[en] We describe a method for preparation of crystalline silver telluride films by cathodic deposition from dimethyl sulfoxide (DMSO) solutions containing 0.1 M NaNO₃, 5.0 mM AgNO₃ and 3.5-7.0 mM TeCl₄. X-ray diffraction data indicated that the deposited silver telluride films could be adjusted from Ag excess and stoichiometric monoclinic Ag₂Te to hexagonal Ag₇Te₄ by increasing the concentration of TeCl₄ in the electrolyte or lowering the deposition potential. The Ag₂Te film is gray and the Ag₇Te₄ film is dark blue-gray and mirror like adhered strongly to the substrates. Scanning electron microscopy images show that Ag₂Te films were formed with globular grains with average diameters of more than 1 μm. In contrast, Ag₇Te₄ film consists of triangles characteristic of a (1 1 1) single-crystal with a hexagonal structure in average sizes of about 0.4 μm. The X-ray photoelectron spectra (XPS) indicated that the binding energies deviation of Te3d in Ag₇Te₄ is less than that in Ag₂Te, which is consistent with the apparent valences of Te in Ag₂Te and Ag₇Te₄. Finally, the cathodic deposition reactions were studied by cyclic voltammetry

[en] While b.c.c. metals deform plastically by dislocation motion or deformation twinning, the atomistic mechanisms governing the choice of deformation modes are not well established. Molecular dynamics simulations using the Finnis-Sinclair potential were carried out to explore the pressure dependence of the deformation response of b.c.c. molybdenum. The crystal was sheared in (1 1 2)[1-bar 1-bar 1] under various confining pressures. The homogeneous nucleation stress of deformation twinning was found to increase with increasing confining pressure. Under sufficient pressure (0 1 1)[1-bar 1-bar 1] dislocations were nucleated instead of twins. Details of the dislocation and twin nucleations were analyzed with the help of the multi-layer generalized stacking fault energies. A two-fault (n=2) metastable twin state was found, in contrast to previous results using pair potentials

[en] Objective: To assess the effect of snapshot freeze (SSF) motion correction algorithm on the image quality of coronary CT angiography (CCTA). Methods: Thirty-one consecutive patients underwent coronary CTA without heart rate control. All of the CCTA images were reconstructed by the means of both standard (STD) and SSF motion correction. Image quality and interpretability of STD and SSF reconstructions were compared. CCTA images were interpreted with Likert 4-points score system by two experienced radiologists. The image qualities were assessed on per-artery and per-segment level, and interpretability was performed on per-segment, per-artery, and per-patient levels. Comparisons of variables were performed with paired Wilcoxon rank sum test and paired Chi-square test. Results: SSF reconstructions showed higher interpretability than STD reconstructions on per-patient [100.0% (31/31) vs 64.5% (20/31), χ"2=9.09, P=0.002] and per-artery [100.0% (124/124) vs 83.9% (104/124), χ"2=18.05, P=0.001] and per-segment level [99.0% (413/417) vs 89.2% (372/417), χ"2=35.56, P=0.001]. Image qualities were higher with the use of SSF than STD reconstructions on LAD [3.3 ± 0.7 vs 2.9 ± 1.0, Z=2.70, P=0.007], LCX [3.1 ±0.8 vs 2.5 ± 1.1, Z=3.23, P=0.001] and RCA [3.3 ±0.6 vs 2.1 ± 0.9, Z=4.60, P=0.001], but they were similar on LM [3.9 ± 0.4 vs 3.7 ± 0.6, Z=1.89, P=0.059]. Image quality was higher with the use of SSF versus STD reconstructions on per-segment [3.5 ± 0.7 vs 3.0 ± 1.0, Z=10.31, P=0.001] level. Conclusions: The use of SSF motion correction algorithm improves image quality and interpretability of coronary CTA without heart rate control. (authors)

