Energy balance for forced two-dimensional incompressible ideal fluid flow.

Cheskidov et al. (2016 Commun. Math. Phys. 348, 129-143. (doi:10.1007/s00220-016-2730-8)) proved that physically realizable weak solutions of the incompressible two-dimensional Euler equations on a torus conserve kinetic energy. Physically realizable weak solutions are those that can be obtained as limits of vanishing viscosity. The key hypothesis was boundedness of the initial vorticity in [Formula: see text], [Formula: see text]. In this work, we extend their result, by adding forcing to the flow. This article is part of the theme issue 'Scaling the turbulence edifice (part 2)'.

Bending, buckling and torsional resistance of rotary and reciprocating glide path instruments.

AIM: To evaluate the bending, buckling and torsional resistance of ProGlider (PG) (Dentsply Sirona, Ballaigues, Switzerland), R-Pilot (RP) (VDW, Munich, Germany) and WaveOne Gold Glider (WOGG) (Dentsply Sirona). METHODOLOGY: Ninety instruments were used: 30 PG (size 0.16, .02v taper), 30 RP (size 0.125, .04 taper) and 30 WOGG (size 0.15, .02v taper). The bending resistance test was performed on 10 randomly selected instruments of each system according to ISO 3630-1 specifications. For the buckling resistance test, a loading was applied in the axial direction of each instrument using a universal test machine, with a 20 N cell and 15 mm min-1 speed, in the axial direction. When a lateral elastic displacement of 1 mm occurred, the force was registered. The torsional resistance test was performed according to ISO 3630-1 specifications. Statistical analysis was performed using one-way anova and post hoc Student-Newman-Keuls test (P < 0.05). RESULTS: WOGG had the lowest bending resistance, whilst RP had the highest bending resistance (P < 0.05). RP also had the highest buckling resistance, and WOGG had the lowest (P < 0.05). PG had intermediate results regarding bending and buckling resistance, with significant differences to RP and WOGG (P < 0.05). RP had the highest torsional strength and the lowest angular deflection when compared to PG and WOGG (P < 0.05). No differences in the torsional strength and angular deflection were observed between WOGG and PG (P> 0.05). CONCLUSION: The glide path instruments had different behaviours in term of bending, buckling and torsional resistance.

A RAPD-PCR-based genetic diversity analysis of Helicoverpa armigera and H. zea populations in Brazil.

Helicoverpa armigera is the most significant pest of agriculture in Asia, Europe, Africa, and Australasia, causing damage to crops greater than US$2 billion annually and until 2013 it was not detected in Brazil. Helicoverpa zea is restricted to the American continent and is important to corn and a secondary pest of cotton and tomatoes. The wide range of crops exploited by H. armigera (mainly cotton, soybeans, chickpea, and corn), the possible mating between these species can promote population shifts, that could be assessed by RAPD-PCR technique. Therefore, the aim of this study was to determine the genetic diversity of H. armigera and H. zea populations by RAPD-PCR analysis. The most important result was the clustering of one H. armigera population in a group predominantly formed by H. zea. It could indicate a possible occurrence of an interspecific cross between these species. This is a concern to Brazilian agriculture due to the possibility of selection of hybrids well adapted to the American environment, which would be inherited from H. zea. The other noxious fact is the possible development of new biotypes resistant to insectides or Bt toxins expressed in transgenic crops, came from H. armigera gene pool.

Leaching behaviour and ecotoxicity evaluation of chars from the pyrolysis of forestry biomass and polymeric materials.

The main objective of this study was to assess the environmental risk of chars derived from the pyrolysis of mixtures of pine, plastics, and scrap tires, by studying their leaching potential and ecotoxicity. Relationships between chemical composition and ecotoxicity were established to identify contaminants responsible for toxicity. Since metallic contaminants were the focus of the present study, an EDTA washing step was applied to the chars to selectively remove metals that can be responsible for the observed toxicity. The results indicated that the introduction of biomass to the pyrolysis feedstock enhanced the acidity of chars and promote the mobilisation of inorganic compounds. Chars resulting from the pyrolysis of blends of pine and plastics did not produce ecotoxic eluates. A relationship between zinc concentrations in eluates and their ecotoxicity was found for chars obtained from mixtures with tires. A significant reduction in ecotoxicity was found when the chars were treated with EDTA, which was due to a significant reduction in zinc in chars after EDTA washing.

