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PubMed2005

1,3-Dipolar reactions involving corannulene: how does its rim and spoke addition vary?

[reaction: see text] Corannulene undergoes 1,3-dipolar reactions with the dipoles, diazomethane, nitrile oxide, and nitrone through its rim and spoke pi bonds; the rim addition yields "one possible" adduct whereas two "regioselective" adducts are formed by spoke addition. Mechanisms of these reactions have been investigated at the B3LYP/6-31G(d) level. Computations show that both rim and spoke additions prefer concerted pathways that lie 2-5 kcal/mol lower in energy than stepwise paths. Stepwise additions can take place in two ways and the activation energies of these two modes differ by 1-2 kcal/mol. A close inspection of the energy profiles reveals that rim addition is more favorable kinetically and thermodynamically than spoke addition in view of lower activation energy and higher exothermicity observed for rim addition. The rim bond of corannulene is more flexible for distortion and also has a stronger double bond (i.e. pi-character) than the spoke bond and this facilitates rim addition over spoke addition. Deformation energy analysis also confirms the above through higher deformation in corannulene from the spoke addition when compared to rim addition. In the spoke addition, regio1 reaction is kinetically more favored than regio2 reaction. Attempts to react corannulene in an endohedral fashion have led to the exohedral adduct. Computed activation energies suggest that corannulene acts as a deactivated dipolarophile compared to ethylene. Even more striking is the observation that rim and spoke double bonds in corannulene are part of the local aromatic system but it shows remarkable reactivity compared to benzene despite the loss of aromaticity during the reaction. This is well indicated by computed NICS values. Inclusion of acetonitrile as solvent through the PCM model increases the reaction rate and exothermicity.

Journal Article↗
PubMed1995

Estimation of non-additive genetic variances in three synthetic lines of beef cattle using an animal model.

Dominance and additive x additive genetic variances were estimated for birth and weaning traits of calves from three synthetic lines of beef cattle differing in mature size. Data consisted of 3,992 and 2,877 records from lines of small-, medium-, and large-framed calves in each of two research herds located at Rhodes and McNay, IA, respectively. Variance components were estimated separately by herd and line for birth weight (BWT), birth hip height (BH), 205-d weight (WW), and 205-d hip height (WH) by derivative-free REML with an animal model. Model 1 included fixed effects of year, sex, and age of dam. Random effects were additive direct (a) and additive maternal (m) genetic with covariance (a,m), maternal permanent environmental, and residual. Model 2 also included dominance (d) and model 3 included dominance plus additive x additive (a:a) effects. In general, only slight changes occurred in other variance components estimates when day was included in Model 2. However, large estimates of additive x additive genetic variances obtained with Model 3 for 4 out of 24 analyses were associated with reductions in estimates of direct additive variances. Direct (maternal) heritability estimates averaged across herd-line combinations with Model 2 were .53(.11), .42(.04), .27(.12), and .35(.04) for BWT, BH, WW, and WH, respectively. Corresponding covariance (a,m) estimates as fractions of phenotypic variance (sigma p2) were .00, .01, .01, and .06, respectively. For maternal permanent environmental effects in Model 2, average estimates of variances as fractions of sigma p2 across herd-line combinations were .03, .00, .05, and .02, for BW, BH, WW, and WH, respectively. Dominance effects explained, on average, 18, 26, 28, and 11% of total variance for BWT, BH, WW, and WH, respectively. Most of the estimates for additive x additive variances were negligible, except for one data set for BWT, two for BH, and one for WH, where the relative estimates of this component were high (.21 to .45). These results suggest that most of the non-additive genetic variance in the traits studied is accounted for by dominance genetic effects.

Animals↗
PubMed2004

Additional coiling of previously coiled cerebral aneurysms: clinical and angiographic results.

