The microstructural evolution and grain growth kinetics of the hot rolled Ti–20Zr–6.5Al–4V (wt.%, TZ20) alloy during subsequent isothermal annealing were investigated. The XRD results show that the ...examined alloy is composed of α and β phases after annealing at temperatures from 750 °C to 850°C. The SEM results show that the microstructure of all annealed specimens is typical basketweave structure with interlaced α plates embedded in β matrix. Thickness growth kinetics of α plate in TZ20 alloy was investigated by designing various heat treatments. The grain growth exponent n, pre-exponential factor K0 and activation energy of boundary migration E of TZ20 alloy during isothermal annealing were determined. Finally, the relationship between thickness increment Δh, annealing temperature T and holding time t of isothermal annealed TZ20 alloy has been deduced. Mechanical properties of the examined alloy with various annealing treatments were also investigated. Tensile results show that the strength changes in the range of 1120MPa to 1246MPa, and the ductility in term of elongation varies from 9.1% to 14.3%. The relation between mechanical properties and microstructure was also discussed. This work is of great significance to guide the manufacture and to promote practical applications of TiZr-based alloys.
•Microstructure of the TZ20 alloy after various treatments was investigated.•Grain growth kinetics of the TZ20 alloy during isothermal annealing was analyzed.•The grain growth exponent n and activation energy E were obtained.•Relation between microstructure and annealing parameters was deduced.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Pheromonicin-SA (Ph-SA) is a newly developed, engineered multidomain peptide that has a bactericidal effect against Staphylococcus aureus. The objective of this study was to characterize innate ...immune responses by Staph. aureus-stimulated bovine mammary epithelial cells (BMEC) following treatment with Ph-SA. Primary BMEC from one lactating Holstein cow were isolated and exposed to Staph. aureus for 2h, and then treated with rifampicin or Ph-SA. Total RNA was isolated from BMEC at 0, 2, 6, 12, and 24h postinfection, and the mRNA expression of selected genes, including toll-like receptor (TLR)2 and TLR4, IL-1β, IL-6, IL-8, tumor necrosis factor α (TNF-α), and lactoferrin, was quantified by real-time PCR. In the rifampicin group, increases in the expression of mRNA for TNF-α, IL-1β, IL-6, IL-8, and lactoferrin were observed at 6h postinfection and in the expression of mRNA for TLR2 but not for TLR4 at 12h postinfection. In the Ph-SA group, increases in the mRNA expression of TLR2, TNF-α, IL-1β, IL-6, IL-8, and lactoferrin were observed at 6h postinfection, and an increase in TLR4 mRNA expression was observed at 24h postinfection. At 24h postinfection, the mRNA expression of TLR4, TNF-α, IL-1β, IL-6, IL-8, and lactoferrin was higher in the Ph-SA group than in the rifampicin group. In conclusion, Ph-SA might promote the expression of mRNA for TLR2, TLR4, the pro-inflammatory cytokines IL-1, IL-6, and TNF-α, the chemotactic factor IL-8, and lactoferrin in Staph. aureus-infected BMEC. Moreover, Ph-SA may be of value as an antibiotic in promoting innate immune responses by Staph. aureus-infected bovine mammary epithelial cells.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
One-dimensional nanostructures of SnO2 with a ribbonlike morphology have been prepared in large scale via rapid oxidation of elemental tin at 1080 °C. The products were characterized with scanning ...electron microscopy, X-ray powder diffraction, transmission electron microscopy, Raman scattering, and photoluminescence spectroscopy. The as-synthesized SnO2 nanoribbons appeared to be single crystals and had preferred 110 and 203 growth directions. The lengths of the nanoribbons were up to several hundreds of micrometers, and the typical width and thickness were in the range of 30−150 nm and 10−30 nm, respectively. The strong photoluminescence of the nanoribbons in the visible region suggested possible applications in nanoscaled optoelectronic devices. A possible growth mechanism for the SnO2 nanoribbons was proposed.
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IJS, KILJ, NUK, PNG, UL, UM
This study aimed to: describe the incidence of thyroid gland involvement in advanced laryngeal cancer, analyse patterns of spread to the thyroid and elucidate predictors of thyroid involvement.
A ...retrospective review was performed on patients who underwent laryngectomy from 1991 to 2015 as a primary or salvage treatment for squamous cell carcinoma of the larynx, hypopharynx or base of tongue. The incidence of thyroidectomy during total laryngectomy, type of thyroidectomy, incidence of gland involvement, route of spread, and positive predictors of spread were analysed and reported.
A total of 188 patients fit the inclusion criteria. Of these, 125 (66 per cent) underwent thyroidectomy. The thyroid was involved in 10 of the 125 patients (8 per cent), 9 by direct extension and 1 by metastasis. Cartilage invasion was a predictor of thyroid gland involvement, with a positive predictive value of 26 per cent.
