Influence of Cryo-Processing and Post-SPD Annealing on Creep Behavior of CP Titanium

The commercial purity of VT1-0 titanium was processed by the rolling process and executed at elevated, room, and cryo-temperatures. These processings led to the formation of an ultrafine-grained microstructure, with the mean grain size at a nanometer level. Some of these materials were statically annealed at a temperature of 823 K for 1 h, which led to significant subgrains and grain coarsening. The constant load creep tests in tension were carried out in argon on all states of materials, at temperatures of 648–723 K and different ranges of applied stresses. From the value of the steady-state creep rate, the control creep mechanisms were determined. The microstructure analyses were carried out via SEM and TEM. It was found that titanium prepared at elevated and room temperatures have a higher creep strength than titanium prepared at cryo-temperatures. Furthermore, the post-SPD —annealing led to a significant decrease in the creep properties. The influence of the preparation temperature on the difference of the creep behavior were discussed and explained using the microstructure analyses of the tests’ samples.     

Origin of the 31P MR signal at 5.3 ppm in patients with critical limb ischemia

An unknown intense signal (P_un) with a mean chemical shift of 5.3 ppm was observed in ³¹P MR spectra from the calf muscles of patients with the diabetic foot syndrome. The aim of the study was to identify the origin of this signal and its potential as a biomarker of muscle injury. Calf muscles of 68 diabetic patients (66.3 ± 8.6 years; body mass index = 28.2 ± 4.3 kg/m²) and 12 age‐matched healthy controls were examined by (dynamic) ³¹P MRS (3 T system, ³¹P/¹H coil). Phantoms (glucose‐1‐phosphate, P_i and PCr) were measured at pH values of 7.05 and 7.51. At rest, P_un signals with intensities higher than 50% of the P_i intensity were observed in 10 of the 68 examined diabetic subjects. We tested two hypothetical origins of the P_un signal: (1) phosphorus from phosphoesters and (2) phosphorus from extra‐ and intracellular alkaline phosphate pools. 2,3‐diphosphoglycerate and glucose‐1‐phosphate are the only phosphoesters with signals in the chemical shift region close to 5.3 ppm. Both compounds can be excluded: 2,3‐diphosphoglycerate due to the missing second signal component at 6.31 ppm; glucose‐1‐phosphate because its chemical shifts are about 0.2 ppm downfield from the P_i signal (4.9 ppm). If the P_un signal is from phosphate, it represents a pH value of 7.54 ± 0.05. Therefore, it could correspond to signals of P_i in mitochondria. However, patients with critical limb ischemia have rather few mitochondria and so the P_un signal probably originates from interstitia. Our data suggest that the increased P_un signal observed in patients with the diabetic foot syndrome is a biomarker of severe muscular damage.     

Brooke-Spiegler syndrome: report of a case with combined lesions containing cylindromatous, spiradenomatous, trichoblastomatous, and sebaceous differentiation

Brooke-Spiegler syndrome is an autosomal dominantly inherited disease with predisposition to cutaneous adnexal neoplasms, most commonly cylindromas and trichoepitheliomas. We report a patient in whom 11 lesions were removed from the scalp and face for various reasons over a period of 3 years. The histopathological survey revealed a plethora of benign adnexal neoplasms showing apocrine, follicular, and sebaceous differentiation occurring independently and conjointly. The histopathological spectrum in our patient included cylindromas, spiradenomas, trichoepitheliomas, small nodular trichoblastomas, and lymphadenomas. Many lesions had hybrid features of two or more neoplasms. By far the most common composite tumor was spiradenocylindroma. Some spiradenocylindromas demonstrated prominent sebaceous or trichoblastomatous differentiation or both. We suggest the terms "sebaceous spiradenocylindroma" and "trichospiradenocylindroma" for these lesions. The occurrence of sebaceous and trichoblastic differentiation in spiradenocylindromas is a further proof that spiradenoma and cylindroma are not eccrine tumors but neoplasms of the folliculosebaceousapocrine unit.     

Comparison of Testing Methods for Evaluating the Resistance of Alkali-Activated Blast Furnace Slag Systems to Sulfur Dioxide

Alkali-activated systems (AAS) represent an ecologically and economically sustainable inorganic binder as an alternative to ordinary Portland cement (OPC). One of the main benefits of AAS is their durability in aggressive environments, which can be equal or even better than that of OPC. In this paper, the influence of the type of alkaline activator in alkali-activated blast furnace slag (AAS) in terms of resistance to sulfur dioxide corrosion was investigated. The durability testing process was based on the CSN EN ISO 3231 standard and simultaneously compared with mortar samples prepared by using Blastfurnace cement CEM III/A 32.5R. The degradation progress was evaluated by employing several different methods such as observing the compressive strength development, weight change evaluation, non-destructive testing methods like ultrasound or impact echo technique, or visual phenolphthalein technique. Subsequently, fundamental characterization of samples by the XRD method was performed during the degradation test. The obtained results indicate that none of the testing methods used could be prioritized over others to determine the resistance of AAS against the action of sulfur dioxide. For this reason, the durability testing of AAS remains an issue, and the development of specific standards considering the behavior of AAS seems necessary.     