BACKGROUND AND PURPOSE: Some cerebral aneurysms that have been coiled reopen over time and additional treatment should be considered to reduce the risk of recurrent hemorrhage. Our purpose was to assess procedural complications and angiographic results of additional coiling in patients with previously coiled but reopened aneurysms and to evaluate protection against (re)bleeding. METHODS: We compared procedural complications of initial coiling of 488 aneurysms in 439 patients with those of 53 additional coiling procedures in 41 reopened aneurysms in 40 patients. Angiographic results of additional coiling were assessed. We compared episodes of (re)bleeding in patients with complete or near-complete aneurysm occlusion after additional coiling with those of patients with incomplete aneurysm occlusion at 6-month follow-up angiography who were not additionally treated or who still had incomplete occlusion after additional coiling. RESULTS: Thirty-five procedural complications occurred in 488 initial coiling procedures, and no complications occurred in 53 additional procedures. Complete or near-complete angiographic occlusion after additional coiling was obtained in 31 (76%) of 41 aneurysms. Rebleeding occurred in two of 29 patients with incomplete aneurysm occlusion but in none of the 31 patients with complete or near-complete occlusion after additional coiling. CONCLUSION: Additional coiling of previously coiled aneurysms has a low procedural complication rate and leads to sufficient occlusion in most aneurysms. The data indicate that successful additional coiling decreases the risk of rebleeding.

Adult↗
PubMed1989

[Some properties of hydrophilic addition-type silicone impression materials].

Addition-type silicone impression materials have the characteristic of low wetting by water; therefore, they are sometimes inconvenient in clinical use. However, hydrophilic addition-type silicone impression materials are said to be improved in this characteristic. In this study, the physical properties of two kinds of hydrophilic addition-type silicone impression materials, namely, Hydrophilic EXAFLEX and EXPRESS, were investigated and compared with the traditional addition-type silicone impression materials. Compression set, strain in compression, consistency, and contact angles of the salivary droplet on the these impression materials were measured in accordance with ADAS no. 19. The following results were obtained: 1. Each compression set of HEM, HEL, EPM, EPL, EPE (hydrophilic addition-type silicone impression materials), having superior property in compression recovering, was less than 0.1%, they were equivalent to one-seventh of that of the traditional addition-type silicone impression materials. 2. Strain in compression of HEM, HEL, EPM, EPF was bigger than that of the traditional addition-type silicone impression materials. 3. Consistency of HEM, HEL, EPM, EPL, EPF was smaller in fluidity than that of the traditional addition-type silicone impression materials. Among all impression materials in this study, only with HEM and HEL could a difference in consistency between wet films and dry films be recognized. 4. Contact angles of all hydrophilic addition-type silicone impression materials were smaller than those of the traditional addition-type silicone impression materials. They were equivalent to two-thirds of that of the traditional addition-type silicone impression materials, and improvement in wetting property of these hydrophilic addition-type silicone impression materials was observed.

Dental Impression Materials↗
PubMed2005

Adverse reactions to food additives.

OBJECTIVES: To summarize the literature related to the classification of food additives and their reported adverse reactions and to provide a practical approach for evaluation of patients suspected of having such reactions. DATA SOURCES: Information was derived from selected reviews and original articles published in peer-reviewed journals and from authoritative textbook chapters, supplemented by the clinical experience of the authors. STUDY SELECTION: Priority was given to studies that used blinded, placebo-controlled oral challenges to confirm adverse reactions to food additives. In addition, selected, appropriately evaluated case reports are included. RESULTS: A large number of food additives are widely used in the food industry. Adverse reactions to additives seem to be rare but are likely underdiagnosed in part due to a low index of suspicion. Numerous symptoms have been attributed to food additive exposure, but the cause-and-effect relationship has not been well demonstrated in all. CONCLUSIONS: Reactions to food additives should be suspected in patients who report symptoms to multiple unrelated foods or to a certain food when commercially prepared but not when homemade and the allergy evaluation rules out a role for food protein. It is also prudent to investigate food additives in patients considered to have idiopathic reactions. There is a minor role for skin testing or in vitro testing. Oral challenge testing with common additives, preferably preceded by a trial of an additive-free diet, is the definitive procedure for detecting the offending agent. Once the specific additive is identified, management is basically avoidance of all its forms.

