[en] Highlights: • Bi₂O₃ addition could promote the grain growth in Sr_0.4Ba_0.6Nb₂O₆ ceramics. • Doping Bi₂O₃ could improve the dielectric constant and lower the dielectric loss. • The dielectric characteristics of doping Bi₂O₃ samples showed relaxation behavior. • The P–E hysteresis loops for doping Bi₂O₃ ceramics became slimmer. -- Abstract: (1 − x) Sr_0.4Ba_0.6Nb₂O₆–xBi₂O₃ (0.00 ≤ x ≤ 0.20) ceramics were prepared by conventional solid-state reaction method. The microstructure, dielectric properties and P–E hysteresis loops of ceramics were investigated via X-ray diffraction, scanning electron microscope (SEM), Agilent E4980A and modified Sawyer–Tower circuit, respectively. XRD results showed the obtained ceramics were of tungsten bronze structure, and second phase Sr_0.4Ba_0.6Bi₂Nb₂O₉ was detected at high doping concentration. SEM results showed suitable Bi₂O₃ addition could reduce the sintering temperature and assist the grain growth. The dielectric characteristics exhibited diffuse phase transition phenomena, which were verified by linear fitting of the modified Curie–Weiss law. Besides, the relaxor ferroelectric properties of ceramics followed the Vogel–Fulcher relationship well. The P–E hysteresis loops became slimmer with increasing the Bi₂O₃ addition, leading to a gradually decrease in both remnant polarization (P_r) and coercive field (E_c)

[en] The rare earth Ce³⁺ and Tb³⁺ ions -doped α-zirconium phosphate [Zr(HPO₄)₂, abbreviated as ZrP] nanosheet phosphors were prepared by direct precipitation process at ambient temperature. The X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence emission and excitation spectra and the fluorescent lifetime measurements were used to characterize the crystal structure, morphology as well as the luminescent properties of the phosphor system. The Ce³⁺ or/and Tb³⁺ ions-doped ZrP system clearly exhibited nanosheet structure, as can be confirmed from their XRD and SEM results. Excited with ultra-violet (UV) light 368 nm, the Ce³⁺/Tb³⁺-codoped ZrP showed intense green emission at 546 nm corresponding to the ⁵D₄→⁷F₅ transition of Tb³⁺. With the increase of Ce³⁺ doping concentration, the luminescent intensity and fluorescence lifetimes of Tb³⁺ were gradually increased. The results manifested that the obvious energy transfer phenomenon from Ce³⁺ to Tb³⁺ happened, and the energy transfer mechanism should be due to the dipole–quadrupole interaction. Moreover, the chromaticity coordinate of ZrP:Ce³⁺,Tb³⁺ nanosheet was also studied, and the emission color can be adjusted from blue-greenish to green by increasing the Ce³⁺ concentration. The ZrP:Ce³⁺,Tb³⁺ nanosheet may be used as a green-light emitting candidate for the optoelectronic devices such as electroluminescence panels or white light-emitting diodes.

[en] Highlights: • The structure of fluorphlogopite was modified by the decrease of layer charge. • Characteristic emission of Eu³⁺ was greatly enhanced as doped to the modified clay. • The emitting color changed from orange-red to red in respect to the original host. • This is a new strategy to enhance the luminescence of inorganic layered materials. - Abstract: In this paper, the lamellar fluorphlogopite was structurally modified by the adjustment of layer charge and the rare earth Eu³⁺ was doped to fluorphlogopite with a subsequent high temperature solid state reaction process. The structural modification involved a preliminary treatment of fluorphlogopite with HNO₃ and oxalic acid to reduce the layer charge density, and part of the charge-reduced fluorphlogopite was converted to a homoionic Na form by ion exchange with NaCl or NaB(C₆H₅)₄. It has been noticed that the interlayer spacing of modified fluorphlogopite is decreased as compared with the original fluorphlogopite due to the ionic radius difference between K⁺ and Na⁺. The photoluminescence study suggests that adjustment of layer charge of fluorphlogopite is beneficial to enhance the luminescence intensity excited with near UV light, and the layered system may be a potential red light component for the use of solid-state lighting and other optoelectronic fields.

