, 12.9 < or = 1.7 kN; p = 0.074); crush displacement (human, 6.1 +/- 1.8 mm; synthetic, 2.8 +/- 0.3 mm; p = 0.000); and crush energy (human, 34.8 +/- 15.9J; synthetic, 18.1 +/- 5.7J; p = 0.023). For the human femurs, there were poor correlations between mechanical properties versus age, size, and bone quality (R2 < or = 0.18), with the exception of crush strength versus bone mineral density (R2 = 0.33) and T-score (R2 = 0.25). Human femurs failed mostly by condyle roll back buckling (15 of 16 cases) and/or unicondylar or bicondylar fracture (7 of 16 cases), while synthetic femurs all failed by wedging apart of the condyles resulting in either fully or partially displaced condylar fractures (6 of 6 cases). These findings have practical implications on the use of a flat plate load applicator to reproduce real-life clinical failure modes of human femurs and the appropriate use of synthetic femurs. To the authors knowledge, this is the first study to have done such an assessment on human and synthetic femurs.
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Losartan versus atenolol-based antihypertensive treatment reduces cardiovascular events especially well in elderly patients: the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study.
J. Hypertens.
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The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study has previously demonstrated a beneficial effect of losartan compared to atenolol-based antihypertensive treatment in patients with essential hypertension and left-ventricular hypertrophy (LVH). However, patient age often influences the choice of antihypertensive drugs. Therefore, we investigated the influence of age on the effects of losartan versus atenolol-based antihypertensive treatment.
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CRP and suPAR are differently related to anthropometry and subclinical organ damage.
Int. J. Cardiol.
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Low-grade inflammation is a marker for cardiovascular disease (CVD). The inflammatory biomarkers C-reactive protein (CRP) and soluble urokinase plasminogen activator receptor (suPAR) independently predict CVD. We tested the hypothesis that these biomarkers reflect different aspects of the inflammation associated with CVD.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.