Allergens↗
PubMed2003

Food additives used in meat processing according to the Polish and European Union legislation.

This paper presents the legal regulations related to the use of food additives in meat production in Poland and the European Union. The Polish legal definition of food additives is given as well as the classification of permitted food additives added to food and stimulants by their technological function. In addition, a definition of processing aids in the food industry is included. It shows that Polish legislation includes food additives used to ensure or improve food nutritional value, whereas in the EU legislation, these substances are not included in the list of food additives. Moreover, the Council Directives include food additive specific purity criteria, whereas the Polish regulations do not mention the legal regulations of this issue in practice. The European Union use mechanisms and procedures for the introduction of new food additives into internal markets as well as controlling the circulation of additives. The Polish legislation in practice, however, does not determine approval or methods for the introduction of new food additives to the market. Legal regulations on the monitoring of food additives no exist.

Animals↗
PubMed2004

Logistic versus additive EuroSCORE. A comparative assessment of the two models in an independent population sample.

OBJECTIVE: Validation of EuroSCORE outside the boundaries of the original database has been limited to the additive model and has occasionally shown inconsistencies. Therefore we sought to validate the logistic model and assess its predictive performance compared to the additive approach. METHODS: Twenty-four hundred and twenty-six consecutive patients were prospectively assigned individual expected risks of dying calculated by the logistic and the additive EuroSCORE algorithms. Discriminating ability of the two models was tested by Receiver Operating Characteristic (ROC) curves. Calibration was assessed by the Hosmer-Lemeshow (H-T) test and further explored by additional cross-tabulations. A percent difference among the estimates was calculated and plotted across score groups. The series was then sorted by date of operation and split in halves to separately explore the potential effect of variation of performance. RESULTS: Observed mortality (5.6%) was not significantly different from the additive (5.3%) and the logistic estimates (6.9%). Both models satisfactorily discriminated outcomes (ROC areas of 0.80 and 0.79 for the logistic and the additive model, respectively). The H-T test showed that calibration was good for the logistic model (P=0.12) but turned out being inadequate for the additive model (P<0.0001). Further cross-tabulations confirmed a good correlation among observed and predicted death rates by the logistic model across all groups. The additive model, on the other hand, revealed a propensity to over-predict in medium-risk categories and under-predict in the very high-risk cases. Direct comparison of additive vs logistic estimates showed a similar behaviour demonstrating it as an intrinsic property of the additive approach. The split-file analysis revealed a significantly improved outcome for patients treated in the second half of the series though the predictive performance of the two models was unaltered. CONCLUSIONS: Logistic EuroSCORE reliably predicted outcomes in our series despite the higher risk profile compared to the reference EuroSCORE sample and the observed variation in clinical performance during the study period. The additive model was less precise, exhibiting a predictive distortion which should be accounted for, particularly when employing it at the individual patient level.

Aged↗
PubMed2005

Additive vs. logistic risk models for cardiac surgery mortality.

OBJECTIVE: Logistic regression is most often used to produce a cardiac operative risk model. But the logistic equation requires a computer to solve. Thus, simple additive models have been derived from logistic models by adding the odds ratios or modified coefficients. However, this simplification has no statistical justification, and the additive scores do not equal the original logistic probabilities. METHODS: The EuroSCORE risk model is a very successful and widely used cardiac surgery risk model and it comes in both an additive and a full logistic version. We applied the EuroSCORE model to the 28,337 cardiac surgeries in the Providence Health System Cardiovascular Study Group database. The discrimination of the models was assessed by the c index. The comparison of the mortality predictions of the logistic and the additive model are mostly descriptive and graphical. RESULTS: Theoretical considerations would predict that the additive model greatly underestimates the risk for the higher risk patients, and clinical data confirm this fact. For the 23,463 (83%) cases with complete data, the predicted mortality was 8.3% by the logistic model and 5.4% by the additive model. The discrimination (c index) of the additive (0.794) and logistic (0.791) models was equally good. A modified additive score is proposed (the mean of the logistic predicted mortality for each original additive score) which could be provided as a look-up table along with the scoring sheet. CONCLUSIONS: The additive EuroSCORE gives excellent discrimination, as good as the logistic risk model, but it greatly underestimates the risk of high-risk patients, compared to the logistic. The logistic equation should be used to predicate the mortality when possible. If this is not feasible, a modified additive score could be employed at the bedside. But the logistic should always be used for comparison of providers and for research publications.