[en] Objective: To establish a function model to modulate the tube current according to the chest circumference at Coronary CTA scan, and to evaluate the feasibility of using the function model individually. Methods: Sixty-eight consecutive patients who underwent thoracic scan with automatic current modulation were studied to establish a function model of tube current and chest circumference. The other 64 consecutive patients underwent coronary CTA scan using the new function model. The image quality was scored, and the noise, tube current and radiation dose were recorded and statistically evaluated. Results: The POW function model was the best one to adjust tuber current to the chest circumference (R"2 = 0.691, P < 0.05). The mean image quality score, noise, tube current, radiation dose (CTDI_v_o_l) and dose-length product (DLP) were (3.38±0.72) scores, (31.02±3.97) HU, (390.63±89.30) mA, (34.83±10.72) mGy, (751.67±175.16) mGy·cm, respectively. Conclusions: Tube current modulation based on the chest circumference would be feasible to reduce the radiation dose individually in coronary CT angiography. (authors)

[en] A nanowire array of metal-organic complex copper-tetracyanoquinodimethane (CuTCNQ) was obtained by depositing a layer of copper in the bottom of anodic alumina template channels during a vapor-induced reaction method. SEM observation showed that the channel diameters of anodic alumina membranes prepared under 40 V and 200 V are about 60 nm and 200 nm, respectively, and CuTCNQ nanowire arrays were synthesized in these channels. Nanodevice prototypes with electrical switching characteristics based on a CuTCNQ nanowire array were fabricated, whose reproducible electrical switching and memory effects were observed. The on-off ratio for switching reaches 10⁴. The potential applications in information storage devices are also discussed

[en] The purpose of this study was to examine the protective effects of intracellular homogeneous melanin produced by Lachnum YM156 (LIM) against ultraviolet B (UVB) induced damage in mice. The possible structural formula of the LIM was concluded based on elemental analysis, ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and mass spectrometry (MS). The LIM was modified by arginine to improve its water solubility and biological activities. LIM and ALIM show significant anti-radiation activity in which LIM and ALIM protect the skin under UV radiation. Results indicate that activities of anti-oxidant enzymes in skin were improved after treatment of LIM or ALIM. In addition, LIM and ALIM inhibited over expression of the pro-inflammatory cytokines, including interleukin (IL)-1α, IL-1β, and IL-6 and tumor necrosis factor-α (TNF-α). The protection ability of ALIM was higher than that of LIM at the same dose. Thus, applied LIM and ALIM may be a promising radiation-protective agent.

[en] Objective: To study the imaging findings of eosinophilic hepatic infiltration on multi- slice spiral CT. Methods: A retrospective analysis was performed to assess the multi-slice spiral CT imaging findings of 10 eases of pathologically confirmed eosinophilic hepatic infiltration. Evaluations were made regarding the lesions' number, site, shape, margin, size, density, enhancement pattern and the relationship between lesions and portal veins. Results: CT demonstrated a single lesion in 2 cases, multiple lesions in 5 and diffuse infiltrative lesions in 3. All lesions were located in subcapsular parenchyma or surrounding the portal vein. Most subcapsular lesions were wedge-shaped, and lesions in the deep parenchyma were irregular. Larger lesions were wedge-shaped or irregular while smaller ones were round or oval. Their size ranged from 4 to 48 mm. On pre-contrast images, these lesions showed slightly low density or isodensity with fuzzy edge. During the arterial phase of post-contrast CT, these lesions exhibited slight enhancement or no enhancement. All lesions were notable and showed relatively low density with homogeneous enhancement and well-defined margin, while centrally heterogeneous enhancement was found in 2 eases during portal venous phase. Isodensity was found in 8 cases during delayed phase, and slightly low density for minor lesions in 2 cases with diffuse lesions. Branches of portal vein was found infiltrated by all lesions, without filling defect or obstruction; low-attenuated stripes surrounding branches of portal vein were found in 3 cases. Conclusion: The multi-slice spiral CT findings of eosinophilic hepatic infiltration are relatively specific, and three-phase dynamic CT studies can be a valuable tool for the diagnosis of this disease. (authors)

