The implementation of a hepatitis C testing service in community pharmacies: I-COPTIC consensus statement.

OBJECTIVES: This aimed to develop a blueprint for an effective community pharmacy Hepatitis C virus (HCV) testing service by producing a consensus statement. STUDY DESIGN: This was a modified Delphi process. METHODS: We recruited a heterogenous panel of experts (who had been involved in the setup or delivery of a community pharmacy HCV testing service) by purposive and chain referral methods. We had three rounds of a modified Delphi process. The first was a series of questions with free text responses and was analysed using thematic analysis, and the second and third were statements for the respondents to rate using a 7-point Likert scale. Consensus was predefined in a published protocol, and the results were reviewed by a public and patient involvement panel before the statement was finalised. RESULTS: We had 24 participants, including community and hospital-based pharmacists, local pharmaceutical committee members, charity representatives (Hepatitis C Trust), local clinical service lead, nurse specialists and doctors. The response rate of the first, second and third rounds were 100%, 96% and 88%, respectively. After the third round, we had 60 statements that reached consensus. We discussed the accepted statements with a patient and public involvement group. We used these statements to produce the I-COPTIC statement and a graphical summary. CONCLUSIONS: We developed a blueprint for the design of a gold standard community pharmacy HCV testing service. We believe this will support the successful implementation of community pharmacy testing for HCV. Community pharmacy testing is an important service to help achieve and maintain HCV elimination.

Antimicrobial activity and biologic potential of silver-substituted calcium phosphate constructs produced with self-propagating high-temperature synthesis.

There is significant demand for synthetic bone substitute materials that can decrease the incidence of implant-based bacterial infections. The intent of this research was to evaluate the antimicrobial activity and biologic potential of calcium phosphate (CaP) constructs substituted with silver (Ag) that were produced via self-propagating high-temperature synthesis (SHS). SHS is a combustion synthesis technique that has successfully generated porous CaP bioceramics intended for use in bone repair. SHS reactions are highly versatile; dopants can be added to the reactant powders to alter product chemistry and morphology. In this research, Ag powder was added to the reactants generating porous CaP constructs containing 0.5, 1, or 2 wt% Ag. Antibacterial performance of the constructs was assessed against Escherichia coli, a representative model for Gram-negative bacteria. Liquid solutions (1 µg/mL) of CaP-Ag particles to phosphate buffered saline were incubated with 10(5) cells/mL. After 24 h, 10 µL of solution were spread on an LB agar plate and cultured for 24 h at 37 °C. Samples cultured with CaP-Ag showed complete bacterial inhibition while the controls (E. coli only and CaP without Ag) exhibited significant colony formation. The effects of Ag concentration on cytotoxicity and biocompatibility were tested in vitro. At 7 days, osteoblasts uniformly enveloped the CaP-Ag particles and displayed a healthy flattened morphology suggesting the concentrations of Ag incorporated into constructs were not cytotoxic. CaP-Ag constructs produced via SHS represent a source of synthetic bone substitute materials that could potentially inhibit, or reduce the incidence of post-operative bacterial infections.

Depression of action potential characteristics and a decreased space constant are present in postischemic, reperfused myocardium.

Brief periods of ischemia and reperfusion may lead to arrhythmias and delayed epicardial activation. To determine the nature of the electrophysiologic substrate and to gain insight into potential mechanisms underlying the electrophysiologic and hemodynamic abnormalities that develop in this setting, standard microelectrode techniques were used to measure action potential characteristics, conduction velocity, and space constants in canine isolated epicardial preparations removed after a 15-min anterior descending artery occlusion and 20-min reflow period in vivo. Our results demonstrate a significant reduction in conduction velocity (0.78 +/- 0.38 vs. 0.31 +/- 0.12 m/s, P less than 0.001), space constant (1.05 +/- 0.42 vs. 0.45 +/- 0.12 mm, P = 0.004), resting membrane potential (81.3 +/- 2.5 vs. 61.7 +/- 7.8 mV, P less than 0.001), action potential amplitude (94.1 +/- 4.2 vs. 64.1 +/- 1.5 mV, P less than 0.001), and dV/dT (164.7 +/- 37.3 vs. 52.6 +/- 19.7 V/s, P less than 0.001) in postischemic reperfused myocardium. The space constant and dV/dT each correlated with conduction velocity; in addition, the space constant was an independent predictor of conduction velocity in these tissues. These electrophysiologic abnormalities may play a role in the arrhythmias and abnormalities of contraction present in postischemic, reperfused myocardium.