Cardiac Surgical Procedures↗
PubMed1998

Additional procedures after the initial vitrectomy or tap-biopsy in the Endophthalmitis Vitrectomy Study.

OBJECTIVE: The study aimed to assess the frequency, indications, and outcome of additional ocular procedures after initial treatment of vitrectomy (VIT) or tap-biopsy (TAP) for patients with endophthalmitis after cataract extraction. DESIGN: The study design was an analysis of observational data collected as part of a multicenter, randomized clinical trial. PARTICIPANTS: Of the 420 patients enrolled in the Endophthalmitis Vitrectomy Study, the 148 who had additional procedures were compared with the 272 who did not. MAIN OUTCOME MEASURES: The types, indications, and number of additional ocular procedures were assessed. A masked examiner measured visual acuity 9 to 12 months after study entry. RESULTS: Within 1 week of study entry, 8% of VIT eyes and 13% of TAP eyes underwent additional procedures, 14% for complications of the initial procedure and 86% for worsening ocular inflammation or infection. Cultures were obtained in 33 of the 38 eyes operated on for worsening inflammation or infection and were positive in 42%. Cultures obtained from the early additional procedures were positive more frequently in eyes with an initial TAP (71%) than in eyes with an initial VIT (13%). Both virulence of initial microbiologic organism isolated and poor presenting vision were risk factors for requirement of reoperation. In all cases in which a single organism was cultured at the initial procedure, when the reculture was positive, it was the same organism. Late additional procedures (after 7 days) were required in 27% of patients. Visual outcome was much worse for eyes that had an additional procedure compared to eyes that did not, and this was especially the case for eyes that had an early additional procedure. Only 15% of eyes that had an early additional procedure achieved 20/40 visual acuity as compared to 57% of eyes that did not. CONCLUSION: Need for an additional procedure was a marker of more severe disease, and patients who underwent additional procedures achieved poorer visual acuity at final follow-up.

Bacteria↗
PubMed1999

The additive effect of latanoprost to maximum-tolerated medications with low-dose, high-dose, or no pilocarpine therapy.

OBJECTIVE: To assess the efficacy of latanoprost additive therapy in patients with intraocular pressure (IOP) out of control while taking maximum-tolerated medications and to determine whether pilocarpine therapy has a dose-dependent adverse effect on the efficacy of latanoprost therapy. DESIGN: Noncomparative case series. PARTICIPANTS: Sixty-one eyes of 61 patients with chronic glaucoma with IOP out of control while receiving maximum-tolerated medications were treated with latanoprost additive therapy on a compassionate basis. MAIN OUTCOME MEASURES: Follow-up was up to 22 months with a mean of 13.9 +/- 5.7 months. Kaplan-Meier survival analysis with Mantel-Cox log-rank test was performed to determine the overall success of latanoprost additive therapy and to compare the success rates of high-dose pilocarpine, low-dose pilocarpine, and no pilocarpine therapies. The criterion for success was avoiding glaucoma surgery with IOP decrease of 20% or greater and final IOP less than 22 mmHg. The IOP change and its significance for patients satisfying and failing the criterion for success also were determined to assess the latanoprost additive therapy. In addition, a number of pretreatment variables, including pilocarpine therapy, were analyzed for a significant effect on the efficacy of latanoprost additive therapy using Cox proportional hazards regression analysis. RESULTS: Latanoprost additive therapy significantly lowered mean IOP by 3.9 +/- 5.5 mmHg at 3 months and by 3.5 +/- 5.8 mmHg at 12 months. The cumulative success rate of the latanoprost additive therapy was 70% at 1 month, 42% at 3 months, 40% at 6 months, and 30% at 12 months. Of the variables studied, only increased number of previous incisional glaucoma surgeries and IOP greater than 24 mmHg before latanoprost additive therapy were significant prognostic factors for failure of latanoprost additive therapy. Pilocarpine therapy in any dose had no significant effect. CONCLUSION: This study supports a trial of latanoprost additive therapy before glaucoma surgery in patients with IOP out of control while receiving maximum-tolerated medications irrespective of pilocarpine therapy and the pilocarpine dosage, especially when the number of previous incisional glaucoma surgery is less than three and the IOP is less than 25 mmHg.