[en] To investigate structure–property relationship of polymer-based curcumin solid dispersion (SD), three acrylic polymers were used to formulate curcumin SD by solvent evaporation method. Curcumin Eudragit EPO SD (cur@EPO), curcumin Eudragit RS PO SD (cur@RSPO) and curcumin Eudragit RL PO SD (cur@RLPO) showed deep red, golden orange and reddish orange color, respectively. Cur@RSPO entrapped 15.42 wt% of curcumin followed by cur@RL PO and cur@EPO. FTIR spectra indicated that in cur@EPO, curcumin may transfer hydrogen to the dimethylaminoethyl methacrylate group and thus change its color to red. In contrast, curcumin may form hydrogen bonding with Eudragit RS PO and Eudragit RL. Curcumin exists in amorphous state in three SDs as proved by differential scanning calorimetry and X-Ray diffraction measurement. In vitro digestion presented that lower pH value in simulated gastric fluid (SGF) stimulates the curcumin release from cur@EPO while permeability influences the release profile in other two SDs. When in simulated intestinal fluid (SIF), first order release model governs the release behaviors of all three SDs which showed sustained release pattern. Our results are helpful to elucidate how structure of polymer may impact on the major properties of curcumin contained SD and will be promising to broaden its therapeutic applications. (author)

[en] Objective: To evaluate the value of iterative reconstruction (iDose) in low-dose CT cardiac imaging in patients with congenital heart disease (CHD). Methods: Eighty-eight consecutive CHD patients referred for preoperative or post-operative CT were randomly diveded into 4 groups and undergone a prospective ECG-gated MDCT angiography with protocol A (routine low-dose depending on patient weight), B (30% of A), C (50%), and D (70%D), respectively. Filtered back projection (FBP) and grades 2, 4, 6 of iDose were used for all reconstruction. Noises were measured at the root of ascending aorta and main pulmonary artery. Image qualities were graded (scale from one to five) and compared among 4 groups. Results: The lowest image noise was measured in images reconstructed with grade 6 of iDose(P < 0.05) while the highest one was measured in that with FBP in all groups. The subjective scores in Group D with iDose 6 reconstruction were no less than 3. The subjective score in Group D with iDose 6 was similar to that in Group A with FBP. Effective radiation dose in group D was (0.65±0.43) mSv. Conclusion: Using iDose technique would reduce noise and improve image quality effectively. Grade 6 of iDose might be the best choice and would reduce effective dose by 70% in MDCT angiography in CHD patients. (authors)

[en] Objective: To investigate the clinical value of multi-detector computed tomography (MDCT) in the diagnosis of Takayasu's arteritis. Methods: MDCT, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels of 32 patients with Takayasu's arteritis were analyzed retrospectively. Image processing included multi-planar reformation (MPR), maximum intensity projection (MIP), and volume rendering reconstruction (VR). Results: The patients were classified Lupi-Herrea type I (10), type II (9), type III (8) and type IV (5). Of 134 abnormal vessels, 112 were stenotic or occlusive, 8 were dilated and 14 were mixed. The vessel wall thickness was 1.3-8.6 mm (average 3.65 ± 1.58 mm) with significantly (P < 0.05) thicker walls in the active phase (2.7-8.6 mm) than that in the resting phase (1.3-6.0 mm). There was heterogeneous contrast enhancement of the vessel walls in the active phase (80.0%), mild enhancement (9.0%) and calcification (31.8%) in the resting phase. Conclusion: MDCT can accurately demonstrate the type, phase and extent of lesions and can be used as the first imaging study for diagnosing Takayasu's arteritis. (authors)