Nanoscale surface analysis on second generation advanced high strength steel after hot dip galvanizing.

Second generation advanced high strength steel is one promising material of choice for modern automotive structural parts because of its outstanding maximal elongation and tensile strength. Nonetheless there is still a lack of corrosion protection for this material due to the fact that cost efficient hot dip galvanizing cannot be applied. The reason for the insufficient coatability with zinc is found in the segregation of manganese to the surface during annealing and the formation of manganese oxides prior coating. This work analyses the structure and chemical composition of the surface oxides on so called nano-TWIP (twinning induced plasticity) steel on the nanoscopic scale after hot dip galvanizing in a simulator with employed analytical methods comprising scanning Auger electron spectroscopy (SAES), energy dispersive X-ray spectroscopy (EDX), and focused ion beam (FIB) for cross section preparation. By the combination of these methods, it was possible to obtain detailed chemical images serving a better understanding which processes exactly occur on the surface of this novel kind of steel and how to promote in the future for this material system galvanic protection.

Aerosol pollution from small combustors in a village.

Urban air pollution is widely recognized. Recently, there have been a few projects that examined air quality in rural areas (e.g., AUPHEP project in Austria, WOODUSE project in Denmark). Here we present the results within the International Cooperation Project RER/2/005 targeted at studying the effect of local combustion processes to air quality in the village of Brzezina in the countryside north-west of Wroclaw (south western Poland). We identified the potential emission sources and quantified their contributions. The ambient aerosol monitoring (PM(10) and elemental concentrations) was performed during 4 measurement cycles, in summer 2009, 2010 and in winter 2010, 2011. Some receptor modeling techniques, factor analysis-multiple linear regression analysis (FA-MLRA) and potential source localization function (PSLF), have been used. Different types of fuel burning along with domestic refuse resulted in an increased concentration of PM(10) particle mass, but also by an increased in various other compounds (As, Pb, Zn). Local combustion sources contributed up to 80% to PM(10) mass in winter. The effect of other sources was small, from 6 to 20%, dependently on the season. Both PM(10) and elemental concentrations in the rural settlement were comparable to concentrations at urban sites in summer and were much higher in winter, which can pose asignificant health risk to its inhabitants.

Ambient particulate matter source apportionment using receptor modelling in European and Central Asia urban areas.

This work presents the results of a PM2.5 source apportionment study conducted in urban background sites from 16 European and Asian countries. For some Eastern Europe and Central Asia cities this was the first time that quantitative information on pollution source contributions to ambient particulate matter (PM) has been performed. More than 2200 filters were sampled and analyzed by X-Ray Fluorescence (XRF), Particle-Induced X-Ray Emission (PIXE), and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to measure the concentrations of chemical elements in fine particles. Samples were also analyzed for the contents of black carbon, elemental carbon, organic carbon, and water-soluble ions. The Positive Matrix Factorization receptor model (EPA PMF 5.0) was used to characterize similarities and heterogeneities in PM2.5 sources and respective contributions in the cities that the number of collected samples exceeded 75. At the end source apportionment was performed in 11 out of the 16 participating cities. Nine major sources were identified to have contributed to PM2.5: biomass burning, secondary sulfates, traffic, fuel oil combustion, industry, coal combustion, soil, salt and "other sources". From the averages of sources contributions, considering 11 cities 16% of PM2.5 was attributed to biomass burning, 15% to secondary sulfates, 13% to traffic, 12% to soil, 8.0% to fuel oil combustion, 5.5% to coal combustion, 1.9% to salt, 0.8% to industry emissions, 5.1% to "other sources" and 23% to unaccounted mass. Characteristic seasonal patterns were identified for each PM2.5 source. Biomass burning in all cities, coal combustion in Krakow/POL, and oil combustion in Belgrade/SRB and Banja Luka/BIH increased in Winter due to the impact of domestic heating, whereas in most cities secondary sulfates reached higher levels in Summer as a consequence of the enhanced photochemical activity. During high pollution days the largest sources of fine particles were biomass burning, traffic and secondary sulfates.

Serial exercise testing up to 6 years after coronary bypass surgery: behavior of exercise parameters in groups with different degrees of revascularization determined by postoperative angiography.