Adult↗
PubMed2002

Effect of metal-oxide addition on the sintering of beta-calcium orthophosphate.

The effect of metal-oxide addition (1 approximately 10 mol %) on the sintering of beta-calcium orthophosphate (beta-Ca(3)(PO(4))(2)) was examined by pressureless sintering at 1070 degrees C for 5 h. The metal-oxide additives used were as follows: (i) monovalent metal-oxides, Li(2)O, Na(2)O, and K(2)O; (ii) divalent metal-oxides, MgO, CaO, SrO, and BaO; (iii) trivalent metal-oxides, Al(2)O(3) and Fe(2)O(3); and (iv) tetravalent metal-oxides, SiO(2), TiO(2), and ZrO(2). The relative densities of the sintered beta-Ca(3)(PO(4))(2) compacts were reduced with increasing amounts of monovalent and divalent metal-oxide additions, except for the case of MgO addition when the relative density remained with increasing amount of MgO up to 4 mol %. In the case of trivalent metal-oxide additions, the relative density of sintered beta-Ca(3)(PO(4))(2) compact was reduced with increasing amount of Al(2)O(3) addition, whereas it was enhanced with increasing amount of Fe(2)O(3) addition and reached 98.7% at 10 mol % Fe(2)O(3) addition. In the case of tetravalent metal-oxide additions, relative densities of the sintered beta-Ca(3)(PO(4))(2) compacts were slightly reduced with increasing amounts of SiO(2) and ZrO(2) additions, whereas no appreciable changes in the relative density were observed with increasing amount of TiO(2) addition.

Journal Article↗
PubMed2004

Epistasis and the temporal change in the additive variance-covariance matrix induced by drift.

The effect of population bottlenecks on the components of the genetic covariance generated by two neutral independent epistatic loci has been studied theoretically (additive, covA; dominance, covD; additive-by-additive, covAA; additive-by-dominance, covAD; and dominance-by-dominance, covDD). The additive-by-additive model and a more general model covering all possible types of marginal gene action at the single-locus level (additive/dominance epistatic model) were considered. The covariance components in an infinitely large panmictic population (ancestral components) were compared with their expected values at equilibrium over replicates randomly derived from the base population, after t consecutive bottlenecks of equal size N (derived components). Formulae were obtained in terms of the allele frequencies and effects at each locus, the corresponding epistatic effects and the inbreeding coefficient Ft. These expressions show that the contribution of nonadditive loci to the derived additive covariance (covAt) does not linearly decrease with inbreeding, as in the pure additive case, and may initially increase or even change sign in specific situations. Numerical examples were also analyzed, restricted for simplicity to the case of all covariance components being positive. For additive-by-additive epistasis, the condition covAt > covA only holds for high frequencies of the allele decreasing the metric traits at each locus (negative allele) if epistasis is weak, or for intermediate allele frequencies if it is strong. For the additive/dominance epistatic model, however, covAt > covA applies for low frequencies of the negative alleles at one or both loci and mild epistasis, but this result can be progressively extended to intermediate frequencies as epistasis becomes stronger. Without epistasis the same qualitative results were found, indicating that marginal dominance induced by epistasis can be considered as the primary cause of an increase of the additive covariance after bottlenecks. For all models, the magnitude of the ratio covAt/covA was inversely related to N and t.