Microbialite response to an anthropogenic salinity gradient in Great Salt Lake, Utah.

A railroad causeway across Great Salt Lake, Utah (GSL), has restricted water flow since its construction in 1959, resulting in a more saline North Arm (NA; 24%-31% salinity) and a less saline South Arm (SA; 11%-14% salinity). Here, we characterized microbial carbonates collected from the SA and the NA to evaluate the effect of increased salinity on community composition and abundance and to determine whether the communities present in the NA are still actively precipitating carbonate or if they are remnant features from prior to causeway construction. SSU rRNA gene abundances associated with the NA microbialite were three orders of magnitude lower than those associated with the SA microbialite, indicating that the latter community is more productive. SSU rRNA gene sequencing and functional gene microarray analyses indicated that SA and NA microbialite communities are distinct. In particular, abundant sequences affiliated with photoautotrophic taxa including cyanobacteria and diatoms that may drive carbonate precipitation and thus still actively form microbialites were identified in the SA microbialite; sequences affiliated with photoautotrophic taxa were in low abundance in the NA microbialite. SA and NA microbialites comprise smooth prismatic aragonite crystals. However, the SA microbialite also contained micritic aragonite, which can be formed as a result of biological activity. Collectively, these observations suggest that NA microbialites are likely to be remnant features from prior to causeway construction and indicate a strong decrease in the ability of NA microbialite communities to actively precipitate carbonate minerals. Moreover, the results suggest a role for cyanobacteria and diatoms in carbonate precipitation and microbialite formation in the SA of GSL.

The monitoring of activity at home after total hip arthroplasty.

AIMS: Total hip arthroplasty (THA) has well known subjective benefits, but little is known objectively about the recovery of mobility in the early post-operative period. PATIENTS AND METHODS: A total of 33 patients aged > 60 years who underwent elective primary THA had their activity monitored for 30 days post-operatively using an at-home (Fitbit) ankle accelerometer. Their mean age was 70.7 years (61 to 86); 15 (45.5%) were female. The rate of compliance and the mean level of activity were determined. Comparisons between subgroups based on age, body mass index (BMI), surgical approach, and the destination of the patients when discharged were also performed. RESULTS: The mean compliance over the 30 days was 26.7 days (16 to 30; 89%) of use. The mean number of steps increased from 235 (5 to 1152) to 2563 (87 to 7280) (p < 0.001) between the first and the 30th post-operative day. Age < 70 years and an anterior surgical approach were significantly associated with higher levels of activity (1600 to 2400 (p = 0.016 to 0.031) and 1000 to 1800 (p = 0.017 to 0.037) more steps per day, respectively) between the second and the fourth week post-operatively. There was also a trend towards higher levels of activity in those who were discharged to their home rather than to a nursing facility (a mean of 1500 more steps per day, p = 0.02). BMI greater or less than 30 kg/m2 was not predictive of activity (p = 0.45 to 0.98). CONCLUSION: At-home remote mobility monitoring using existing commercially available technology is feasible in patients who have undergone THA. It showed a clear trend towards increased activity with the passage of time. Additionally, the remote device was able to detect differences in levels of activity clearly between patients in relation to variables of interest including age, BMI, surgical approach, and the destination of the patient at the time of discharge from hospital. Such monitoring may allow for the early identification and targeted intervention in patients who recover slowly. Cite this article: Bone Joint J 2016;98-B:1450-4.

Cellular electrophysiologic characteristics of chronically infarcted myocardium in dogs susceptible to sustained ventricular tachyarrhythmias.

Standard microelectrode techniques were used to record transmembrane potentials and determine conduction characteristics in regions of mottled infarcts of canine epicardium, 3 to 5 days or 8 to 15 days after left anterior descending coronary artery occlusion and reperfusion. At 3 to 5 days, resting potential, action potential amplitude, maximal rate of depolarization and action potential duration at 30% repolarization were significantly reduced in the infarcted region. Cells on the epicardial surface showed improvement in resting potential, action potential amplitude and rate of depolarization between 3 to 5 days and 8 to 15 days after infarction. In normal noninfarcted tissues, conduction velocity parallel to fiber orientation was 0.54 +/- 0.06 m/s (mean +/- standard deviation). Slow conduction in infarcted regions ranged from 0.015 to 0.2 m/s. Action potentials recorded from slowly conducting regions tended to include cells with more depressed amplitude and rate of depolarization than other cells in infarcted regions; they also had inappropriately depressed overshoot relative to their resting potential. Action potentials in slowly conducting areas where local conduction block occurred were associated with prepotentials and notches on their depolarization and repolarization phases. The prepotentials and notches appeared to be caused by electrotonic interactions resulting from microcircuitous conduction around or across inexcitable areas. These findings demonstrate that areas of slow conduction are heterogenously distributed in the mottled infarct and suggest that disruptions in cell to cell electrical continuity and decreased excitability may contribute to this slow conduction.

