The geometrical properties of streamlines, such as the curvatures, directions and positions, are studied in steady inviscid compressible flow fields via differential geometry theories and conservation laws. The influences of the streamline geometries on the flow speeds and pressures are also identified and discussed. By transforming the streamlines to fill the domain and satisfy the boundary conditions, a unified geometry-based solver, the streamline transformation method, is proposed for both subsonic and supersonic regions. The governing equations and boundary conditions along streamlines and shock waves are also derived. This method is verified by numerical results of three typical flow fields, including the subsonic channel flow, the supersonic downstream of attached shock waves and especially the subsonic/supersonic downstream of detached bow shock waves. Both two-dimensional planar and axisymmetric flow fields are considered. Compared with the results from computational fluid dynamics, good agreements are achieved by this method, while fewer computational resources, by an order of magnitude, are consumed. Features of these flow fields are also analysed from a geometrical perspective, such as flow speeds and pressures deviated by the wall curvatures, and three-dimensional effects in the after-shock flow fields. For a hyperbolic-shaped bow shock wave, the stand-off distances and the transitions from subsonic to supersonic regions are also discussed. As indicated by the accuracy, efficiency and applicability in a wide range of flow speeds, the streamline transformation method would be a potential candidate for the theoretical analysis and inverse design of high-speed flow fields, especially where the subsonic regions exist downstream of strong shock waves.

High-performance mullite-based composite ceramics were prepared successfully using natural kaolin and alumina as raw materials and ZrO2 as an additive. The influence of sintering temperature and ZrO2 content on the sintering behaviour and mechanical properties of zirconia-toughened mullite ceramics was studied systematically. With increasing sintering temperature from 1450°C to 1560°C, the primary phases of as-sintered composite ceramics were mullite and corundum with a small amount of ZrO2, and the bulk density of the composite ceramics increased from 2.29 to 2.72 g cm–3. Furthermore, the ZrO2 phase transition promoted transgranular fracture, and ZrO2 grains were pinned at the grain boundaries, thereby enhancing the mechanical strength of the composite ceramics. Moreover, the AZS12 sample, with 12 wt.% ZrO2 and sintered at 1560°C, had the greatest flexural strength and fracture toughness of 91.6 MPa and 2.47 MPa m–1/2, respectively. Adding ZrO2 to the composite ceramics increased their flexural strength by ~37.6%.

The overuse of antibiotics and the rapid emergence of antibiotic resistance prompted the launch of an antimicrobial stewardship programme in 2011. This study aimed to investigate the trends and correlations between antibiotic consumption and resistance of Staphylococcus aureus in a tertiary hospital of northwest China from 2010 to 2016. Trends were analysed by linear regression, and correlations were assessed by an autoregressive integrated moving average model. The total consumption of antibiotics halved during the 7-year study period, while the rates of resistance of S. aureus decreased significantly or remained stable; methicillin-resistant S. aureus (MRSA) declined markedly, from 73.3% at the beginning of the study to 41.4% by the end. This latter decrease was significantly correlated with the consumption of several classes of antibiotics. In conclusion, reduction in antibiotic use impacted significantly on resistance rates and contributed to a decline in MRSA prevalence.

Familial monozygotic (MZ) twinning reports are rare around the world, and we report a four-generation pedigree with seven recorded pairs of female MZ twins. Whole-genome sequencing of seven family members was performed to explore the featured genetic factors in MZ twins. For variations specific to MZ twins, five novel variants were observed in the X chromosome. These candidates were used to explain the seemingly X-linked dominant inheritance pattern, and only one variant was exonic, located at the 5′UTR region of ZCCHC12 (chrX: 117958597, G > A). Besides, consistent mitochondrial DNA composition in the maternal linage precluded roles of mitochondria for this trait. In this pedigree, autosomes also contain diverse variations specific to MZ twins. Pathway analysis revealed a significant enrichment of genes carrying novel SNVs in the epithelial adherens junction-signaling pathway (p = .011), contributed by FGFR1, TUBB6, and MYH7B. Meanwhile, TBC1D22A, TRIOBP, and TUBB6, also carrying similar SNVs, were involved in the GTPase family-mediated signal pathway. Furthermore, gene-set enrichment analysis for 533 genes covered by copy number variations specific to MZ twins illustrated that the tight junction-signaling pathway was significantly enriched (p < .001). Therefore, the novel changes in the X chromosome and the provided candidate variants across autosomes may be responsible for MZ twinning, giving clues to increase our understanding about the underlying mechanism.

Objectives: Curative hepatectomy and tumor thrombectomy for hepatocellular carcinoma with complicating biliary tumor thrombosis (HCC/BTT) is associated with high surgical morbidity and mortality. This retrospective study evaluated the effectiveness and safety of neoadjuvant transcatheter arterial chemoembolization (TACE) in HCC/BTT patients scheduled for curative resection.

Methods: Thirty consecutive patients with diagnosed HCC/BTT were hospitalized for neoadjuvant TACE and elective curative liver resection (group A; n=20) or curative liver resection alone (group B; n=10). The primary outcome measure was median survival.