Analysis of Variance↗
PubMed2006

Testing for additivity at select mixture groups of interest based on statistical equivalence testing methods.

Several assumptions, defined and undefined, are used in the toxicity assessment of chemical mixtures. In scientific practice mixture components in the low-dose region, particularly subthreshold doses, are often assumed to behave additively (i.e., zero interaction) based on heuristic arguments. This assumption has important implications in the practice of risk assessment, but has not been experimentally tested. We have developed methodology to test for additivity in the sense of Berenbaum (Advances in Cancer Research, 1981), based on the statistical equivalence testing literature where the null hypothesis of interaction is rejected for the alternative hypothesis of additivity when data support the claim. The implication of this approach is that conclusions of additivity are made with a false positive rate controlled by the experimenter. The claim of additivity is based on prespecified additivity margins, which are chosen using expert biological judgment such that small deviations from additivity, which are not considered to be biologically important, are not statistically significant. This approach is in contrast to the usual hypothesis-testing framework that assumes additivity in the null hypothesis and rejects when there is significant evidence of interaction. In this scenario, failure to reject may be due to lack of statistical power making the claim of additivity problematic. The proposed method is illustrated in a mixture of five organophosphorus pesticides that were experimentally evaluated alone and at relevant mixing ratios. Motor activity was assessed in adult male rats following acute exposure. Four low-dose mixture groups were evaluated. Evidence of additivity is found in three of the four low-dose mixture groups. The proposed method tests for additivity of the whole mixture and does not take into account subset interactions (e.g., synergistic, antagonistic) that may have occurred and cancelled each other out.

Animals↗
PubMed2000

Efficient improvement of silage additives by using genetic algorithms.

The enormous variety of substances which may be added to forage in order to manipulate and improve the ensilage process presents an empirical, combinatorial optimization problem of great complexity. To investigate the utility of genetic algorithms for designing effective silage additive combinations, a series of small-scale proof of principle silage experiments were performed with fresh ryegrass. Having established that significant biochemical changes occur over an ensilage period as short as 2 days, we performed a series of experiments in which we used 50 silage additive combinations (prepared by using eight bacterial and other additives, each of which was added at six different levels, including zero [i.e. , no additive]). The decrease in pH, the increase in lactate concentration, and the free amino acid concentration were measured after 2 days and used to calculate a "fitness" value that indicated the quality of the silage (compared to a control silage made without additives). This analysis also included a "cost" element to account for different total additive levels. In the initial experiment additive levels were selected randomly, but subsequently a genetic algorithm program was used to suggest new additive combinations based on the fitness values determined in the preceding experiments. The result was very efficient selection for silages in which large decreases in pH and high levels of lactate occurred along with low levels of free amino acids. During the series of five experiments, each of which comprised 50 treatments, there was a steady increase in the amount of lactate that accumulated; the best treatment combination was that used in the last experiment, which produced 4.6 times more lactate than the untreated silage. The additive combinations that were found to yield the highest fitness values in the final (fifth) experiment were assessed to determine a range of biochemical and microbiological quality parameters during full-term silage fermentation. We found that these combinations compared favorably both with uninoculated silage and with a commercial silage additive. The evolutionary computing methods described here are a convenient and efficient approach for designing silage additives.

Algorithms↗
PubMed2004

Coronary risk factors in Kawasaki disease treated with additional gammaglobulin.

