Bitumen Binders Modified with Sulfur/Organic Copolymers

With the continuing growth of waste sulfur production from the petroleum industry processes, its utilization for the production of useful, low-cost, and environmentally beneficial materials is of primary interest. Elemental sulfur has a significant and established history in the modification of bitumen binders, while the sulfur-containing high-molecular compounds are limited in this field. Herein, we report a novel possibility to utilize the sulfur/organic copolymers obtained via the inverse vulcanization process as modifiers for bitumen binders. Synthesis and thermal characterization (TGA-DSC) of polysulfides derived from elemental sulfur (S₈) and unsaturated organic species (dicyclopentadiene, styrene, and limonene) have been carried out. The performance of modified bitumen binders has been studied by several mechanical measurements (softening point, ductility, penetration at 25 °C, frass breaking point, adhesion to glass and gravel) and compared to the unmodified bitumen from the perspective of normalized requirements concerning polymer-modified bitumen. The interaction of bitumen binder with sulfur/organic modifier has been studied by means of FTIR spectroscopy and DSC measurements. The impact of the modification on the performance properties of bitumen has been demonstrated. The bitumen binders modified with sulfur/organic copolymers are in general less sensitive to higher temperatures (higher softening point up to 7 °C), more resistant to permanent deformations (lower penetration depth), and more resistant to aging processes without intrusive deterioration of parameters at lower temperatures. What is more, the modification resulted in significantly higher adhesion of bitumen binders to both glass (from 25% up to 87%) and gravel surfaces in combination with a lower tendency to form permanent deformations (more elastic behavior of the modified materials).     

Contemporary use of P2Y12 inhibitors in patients with ST-segment elevation myocardial infarction referred to primary percutaneous coronary interventions in Poland: Data from ORPKI national registry

Journal of Thrombosis and Thrombolysis - According to guidelines, it is recommended to give P2Y12 inhibitors (preferably ticagrelor or prasugrel) at the time of first medical contact in patients...     

Primary Angioplasty in Patient with St-Segment Elevation Myocardial Infarction in the Setting of Intentional Carbon Monoxide Poisoning

Background

ST-segment elevation myocardial infarction (STEMI) due to coronary artery occlusion in the setting of acute carbon monoxide (CO) poisoning is a very rare presentation.

Objective

Our aim was to report on the use of primary angioplasty in a patient with STEMI in the setting of CO poisoning.

Case Report

A 36-year-old man with retrosternal chest pain was admitted after exposure to CO. The initial electrocardiogram (ECG) showed ST depression in I, aVL, and V3−V4 with slight ST elevation in II, III, aVF leads. Toxic carboxyhemoglobin level of 22% and troponin I of 2.19 μg/L were confirmed. After oxygen therapy the chest pain diminished, but after about 15 h it returned. The repeat ECG revealed normalization of previous ST depression with persistent ST elevation in II, III, aVF leads. The troponin I concentration was 5.94 μg/L. An echocardiogram demonstrated an apex hypokinesia involving the adjacent segments of the anterior and lateral wall. On the coronary angiogram, an acute occlusion of the distal left anterior descending coronary artery was confirmed. Primary percutaneous coronary intervention (PCI) of the infarct-related artery was performed. After PCI, the patient was symptom free and had partial ST-segment elevation resolution. The patient was discharged home after 7 days, with persistent ST-T changes and mild hypokinesia of the apex suggesting myocardial injury.

Conclusions

Patients with toxic CO exposure who have symptoms of STEMI should be carefully evaluated with serial ECG, cardiac necrosis marker measurements, and an echocardiogram. When there is evidence of myocardial injury, a wider use of coronary angiography can identify patients who could benefit from PCI.     