There is a low incidence of thyroid gland involvement in laryngeal carcinoma. Most cases of gland involvement occurred by direct extension. Thyroidectomy during laryngectomy should be considered for advanced stage tumours with cartilage invasion.
The dissolution of MnS inclusions could induce pitting corrosion in stainless steels, but its dissolution mechanism is poorly understood at the atomic scale. With the help of
ab initio
molecular ...dynamics calculations, one inevitable step in the dissolution of MnS is studied by simulating the process of one Mn ion leaving the surface. The reaction mechanism is determined to contain three steps with two large barriers and a small one, leading to two slow steps in the Mn ion dissolution. Comparing to the Na ion dissolution from NaCl, the barriers of the Mn ion dissolution are much larger, which is a reflection of their different electronic structures.
Energy curves of Mn ion dissolution.
We investigate the process e+e- → K$\bar{K}$J/ψ at center-of-mass energies from 4.189 to 4.600 GeV using 4.7 fb-1 of data collected by the BESIII detector at the BEPCII collider. The Born cross ...sections for the reactions e+e- → K+K-J/ψ and $K_s^0$$K_s^0$J/ψ are measured as a function of center-of-mass energy. The energy dependence of the cross section for e+e-→ K+K-J/ψ is shown to differ from that for π+π-J/ψ in the region around the Y(4260). In addition, there is evidence for a structure around 4.5 GeV in the e+e- → K+K-J/ψ cross section that is not present in π+π-J/ψ.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Vertical profiles of aerosol extinction coefficients were measured by a micro-pulse lidar at Naqu (31.5 degree N, 92.1 degree E; 4508 m a.m.s.l.), a meteorological station located on the central part ...of the Tibetan Plateau during summer 2011. Observations show a persistent maximum in aerosol extinction coefficients in the upper troposphere-lower stratosphere (UTLS). These aerosol layers were generally located at an altitude of 18-19 km a.m.s.l., 1-2 km higher than the tropopause, with broad layer depth ranging approximately 3-4 km and scattering ratio of 4-9. Daily averaged aerosol optical depths (AODs) of the enhanced aerosol layers in UTLS over the Tibetan Plateau varied from 0.007 to 0.030, in agreement with globally averaged levels of 0.018 plus or minus 0.009 at 532 nm from previous observations, but the percentage contributions of the enhanced aerosol layers to the total AOD over the Tibetan Plateau are higher than those observed elsewhere. The aerosol layers in UTLS wore off gradually with the reducing intensity of the Asian monsoon over the Tibetan Plateau at the end of August. The eruption of Nabro volcano on 13 June 2011 is considered an important factor to explain the enhancement of tropopause aerosols observed this summer over the Tibetan Plateau.
We studied the influence of Dexmedetomidine on cognitive function in children during the recovery period of general anesthesia.
Ninety-three children who underwent general anesthesia were selected ...and randomly divided into (1) the control group, (2) the dexmedetomidine group, and (3) the dezocine group. Fentanyl, propofol, and rocuronium were used in all patients to induce anesthesia, while sevoflurane inhalation and propofol were used to maintain anesthesia. In the control group, 20 ml NS were infused intravenously 10 min before anesthetic induction. In the dexmedetomidine group, 1.0 μg/kg dexmedetomidine in 20 ml was infused for 10 min. In the dezocine group, 0.1 mg/kg dezocine in 20 ml was infused for 10 min. Mean arterial blood pressure, average heart rate, and average oxygen saturation (SaO2) were compared at the following time points: end of surgery (T0), before extubation (T1), during extubation (T2), and 30 min after extubation (T3). The VAS scale, Ramsay sedation score, delirium grading scale and occurrence of adverse reactions at 30 min after extubation were recorded. The occurrence of postoperative cognitive dysfunction (POCD) and the expression of serum neuron-specific enolase (NSE) and IL-6 at postoperative days 1 and 7 were recorded.
Comparing mean arterial blood pressure, average heart rate, and average oxygen saturation (SaO2) at the different time points in the dexmedetomidine group, there were no statistically significant differences (p>0.05). The difference in the occurrence of adverse reactions in the different groups was statistically significant (p<0.05). The occurrence of postoperative cognitive dysfunction (POCD) at postoperative day 1 was significantly higher in the control group than the other two groups (p<0.05), and on the postoperative day 7th, the differences were not statistically significant (p>0.05). Regarding the expression of neuron-specific enolase (NSE) and IL-6, the levels were the highest in the control group, followed by the dezocine group (p<0.05).
The dexmedetomidine is safer than dezocine in aspects of hemodynamics, sedation, analgesia, degree of delirium, occurrence of adverse reactions, and postoperative cognitive dysfunction (POCD). The improvement in the occurrence of postoperative cognitive dysfunction (POCD) is related to the levels of serum neuron-specific enolase (NSE) and IL-6.
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