AIMS: To assess the hypothesis that an additional intravenous gammaglobulin (IVGG) infusion, if administered early, may prevent coronary artery lesions (CAL) in patients with Kawasaki disease (KD) who do not respond to initial IVGG therapy. METHODS: Forty four KD patients (17 with CAL and 27 without CAL), treated with additional IVGG because of persistent or recrudescent fever after initial IVGG therapy, were studied. Main outcome measures were the presence of CAL by echocardiography and the number of febrile days before and after start of additional IVGG infusion (pre- and post-additional IVGG). RESULTS: In univariate analyses, risk factors for CAL were the number of febrile days pre-additional IVGG, the number of febrile days post-additional IVGG, the number of days that initial IVGG was divided over, the white blood cell count pre- and post-additional IVGG, and the C reactive protein concentration pre-additional IVGG. In a multivariate analysis, the only independent risk factor was the number of febrile days pre-additional IVGG (> or =10 days; odds ratio 7.86; 95% CI 1.44 to 42.8; p = 0.02). CONCLUSIONS: Among KD patients with persistent or recrudescent fever after initial IVGG therapy, administration of additional IVGG before the first 10 febrile days was associated with a decreased prevalence of CAL, when compared with the prevalence in those who were retreated later. An additional IVGG infusion, if administered early, may prevent CAL in initial IVGG non-responders.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Case study I: application of the divalent cation bridging theory to improve biofloc properties and industrial activated sludge system performance-direct addition of divalent cations.

The objectives of this study were to examine the application of the divalent cation bridging theory (DCBT) to improve settling, dewatering, and effluent quality in pilot-scale reactors and a full-scale system treating an industrial wastewater. This was accomplished by lowering the monovalent-to-divalent (M/D) cation ratio by direct divalent cation addition. Research has shown that the M/D ratio is a potential indicator for settling and dewatering problems at wastewater treatment plants, and M/D ratios above 2 have been associated with poor settling, dewatering, and effluent quality. The M/D ratio of the wastewater in this study ranged from 6 to 20. The cations studied were calcium and magnesium. Results showed that the addition of calcium improved floc properties compared to control reactors with no calcium addition. The reductions in sludge volume index, effluent chemical oxygen demand (COD), and effluent total suspended solids (TSS) were approximately 35, 34, and 55%, respectively, when the M/D ratio was decreased to approximately 2:1. In addition, the cake solids from a belt filter press simulator increased by 72% and the optimum polymer dose required for conditioning was reduced by 70% in the reactor fed the highest calcium concentration when compared to control reactors with no calcium addition. The addition of calcium also decreased the negative effect of high filamentous organism numbers. In general, the addition of magnesium (Mg2+) had similar effects on effluent quality and dewatering properties, although some differences were measured. A full-scale test using calcium addition was performed. Measurements of effluent quality and floc properties were performed before, during, and after the calcium (Ca2+) addition period. The average M/D ratio during these periods was 6.2, 4.6, and 14.0, respectively. The addition of Ca2+ decreased the effluent five-day biochemical oxygen demand, effluent TSS, and effluent COD. The increased Ca2+ concentration also improved dewatering measured by a decrease in specific resistance to filtration and capillary suction time. Overall, the addition of divalent cations to the pilot- and full-scale activated sludge systems improved floc properties and the data fit well with the DCBT.

Calcium↗
PubMed2004

Importance of complex additional stenosis after primary angioplasty for acute myocardial infarction in medium-term prognosis.