Results: Group A had a significantly shorter overall operative time (160±25 versus 190±35 min; p < .01) and duration of inflow control (14.3±3.6 versus 25.1±5.1 min; p < .01) and significantly less intraoperative blood loss (150±35 versus 520±75 ml; p < .01) and transfusion (100±40 versus 375±55 ml; p < .01) as compared to group B. Among patients undergoing both thrombectomy and curative resection, the median survival of group A was significantly longer than that of group B (28.5 [9–54] versus 21.5 [6–39] months; p < .01); among those who received thrombectomy alone, the median survival of group A was also significantly longer than that of group B (12.8 [6–25] versus 4.5 [2–7] months; p < .01).

Conclusions: Neoadjuvant TACE significantly reduced the surgical risk of curative liver resection and significantly prolonged median survival in HCC patients with complicating BTT.

This paper describes the use of self-patterning anodic aluminum oxide (AAO) layers to enable localized metal contacts and to achieve passivation for the rear surface of silicon solar cells. There are no commercially available technologies that are capable of patterning localized contacts on silicon solar cells with low cost, high-throughput, and robust processing, especially when closely spaced small-area openings are required. In the approach described, nanoporous AAO layers were formed by anodizing aluminum over intervening dielectrics on textured silicon wafers. When the anodized test structures were fired in a belt furnace, localized contacts formed at peaks and valleys of the alkaline-textured silicon surface. Furthermore, the anodization contributed ∼35 mV increment in the implied Voc of the test structures. Low contact resistivity was demonstrated and the proposed contacting mechanism for this innovative localization suggested that the contact percentage can be controlled by varying the anodization duration and/or the surface morphology.

KLa2Ti3O9.5 and KLa2Ti3O9.5:Er3+ nanocrystals were successfully synthesized using a hydrothermal method and a subsequent calcination treatment. The band gap (Eg) of the KLa2Ti3O9.5 nanocrystals was calculated to be about 2.56 eV by means of the reflectance diffusion technique. Under 980-nm excitation, the KLa2Ti3O9.5:Er3+ nanocrystals emitted intense green (2H11/2/4S3/2 → 4I15/2) and red (4F9/2 → 4I15/2) upconversion (UC) luminescence. In comparison with pure KLa2Ti3O9.5, the KLa2Ti3O9.5:Er3+ nanocrystals exhibited a higher activity for water splitting into H2 under simulated solar light irradiation. We suggest that the enhancement of photocatalytic activity is related to the Brunauer-Emmett-Teller (BET) surface area and UC luminescence of KLa2Ti3O9.5:Er3+.

Carbon-coated lithium iron phosphate (C-LiFePO4) particles have been synthesized by a solid-state reaction process. Particles surface morphology, olivine-type phase structures and the carbon shell-core structures are investigated in details by transmission electron microscopy (TEM, HRTEM) imaging and electron diffraction (SAED) patterns. Homogenous features of carbon coating of the LiFePO4 particles surface are obviously revealed. HR-TEM imaging and X-ray photoelectron spectroscopy (XPS) confirmed an amorphous sp2 type conducting coating layer on the surface of LiFePO4 particles. Particles shape and size showed the clear single-crystal nature of the phospho-olivine type structures with the rough spherical features of 50-250 nm size range. The characteristics of sp2 type carbon-coating on the LiFePO4 particles surfaces allows improving the electrical conductivity and reducing the diffusion path of the lithium ions, as directly evidenced from electrochemical tests of charge-discharge cycling.

The Y-doped (Hf0.6Zr0.4)1-xYxNiSn (x = 0, 0.01, 0.02, 0.04, 0.06, 0.1, and 0.2) half-Heusler alloys have been prepared by levitation melting and spark plasma sintering. The effect of Y doping on thermoelectric properties of the alloys was investigated in the temperature range of 300–900 K. Y-doped samples had the lower electrical conductivity compared with the parent compound without Y doping. The thermal conductivity had weak dependence on Y doping content. The absolute values of Seebeck coefficient decreased significantly when x < 0.04. The sign of Seebeck coefficient turned from negative to positive at room temperature for x = 0.04 and 0.1, which means that the hole carriers became dominant in these alloys. However, the alloys changed to n-type conduction again at high temperatures. The maximum figure of merit value of about 0.45 was obtained at 780 K for the undoped sample.

Europium-doped lutetium oxide (Lu2O3:Eu3+) nanophosphors were synthesized via modified combustion technique using urea as the fuel and metal nitrates as oxidants. The pellets prepared from the calcined nanocrystalline powders were vacuum sintered up to 1750 °C leading to very translucent ceramic. The products were characterized by x-ray diffraction to ascertain phase purity. The microstructures reveal the nanocrystalline nature of the powders. We have illustrated the crystallite size dependence and the influence of Eu3+ activation of Lu2O3:Eu3+ nanophosphors on Raman scattering. We have also demonstrated the particle size dependence of emission characteristics of nanophosphors and ceramics. Our results suggest that although the processed ceramics display superior emission characteristics, the nanocrystalline phosphor powders calcined at 1100 °C also display reasonably good emission characteristics, illustrating the possibility of their applications in display technology.