Differential effects of procainamide, lidocaine and acetylstrophanthidin on body surface potentials and epicardial conduction in dogs with chronic myocardial infarction.

Twenty-eight anesthetized mongrel dogs were studied 2 to 74 months after experimental myocardial infarction in order to examine the effects of procainamide, lidocaine and acetylstrophanthidin on conduction within the infarcted region and the way such effects relate to changes in body surface potentials and antiarrhythmic efficacy. In each animal, 100 to 200 QRS complexes in the X, Y, Z leads were signal averaged, vector summed and high pass filtered at 50 Hz. Susceptibility to ventricular arrhythmia was evaluated using routine programmed ventricular extrastimulation in the anesthetized open chest animal. Epicardial electrograms were sequentially recorded at 45 standard sites within the infarcted region and referenced to the beginning of the QRS complex. Of the three agents, only procainamide exhibited antiarrhythmic action whereas lidocaine and acetylstrophanthidin produced inconsistent effects. Procainamide prolonged the time at which activity in the epicardial electrographic recordings ended relative to the beginning of the body surface QRS complex. This effect was significantly greater in electrograms that ended late in the QRS complex in the control state than for those that ended earlier. Such preferential effect on more abnormal sites was reflected on the body surface as a greater effect of procainamide in prolonging the lower energy terminal portion of the signal-averaged QRS complex than the earlier high energy portion. In contrast, lidocaine significantly prolonged the time at which electrograms ended only for those relatively normal electrograms that ended early in the QRS complex in the control state. In the signal-averaged body surface QRS complex, lidocaine produced a small but significant prolongation of the early high energy portion of the QRS complex but no change in the late portion. Acetylstrophanthidin produced a significant prolongation in early-ending electrograms and, surprisingly, significantly shortened the end time of electrograms that ended late in the QRS complex in the control state. Such effects were not reflected, however, on the body surface because acetylstrophanthidin had no significant effect on either the early or the late portion of the QRS complex. It is concluded that procainamide's differential effect between early- and late-ending electrograms is detected on the body surface by a greater prolongation in the terminal portion of the QRS complex. The signal-averaged body surface QRS complex is less sensitive in detecting the more subtle effects on conduction caused by lidocaine and acetylstrophanthidin.(ABSTRACT TRUNCATED AT 400 WORDS)

Erythema nodosum associated with acute cytomegalovirus mononucleosis in an adult.

Acute cytomegalovirus mononucleosis has been associated with maculopapular rashes, petechiae, purpura, urticaria, ulcerative lesions, and vesicular eruptions. Although erythema nodosum has been reported in association with a number of infectious and noninfectious diseases, to our knowledge it has not been associated with cytomegalovirus infections. We report the first case of an adult patient with acute cytomegalovirus mononucleosis who presented with erythema nodosum.

Identification of conduction block in cardiac muscle: in vitro observations in canine epicardium.

OBJECTIVE: The aim was to examine the ability of several previously proposed criteria and of "vector mapping" to distinguish slow conduction from conduction block in canine myocardium. METHODS: Two different in vitro preparations of canine epicardium were used. In 10 tissues, an anatomical barrier was simulated by a cut (five longitudinal and five transverse to fibre orientation). Eleven tissues removed two weeks after occlusion-reperfusion infarction were also studied. Isochronal activation maps were constructed from extracellular and intracellular recordings and vector loops formed by summing two orthogonally recorded bipolar electrograms were used to indicate the direction of cardiac activation. RESULTS: In the cut model, electrograms recorded from over the anatomical barrier were usually normal or showed double potentials but could occasionally be fractionated. Isochronal activation maps obtained from extracellular recordings were able to identify five of five anatomical barriers transverse to, but only one of five barriers longitudinal to, fibre orientation. The direction of cardiac activation indicated by vector loops identified conduction block in all 10 preparations. In 11 tissues removed from canine ventricles with experimental myocardial infarction, microelectrode recordings were used to characterise regions as either slow conduction or conduction block. Isochronal activation patterns obtained from extracellular recordings generally showed impulses proceeding through zones of conduction and around zones of conduction block but disagreed with the results of microelectrode impalements in two of 11 cases. Electrogram morphology was also not always able to distinguish slow conduction from block. The direction of cardiac activation determined by vector mapping accurately characterised all regions of tissue as showing either slow conduction or conduction block. CONCLUSIONS: Limited regions of conduction block or slow conduction are frequently present in epicardial tissues removed from experimental myocardial infarction. The morphology of extracellular electrograms and isochronal activation mapping performed from extracellular recordings is often but not always able to distinguish slow conduction from conduction block. Vector mapping is useful in distinguishing slow conduction from conduction block in these situations and may help evaluate myocardial conduction patterns.