BACKGROUND: There is some controversy about the ideal type of revascularization in the context of primary angioplasty (percutaneous coronary intervention--PCI) for acute myocardial infarction (AMI). The presence of additional stenosis, especially if complex, can have an impact on prognosis. OBJECTIVES: To evaluate medium-term (1-year) prognosis according to the presence of complex additional stenosis after primary PCI. POPULATION AND METHODS: A retrospective study of 138 consecutive patients admitted to our unit for ST-segment elevation AMI who underwent primary PCI. Patients were followed up for 1 year and divided in 2 groups: without complex additional stenosis (n = 69, 61 +/- 14 years, 62% males) and with complex additional stenosis (n = 69, 65 +/- 13 years, 73% males, p = NS). We evaluated demographic characteristics, risk factors for coronary artery disease, previous cardiac history and signs of heart failure on admission. Angiographic characteristics, medication and PCI outcome were also evaluated. The impact of these variables on the combined end-point of death, reinfarction, and myocardial revascularization at 1 year was assessed. RESULTS: The angiographic success rate was 96.4%. Twenty-four percent of patients were aged 75 years or over and 4.3% of the total population were in Killip class IV on admission. Anterior AMI was slightly more common in the non-complex additional stenosis group (60% vs. 44%, p = 0.06), and inferior AMI in the complex additional stenosis group (26% vs. 42%, p = 0.07). One-vessel disease was more prevalent in the group without complex additional stenosis, as expected (86% vs. 11%, p < 0.001) and stent implantation was also more frequent in this group (96% vs. 86%, p = 0.08). There were no differences in other variables. Death/reinfarction/revascularization was more frequent in the group with complex additional stenosis (13% vs. 32%, p = 0.014). Sixty-seven per cent of the events occurred in the first 30 days of follow-up. At 1 year, univariate predictors of outcome were Killip class > or = 2, TIMI flow < 3 in the infarct-related vessel after PCI, non-use of glycoprotein IIb/IIIa receptor antagonists, beta-blockers or statins, multivessel disease, and the presence of complex additional stenosis (log rank, p = 0.003). Using multivariate regression analysis, the independent predictors of outcome at 1 year were Killip class > or = 2 (OR 0.28; 95% CI 0.08-0.93, p = 0.037) and the presence of complex additional stenosis (OR 0.32; 95% CI 0.12-0.84, p = 0.020). CONCLUSIONS: The presence of complex additional stenosis after primary PCI had a worse prognosis at 1 year, suggesting the need for further interventions to stabilize the plaque, particularly in the first 30 days after AMI.

Adult↗
PubMed2002

Irish National Food Ingredient Database: application for assessing patterns of additive usage in foods.

Patterns of food additive usage in the Irish food supply and changes in patterns of usage between 1995-97 and 1998-99 were assessed by means of an Irish National Food Ingredient Database (INFID). Of the 300 additives permitted for use according to the European Union food additives Directives, some 54% were recorded in foods in INFID. Colours, emulsifiers and acids were the most frequently used additive categories, representing 18, 13 and 12% of the total additives used, respectively. Colours were most commonly recorded in sauces (n = 182 brands, 26% of sauces), emulsifiers were most commonly recorded in biscuits (n = 181 brands, 47% of biscuits) and acids were most commonly recorded in sauces (304 brands, 43% of sauces). Carotenes (E160a), Annatto (E160b), mono- and diglycerides of fatty acids (E471) and citric acid (E330) were the most commonly used colour, emulsifier and acid, respectively. All diet soft drinks (n = 37), low-fat spreads (n = 25) and liver pâtés (n = 10) recorded the use of at least one additive. When expressed in terms of the number of brands that contain additives, sauces (n = 522, 73% of sauces), biscuits (n = 323, 84% of biscuits) and preserves (n = 321, 85% of preserves) were ranked highest. For most categories of additive (n = 24), there appeared to be a minimal change in qualitative additive usage between 1995-97 and 1998-99. However, there was a significant increase in the frequency of use of emulsifiers (p < 0.001), acids (p < 0.01), sweeteners (p < 0.05) and acidity regulators (p < 0.05), and a significant decrease in the frequency of use of antioxidants (p < 0.05) during the period 1998-99 compared with 1995-97. Despite changes in additive usage patterns, it appeared that changes in the types of brands on sale between both periods were more apparent than actual changes in qualitative ingredient formulations across brands, as some 17% of brands that were on sale in 1995-97 were no longer on sale in 1998-99.

Databases, Factual↗