Balloon dilatation in acute myocardial infarct in routine clinical practice: results of the register of the Working Society of Leading Cardiologic Hospital Physicians in 4,625 patients

Balloon angioplasty as the treatment of first choice in the setting of an acute myocardial infarction (AMI) is gaining widespread acceptance because of favourable results from specialised centres concerning high patency rates and low mortality. This study reports the results of angioplasty for AMI at large community hospitals during 1992-1995. 4625 procedures were performed at 68 centres of the Arbeitsgemeinschaft Leitender Kardiologischer Krankenhaus?rzte (ALKK). The age of the patients was 60.8 +/- 11.3 years, with 75.1% men. The infarct related artery was the left anterior descendent in 43%, the right coronary artery in 37%, the circumflex artery in 16%, a bypass graft in 2.3% and the left main stem in 1.4% of patients. The success rate (residual stenosis < 50%) of the intervention was 86%. There was a wide range of procedures per centre, with a median of 40 AMI angioplasties per year and centre. The amount of angioplasties for AMI in relation to all angioplasties performed during this period rose from 5.2% in 1992 to 5.9% in 1995 (p = 0.01). Local complications at the puncture site occurred in 3.2%, with the need for a surgical intervention in 1.1% of patients. In 273 (5.9%) of the patients a second angioplasty was performed during the hospital stay. Aortocoronary bypass surgery was performed in 3% of the patients. Hospital mortality was 9.5% (438/4625 patients). The mortality rate remained constant during the years investigated (1992: 10.6%; 1993: 8.6%; 1994: 9.7%; 1995: 9.8%; p = ns). Higher mortality was observed in older patients, patients with multiple vessel disease, the left anterior descending artery or a bypass graft as infarct related artery as well as in patients with failed reperfusion (residual stenoses > 50%). Hospitals with a case load of more than 40 angioplasties for AMI per year showed a lower mortality as compared to the others. In clinical practice at large community hospitals results of angioplasty for AMI concerning mortality, complications and technical success rate are comparable to those of highly specialised centres. The absolute numbers of angioplasties for AMI increased constantly over the years.     

Reynolds number-dependent permeability of wastewater sludge flocs

Most theoretical models assume constant permeability of wastewater sludge floc. This work shows that, at creeping flow limit with small intrafloc Reynolds number, the permeability of floc can not only be affected by floc structure, but also by the external flow condition. The three-dimensional structure of flocs using the fluorescence in situ hybridization (FISH) and the confocal laser scanning microscope (CLSM) was firstly probed. Then, the volumetric grid models for sludge flocs were constructed. We noted that the floc permeability could keep unchanged, increased, or decreased at increased Reynolds number (Re). Flow redistribution among channels of various sizes contributes to the noted Re-dependent permeability of flocs.     

Local heat transfer measurements of plate finned-tube heat exchangers by infrared thermography

An experimental study is performed using an infrared thermovision to monitor temperature distribution over a plate-fin surface inside the plate finned-tube heat exchangers. The differentiation of the temperature function is derived to determine the local convective heat transfer coefficients on the tested fin, using a local element lumped conduction equation included the convective effect on the boundaries with experimental data. It is disclosed that the infrared thermography is capable of rapidly detecting location and extent of transition and separation regions of the boundary layer over the whole surface of the tested models. Through the comparison of the test results on the strategy region of the in-line and staggered arrangements, it is more easy to understand or interpret the detailed dynamic phenomena of flow existed in the heat exchangers. In addition, the experimental results demonstrate that the averaged heat transfer coefficient of staggered configuration is 14-32% higher than that of in-lined configuration     

Steady-state and transient photoconductivity in hydrogenated amorphous silicon nitride films

Amorphous SiN_x:H films were prepared by the rf glow-discharge decomposition of ammonia/silane gas mixture with varying nitrogen content. The steady-state photoconductivity and its dependence on light intensity have been investigated in a-SiN_x:H as a function of temperature between 100 and 420 K. The electron drift mobility of a set of SiN_x:H samples has been determined from their steady-state photoconductivity and response time measurements. The results suggest that electron drift mobility of the samples was nearly unchanged for a low nitrogen content. Two samples containing lowest nitrogen showed higher photoconductivity than that of unalloyed sample within a temperature range including the room temperature.     

Energy Metabolites as Biomarkers in Ischemic and Dilated Cardiomyopathy

With more than 25 million people affected, heart failure (HF) is a global threat. As energy production pathways are known to play a pivotal role in HF, we sought here to identify key metabolic changes in ischemic- and non-ischemic HF by using a multi-OMICS approach. Serum metabolites and mRNAseq and epigenetic DNA methylation profiles were analyzed from blood and left ventricular heart biopsy specimens of the same individuals. In total we collected serum from n = 82 patients with Dilated Cardiomyopathy (DCM) and n = 51 controls in the screening stage. We identified several metabolites involved in glycolysis and citric acid cycle to be elevated up to 5.7-fold in DCM (p = 1.7 × 10⁻⁶). Interestingly, cardiac mRNA and epigenetic changes of genes encoding rate-limiting enzymes of these pathways could also be found and validated in our second stage of metabolite assessment in n = 52 DCM, n = 39 ischemic HF and n = 57 controls. In conclusion, we identified a new set of metabolomic biomarkers for HF. We were able to identify underlying biological cascades that potentially represent suitable intervention targets.     