Predictors of outcome in AIDS patients receiving zidovudine.

Fifty-eight AIDS patients who previously had Pneumocystis carinii pneumonia (PCP) were enrolled in an open trial of zidovudine therapy. We analyzed baseline clinical and laboratory parameters to identify predictors of outcome. Fifty-eight patients were followed for a mean of 26.5 weeks. There were 17 deaths; the probability of survival at 24 weeks was 0.81. Forty-one participants had unsuccessful outcomes, which included new opportunistic infections (24), progressive neurologic deterioration (2), and drug toxicity, excluding anemia, necessitating discontinuation of zidovudine (15). Only 24 subjects (41%) were receiving zidovudine at the end of the study period including 17 who had neither opportunistic infection nor toxicity. Low baseline hemoglobin level (p less than 0.001) and poor performance status as measured by the Karnofsky scale (p less than 0.01) independently predicted unsuccessful outcome and early death. Low hemoglobin (p = 0.001), low platelet count (p = 0.016), and increased time since PCP (p = 0.008) predicted development of drug toxicity. Neither CD4 lymphocyte count nor p24 antigenemia correlated with outcome.

Randomized study of intravenous/oral ciprofloxacin versus ceftazidime in the treatment of hospital and nursing home patients with lower respiratory tract infections.

This study determined the efficacy of intravenous ciprofloxacin in the treatment of institutionalized patients with lower respiratory tract infections. Hospitalized adults with hospital/nursing home-acquired pneumonia were randomly assigned to receive either intravenous ciprofloxacin or ceftazidime. When deemed feasible, therapy was changed to oral ciprofloxacin for patients who received ciprofloxacin intravenously or to any alternative oral therapy for patients who received ceftazidime. All 23 patients who received ciprofloxacin had a favorable response versus 15 of 21 patients who received ceftazidime (p less than 0.025). One patient with a favorable response to ceftazidime developed a superinfection and one patient had a relapse during subsequent alternative oral therapy. However, patients who received ceftazidime were more severely ill than those who received ciprofloxacin on the basis of APACHE II scores.

Effects of aminophylline on the threshold for initiating ventricular fibrillation during respiratory failure.

Cardiac arrhythmias have frequently been reported in association with respiratory failure. The possible additive role of pharmacologic agents in precipitating cardiac disturbances in patients with respiratory failure has only recently been emphasized. The effects of aminophylline on the ventricular fibrillation threshold during normal acid-base conditions and during respiratory failure were studied in anesthetized open chest dogs. The ventricular fibrillation threshold was measured by passing a gated train of 12 constant current pulses through the ventricular myocardium during the vulnerable period of the cardiac cycle. During the infusion of aminophylline, the ventricular fibrillation threshold was reduced by 30 to 40 percent of the control when pH and partial pressures of oxygen (PO2) and carbon dioxide (CO2) were kept within normal limits. When respiratory failure was produced by hypoventilation (pH 7.05 to 7.25; PC02 70 to 100 mm Hg: P02 20 to 40 mm Hg), infusion of aminophylline resulted in an even greater decrease in ventricular fibrillation threshold to 60 percent of the control level. These experiments suggest that although many factors may contribute to the increased incidence of ventricular arrhythmias in respiratory failure, pharmacologic agents, particularly aminophylline, may play a significant role.

Relation of the endocardial and epicardial ventricular fibrillation thresholds of the right and left ventricle.

