Optimal conditions for blood collection for circulating tumor DNA (ctDNA) are still being developed. Although both Streck and EDTA tubes are commonly used, their ability to stabilize ctDNA as a ...function of time and temperature post-collection has not been thoroughly studied. Additionally, the potential utility of CellSave tubes (commonly used for circulating tumor cell) for ctDNA measurements has not been studied.
Blood was collected into Streck, EDTA, and CellSave tubes from ten patients with metastatic breast cancer enrolled in the MI-ONCOSEQ tumor sequencing program at the University of Michigan and kept either on ice or at room temperature until plasma isolation. Plasma was processed after 2, 6, and 48h post-collection. We used droplet digital PCR (ddPCR) to quantify plasma ctDNA and wild-type DNA for six patients who had tumor tissue mutations represented in commercially available ddPCR assays.
ctDNA abundance was similar and stable for up to 6h in all tube types, and there was no effect of storage temperature on the yield for Streck and EDTA tubes. After 48h, however, one out of four patients with detectable ctDNA showed a ~50% decline in ctDNA in the EDTA tube, and three out of six patients showed a 2–3-fold increase in wild-type DNA in the EDTA tube.
Streck, EDTA, and CellSave tubes showed similar performance in preserving ctDNA for up to 6h before plasma isolation. Streck and CellSave tubes more consistently stabilized ctDNA and wild-type DNA at 48h than EDTA tubes.
•All three tubes are effective in stabilizing ctDNA and genomic DNA if plasma is isolated within 6hours.•If plasma processing is delayed for 48hours, EDTA tubes can show an increase in WT DNA.•CellSave tubes can show a modest but statistically significant decline in WT DNA in some patients.•Streck tubes provide extended stability if kept at room temperature.
We report on the synthesis of complex lead‐free perovskite‐type (1−x)(Ba0.8Ca0.2)TiO3–xBi(Mg0.75W0.25)O3 (BCT‐xBMW) and (1−x)(Ba0.8Ca0.2)TiO3‐xBi(Mg0.75Mo0.25)O3 (BCT‐xBMM) solid solutions via ...conventional solid‐state reaction route. The sintering temperature was adjusted as a function of composition x to obtain dense samples (relative densities over 95%) at the same time minimizing bismuth evaporation. X‐ray diffraction analysis shows the formation of single‐phase perovskites for 0 ≤ x ≤ 0.10 in the BCT‐xBMW series and increasing concentrations of impurity phases for x ≥ 0.15 and for x ≥ 0.05 in BCT‐xBMM. A transition from a tetragonal to pseudo‐cubic perovskite structure is observed in BCT‐xBMW and BCT‐xBMM at x = 0.05. The dielectric response has been characterized between −60°C and 300°C for BCT‐xBMW, and between 30°C and 300°C for BCT‐xBMM using impedance spectroscopy, showing a transition from ferroelectric to relaxor‐like behavior at x ≥ 0.05. Additional polarization and Raman spectroscopy measurements reveal the occurrence of highly disordered systems. Analysis of the Raman spectra indicates structural phase changes and lattice modifications caused by chemical substitution. For the composition 0.8Ba0.8Ca0.2TiO3‐0.2Bi(Mg0.75W0.25)O3, a temperature‐stable permittivity of about 600 (±15% between −60°C and 300°C) and small losses of tanδ < 0.02 for T ≤ 230°C at 1 kHz are observed, making it a suitable dielectric material for high‐temperature capacitors.
The current lithium-ion battery remaining useful life (RUL) prediction techniques are mainly developed dependent on offline training data. The loaded current, temperature, and state of charge of ...lithium-ion batteries used for electric vehicles (EVs) change dramatically under the working conditions. Therefore, it is difficult to design acceleration aging tests of lithium-ion batteries under similar working conditions as those for EVs and to collect effective offline training data. To address this problem, this paper developed an RUL prediction method based on the Box-Cox transformation (BCT) and Monte Carlo (MC) simulation. This method can be implemented independent of offline training data. In the method, the BCT was used to transform the available capacity data and to construct a linear model between the transformed capacities and cycles. The constructed linear model using the BCT was extrapolated to predict the battery RUL, and the RUL prediction uncertainties were generated using the MC simulation. Experimental results showed that accurate and precise RULs were predicted with errors and standard deviations within, respectively, -20, 10 cycles and 1.8, 7 cycles. If some offline training data are available, the method can reduce the required online training data and, thus, the acceleration aging test time of lithium-ion batteries. Experimental results showed that the acceleration time of the tested cells can be reduced by 70%-85% based on the developed method, which saved one to three months' acceleration test time compared to the particle filter method.