[en] Objective: To evaluate effects on image quality and effective radiation with the dose reduction protocol adapted by body mass index (BMI) in coronary artery CT angiography with discovery 750 HD. Methods: Two hundred and seven patients suspected with coronary artery disease (CAD) were enrolled in Group A who were underwent CT angiography with routine radiation, and another 242 patients were enrolled in Group B who received a new scanning protocol with tube voltage and tube current modulation depending on the BMI. The scores of image quality, signal noise ratio(SNR), CT dose index (CTDI_vol), and effective dose (E) were compared and the correlation between the scanning parameters and E was analyzed. Results: The mean radiation dose in Group B(1.2, ranging from 0.8 to 2.5 mSv) was significantly lower than that in Group A(1.9, ranging from 1.5 to 2.3 mSv; Z = -6.24, P < 0.05). The multivariate regression analysis revealed that the first factor affecting effective radiation dose ranked as scanning mode, tube voltage, tube current, and scan length, respectively. The image quality between two groups was not significantly different. The SNR in Group B was greater than that in Group A (Z = -2.22, P < 0.05). Conclusions: Dose reduction protocol in coronary artery CT angiography with discovery 750 HD would help to reduce the radiation dose effectively without sacrificing image quality. (authors)

[en] The problem of delay-dependent asymptotic stability criteria for neural networks (NNs) with time-varying delays is investigated. An improved linear matrix inequality-based delay-dependent stability test is introduced to ensure a large upper bound for time-delay. A new class of Lyapunov functional is constructed to derive some novel delay-dependent stability criteria. Finally, a numerical example is given to demonstrate the effectiveness of the proposed method.

[en] The outbreak of pneumonia caused by novel coronavirus (SARS-CoV-2) in Wuhan, China, at the end of 2019 quickly escalated into a global health emergency. Since its outbreak until the 29th of April 2020, the pandemic has affected more than 3 million of people and caused 207,973 deaths globally. SARS-CoV-2 belongs to the β-coronavirus genus of the Coronavirus family, and it shares the same subfamily with severe acute respiratory syndrome-associated coronavirus (SARS-CoV) and Middle East respiratory syndrome-associated coronavirus (MERS-CoV), all of which lead to severe pneumonia. For cancer patients, especially those with lung cancers, their immune systems are compromised due to the disease itself as well as the treatment for cancer. The weakened immunity of these patients puts them at a higher risk of not only developing diseases but severe diseases. In this study, through a literature review and data collection, we focus on the selection and consideration of antitumor treatment strategies for advanced lung cancer during the coronavirus disease 2019 (COVID-19) epidemic.

[en] The identification and characterization of critical nuclei is a long-standing issue in the rapid solidification of metals and alloys. An ambiguous description for their sizes and shapes used to lead to an overestimation or underestimation of homogeneous nucleation rates $I\left(T\right)$ in the framework of classical nucleation theory (CNT). In this paper, a unique method able to distinguish the critical nucleus from numerous embryos is put forward on the basis of configuration heredities of clusters during rapid solidifications. As this technique is applied to analyze the formation and evolution of various fcc-Al single crystal clusters in a large-scale molecular dynamics simulation system, it is found that the size n _c and geometrical configuration of critical nuclei as well as their liquid–solid interfacial structure can be determined directly. For the present deep super-cooled system with an undercooling of $T_{\mathrm{m}}=0.42T_{\mathrm{m}}^{\mathrm{c}\mathrm{a}\mathrm{l}}$, the average size of critical nuclei is demonstrated to be $\stackrel{¯<!--\; ??\; -->}{n_{\mathrm{c}}}\approx <!--\; ???\; -->26$, but most of which are non-spherical lamellae. Also, their liquid–solid interfaces are revealed to be not an fcc-liquid duplex-phase interface but an fcc/hcp-liquid multi-phase structure. These findings shed some lights on the CNT, and a good agreement with previous simulations and experiments in $I\left(T\right)$ indicates this technique can be used to explore the early-stage of nucleation from atomistic levels. (paper)