Removal of phosphorus from wastewaters by biomass ashes.

Removal batch assays of phosphates from a synthetic wastewater (SWW) and a pulp and paper mill wastewater (PPWW) with two forestry biomass ashes were performed. The supernatants were not only chemically characterized but also the ecotoxicity was determined using two organisms: Vibrio fischeri and Artemia franciscana. The addition of fly ash and bottom ash to the SWW in solid/liquid (S/L) ratios of 3.35 and 9.05 g L(-1), respectively, achieved removal percentages of phosphates >97% for both ashes. The addition of fly ash and bottom ash to the PPWW in S/L ratios of 34.45 and 46.59 g L(-1), respectively, yield removal percentages of phosphates >90% for both ashes. According to the results of the Langmuir and Freundlich isotherms, the removal of phosphates from the SWW was mainly explained by surface removal mechanisms, while the removal from the PPWW was partially explained by multi-layer mechanisms. The supernatants resulting from the treatment of SWW and PPWW with both biomass ashes did not present acute ecotoxicity.

Customized palatal guide and splint for maxillary expansion.

Customization in orthognathic surgery allows better precision and a reduced surgical time. In Le Fort I osteotomy surgery, the maxillary segmentation is considered one of the most unstable procedures due to transverse instability. Various different types of palatal device have been proposed to address this instability. This note describes a customized bone-borne palatal guide and splint that may help surgeons shorten the surgical time and achieve better three-dimensional repositioning, with more postoperative comfort for the patient and occlusal control for the surgeon.

Production of thermoplastic starch and poly (butylene adipate-co-terephthalate) films assisted by solid-state shear pulverization.

A novel processing technique involving Solid-State Shear Pulverization (SSSP) was used to produce thermoplastic starch (TPS) and Poly (Butylene Adipate-co-Terephthalate) (PBAT) films to improve processability and produce well-dispersed blends. Four different compositions (50-80 wt% TPS content) were processed using two different production routes. In one instance, the compositions were pre-treated by SSSP before melt extrusion (SSSPE). Secondly, starch was initially plasticized and thereafter blended with PBAT by melt extrusion (EXT) method. Flat films were produced using both routes and processability, visual and tactical aspects, mechanical and optical properties, crystallinity, and water absorption behavior were evaluated. High starch content films (70 and 80 wt%) prepared based on SSSP incorporation showed easier processability, and better visual aspect and mechanical integrity than EXT ones. However, EXT films with 50 and 60 wt% of starch presented higher elongation at break and lower water absorption due to finer dispersion of TPS and better starch plasticization.

Estimating the prevalence of inflammatory bowel disease in Portugal using a pharmaco-epidemiological approach.

PURPOSE: To estimate inflammatory bowel disease (IBD) prevalence in Portugal from 2003 to 2007, and to obtain disease, sex and age specific estimates. METHODS: A pharmaco-epidemiological approach based on intestinal anti-inflammatory (IAI) drugs consumption was used. Proportion of patients taking IAI drugs and mean prescribed daily dose (PDD) were estimated from a sample of 513 IBD patients. Assumptions were made about unknown parameters and sensitivity analysis performed: drug compliance (80% in base case; range 70-85%) and proportion of sulphasalazine used in IBD (52%; range 40-80%). Sex and age specific estimates were based on a proposed methodological extension and results from a nationwide (n = 5893) cross-sectional study. RESULTS: IBD prevalence increased from 86 patients per 100 000 in 2003 to 146 in 2007. Regions more affected were Lisboa and Porto (173 and 163 per 100 000 in 2007, respectively). Prevalence increased from 42 and 43 per 100 000 in 2003 to 71 and 73 in 2007, respectively for ulcerative colitis (UC) and Crohn's disease (CD). In 2007, prevalence was higher in the 40-64 age stratum for UC (99 per 100 000) and in the 17-39 stratum for CD (121). Prevalence was consistently higher in females. CONCLUSIONS: Portugal is half way between countries with the highest and lowest IBD prevalence, but is steeply making the road to the highest-level group. Despite limitations of the proposed methods, assumptions were reasonable and estimates seem to be valid. Feasibility and comparability of this methodology makes it an interesting tool for future studies on IBD epidemiology.

Extended cyclic fatigue life of F2 ProTaper instruments used in reciprocating movement.