Reproducibility of tissue Doppler parameters of asynchrony in patients with advanced LV dysfunction.

AIMS: To assess the reproducibility of tissue Doppler myocardial velocities in patients with dilated ventricles and markedly reduced systolic function (ejection fraction <35%). METHODS AND RESULTS: Forty-one patients referred for cardiac resynchronization therapy (CRT) were evaluated using tissue Doppler echocardiography. The inter and intra-individual reproducibility of peak systolic myocardial velocities and the intra-ventricular delay in three apical projections was assessed by repeated evaluation of each registered data set. Variability (measured by the coefficient of variation) ranged between 18 and 56% for the peak systolic velocities and between 32 and 117% for the time intervals. CONCLUSION: The reproducibility of the tissue Doppler echocardiography parameters (peak systolic myocardial velocity and intra-ventricular delay) was poor in our set of patients with dilated left ventricles and low ejection fraction. The most probable causes of our poor results are discussed including the missing standardization of the TDI measurements.     

Selfish supernumerary chromosome reveals its origin as a mosaic of host genome and organellar sequences

Supernumerary B chromosomes are optional additions to the basic set of A chromosomes, and occur in all eukaryotic groups. They differ from the basic complement in morphology, pairing behavior, and inheritance and are not required for normal growth and development. The current view is that B chromosomes are parasitic elements comparable to selfish DNA, like transposons. In contrast to transposons, they are autonomously inherited independent of the host genome and have their own mechanisms of mitotic or meiotic drive. Although B chromosomes were first described a century ago, little is known about their origin and molecular makeup. The widely accepted view is that they are derived from fragments of A chromosomes and/or generated in response to interspecific hybridization. Through next-generation sequencing of sorted A and B chromosomes, we show that B chromosomes of rye are rich in gene-derived sequences, allowing us to trace their origin to fragments of A chromosomes, with the largest parts corresponding to rye chromosomes 3R and 7R. Compared with A chromosomes, B chromosomes were also found to accumulate large amounts of specific repeats and insertions of organellar DNA. The origin of rye B chromosomes occurred an estimated ～1.1-1.3 Mya, overlapping in time with the onset of the genus Secale (1.7 Mya). We propose a comprehensive model of B chromosome evolution, including its origin by recombination of several A chromosomes followed by capturing of additional A-derived and organellar sequences and amplification of B-specific repeats.     

Endovascular treatment of abdominal aortic aneurysms--6 years of experience with Ella stent-graft system

PURPOSE: Evaluation of 6-year results of abdominal aortic aneurysm (AAA) treatment by Ella stent-grafts with regard to safety and effectivity in relation to morphology of the aneurysm. METHODS: From a group of 172 patients with AAA, in whom elective endovascular treatment was considered, 120 of them (69.8%) were found to be suitable for this type of therapy. The bifurcated type of stent-graft was implanted in 97 patients, uniiliacal type in 19 patients and only four patients were found to be suitable for tubular type of stent-graft. Additional necessary procedures (internal iliac artery occlusion or contralateral common iliac artery occlusion in a group of patients with uniiliacal type of stent-graft) were performed surgically during the stent-graft implantation. CT and US controls were performed at 3, 6 and 12 months after implantation, later every 12 months. RESULTS: Primary technical success was achieved in 109 of the 120 patients (91%). Primary endoleak was recorded in 11 patients (primary endoleak type Ia in seven patients, type Ib in three patients and type IIIa in one patient). Assisted technical success after reintervention or spontaneous seal was 98.3%. Surgical conversion was indicated in two patients (1.7%). Perioperative mortality rate was 3.3%. Total average follow-up period was 20.7 months (range from 2 to 60 months). In nine patients (7.5%) secondary endoleak type II was found at control CT or US, in three patients partial thrombosis of the stent-graft was found. There was no aneurysm rupture during follow-up. CONCLUSION: Treatment of AAA with Ella stent-graft system is effective and safe. Bifurcated stent-graft is the most frequently used type. Uniiliacal type of stent-graft is used by us only in cases of complicated morphology.     

Comparison of the Temporary Dynamics of NGF and BDNF Gene Expression in Rat Hippocampus,Frontal Cortex,and Retina Under Semax Action

Neurotrophins are a family of structurally related proteins that regulate the survival, differentiation, and maintenance of function of different neuron populations. Some peptides are able to affect the production and activity of neurotrophins. One of these synthetic peptides is heptapeptide Semax, an analog of the N-terminal adrenocorticotropic hormone fragment 4-10. It is known that Semax has effects on learning and memory formation and exerts some neuroprotective effects in rodents and humans. Male Wistar rats were treated for 20 min, 40 min, 90 min, 3 h, 8 h, and 24 h with Semax. Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) gene expression in rat brain and retina was analyzed by real-time polymerase chain reaction. It was revealed that after Semax administration the multidirectional activation of the expression of the genes under investigation in the hippocampus, frontal cortex, and retina was observed. The expression of both neurotrophin genes was decreased in rat hippocampus and retina 20 min after Semax administration and was increased in the frontal cortex. The expression levels of NGF remained practically constant in the retina at the initial stage, whereas the expression levels of BDNF were significantly increased 90 min after Semax administration.