The grain boundary embrittlement in a binary Fe–12Mn is due to the grain boundary segregation of Mn. During tempering at 400°C (higher than the equilibrium eutectoid reaction temperature 247°C), ...reverted austenite particles were formed at lath and grain boundaries through the equilibrium reaction of lath martensite to ferrite+austenite. Surprisingly, hydrostatic pressure, which is induced by the transformation of epsilon martensite to austenite during heating at the tempering temperature, resulted in the nonequilibrium eutectoid reaction producing α-Mn precipitates at the interface between lath martensite and the transformed austenite during the tempering. The segregation concentration kinetics of Mn formed a convex profile due to the active grain boundary precipitation of the reverted austenite particles and the α-Mn particles, which act as a sink for the segregated Mn. Finally, the convex segregation profile of Mn corresponded to the concave profile of intergranular fracture strength.
Phase transition of Cu precipitates during aging of an Fe–3Si–2Cu alloy was studied by transmission electron microscopy. The precipitation of 3–5-nm-sized body-centered cubic (bcc) Cu in ferrite ...matrix was confirmed by high-angle annular dark-field scanning transmission electron microscopy imaging. The bcc Cu precipitates transformed to 9R Cu as they grew. Many 9R Cu precipitates were twinned, but untwinned 9R Cu particles were also observed. The 9R Cu transformed to twinned face-centered cubic (fcc) Cu by the glide of ±a/3 1009R Shockley-type partial dislocations. Formation of the 3R structure previously reported could not be confirmed in this study. Finally, twins in fcc Cu precipitates disappeared to form stable fcc Cu particles. The importance of electron beam-orientation-dependent moiré fringes in the correct identification of Cu structure is discussed in detail.
Despite intense studies into silicon anode materials, the large volume expansion of silicon remains a significant problem that reduces battery performance and shortens battery life. In this paper, a ...procedure to increase the cycle life of the silicon anode in full-cell configuration using a simple pre-lithiation method is proposed. By precisely controlling the thickness of the pre-deposited lithium through evaporation, the volume change of the silicon-containing anodes can be effectively reduced during discharge. A coin-cell fabricated with a high-capacity cathode and the pre-lithiated silicon–graphite anode shows improvements in cycling performance, as well as a higher discharge capacity. Electrochemical and microscopic analysis confirm that pre-lithiation successfully suppresses the volumetric changes. Thus, this work provides an effective method for the preparation of long-cycle-life Li-ion batteries containing silicon-based anodes.
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•The mechanism for improving cycle life through pre-lithiation was proposed and proved.•A pre-lithiation method is proposed by lithium evaporation on a Si-Gr anode.•Precisely controlled pre-lithiated cells prevent complete shrinkage of the silicon.•Enhanced cycle life and a high areal capacity were achieved at a high current densities.
The phosphorus segregation concentration at grain boundary/carbide interfaces of 2.25Cr–1.5W heat-resistant steels under tensile stress shows a broad convex profile in a log time versus segregation ...concentration plot. The decrease in phosphorus segregation concentration after the maximum in the convex profile is due to the formation of new equilibrium MC carbides on the surface of the pre-formed M23C6 carbides and its partitioning effect of the phosphorus segregated at the M23C6 carbide interface to the interface of the new MC carbides.
We conducted a population-based retrospective cohort study to investigate the influence of hospital volume, delay of surgery, and both together on the long-term survival of postoperative cancer ...patients.
Using information from the Korea Central Cancer Registry from 2001 through 2005 and the National Health Insurance claim database, we determined survival for 147 682 patients who underwent definitive surgery for any of six cancers.
Regardless of cancer site, surgical patients in low- to medium-volume hospitals showed significantly worse survival adjusted hazard ratio (aHR) = 1.36–1.86 than those in high-volume hospitals in multivariable analyses. Among the latter, treatment delays > 1 month were not associated with worse survival for stomach, colon, pancreatic, or lung cancer but were for rectal aHR = 1.28; 95% confidence interval (CI), 1.17–1.40 and breast (aHR = 1.59; 95% CI, 1.37–1.84) cancer. For patients in low- to medium-volume hospitals, treatment delay was associated with worse survival for all types of cancer (aHR = 1.78–3.81).
Our findings suggest that the effect of hospital volume and surgical treatment delay on overall survival of cancer patients should be considered in formulating or revising national health policy.
Extended Hall–Petch relationships for yield (
σ
y
), cleavage (
σ
cl
) and intergranular fracture (
σ
ig
)
strengths of pure iron have been established through the direct calculation of the ...proportional constant
(
k
)
and the estimation of the friction stress
(
σ
0
)
. The magnitude orders of
k
and
σ
0
are generally
k
y
<
k
cl
<
k
ig
and
σ
y
0
<
σ
cl0
<
σ
ig0
, respectively. Based on the Hall–Petch relationships, micro-yielding in a bcc steel occurs at the instance that the pile-up dislocations within a specific grain showing the Schmid factor of 0.5 propagate into the neighboring grain. The initial brittle crack is formed at the instance that the flow strength exceeds the brittle fracture strength. Once the brittle crack is formed, it grows catastrophically. Due to the smallest and
k
y
and
σ
y0
, the cleavage and the intergranular fracture occur always after micro-yielding. The {100} cleavage fracture of the steel is due to the lowest theoretical {100} cleavage strength. Due to the thermal components included in cleavage and intergranular fracture strengths, they show also the temperature and strain rate dependence observed in yield strength. The increase in susceptibility to brittle fracture with decreasing temperature and increasing strain rate is due to the increase in dislocation density which causes the high work hardening rate.