AIM: To evaluate the cyclic fatigue fracture resistance of engine-driven F2 ProTaper instruments under reciprocating movement. METHODOLOGY: A sample of 30 NiTi ProTaper F2 instruments was used. An artificial canal was made from a stainless steel tube, allowing the instruments to rotate freely. During mechanical testing, different movement kinematics and speeds were used, which resulted in three experimental groups (n = 10). The instruments from the first group (G1) were rotated at a nominal speed of 250 rpm until fracture, whilst the instruments from the second group (G2) were rotated at 400 rpm. In the third instrument group (G3), the files were driven under reciprocating movement. The time of fracture for each instrument was measured, and statistical analysis was performed using parametric methods. RESULTS: Reciprocating movement resulted in a significantly longer cyclic fatigue life (P < 0.05). Moreover, operating rpm was a significant factor affecting cyclic fatigue life (P < 0.05); instruments used at a rotational speed of 400 rpm (approximately 95 s) failed more rapidly than those used at 250 rpm (approximately 25 s). CONCLUSIONS: Movement kinematics is amongst the factors determining the resistance of rotary NiTi instruments to cyclic fracture. Moreover, the reciprocating movement promoted an extended cyclic fatigue life of the F2 ProTaper instrument in comparison with conventional rotation.

Mechanical behavior of ropes based on polypropylene (PP) and poly(ethylene terephthalate) (PET) multifilament yarns for Achilles tendon partial substitution.

In some clinical cases, attending to the type and extension of the Achilles tendon injury, a partial replacement of the tissue may be needed. Driven by this, the authors developed different structures based on polypropylene (PP) or poly (ethylene terephthalate) (PET) multifilament yarns, using a textile technology-based technique, in order to mimic the fibrous structure of tendons. Those structures are based on a core/shell system, being the core composed by several sub-components (braids) and the shell based on braided yarns enclosing the core. It was observed that the load at failure of ropes is mainly defined by the number of yarns that compose it, but the strain level is mostly influenced by the production take-up rate of the core braids and consequently by the braid angle. The ropes stiffness level results from a combination of the yarns number and braid angle of the core braids. The structure based on PET yarns revealed a non-linear force-strain curve similar to a typical curve of a natural Achilles tendon (AT), presenting a load at failure, strain to failure and stiffness levels very promising for AT replacement. Moreover, the PET rope also revealed a very promising fatigue and appropriate creep resistance for the final application, being in accordance with what has been reported for native AT.

Inflammatory bowel disease: a patient's and caregiver's perspective.

The purpose of this study was to conduct a survey examining the impact of inflammatory bowel disease (IBD) on patients' and their caregivers' daily activities. Questionnaires were distributed to patients registered in the APDI (Portuguese Association for IBD) database and their respective caregivers in 2007. Of 422 patient respondents, 251 had Crohn's disease (CD) and 171 had ulcerative colitis (UC), with the majority of patients being women (58.1%) and aged over 40 years (37.4%). The number of disease flares experienced by IBD patients was slightly higher for patients with CD than for patients with UC (2.64 vs. 2.34), and surgery was more often required in CD patients as compared to UC patients (42.4 vs. 7%). Sixty percent (60%) of patients reported having no problems with mobility, daily activities, or personal hygiene; however, over half of all patients experienced some pain and anxiety. Adult patients and children and adolescents respectively experienced time off work or school due to their disease but caregivers were not affected in this regard. The caregivers life (N=324) was affected by anxiety, with the major concern reported as the risk of the patient developing cancer. Both IBD patients and caregivers thought that the provision of information on new drugs and contact time with a doctor would have the biggest impact on improving care. The symptoms and complications of IBD have a considerable impact on the lives of patients and their caregivers, and several actions could be taken to improve their care.

Spatial Accessibility and Social Inclusion: The Impact of Portugal's Last Health Reform.

