Artificial Anisotropy in Ge2Sb2Te5 Thin Films after Femtosecond Laser Irradiation

Ge₂Sb₂Te₅ (GST225) looks to be a promising material for rewritable memory devices due to its relatively easy processing and high optical and electrophysical contrast for the crystalline and amorphous phases. In the present work, we combined the possibilities of crystallization and anisotropic structures fabrication using femtosecond laser treatment at the 1250 nm wavelength of 200 nm thin amorphous GST225 films on silicon oxide/silicon substrates. A raster treatment mode and photoexcited surface plasmon polariton generation allowed us to produce mutually orthogonal periodic structures, such as scanline tracks (the period is 120 ± 10 μm) and laser-induced gratings (the period is 1100 ± 50 nm), respectively. Alternating crystalline and amorphous phases at the irradiated surfaces were revealed according to Raman spectroscopy and optical microscopy studies for both types of structures. Such periodic modulation leads to artificial optical and electrophysical anisotropy. Reflectance spectra in the near infrared range differ for various polarizations of probing light, and this mainly results from the presence of laser-induced periodic surface structures. On the other hand, the scanline tracks cause strong conductivity anisotropy for dc measurements in the temperature range of 200–400 K. The obtained results are promising for designing new GST225-based memory devices in which anisotropy may promote increasing the information recording density.     

Optimization of the High-Shear Wet Granulation Wetting Process Using Fuzzy Logic Modeling

A fuzzy model has been developed for the optimization of high-shear wet granulation wetting on a plant scale depending on the characteristics of pharmaceutical active substance particles. The model optimized on the basis of experimental data involves a set of rules obtained from expert knowledge and full-scale process data. The skewness coefficient of particle size distribution and the tapped density of the granulated mixture were chosen as the model input variables. The output of the fuzzy ruled system is the optimal quantity of wetting liquid. In comparison to manufacturing practice, a very strong sensitivity of the optimal quantity of the added wetting liquid to the size and shape of the active substance particles has been identified by fuzzy modeling.     

Blastocyst development after sperm selection at high magnification is associated with size and number of nuclear vacuoles

Spermatozoa selection at high magnification before intracytoplasmic sperm injection seems to be positively associated with pregnancy rates after day 3 embryo transfers. The aim was to demonstrate an association between the presence of vacuoles in sperm nuclei and the competence of embryos to develop to day 5. Grading of spermatozoa at x 6000-x 12,500 magnification: grade I, no vacuoles; grade II, or=1 large vacuole; grade IV, large vacuoles with other abnormalities. The outcome of embryo development in a group of 25 patients after sibling oocyte injection with the four different grades of spermatozoa showed no significant difference in embryo quality up to day 3. However, the occurrence of blastocyst formation was 56.3 and 61.4% with grade I and II spermatozoa respectively, compared with 5.1% with grade III and 0% with grade IV respectively (P < 0.001). Spermatozoa selection at high magnification using Nomarski interference contrast is useful to identify more precisely the size and the number of nuclear vacuoles that greatly exert a negative effect on embryo development to the blastocyst stage. These observations confirm previous studies pointing to possible 'early and late paternal effects', both of which may have an impact on early embryonic development.     

Frequency of selected thrombophilias in women with placental abruption

OBJECTIVE: There is a growing view that inherited or acquired thrombophilia may predispose a woman towards an adverse pregnancy outcome. The aim of this study was to investigate whether risk factors for placental abruption because of such thrombophilias (such as carriership of factor V Leiden (FVL), prothrombin G20210A gene mutation and homozygous MTHFR C677T) might be used as a predictor for placental abruption. METHODS: A retrospective case-control study conducted at the University Hospital, Palacky University, Olomouc, Czech Republic. One hundred and eighty women with placental abruption out of 20,175 deliveries (0.79%) were compared to 196 unselected gravidae. A detailed medical history was taken with special reference to factors related to hypercoagulation and blood was drawn for polymerase chain reaction analysis. The prevalence of FVL, prothrombin G20210A and MTHFR C677T was related to placental abruption. RESULTS: The heterozygous form of FVL was present in 20of 142 cases (14.1%) in the placental abruption group, compared to ten of 196 (5.1%) in the control group (odds ratio 3.0, 95% confidence interval 1.4-6.7). CONCLUSIONS: We found that factor V Leiden is a significant risk factor for placental abruption.     