To evaluate the behavior of exercise parameters in patients with different angiographically defined degrees of revascularization, serial exercise tests were analyzed in 435 patients 1 to 6 years after coronary artery bypass grafting (CABG). All patients had undergone postoperative angiography 2 to 12 months after CABG to determine the degree of revascularization achieved. Revascularization was complete in 182 patients (all significantly stenosed arteries had patent grafts), sufficient in 176 patients (at least the dominant artery supplying the left ventricle had a patent graft) and incomplete in 57 patients (the dominant artery supplying the left ventricle had a closed graft). Twenty patients had all grafts occluded. Exercise tolerance, angina-free exercise tolerance (angina threshold), maximal double product, prevalence of greater than or equal to 0.1 mV exercise-induced S-T segment depression, and the prevalence of the combination of S-T segment depression plus angina pectoris were determined in serial exercise tests (average of 3.0 postoperative exercise tests per patient for a mean follow up of 3.5 years). Patients with complete, sufficient, and incomplete revascularization showed improvement of all exercise parameters for 6, 4, and 1 year after CABG, respectively. Patients with all grafts occluded had improvement of only some exercise parameters. Five years after CABG, exercise tolerance was improved by 24 W (p less than 0.0005) and 21 W (p less than 0.005) in patients with complete and sufficient revascularization, respectively, and not improved in patients with incomplete revascularization or with all grafts occluded. The angiographically determined completeness of revascularization correlates with the extent and the duration of improvement of exercise parameters after CABG.

Interval training in patients with severe chronic heart failure: analysis and recommendations for exercise procedures.

This study analyzes a new exercise training procedure, which includes interval exercise training on cycle ergometer (IntCT) (30-s work phases/60-s recovery phases) and on treadmill (60-s work and recovery phases each). Training was applied for 3 wk in 18 patients with severe chronic heart failure (CHF) ((mean +/- SEM) age 52 +/- 2 yr, ejection fraction 21 +/- 1%). Peak VO2 was increased from 12.2 +/- 0.7 to 14.6 +/- 0.7 ml-kg-1 min-1 owing to training (P < 0.001). A specific steep ramp test (work rate increments 25 W.10 s-1) was developed to derive exercise intensity for work phases in IntCT, which was 50% of the maximum work rate achieved. Steep ramp test was performed at the start of the study to determine the initial training work rate, then weekly to readjust it. Since the maximum work rate achieved from this test increased weekly (144 +/- 10 W -->172 +/- 10 W-->200 +/- 11 W; P < 0.001), the training work rate also increased (72 +/- 4 W-->86 +/- 6 W-->100 +/- 7 W; P < 0.001). Physical responses to IntCT were measured. There was no significant change in heart rate, blood pressure, and ratings of perceived exertion (RPE) using a Borg Scale between the first and the third week of training (heart rate 88 +/- 3 b.min-1; blood pressure 115 +/- 4/80 +/- 2 mm Hg; leg fatigue 12 +/- 1; dyspnea 10 +/- 1). Mean lactate concentration (1.70 +/- 0.09 mmol-1-1) indicated an overall aerobic range of training intensity. When compared with the commonly used intensity level of 75% peak VO2 from an ordinary ramp test (work rate increments 12.5 W.min-1), the performed training work rate was more than doubled (240%; P < 0.0001) while cardiac stress was lower (86%; P < 0.01). Values of norepinephrine and epinephrine as well as of RPE corresponded to those measured at 75% peak VO2. Interval exercise training is thus recommended for selected patients with CHF as it allows intense exercise stimuli on peripheral muscles with minimal cardiac strain. Using a steep ramp test, training work rate can be determined and readjusted weekly during initial training period.

Exercise tolerance and working capacity after valve replacement.

Between 1978 and 1987, 1270 patients who survived single aortic or mitral valve replacement at the Rehabilitation Center in Bad Krozingen, Germany, underwent a comprehensive rehabilitation program. The preoperative diagnosis was isolated aortic stenosis in 425, isolated aortic regurgitation in 159, mixed aortic lesion in 211, isolated mitral stenosis in 208, isolated mitral insufficiency in 137 and mixed mitral lesion in 130 cases. Follow up examinations were carried out one and six months after surgery, and at yearly intervals thereafter. Exercise testing was performed with an electrically braked bicycle ergometer in the supine position, and the load was increased by 25 or 50 watts every two minutes until fatigue, severe angina, more than 0.3 mV ST-segment depression, or 80% of the age predicted maximum heart rate was achieved. Patients after aortic valve replacement had a better exercise performance one month after operation than did those after mitral valve replacement. Those with mitral stenosis showed more severe impairment of exercise tolerance than did the mitral insufficiency group. There was a steady increase in exercise tolerance between one and six months postoperatively, both in patients with aortic and those with mitral valve replacement, but the difference in performance between the two groups was still present (72% versus 57% of normal). The results of univariate and multivariate analyses showed that the preoperative employment status was the most important factor for postoperative return to work, followed by gender (male > female), exercise tolerance and valualar lesion (aortic > mitral).(ABSTRACT TRUNCATED AT 250 WORDS)

Recreational swimming in CHD patients and healthy control subjects in relation to left heart function.