[en] Let $R_{r_0},R_{r_1}:{\mathbb{S}}^1⟶<!--\; ???\; -->{\mathbb{S}}^1$ be rotations on the unit circle ${\mathbb{S}}^1$ and define $f:{\mathrm{\Sigma <!--\; ??\; -->}}_2\times <!--\; ??\; -->{\mathbb{S}}^1⟶<!--\; ???\; -->{\mathrm{\Sigma <!--\; ??\; -->}}_2\times <!--\; ??\; -->{\mathbb{S}}^1$ as $$f(x,t)=(\mathrm{\sigma <!--\; ??\; -->}(x),R_{r_{x_1}}(t)),$$ for $x=x_1{x}_2\cdots <!--\; ???\; -->\in <!--\; ???\; -->{\mathrm{\Sigma <!--\; ??\; -->}}_2:=\{0,1{\}}^{\mathbb{N}}$, $t\in <!--\; ???\; -->{\mathbb{S}}^1$, where $\mathrm{\sigma <!--\; ??\; -->}:{\mathrm{\Sigma <!--\; ??\; -->}}_2⟶<!--\; ???\; -->{\mathrm{\Sigma <!--\; ??\; -->}}_2$ is the shift, and $r_0$ and $r_1$ are rotational angles. It is first proved that the system $({\mathrm{\Sigma <!--\; ??\; -->}}_2\times <!--\; ??\; -->{\mathbb{S}}^1,f)$ exhibits maximal distributional chaos for any $r_0,r_1\in <!--\; ???\; -->\mathbb{R}$ (no assumption of $r_0,r_1\in <!--\; ???\; -->\mathbb{R}\setminus <!--\; ???\; -->\mathbb{Q}$), generalizing Theorem 1 in Wu and Chen (Topol. Appl. 162:91–99, 2014). It is also obtained that $({\mathrm{\Sigma <!--\; ??\; -->}}_2\times <!--\; ??\; -->{\mathbb{S}}^1,f)$ is cofinitely sensitive and $({\stackrel{^<!--\; ^\; -->}{\mathcal{M}}}^1,{\stackrel{^<!--\; ^\; -->}{\mathcal{M}}}^1)$-sensitive and that $({\mathrm{\Sigma <!--\; ??\; -->}}_2\times <!--\; ??\; -->{\mathbb{S}}^1,f)$ is densely chaotic if and only if $r_1-<!--\; ???\; -->r_0\in <!--\; ???\; -->\mathbb{R}\setminus <!--\; ???\; -->\mathbb{Q}$.

[en] Objective: To investigate the image quality and radiation dose of the wider detector array CT scanner with low dose scanning mode in young children with congenital heart disease. Methods: Totally 100 consecutive pediatric patients younger than 3 years with congenital heart disease were enrolled. They were divided into two groups. The low dose group with fifty patients underwent axial CT scanning with ECG gating, and the control group with fifty patients were scanned with volume helical shuttle (VHS) technique. CT number and noise of two groups images at the level of ascending aorta, main pulmonary artery, left ventricle, descending aorta and adjacent muscle were measured, and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The double blind method was used to evaluate subjective image quality of the level of intra-cardiac, extra-cardiac and coronary artery. Effective dose was also calculated for both groups. Results: No significant difference was found in the CT number, image noise, SNR, and CNR between the two groups in the same anatomic regions (P > 0.05). No significant difference was found in subjective image quality between the two groups for the intra-cardiac and extra-cardiac structure (P > 0.05). The subjective image quality of coronary artery was significant higher in low dose group than the control group (4.10 ± 0.90 vs. 2.88 ± 0.82, Z = -5.818, P < 0.05). Effective dose was (0.57 ± 0.30) mSv in group A and (2.39 ± 1.15) mSv in group B with dose savings of 76% (t = -11.642, P < 0.05). Conclusions: The wider detector array CT scanner with low dose scanning mode can improve image quality with lower radiation dose. (authors)

[en] A facile and green method was employed to prepare large-scale free-standing TiO₂ nanotube (TNT) arrays, in which as-anodized TiO₂ nanotube films prepared in organic electrolytes with thickness ranging from seven to tens of micrometers were then ultrasonicated in a mix solution of ethanol and water. By controlling the ratio of ethanol to water, the time and the power of ultrasonication, large-scale free-standing TiO₂ nanotube arrays without any crack could be detached from the Ti substrates. Hydrogen sensing results demonstrated that the free-standing TNT film is more sensitive than a film with Ti substrates when exposed to 1000 ppm hydrogen ambient