Ventricular fibrillation thresholds were measured on the endocardium and epicardium of the right or left ventricle, or both, in 13 dogs. The electrodes, introduced through a right or left atriotomy to avoid injury to the ventricles, were aligned opposite and parallel to each other on the endocardium and epicardium. The ventricular fibrillation threshold was measured during atrial pacing by delivering a train of impulses to the ventricle during the vulnerable period after every 12th paced complex in 1 milliampere (mA) increments of current until fibrillation ensued. The mean (+/- standard deviation) right ventricular epicardial and endocardial fibrillation thresholds were 18.3 +/- 5.3 and 17.6 +/- 5.3 mA, respectively, (values not significantly different). However, the fibrillation threshold of 36.1 +/- 9.5 mA in the left ventricular epicardium was significantly higher than the value of 20.7 +/- 9.4 mA on the left ventricular endocardium. These data suggest that the proximity of the fibrillating electrodes and Purkinje network may be a factor in the measurement of ventricular vulnerability.

Electrophysiologic studies on atrioventricular nodal Wenckebach cycles.

Wenckebach cycles with a 4:3 ratio, produced by rapid atrial pacing, were studied in 27 anesthetized denervated dogs using programmed stimulation. A test stimulus (S') could be inserted after any preselected beat of the Wenckebach cycle. An on-line computer measured the atrial (A) to His bundle (H) intervals. In all dogs a progressive increase in atrioventricular (A-V) nodal refractoriness was seen in the effective refractory period for each beat and a rightward shift of the A'-H' relative to the A-A' refractory curves. Atypical Wenckebach cycles could be produced by small changes in the basic cycle length. No evidence for reentry was found from the refractory curves of Wenckebach cycles and by interruption of stimulation after the third stimulus of a 4:3 Wenckebach cycle. Analysis of the A'-H' relative to the H-A' refractory curves did not confirm a positive feedback mechanism. In order to mimic a Wenckebach cycle, a blocked premature beat was inserted during stressed 1:1 conduction. The changes in the refractory curves for successive beats after the premature beat were rate-dependent and similar to those in Wenckebach cycles but smaller in magnitude. In Wenckebach cycles there is a progressive increase in refractoriness, caused by cumulative effect similar to that seen after a blocked beat during stressed 1:1 conduction, until block occurs and the cycle resets.

Changes in cardiac excitability and vulnerability in NMR fields.

Alterations in ventricular excitability and vulnerability were assessed in nine isolated perfused rabbit hearts in and out of static external magnetic fields (4.7 tesla) associated with radiofrequency pulsing (5 gauss). Ventricular refractoriness was assessed with the strength interval relationship in and out of the NMR magnet. Strength interval curves were measured at threshold, at the midpoint of the strength interval relationship, and at 10 mA. The refractory period measured at threshold was 193 +/- 24 mS outside the magnet and 195 +/- 24 mS inside the magnet (P = ns). Ventricular refractoriness measured at the midpoint of the strength interval curve was 169 +/- 16 mS outside and 167 +/- 17 mS in the magnet (P = ns). At 10 mA the refractory period outside of the magnet was 162 +/- 16 mS and 161 +/- 17 mS in the magnet (P = ns). To assess ventricular vulnerability the repetitive response threshold and the ventricular fibrillation threshold were also determined in and out of the NMR magnet. The repetitive response threshold was 61 +/- 16 mA out of the magnet and 75 +/- 24 mA inside the magnet. This was significant at the P = 0.04 level. The ventricular fibrillation threshold was 71 +/- 14 mA out of the magnet and 81 +/- 20 mA in the magnet (P = ns). In summary, static magnetic fields associated with radiofrequency pulsing have no measureable effect on the strength interval relationship. There is no increase in ventricular vulnerability as assessed by the repetitive response threshold and the ventricular fibrillation threshold.

Incessant atrial tachycardias in a dog with tricuspid dysplasia. Clinical management and electrophysiology.

In a dog, tricuspid regurgitation due to congenital tricuspid dysplasia resulted in extreme right heart enlargement and right heart failure. Incessant supraventricular tachycardias were present, requiring the intravenous administration of verapamil to reduce the ventricular rate. Oral therapy using a combination of verapamil and quinidine was partially effective in controlling the ventricular rate during the following week. At that time, electrophysiologic studies were performed. They revealed that a succession of several atrial tachycardias with different cycle lengths, including one episode of atrial flutter, was present. Atrial activity was spanning the majority of the cycle length in all these arrhythmias. Epicardial mapping was performed during the atrial flutter. This enabled the detection of a depolarization wave-front traveling counterclockwise from the dorsolateral right atrium toward the right appendage, following the tricuspid valve annulus. No areas of abnormal conduction were detected. Because programmed electric stimulation maneuvers could not be performed, definitive conclusions about the mechanism of the arrhythmia could not be drawn. The two most likely possibilities were circus movement using part of the dilated tricuspid valve annulus as an anatomic barrier or a leading circle type of re-entry.