Health policies seek to promote access to health care and should provide appropriate geographical accessibility to each demographical functional group. The dispersal demand of health-care services and the provision for such services at fixed locations contribute to the growth of inequality in their access. Therefore, the optimal distribution of health facilities over the space/area can lead to accessibility improvements and to the mitigation of the social exclusion of the groups considered most vulnerable. Requiring for such, the use of planning practices joined with accessibility measures. However, the capacities of Geographic Information Systems in determining and evaluating spatial accessibility in health system planning have not yet been fully exploited. This paper focuses on health-care services planning based on accessibility measures grounded on the network analysis. The case study hinges on mainland Portugal. Different scenarios were developed to measure and compare impact on the population's accessibility. It distinguishes itself from other studies of accessibility measures by integrating network data in a spatial accessibility measure: the enhanced two-step floating catchment area. The convenient location for health-care facilities can increase the accessibility standards of the population and consequently reduce the economic and social costs incurred. Recently, the Portuguese government implemented a reform that aimed to improve, namely, the access and equity in meeting with the most urgent patients. It envisaged, in terms of equity, the allocation of 89 emergency network points that ensured more than 90% of the population be within 30 min from any one point in the network. Consequently, several emergency services were closed, namely, in rural areas. This reform highlighted the need to improve the quality of the emergency care, accessibility to each care facility, and equity in their access. Hence, accessibility measures become an efficient decision-making tool, despite its absence in effective practice planning. According to an application of this type of measure, it was possible to verify which levels of accessibility were decreased, including the most disadvantaged people, with a larger time of dislocation of 12 min between 2001 and 2011.

Adding value to gasification and co-pyrolysis chars as removal agents of Cr3.

The present work aims to assess the efficiency of chars, obtained from the gasification and co-pyrolysis of rice wastes, as adsorbents of Cr3+ from aqueous solution. GC and PC chars, produced in the gasification and co-pyrolysis, respectively, of rice husk and polyethylene were studied. Cr3+ removal assays were optimised for the initial pH value, adsorbent mass, contact time and Cr3+ initial concentration. GC showed a better performance than PC with about 100% Cr3+ removal, due to the pH increase that caused Cr precipitation. Under pH conditions in which the adsorption prevailed (pH<5.5), GC presented the highest uptake capacity (21.1mg Cr3+ g-1 char) for the following initial conditions: 50mg Cr3+ L-1; pH 5; contact time: 24h;L/S ratio: 1000mLg-1. The pseudo-second order kinetic model showed the best adjustment to GC experimental data. Both the first and second order kinetic models fitted well to PC experimental data. The ion exchange was the dominant phenomenon on the Cr3+ adsorption by GC sample. Also, this char significantly reduced the ecotoxicity of Cr3+ solutions for the bacterium Vibrio fischeri. GC char proved to be an efficient material to remove Cr3+ from aqueous solution, without the need for further activation.

Dysregulation of peripheral and central chemoreflex responses in Chagas' heart disease patients without heart failure.

BACKGROUND: The peripheral and central chemoreflexes are important autonomic mechanisms for regulating breathing and cardiovascular function. Although pathological inflammatory infiltration of the peripheral chemoreceptors and central nervous system has been reported in Chagas' disease, functional evaluation of chemoreflexes has not yet been performed. METHODS AND RESULTS: The hypothesis that chemoreflex function is altered in patients with Chagas' heart disease (CH) but normal left ventricle function was tested in 12 CH patients and 13 matched control subjects. The ventilatory rate, minute ventilation, heart rate, mean arterial pressure, forearm blood flow, forearm vascular resistance, and venous norepi-nephrine responses to hypoxia and hypercapnia were determined. During hypoxia, the decrease in oxygen saturation was smaller in CH patients, despite a similar ventilatory response between groups. Both groups showed an increase in heart rate during hypoxia, but this response was blunted in CH patients. Although the mean arterial pressure response to hypoxia was similar in both groups, forearm vascular resistance significantly decreased in control subjects while remaining unchanged in CH patients. Moreover, a significant increase in plasma norepinephrine levels elicited by stimulation of peripheral chemoreceptors was observed only in the CH group. During hypercapnia, the increase in minute ventilation was smaller in CH patients, who did not exhibit the increase in norepinephrine observed in control subjects. CONCLUSIONS: These data suggest that CH potentiates respiratory, cardiovascular, and autonomic responses to peripheral chemoreceptor activation by hypoxia in patients with normal left ventricular function. The ventilatory and sympathetic responses to central chemoreceptor activation by hypercapnia, however, are significantly blunted.

Blood pressure influences the occurrence of complex ventricular arrhythmia in hemodialysis patients.