Assessment of left atrial appendage function by transesophageal echocardiography in patients two weeks after acute coronary syndromes

Background For many years in ischemic heart disease, ventricles rather than atria received attention so not much is known about left atrial function in left ventricular ischemia. Objective Our study aimed to evaluate left atrial appendage (LAA) function by means of biplane transesophageal echocardiography in patients ten days after acute coronary syndromes (ACS). Methods The study was performed on 16 adult patients (65.9±9.9 years old) in whom transesophageal echocardiography was done 10 days after ACS. The following left atrial appendage (LAA) planimetric parameters were analyzed: LAA transversal dimension, LAA longitudinal dimension,LAA maximal area, and LAA minimal area. LAA ejection fraction was calculated and analyzed. The following LAA Doppler parameters were analyzed: the peak LAA emptying and the peak LAA filling velocities. The control group consisted of 14 patients (43±14.6 years old) without cardiovascular diseases. Results Both LAA longitudinal dimension and LAA transversal dimension were significantly higher in patients with ACS than in control patients. The same was observed for LAA maximal area. Also LAA ejection fraction was higher in patients with ACS . LAA minimal area did not differ in the patients in either group. LAA peak emptying flow (LAAE) and LAA peak filling flow (LAAF) were significantly higher in patients of the study group than of the control group. Conclusion Our study shows that two weeks after acute coronary syndrome LAA as a reservoir as well as a pump works at a higher level than it does in the control group. (J Geriatr Cardiol 2005; 2(4):198-201)     

Impact of early abciximab administration on myocardial reperfusion in patients with ST-segment elevation myocardial infarction pretreated with 600 mg of clopidogrel before percutaneous coronary intervention

Early rapid platelet inhibition with abciximab before primary percutaneous coronary intervention (PPCI) for ST-segment elevation myocardial infarction (STEMI) is suggested as beneficial. In previous studies on early abciximab administration clopidogrel was administered in cathlab in low loading dose. We investigated the role of early abciximab administration on top of early clopidogrel 600 mg loading dose in patients with STEMI treated with PPCI. A total of 73 non-shock STEMI < 6 h patients admitted to remote hospitals with anticipated delay to PPCI < 90 min were randomly assigned to three study groups—24 pts received abciximab before transfer to cathlab (early = group EA), 27 in cathlab during PPCI (late = group LA) and in 22 abciximab administration was left to operator’s discretion during PPCI (selective = SA; given in 22.7% of patients). All patients received clopidogrel (600 mg), aspirin and heparin (70 U/kg) before transfer to cathlab. Angiography revealed more frequent infarct-related artery patency (TIMI 2 + 3: EA vs LA vs SA: 45.8 vs 18.5 vs 13.6%, P = 0.024), better myocardial tissue perfusion (MBG 2 + 3: EA vs LA vs SA: 45.8 vs 14.8 vs 13.6%, P = 0.02) in EA group in baseline angiography. There was no difference in these angiographic parameters and ECG ST-segment resolution after PPCI. In multivariate analysis early abciximab administration was an independent predictor of infarct-related artery patency in baseline angiography (OR 6.5; 95% CI 1.83–23.1; P = 0.004). Early abciximab administration before transfer for PPCI in patients with STEMI pretreated with 600 mg of clopidogrel results in more frequent infarct-related artery patency and better myocardial tissue perfusion before PPCI.     

Gene Polymorphisms of Novel Immunotolerant Molecule BTLA: Distribution of Alleles,Genotypes and Haplotypes in Polish Caucasian Population

B and T lymphocyte attenuator (BTLA) is one of the members of immunoglobulin superfamily which, like CTLA-4 and PD-1, is involved in down regulation of immune response. Despite the important role of BTLA in maintaining immune homeostasis, relatively little studies were devoted to the relationship of polymorphisms in the gene encoding BTLA with susceptibility to autoimmune disease and cancer. Moreover, all published works were done in Asian populations. BTLA gene is located on chromosome 3 in q13.2 and consists of five exons. The aim of this study was to investigate the alleles, genotypes and haplotypes frequency of selected BTLA gene polymorphisms in Caucasian population originating from Poland. For this study, the single-nucleotide polymorphisms (SNPs) were chosen on the basis of literature data. Additionally, the tag dSNP under linkage equilibrium r ² > 0.8 and available at the National Center for Biotechnology Information (NCBI) for Caucasian population of rare alleles at a frequency greater than 5 % have been chosen using the NCBI database. The ten BTLA SNPs investigated were: rs1844089, rs2705535, rs9288952, rs9288953, rs1982809, rs2633580, rs2705511, rs2705565, rs76844316, rs16859633. For all SNPs selected on the basis of literature data the significantly different distributions of genotypes between Asian and Caucasian populations were observed.