Synchrotron single-crystal XRD, IR-, Raman spectroscopy and high pressure study of synthetic krieselite

Spontaneous crystals of krieselite (Ge analogue of topaz) with the chemical formula Al₂[(Ge_0.75Si_0.25)O₄](F_1.63OH_0.37) were synthesized using a thermo-gradient hydrothermal method at a temperature of 600/650 °C and pressure of 100 MPa. The unit cell parameters are: a = 8.9732(8) Å, b = 8.4823(7) Å, c = 4.7379(5) Å, V = 360.62(6) ų, space group Pnma. The F^-/OH^- content of the samples was refined by FTIR spectroscopy method. Raman spectroscopy showed the main differences between the spectra of krieselite and topaz at the ambient conditions. The assignment of observed and calculated A_g bands (cm^-1) for non-polarized Raman spectra was carried out. Using in situ Raman spectroscopy at high pressures, the dependence of the shift in the position of the main bands of the krieselite Raman spectrum on the pressure was established, and the corresponding paths of pressure induced distortion of crystal structure was assumed. According to the data of Raman spectroscopy, it was revealed that krieselite does not undergo the phase transitions up to 30 GPa. The probable way of crystal structure distortion within the space group Pnma was proposed based on simulation of high-pressure Raman spectra.

Irradiation capsule design for neutron coloration of topaz in a WWR-K reactor

This study justifies irradiation capsule design calculations used for efficient coloring of topaz in a WWR-K reactor. Various radiation screens used for removing thermal and epithermal neutrons and their influence on the activation of the main impurities in topaz are considered. Neutron analysis has been performed by means MCNP transport code. It is shown that the use of a sandwich screen composed of boron carbide and tantalum decreases the fraction of thermal neutrons by 24% and increases the fraction of fast neutrons by 15%. These are the optimal neutron conditions for topaz irradiation in a WWR-K reactor. Thermal analysis has been performed by means Comsol code and two approaches were taken: conservative and realistic. A thermo-physical analysis with a conservative approach showed that for boron carbide and tantalum screen the temperatures under forced and natural convection modes were 134°С and 274°С, respectively. The temperature of the case body was 75 °C with forced cooling and 238 °C without cooling. In case of realistic approach, the topaz temperature does not exceed 65°С if regular cooling of the irradiation capsule is ensured. Calculation results showed the importance of the ensure circulation between topaz during irradiation, which makes it possible to reduce the temperature of topaz by almost half.

Patient-Perceived Recovery and Outcomes after Bipolar Radiofrequency Controlled Ablation with Platelet-Rich Plasma Injection for Refractory Plantar Fasciosis

Previous studies have documented persistent postoperative symptoms and limitations following plantar fasciotomy using patient-reported outcome measures (PROMs). The incomplete recovery (resolution) has been theorized to occur from altered foot biomechanics, and alternative treatment methods have continued to gained popularity for addressing refractory plantar fasciosis (RPF). The purpose of the present study was to assess patient-perceived recovery (PPR) and outcomes after bipolar radiofrequency controlled ablation (BRC) with platelet-rich plasma (PRP) injection for RPF. From July 2006 to July 2016, 43 patients (52 procedures) were enrolled. PROMS were prospectively obtained and compared between patients who perceived themselves as recovered without/residual deficits (recovered-resolved, recovered-not resolved) and those not recovered. Holistic satisfaction, procedure-specific satisfaction, complications, reoperations, and failure were recorded. Overall, 67.4% perceived themselves as recovered-resolved, 23.3% as recovered-not resolved, and 9.3% as not recovered. Holistic and procedure specific satisfaction were high (90.7% and 88.4%), with a mean modified Foot Function Index of 11.65, visual analog scale for pain 1.5, and failure rate of 9.3% at a median of 53 months (interquartile range 33 to 83). In the present study, outcomes with BRC with PRP injection compared favorably to the long-term outcomes reported for partial and complete plantar fasciotomy. Although 14 patients (32.6%) continued to have some postoperative symptoms, 71% indicated that they were satisfied with their symptoms, and 64% would undergo a similar procedure again. Therefore, despite the study's shortcomings, a patient's ability to cope appears to have a role in recovery from RPF.

Acute exposure to the penconazole-containing fungicide Topas partially augments antioxidant potential in goldfish tissues

Penconazole is a systemic fungicide commonly used in agriculture as the commercial preparation Topas. Although triazole fungicides are widely found in the aquatic environment, little is known about their acute toxicity on fish. In this study we assessed the effects of short-term exposure to Topas on some parameters of homeostasis of reactive oxygen species (ROS), such as the levels of markers of oxidative stress and parameters of the antioxidant defense system of goldfish (Carassius auratus L.). Gills appeared to be the main target organ of Topas toxicity, showing the greatest number of parameters affected. Gills of Topas-treated fish showed a higher content of low (L-SH) and high (H-SH) molecular mass thiols and higher activities of superoxide dismutase (SOD), catalase, glutathione reductase (GR), glutathione-S-transferase (GST), and glucose-6-phosphate dehydrogenase (G6PDH) as well as reduced carbonyl protein content (CP), as compared with those in the control group. In the liver, goldfish exposure to 15-25mgL^-1 Topas resulted in a higher L-SH and H-SH content, but lower CP levels and activity of GST. In kidney, Topas exposure resulted in higher activities of glutathione peroxidase (GPx) and G6PDH, but lower L-SH content and activity of GST. The results of this study indicate that acute goldfish exposure to the triazole fungicide Topas increased efficiency of the antioxidant system in fish gills, liver, and kidney. This could indicate the development of low intensity oxidative stress which up-regulates defense mechanisms responsible for protection of goldfish against deleterious ROS effects.