In this work, a novel body-centered tetragonal boron nitride (bct-BN)-reinforced 6351Al-based cast metal matrix composite of various reinforcement contents is synthesized for the first time adopting ...a low-cost hybrid route of liquid metal infiltration-cum-stir casting followed by subsequent treatments of forging and age hardening. Not only a new low-density ultra-hard reinforcement (bct-BN) is incorporated but also a new hybrid casting route pertinent to the low-density reinforcement incorporation is attempted for the first time in order to achieve high specific ultimate tensile strength (SUTS) value. As a noteworthy outcome, a significant value of SUTS (113 MPa/g cm
−3
) and modest ductility (%Elongation = 10) are achieved in 6351Al-12.3 vol.% BN composite on casting followed by forging and age hardening treatments that is quite comparable or superior to many common aluminum-based metal matrix composites and steels for structural application. In view of structure-property correlation, such an enhanced property (YS = 196 MPa, UTS = 291 MPa, % Elongation = 10, SUTS = 113 MPa/g cm
−3
) as compared to the initial property of cast 6351Al alloy (YS = 131 MPa, UTS = 144 MPa, % Elongation = 2, SUTS = 56 MPa/gcm
−3
) is attributed to reinforcement effect of coherent bct-BN particles, matrix grain refinement effect on bct-BN particle incorporation, evolution of nano-twinned region within BN particle on forging and the age hardening effect of coherent Mg
5
Si
6
(
β
″) precipitates. This asserts an emergence of a new cost-effective structural material in the form of 6351Al/bct-BN composite.
This work is related to the study of a leadfree ferroelectric material and thus piezoelectric material. The Barium zirconate titanate-barium calcium titanate (BZT - BCT) doped with 2% of niobium is ...an alternative to the toxic Lead zirconate titanate commonly known as PZT, which is the most used material in piezoelectric application, also it is a ferroelectric and thus a piezoelectric material. Nb-doped BZT - BCT piezoceramic thin films were grown by means of repeated chemical solution deposition routes (sol gel method) over platinum coated silicon 700μm-thick wafer. The chemical solution has been appositely prepared containing the stoichiometric amounts of metals to obtain the perovskitic structure of formula 0.5BaZr 0.19 Ti 0.79 Nb 0.02 O 3 - 0.5Ba 0.7 Ca 0.3 Ti 0.98 Nb 0.02 O 3 . A platinum electrode was sputtered through shadow mask and the wafer has been cut to obtain device prototypes made of niobium doped BZT - BCT whose ferroelectric characteristics (PE loops) by varying the frequency and voltage have been studied on square capacitors of different areas. While cantilevers structures were used to assess the piezoelectric properties for pristine and poled state material by a laser vibrometer. In the case of the best stack, different poling processes were performed to find the best conditions which have led to an improvement in the ferroelectric behavior and an increase of the displacement of about 4 times.
In this study, as a BaSnTiO3 structure based material, (1-x)Ba(Sn,Ti)O3-x(Ba,Ca)TiO3 piezoelectric ceramic was investigated for piezoelectric applications. Even though high piezoelectric properties, ...low Curie temperature is the obstacles for the applications. To increase Curie temperature of BaSnTiO3 material, (Ba,Ca)TiO3 ceramic was added. (Ba,Ca)TiO3 ceramic has shorter a-parameters compared with that of BaSnTiO3 ceramics, while c-parameter remains similar values of 4.02 Å. Due to the increased strain of (1-x)Ba(Sn,Ti)O3-x(Ba,Ca)TiO3, the Curie temperature can be controlled. Also, we have analyzed the structural and piezoelectric properties of a (1-x)Ba(Sn,Ti)O3-x(Ba,Ca)TiO3 system for application to an energy harvesting system. (1-x)Ba(Sn,Ti)O3-x(Ba,Ca)TiO3 ceramics with x = 0.4, 0.5, 0.55, 0.6, and 0.7 were synthesized and analyzed at sintering temperatures from 1455 to 1505 °C. We investigated the piezoelectric charge coefficient and P-E hysteresis loops. Results showed that the optimized composition of (1-x)Ba(Sn,Ti)O3-x(Ba,Ca)TiO3 ceramics was x = 0.55, sintered at 1480 °C. As lead-free piezoelectric ceramics, it is expected that (1-x)Ba(Sn,Ti)O3-x(Ba,Ca)TiO3 ceramics will be promising candidates for various applications.