We examined the influence on heart rate, blood pressure, lactate, glucose, and catecholamine levels of moderate recreational swimming at a mean time of 5.2 to 9 minutes with mean speed of 0.33 to 0.49 m/s in 25 CHD patients and 8 healthy control subjects. During swimming, changes in these exercise-related parameters were observed such as were only found in seated ergometry trials at levels above 100 to 175 W. We consider these changes tolerable for patients with mild left heart damage (n = 13; ejection fraction 54 +/- 7%; exercise capacity 2.1 +/- 0.4 W/kg). They may indicate overexertion in patients with marked damage to the left heart (n = 12; ejection fraction 44 +/- 5%; exercise capacity 1.3 +/- 0.4 W/kg). Six of the 12 patients with marked left heart damage stopped swimming before the planned time had elapsed for subjective (overexertion) or objective (arrhythmia) reasons.

[ST segment changes in long-term stored ECG]. / ST-Streckenveränderung im Langzeit-Speicher-EKG.

The diagnostic value of ST-changes in the ECG in temporary myocardial ischemia is described: the importance of detecting "silent" ischemia is stressed. Methods for long-time-ECG-recordings are frequency- as well as amplitude-modulations.

Disposing of hazardous waste. An update on waste management studies.

Waste management in the dental office is not a limited issue involving only dentists from the Region of Hamilton-Wentworth. While the ODA has had the opportunity to work with the Hamilton Academy of Dentistry and has the support of this society for a two-phased project, the Metro Toronto component societies will be joining the existing MOEE/Hamilton study. The MOEE in Halton-Peel has informed us that they will be conducting a similar survey and study. The committee would like to thank the Executive of the Hamilton Academy of Dentistry who have provided needed follow-up on this project. We look forward to the cooperation of individual dentists in all communities involved in this environmental study. Dentists are encouraged to complete the survey and to consider volunteering to take part in the in-office sample study. If you have any questions, we invite you to contact members of the Health Care Committee or the staff in the Department of Professional Affairs.

[Possibilities and limits of ambulatory coronary groups]. / Möglichkeiten und Grenzen der "ambulanten Koronargruppen".

Physical exercise has become more and more popular as a treatment method in outpatients with coronary artery disease. The number of outpatient groups in the Federal Republic of Germany grew from 80 to 424 groups between 1978 and 1982. Exercise may have a favourable effect on various cardiovascular risk factors because it reduces bodyweight, blood pressure, LDL and VDL cholesterol and raises HDL cholesterol. It also improves work tolerance by raising the double product of heart rate and blood pressure at comparable workloads, as well as stroke volume and arteriovenous oxygen difference; the result is reduced myocardial oxygen demand. The favourable effect of exercise on the prognosis of patients after myocardial infarction has thus far only been demonstrated in one randomized study (14). That this has not been possible in other studies is mainly due to methodological problems such as sample size, drop-out, drop-in, and others. Nevertheless, it may be concluded that correctly conducted physical training in carefully selected patients with coronary artery disease improves cardiovascular function, quality of life and possibly even prognosis.

[Pindolol in myocardial infarction patients: (author's transl)]. / Pindolol bei Herzinfarkt-Patienten.

Exercise tests were performed in 521 post-infarction patients to consider the acute effect of 5 mg pindolol orally. The main results are: In patients with an initial heart rate(HR) of more than 68 beats/min the HR at rest was reduced. This reduction was more pronounced the higher the initial HR. With HR below 68 beats/min there was a slight increase due to the intrinsic sympathomimetic activity of pindolol. In exercise testing the decrease in HR also correlated positively with the initial values. During the first test run (i. e. without pindolol) angina pectoris was observed in 88 patients. 70% of these patients showed an improvement or total disappearance of angina when pretreated with pindolol. Without medication, 66 patients showed ventricular extrasystoles which diminished or disappeared in 40 after pindolol.

Provocative test in early post-infarction angina: exercise test.

Nowadays, the majority of patients undergoing aortocoronary bypass surgery have a history of myocardial infarction. In our first series of 1000 patients operated between 1973 and 1979, about two thirds of the patients had suffered myocardial infarction; about 80% of them within the previous three months. The method most frequently used to select post-infarction patients for coronary angiography is a simple exercise test. The post-infarction period in the context of this symposium was defined as the first 12 weeks after infarction. As far as exercise tests are concerned, we may divide this period into three subperiods: the very early post-infarction period, especially the first week after infarction. Exercise testing does not play a role in this very early period; the second period is the time of an early post-infarction exercise test or the predischarge exercise test (second and third week); from the fourth to the twelfth week in many European countries, rehabilitation measures will follow, usually in a special institution. This is the time of what we will call in short 'the late post-infarction exercise test'.

[Condition following myocardial infarct: which studies at what time and with what patients?]. / Zustand nach Herzinfarkt: welche Untersuchungen zu welchem Zeitpunkt und bei welchen Patienten?