Refining Genotypes and Phenotypes in KCNA2-Related Neurological Disorders

Pathogenic variants in KCNA2, encoding for the voltage-gated potassium channel K_v1.2, have been identified as the cause for an evolving spectrum of neurological disorders. Affected individuals show early-onset developmental and epileptic encephalopathy, intellectual disability, and movement disorders resulting from cerebellar dysfunction. In addition, individuals with a milder course of epilepsy, complicated hereditary spastic paraplegia, and episodic ataxia have been reported. By analyzing phenotypic, functional, and genetic data from published reports and novel cases, we refine and further delineate phenotypic as well as functional subgroups of KCNA2-associated disorders. Carriers of variants, leading to complex and mixed channel dysfunction that are associated with a gain- and loss-of-potassium conductance, more often show early developmental abnormalities and an earlier onset of epilepsy compared to individuals with variants resulting in loss- or gain-of-function. We describe seven additional individuals harboring three known and the novel KCNA2 variants p.(Pro407Ala) and p.(Tyr417Cys). The location of variants reported here highlights the importance of the proline(405)–valine(406)–proline(407) (PVP) motif in transmembrane domain S6 as a mutational hotspot. A novel case of self-limited infantile seizures suggests a continuous clinical spectrum of KCNA2-related disorders. Our study provides further insights into the clinical spectrum, genotype–phenotype correlation, variability, and predicted functional impact of KCNA2 variants.     

3D Printing of Polyvinylidene Fluoride Based Piezoelectric Nanocomposites: An Overview

Recently, polyvinylidene fluoride (PVDF) based nanocomposites have attracted much attention for next-generation wearable applications such as promising piezoelectric energy harvesters (nanogenerators), energy storage devices, sensing devices, and biomedical devices due to their high flexibility, and high dielectric and piezoelectric properties. 3D printing technology, PVDF based piezoelectric nanocomposites, the studies based on 3D printing of PVDF based piezoelectric nanocomposites by inkjet printing and fused deposition modeling, and enhancements of energy harvesting and storage performance of nanocomposites by structural design are comprehensively overviewed here. An insight is provided into 3D printing techniques, structure and properties of PVDF based polymers, various nanofillers and production methods for nanocomposites, solutions to enhance β phase (crystallinity) of PVDF, and improvements of nanocomposites’ breakdown strength, discharged energy density, and piezoelectric power output by mentoring structural design.     

Effect of the use of mineral filler on the properties of concrete

Engineers of the concrete technology are increasingly concerned with the material passing through a sieve of the size under 0.149 mm. Materials called very fine aggregate or mineral filler may affect the performance of concrete in an either positive or a negative way. Discussions on aggregate containing very fine material are vitally important. Washing the aggregate residue has been the sole way to solve this matter to date. This is mainly based on the debatable opinion that materials of this kind are regarded as clay material. The goal of the study was to determine how the content of mineral filler might affect properties of concrete. Two types of aggregates with different amounts of cement and mineral filler were used. Basically, mineral filler replaced sand. The effect of applying different amounts of mineral filler on concrete was then determined. The addition of 7-10% of mineral filler to fine aggregate (0-2 mm) was found to considerably improve the properties of concrete.     

Effect of chromium aging on the structural and thermal properties of chromium polyacrylate

The effects of aging time of Cr(III) solutions on the structural, thermal, magnetic, and morphological properties of chromium polyacrylate complexes were studied. Chromium retention was found to increase with longer aging periods. IR spectra revealed the formation of polychelate structures with noticeable changes on aging. The interaction of multivalent, polynuclear Cr(III) species with the polymer backbone resulted in a decrease in thermal stability for the complexes prepared from olated chromium solutions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 490–493, 2005     

Activities of MFI-Supported Rhenium Catalysts for the Aromatization of Methane: Effect of Cationic Form of the Inorganic Carrier

MFI type inorganic carrier was used in two different cationic forms, hydrogen and calcium respectively. MFI-supported molybdenum and rhenium catalysts were prepared. The activities of the catalysts were compared for the aromatization reaction of methane. Higher activity values were attained with the catalysts supported on HZSM-5. Aromatics were also observed with the catalysts supported on CaZSM-5, despite their deficiency in acid sites. Highly dispersed rhenium is expected to be formed with the use of the inorganic carrier in calcium form. On the other hand, lower reaction rates were observed with rhenium supported on CaZSM-5, in spite of the improved dispersion of the active rhenium species on this catalyst. This was interpreted in terms of the critical role of the acid sites in the conversion of methane to aromatics, compared to the improved dispersion of the active metal.