We investigated the relationship between blood pressure and the occurrence of complex ventricular arrhythmias (multiform, couplets, or runs) as assessed by 48-hour Holter monitoring in 74 stable long-term hemodialysis patients (44.5 +/- 12 years old; 54% men; 74% whites; dialysis duration, 51.3 +/- 36.1 months; systolic pressure, 146.6 +/- 19.3 mm Hg; diastolic pressure, 89.2 +/- 12.1 mm Hg; prevalence of arterial hypertension, 33.8%). Systolic and diastolic pressures represented the average of all predialysis determinations during the 3 months preceding the tests. Hemodialysis was performed midway through the Holter monitoring period. M-mode and bidimensional echocardiograms and myocardial perfusion tests were also obtained from all patients. Complex arrhythmias were observed in 37 individuals (50%). Univariate analysis showed that systolic pressure (P < .001), diastolic pressure (P < .05), age (P < .001), left ventricular posterior wall thickness (P < .01), left ventricular mass index (P < .05), and ischemic alterations on myocardial perfusion tests (P < .005) were significantly associated with complex arrhythmias. With the use of a multivariate model (stepwise logistic regression analysis) only systolic pressure (P < .01) and age (P < .05) were independently associated with complex arrhythmias. Sex; angina; dialysis duration; New York Heart Association functional class; use of digitalis; plasma levels of creatinine, sodium, potassium, calcium, and phosphate; hematocrit; left ventricular fractional shortening; left ventricular diastolic diameter; and ST segment deviation were not correlated with complex arrhythmias. The severity and frequency of complex arrhythmias were not influenced by hemodialysis. At follow-up (5 to 80 months) 5 patients had died of sudden death, 4 of whom were hypertensive and older than 45 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipid metabolism alterations in normotensive subjects with positive family history of hypertension.

Metabolic abnormalities are usually reported in hypertensive patients. These metabolic alterations seem to begin in childhood. The young offspring of hypertensive parents have not been studied thoroughly for metabolic alterations. The aim of this study was to examine the level of total cholesterol, LDL cholesterol, VLDL cholesterol, HDL cholesterol, uric acid, glycemia, aldosterone, and plasma renin activity in a population of 42 young, slender normotensive subjects with positive family history of hypertension (FH+) or negative family history of hypertension (FH-). Measurements were made in 20 young normotensive subjects (age 21.1+/-2.2 years, 11 males, 15 white, 5 oriental, body mass index of 22.1+/-2.3 kg/m2) with FH+ and 22 young normotensive subjects (age 19.9+/-1.4 years, 17 males, 17 white, 5 oriental, body mass index of 22.1+/-2.3 kg/m2) with FH-. The total cholesterol (4.47+/-0.8 versus 3.95+/-0.6 mmol/L), LDL cholesterol (2.74+/-0.63 versus 2.36+/-0.61 mmol/L), VLDL cholesterol (0.5+/-0.25 versus 0.35+/-0.09 mmol/L), and triglycerides (2.52+/-1.26 versus 1.76+/-0.5 mmol/L) were significantly elevated (P<.05) in the FH+ group compared with the FH- group. The total cholesterol/HDL cholesterol ratio was significantly higher in the group with a positive family history of hypertension (3.75+/-0.02 versus 3.11+/-0.02, P<.05). Glycemia was slightly elevated in the FH+ group (2.16+/-0.29 mmol/L) but was not significantly different from that of the FH- group (2+/-0.2 mmol/L). Uric acid, plasma renin activity, and aldosterone were similar in both groups. We conclude that young, slender normotensive subjects with a positive history of hypertension show alterations in lipid metabolism, suggesting a positive correlation between lipid metabolism and hypertension heredity.

Lack of effect of a single oral dose of cyclosporine on systemic blood pressure and on forearm blood flow and vascular resistance in humans.