AIMS: Cyanobacteria have been used as sustainable bioresource producers for foods, feeds and other valuable natural products. However, selection of a new species (other than Arthrospira), with ...advantageous properties for alimentary purposes, continues to be a challenge due to potential toxicity and low biomass productivity. In this study, we report a valuable filamentous cyanobacterium isolated from Korea. METHODS AND RESULTS: Morphological and phylogenetic analyses demonstrated that the isolate belongs to the genus Leptolyngbya, and consequently designated Leptolyngbya sp. KIOST‐1. Interestingly, Leptolyngbya sp. KIOST‐1 possessed numerous advantageous characteristics for biomass production, similar to Arthrospira. The isolate readily propagated in SOT medium with efficient biomass productivity, and its optimum growth was observed at 30°C under alkaline and saline conditions. Moreover, more than half of the cellular components in Leptolyngbya sp. KIOST‐1 were composed of protein, with approx. 40% of essential amino acids. Most importantly, no significant cytotoxicity was detected in the isolate. CONCLUSIONS: Leptolyngbya sp. KIOST‐1 has a number of advantageous characteristics for alimentary purposes due to its efficient productivity, high protein content and lack of potential cytotoxicity. SIGNIFICANCE AND IMPACT OF THE STUDY: Leptolyngbya sp. KIOST‐1 may be considered a potential candidate for industrial biomass production, similar to Arthrospira.
The phosphorus (P) adsorption characteristic of sesame straw biochar prepared with different activation agents and pyrolysis temperatures was evaluated. Between 0.109 and 0.300 mg L⁻¹ in the form of ...inorganic phosphate was released from raw sesame straw biochar in the first 1 h. The release of phosphate was significantly enhanced from 62.6 to 168.2 mg g⁻¹ as the pyrolysis temperature increased. Therefore, sesame straw biochar cannot be used as an adsorbent for P removal without change in the physicochemical characteristics. To increase the P adsorption of biochar in aqueous solution, various activation agents and pyrolysis temperatures were applied. The amount of P adsorbed from aqueous solution by biochar activated using different activation agents appeared in the order ZnCl₂ (9.675 mg g⁻¹) > MgO (8.669 mg g⁻¹) ⋙ 0.1N-HCl > 0.1N-H₂SO₄ > K₂SO₄ ≥ KOH ≥ 0.1N-H₃PO₄, showing ZnCl₂ to be the optimum activation agent. Higher P was adsorbed by the biochar activated using ZnCl₂ under different pyrolysis temperatures in the order 600 °C > 500 °C > 400 °C > 300 °C. Finally, the amount of adsorbed P by activated biochar at different ratios of biochar to ZnCl₂ appeared in the order 1:3 ≒ 1:1 > 3:1. As a result, the optimum ratio of biochar to ZnCl₂ and pyrolysis temperature were found to be 1:1 and 600 °C for P adsorption, respectively. The maximum P adsorption capacity by activated biochar using ZnCl₂ (15,460 mg kg⁻¹) was higher than that of typical biochar, as determined by the Langmuir adsorption isotherm. Therefore, the ZnCl₂ activation of sesame straw biochar was suitable for the preparation of activated biochar for P adsorption.
ZnO is attracting considerable attention for its possible application to UV light emitters, spin functional devices, gas sensors, transparent electronics and surface acoustic wave devices. There is ...also interest in integrating ZnO with other wide bandgap ceramic semiconductors such as the AlInGaN system. In this paper we summarize recent progress in doping control, materials processing methods such as dry etching and Ohmic and Schottky contact formation, new understanding of the role of hydrogen and finally the prospects for control of ferromagnetism in transition-metal doped ZnO.
Chromosomal rearrangements involving RET, which are found in about 1% of non-small cell lung cancer (NSCLC), define a unique molecular subset. We performed this study to examine the efficacy and ...safety of vandetanib 300 mg daily in this patient population.
This study was a multi-center, open-label, phase II clinical trial. Patients were enrolled if they had metastatic or recurrent NSCLC with a RET rearrangement, which was confirmed by fluorescence in situ hybridization, had progressive disease against platinum-based doublet chemotherapy, and had a performance status of 0–2. The primary endpoint was the objective response rate.
A total of 18 patients were enrolled in this study between July 2013 and October 2015. Patients were aged 35–71 years; three had a performance status of 2, and the majority were a heavily pretreated population (≥ two different previous chemotherapy regimens in 72% of the patients). Among the 17 evaluable patients, three had a partial response (objective response rate = 18%) and eight had a stable disease (disease control rate = 65%). Among these patients, the partial response or disease stabilization was durable for more than 6 months in eight patients. Vandetanib also showed a progression-free survival of 4.5 months, and an overall survival of 11.6 months during a median follow-up duration of 14 months. The safety profile was comparable with previous studies of vandetanib. Most vandetanib-related adverse events were mild with prevalent hypertension and rash (in >70% of patients). Grade 3 toxicity included hypertension (n = 3), QT prolongation (2), and elevation of aminotransferases (1), and as a consequence the dose was reduced in four patients. There were no adverse events associated with grade 4 or 5 toxicity.
Vandetanib is moderately active in pretreated patients with advanced NSCLC-harboring RET rearrangements.
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