The importance of the electrophysiologic substrates in the development of ventricular tachyarrhythmias.

Our electrophysiologic findings are summarized in Table 3. In our animal model of chronic myocardial infarction, induced sustained ventricular tachyarrhythmias occur from 3 days to months following the infarction procedure. Isolated tissues removed from the infarcted region in these animals and studied (table: see text) in vitro reveal regions of slow conduction and local conduction block. These characteristics also persist over this time period and appear to be the substrate responsible for the reentrant excitation at the basis of the ventricular tachyarrhythmias. Our cellular electrophysiologic studies indicate the mechanisms responsible for the abnormal conduction change with time. Up to approximately 2 weeks following the infarction procedure, cellular membrane depolarization is depressed and cell-to-cell electrical continuity is decreased. Both of these factors probably contribute to the slow conduction. Depression in membrane excitability does not seem to play a role. Although an increased dispersion in refractoriness probably contributes to the inducibility of ventricular reentry due to an enhanced propensity for a premature impulse to undergo functional block in one region while continuing to conduct in another region. At two weeks and beyond, action potential depolarization has returned to normal. At this time the sole contributor to the abnormal conduction appears to be cellular electrical uncoupling. Two possibilities for the cause of this cellular uncoupling are as follows: First, the low resistance gap junctions between cells may be modified in the infarcted region causing an increase in internal axial resistance. Another possibility is that the fibrotic matrix in which the surviving cells in the mottled infarct are distributed may contribute to an increase in extracellular resistance as compared to normal myocardium.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of signal averaging to identify low level late potentials in hearts prone to developing tachyarrhythmias.

Our studies have shown that infarcted dogs which exhibit inducible sustained ventricular tachycardia had late potentials and could be distinguished from those with no arrhythmias by the following QRS characteristics. A QRS duration greater than 63 msec and a duration of late activity below 30 microvolts greater than 18 msec. In addition, delayed and fractionated epicardial activation in the infarcted region correlates with late potentials on the body surface. Finally, induced ventricular fibrillation in this animal model appears to have mixed causes and is a non-specific end point.

Critical appraisal of programmed electrical stimulation for evaluating hearts prone to ventricular tachyarrhythmias.

Programmed electrical stimulation has provided a unique new opportunity to evaluate both mechanisms and treatment regimens aimed at preventing ventricular tachyarrhythmias. The variable results that have been reported from different laboratories, undoubtedly are due in part to the differences in programmed electrical stimulation protocols. Although it is unlikely that all laboratories will adapt the same programmed electrical stimulation protocol, it nevertheless is very important that the number of sites of stimulation, stimulus strength, stimulus duration, stimulus polarity, drive train length, and patient population all be listed in order for some comparison between laboratories to be made.

Effects of Ni(2+) on aluminum hydroxide scale formation and transformation on a simulated drinking water distribution system.

Observations of aluminum containing sediments/scales formed within the distribution pipes have been reported for several decades. In this study, the effect of Ni(2+) on the formation and transformation processes of aluminum hydroxide sediment in a simulated drinking water distribution system were investigated using X-ray diffraction spectrum (XRD), Fourier transform infrared spectrum (FT-IR), scanning electron microscope (SEM), and thermodynamic calculation methods. It was determined that the existence of Ni(2+) had notable effects on the formation of bayerite. In the system without Ni(2+) addition, there was no X-ray diffraction signal observed after 400 d of aging. The presence of Ni(2+), however, even when present in small amounts (Ni/Al=1:100) the formation of bayerite would occur in as little as 3d at pH 8.5. As the molar ratio of Ni/Al increase from 1:100 to 1:10, the amount of bayerite formed on the pipeline increased further; meanwhile, the specific area of the pipe scale decreased from 160 to 122 m(2)g(-1). In the system with Ni/Al molar ratio at 1:3, the diffraction spectrum strength of bayerite became weaker, and disappeared when Ni/Al molar ratios increased above 1:1. At these highs Ni/Al molar ratios, Ni5Al4O11⋅18H2O was determined to be the major component of the pipe scale. Further study indicated that the presence of Ni(2+) promoted the formation of bayerite and Ni5Al4O11⋅18H2O under basic conditions. At lower pH (6.5) however, the existence of Ni(2+) had little effect on the formation of bayerite and Ni5Al4O11⋅18H2O, rather the adsorption of amorphous Al(OH)3 for Ni(2+) promoted the formation of crystal Ni(OH)2.