The acute hemodynamic effect of cyclosporine in man is controversial. A randomized, double blind, placebo-controlled, cross-over study was undertaken to evaluate the effect of a single oral dose of cyclosporine (20 mg/kg body weight) on mean blood pressure (MBP), heart rate (HR), forearm blood flow (FBF), and vascular resistance (FVR) in 16 healthy adult subjects. Subjects were studied twice, with an intervening period of 2 weeks, before and after the administration of either cyclosporine or the vehicle olive oil. Blood pressure was measured on brachial and digital arteries. After 30 min of rest, basal measurements were obtained and individuals were randomly assigned to receive either cyclosporine or the vehicle, and the same measurements were repeated 2 h later. Mean whole blood levels of cyclosporine were 1542+/-387 ng/mL (range 1000 to 2550) 2 h after the administration of a single oral dose of cyclosporine. Cyclosporine did not cause any significant change in the hemodynamic parameters when compared with vehicle. Pre- and post-cyclosporine data were as follows (means +/-/SD): MBP (determined by Finapres on the digital artery), 92+/-10 v 95+/-11 mm Hg; HR, 66+/-10 v 68+/-11 beats/min; FBF, 3.90+/-1.3 v 3.8+/-1.8 mL/ 100 mL/min; and FVR, 28+/-9 v 33 +/-18 units, respectively. For the vehicle the results were: MBP, 94+/-9 v 94+/-9; HR, 67+/-9v 67 /-11; FBF, 3.3+/-1.6 v 3.2+/-2.0; FVR, 35+/-14 v 37+/-15, respectively. These figures did not differ from those obtained with the auscultatory method applied to the brachial artery among 10 selected subjects studied with Finapres. In conclusion, we found no evidence that at supratherapeutic doses cyclosporine causes acute increase in blood pressure or peripheral vasoconstriction in humans.

The pressor response to acute hyperlipidemia is enhanced in lean normotensive offspring of hypertensive parents.

Family history is an important predictor of the cardiovascular risk factor cluster associated with insulin resistance. The dyslipidemia associated with insulin resistance may contribute to elevated blood pressure (BP). This study was undertaken to further explore the link between family history, dyslipidemia, and BP regulation. Twenty-three lean normal volunteers with a negative family history (FH-, n = 11) or positive family history (FH+, n = 12) of hypertension were evaluated under baseline conditions and during a 4-h infusion of intralipid and heparin (acute hyperlipidemia). Fasting blood was drawn for lipids including nonesterified fatty acids (NEFA). After 2 and 4 h of intralipid and heparin, blood was drawn for NEFA. The BP was measured at baseline and every 30 min after starting the intralipid and heparin infusion. Baseline triglycerides and very low density lipoprotein cholesterol concentrations were higher in FH+ than FH- subjects (P < .05). However, NEFA increased similarly in both groups during the infusion of intralipid and heparin. The BP and heart rate increased with acute hyperlipidemia in all subjects combined (P < .05). Despite the similar increase of NEFA, mean BP, pulse pressure, and pressure-rate product increased significantly in FH+ subjects but not in FH- volunteers with acute hyperlipidemia. Although systolic BP increased in both groups, the increase was greater in FH+ than in FH- volunteers during acute hyperlipidemia (14 +/- 2 v 10 +/- 2 mm Hg, P < .05). These results suggest that higher plasma lipids combined with a greater pressor response to hyperlipidemia may contribute to the development of high BP in subjects with a family history of hypertension.

Blood pressure and the risk of complex arrhythmia in renal insufficiency, hemodialysis, and renal transplant patients.

Complex arrhythmia is frequent in hemodialysis patients but it is not clear if this is a consequence of dialysis or uremia or is secondary to the hemodynamic and cardiovascular alterations often associated with chronic renal failure. The incidence of complex ventricular arrhythmia (frequent multiform premature beats, couplets, and runs) in 31 subjects who had their uremic status recently corrected by renal transplant (Group 1) and in 23 predialysis (Group 2) and 73 hemodialysis (Group 3) chronic renal failure patients were studied with 24-h Holter monitoring. Patients were not receiving antiarrhythmic drugs or digitalis and significant coronary artery disease was excluded by clinical and noninvasive methods. Complex arrhythmia was two times more frequent in dialysis patients but the difference did not reach statistical significance (Group 1: 16%; Group 2: 17%; Group 3: 34%; chi2 4.9, P = .086). The stepwise model of logistic regression analysis identified systolic blood pressure (odds ratio 1.015, 95% confidence interval [CI] 1.001-1.027, P = .03) and left ventricular systolic dysfunction (odds ratio 7.04, 95% CI 1.3-36.7, P = .02) as the only factors that independently influenced the probability of complex arrhythmia. Age, gender, race, diabetes, smoking status, body mass index, diastolic blood pressure, serum creatinine, hematocrit, left ventricular mass index, and use of diuretics, beta-blockers, angiotensin converting enzyme (ACE) inhibitors, sympatolytics, and calcium channel blockers did not influence the occurrence of complex arrhythmia. The data indicate that blood pressure and myocardial dysfunction are more important determinants of complex arrhythmia than dialysis or uremia in chronic renal disease patients.