This review discusses the stepwise approach to postinfarction patients. For some patients only a few basic steps are needed, for others the whole diagnostic spectrum becomes necessary. The baseline diagnostic workup at the time of discharge from the hospital includes: history, clinical examination and risk factor analysis, ECG at rest; x-ray examination of the heart; Holter-ECG recording and exercise testing. The results of this routine diagnostic program determine whether additional and invasive methods are necessary, e.g. echocardiography, myocardial perfusion scintigraphy, radionuclide angiography and coronary angiography. The indication for coronary angiography should be adjusted to the indications for aortocoronary bypass surgery and aneurysmectomy. In young postinfarction patients and those in specific jobs, coronary angiography is also indicated to improve the evaluation of prognosis.

Catecholamine metabolism in heart failure patients and healthy control subjects.

Parameter of catecholamine metabolism were examined in patients (Groups II to V) in chronic, stable stages of coronary heart disease (n = 45), dilated cardiomyopathy (n = 17) and healthy control subjects (Group I). Plasma and urinary catecholamine patterns, catecholamine plasma half-life and catecholamine metabolism following administration of levodopa were determined. In cases of slight (Group II, ejection fraction (EF) 54 +/- 7%) to marked left-heart damage (Group III, EF 44 +/- 5%), the findings indicate elevated catecholamine excretion and a beginning reduction of plasma clearance as the cause of excessive, circulating and renally excreted catecholamines (applies to noradrenaline, less to adrenaline). The renal 24-h dopamine elimination is already slightly reduced in these patients. In cases of severe left-heart damage, the findings are not uniform. In some cases, noradrenaline at rest and at comparable exercise levels are elevated (Group IV, EF 20 +/- 11%), in some cases they are normal (Group V, EF 16 +/- 4%). The 24-h dopamine elimination is reduced in both groups to 34-41% of normal. Noradrenaline and adrenaline elimination is normal, or reduced (Group V, adrenaline). The exercise-induced, maximum plasma noradrenaline concentrations in Group IV and V are much lower (33-40% of normal) than in the healthy control individuals and patients in Groups II and III. Oral administration of 2-4 g levodopa per day result in a 20- to 40-fold dopamine increase in patients with heart failure (Group IV) and healthy control persons (Group I) (free and conjugated plasma dopamine, as well as free urinary dopamine).(ABSTRACT TRUNCATED AT 250 WORDS)

Does exercise testing with invasive measurements of cardiac output and pressure really contribute?

Quantification of heart failure is possible with hemodynamic parameters such as cardiac output and filling pressure at rest and during exercise. These parameters can easily but invasively be achieved by floating catheter measurements. In our experience, the risk of this method is low but existent. In greater than 20 000 patients with chronic diseases no death occurred in connection with the procedure; 26 patients developed ventricular fibrillation or ventricular tachycardias which made defibrillation necessary in 10 of these patients. In three patients asystolia demanded resuscitation. Hemoptysis did not occur. In the acute stage of a disease, e.g. in the acute myocardial infarction, the risk may be higher, especially if the catheter remains in the circulation for longer periods. The possibilities and limitations of the method will be discussed for the following patient groups: (1) Patients with acute myocardial infarction, (2) Postinfarction patients, (3) Patients with cardiomyopathies, (4) Patients with valvular heart disease.

Exercise testing provides additional prognostic information in angiographically defined subgroups of patients with coronary artery disease.

We examined whether exercise testing with measurement of cardiac output during maximal exercise can provide additional prognostic information for medically treated patients in whom left ventricular function and extent of coronary artery disease are known. We followed 1034 patients with normal or mildly impaired left ventricular function; 410 of these patients (group 1) had single-vessel disease, 316 had double-vessel disease (group 2), and 308 had triple-vessel disease (group 3). In addition, 204 patients with double- or triple-vessel disease and moderately impaired left ventricular function (group 4) were followed. Mean follow-up in these 1238 patients was 4.5 years. End point of follow-up was death. Groups 1, 2, and 3 were divided into terciles according to the maximally achieved values of the following exercise variables: exercise tolerance, angina-free exercise tolerance, maximal heart rate, and cardiac output during maximal exercise. Group 4 was divided into halves accordingly. Survival curves (according to the method of Cutler and Ederer) for group 2 showed a 15% difference in 5 year survival rate between the highest and lowest terciles (p less than .005) by use of the noninvasive variables exercise tolerance, angina-free exercise tolerance, and maximal heart rate (95% vs 80%). The separation into terciles according to cardiac output during maximal exercise resulted in a significant difference in survival rates between the highest and lowest terciles (halves) in all groups of patients. The differences in 5 year survival rates were 9% (p less than .05), 16% (p less than .05), and 19% (p less than .005) for groups 1, 2, and 3, respectively, and 22% for group 4 (p less than .005).(ABSTRACT TRUNCATED AT 250 WORDS)