Monitoring of Ion Mobility in the Cement Matrix to Establish Sensitivity to the ASR Caused by External Sources

The possibility of the formation of an alkali–silicate reaction (ASR) is a crucial issue for the service life of concrete. The coexistence of key parameters such as the presence of alkalis, reactive SiO₂, humidity, and temperature predetermine the possibility of its formation and application. When an ASR gel forms, it results in the concreting cracking and spalling as well as in the deterioration of its overall properties. The risk of ASR depends on the concentration of alkalis and their mobility, which influence their ability to penetrate the concrete. The objective of this study was to determine the ionic mobility of not only Na⁺ and K⁺, but Ca²⁺ as well, from external sources (0.5 and 1.0 mol/L solutions of Na/K carbonate, nitrate, and hydroxide) to a cementitious matrix as the precursor for ASR. The concentrations of ions in both the immersion solutions (ICP) and the cementitious matrix itself (SEM-EDX) were studied as a function of time, from 0 to 120 days, for leaching, and according to temperature (25 and 40 °C). The reaction products were characterized using SEM-EDX. Different diffusion rates and behavior were observed depending on the anion type of the external alkali source. Both sodium and potassium ions in all the three environments studied, namely carbonate, hydroxide, and nitrate, penetrated into the composite and further into its structure by different mechanisms. The action of hydroxides, in particular, transformed the original hydration products into calcium-silicate-hydrate (CASH) or ASR gel, while nitrates crystallized in pores and did not cause any changes in the hydration product. The driving force was the increased temperature of the experiment as well as the increased concentration of the solution to which the test specimen was exposed.     

The role of central autonomic nervous system dysfunction in Takotsubo syndrome: a systematic review

Clinical Autonomic Research - Takotsubo syndrome (TTS), also known as stress cardiomyopathy or “broken heart” syndrome, is a mysterious condition that often mimics an acute myocardial...     

Genomewide profiling of copy‐number alteration in monoclonal gammopathy of undetermined significance

Monoclonal gammopathy of undetermined significance (MGUS) is a benign condition with an approximate 1% annual risk of symptomatic plasma cell disorder development, mostly to multiple myeloma (MM). We performed genomewide screening of copy‐number alterations (CNAs) in 90 MGUS and 33 MM patients using high‐density DNA microarrays. We identified CNAs in a smaller proportion of MGUS (65.6%) than in MM (100.0%, P = 1.31 × 10^?5) and showed median number of CNAs is lower in MGUS (3, range 0–22) than in MM (13, range 4–38, P = 1.82 × 10^?10). In the MGUS cohort, the most frequent losses were located at 1p (5.6%), 6q (6.7%), 13q (30.0%), 14q (14.4%), 16q (8.9%), 21q (5.6%), and gains at 1q (23.3%), 2p (6.7%), 6p (13.3%), and Xq (7.8%). Hyperdiploidy was detected in 38.9% of MGUS cases, and the most frequent whole chromosome gains were 3 (25.6%), 5 (23.3%), 9 (37.8%), 15 (23.3%), and 19 (32.2%). We also identified CNAs such as 1p, 6q, 8p, 12p, 13q, 16q losses, 1q gain and hypodiploidy, which are potentially associated with an adverse prognosis in MGUS. In summary, we showed that MGUS is similar to MM in that it is a genetically heterogeneous disorder, but overall cytogenetic instability is lower than in MM, which confirms that genetic abnormalities play important role in monoclonal gammopathies.