The realization of nontrivial fermions in three-dimensional carbon allotropes greatly facilitates topological applications in carbon based-materials. In this work, we find a topological phase ...transition from T-carbon to bct-C16 based on first principles calculations. After carrying out a heating or a doping process on T-carbon, a new carbon phase termed bct-C16 is obtained. The potential energy and the crystal orbital Hamilton population confirm the phase transition process, respectively. Importantly, we also investigate the quantized Berry phase and drumhead surfaces states, confirming the topological nodal line semimetallic features of bct-C16. Due to the extremely weak spin-orbital coupling effect in carbon, the nodal ring in bct-C16 can be guaranteed to be nearly intact. This work not only provides two methods to obtain the carbon phase bct-C16, but also an avenue for bct-C16 to observe nontrivial fermions.
This paper reports the development of a lead free {Ba(Zr0.2Ti0.8)O3}(1−x){(Ba0.7Ca0.3)TiO3}x – x=0.10, 0.15 and 0.20 – BZT–BCT ceramic solid solution system prepared using a solid-state reaction ...technique. The evolution of the Raman spectra with temperature was used to study the variation of the basic phase transition of BaTiO3 in these compositions. The phase transition temperature on heating was found to decrease to 310K, 300K, and 300K, respectively, with increasing Ca content on BCT end and decreasing Zr content on BZT end of lead free pseudobinary ferroelectric BZT–BCT system. Tetragonal and rhombohedral phase coexistence is observed at room temperature from X-ray diffraction (XRD) spectra. Rhombohedral phase is identified between the 83K and 273K from temperature dependent Raman studies. Raman results are in excellent agreement with those obtained from temperature dependent dielectric measurements. Bulk ceramic BZT–BCT materials have shown interesting temperature dependent dielectric properties and as well as higher values of room temperature dielectric constant ∼7800, 8400, 5200, dielectric tunability ∼82%, figure of merit (FOM) ∼93.71 % with low dielectric loss (tan δ) ∼0.015 to 0.024 and good thermal stability at high sintering temperature (1600°C); they might be one of the strong candidates for dielectric tunable capacitor applications in an environmentally protective atmosphere.
► (1−x)BZT–xBCT ceramic capacitors were fabricated using solid state sintering method. ► (1−x)BZT–xBCT ceramics with high ε∼ 7135 & low loss ∼0.015 are useful in capacitors. ► (1−x)BZT–xBCT ceramics have shown good thermal stability −0.054 to −0.058. ► P–E loops confirms ferroelectric nature of (1−x)BZT–xBCT ceramics. ► These ceramics with tunability ∼82% & FOM 93% are useful in tunable devices.
In bipartite consensus tracking (BCT) tasks for nonlinear multiagent systems (MASs), stochastic disturbances and actuator faults are regarded as essential factors that hamper effective controller ...formulation and tracking precision improvement. To address these difficulties, we design an improved finite-time performance function (FTPF) for a fuzzy fault-tolerant distributed cooperative control scheme to achieve finite-time robust precision BCT tasks for nonlinear MASs. The parameter selection range of the improved FTPF is relaxed, which renders systems to achieve better transient performance. Benefitting from the stochastic Lyapunov stability theory, it is shown that all signals of systems are semiglobal uniformly ultimately bounded in probability, and bipartite consensus errors can satisfy the arbitrary precision with probability in the predefined time. Finally, to verify its effectiveness, the proposed control scheme is applied to BCT tasks of a group of vehicles, which manifests anticipated control performance under various uncertainties.
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