The virtual noncontrast images generated with iodine subtraction from dual-energy CTA images are expected to replace the true noncontrast images for radiation-dose reduction. This study assessed the ...feasibility of virtual noncontrast images for diagnosing SAH.
Eighty-four patients with or without SAH underwent true noncontrast brain CT (the criterion standard for diagnosing SAH). Among them, 37 patients underwent an additional head dual-energy angiography, and the other patients underwent head and neck dual-energy angiography. Virtual noncontrast images were produced on a dedicated dual-energy postprocessing workstation and reconstructed in orientation and section width identical to those in true noncontrast images. The findings on the virtual noncontrast and true noncontrast images were compared at both the individual level and the lesion level. Image noise of the virtual noncontrast and true noncontrast images was also measured and compared. The volume CT dose index and dose-length product were recorded for the radiation-dose analysis.
The sensitivity, specificity, positive predictive value, and negative predictive value of virtual noncontrast images at the individual level and the lesion level were 94.5%, 100%, 100%, 90.6% and 86.7%, 96.9%, 91.8%, 94.8%, respectively. The agreement in the diagnosis of SAH on true noncontrast and virtual noncontrast images reached 92.3% at the individual level and 85.1% at the lesion level. The virtual noncontrast images showed a higher image noise level. The volume CT dose index and dose-length product were obviously reduced without the true noncontrast brain CT scan.
Virtual noncontrast images are a reliable tool for diagnosing SAH, with the advantage of reducing the radiation dose.
To elucidate the relationship between transport properties and phase transformations in mixed-conducting oxides, Sr
0.9Ca
0.1Co
0.89Fe
0.11O
3−
δ
(SCCFO) and SrCoO
3−
δ
(SCO) were chosen as the model ...materials and have been investigated in detail. Oxygen permeation measurements verified that both oxides are well permeable to oxygen at elevated temperatures, e.g., at 900
°C during a cooling procedure, oxygen permeation rates as large as 1.5 and 2.0
mL/min/cm
2 could be obtained with disk-shaped SCCFO and SCO membranes of thickness 1.5
mm, respectively. But when cooled to critical temperatures, the oxygen permeability of these kinds of oxides diminished sharply, which could be recovered by increasing the temperature again to certain values. Abrupt changes on electrical conductivity were also observed for both oxides around the same region of temperature as that of oxygen permeability. As indicated by high-temperature X-ray diffraction and thermal analysis, the SCCFO and SCO systems undergo phase transformation between a low-temperature orthorhombic brownmillerite structure (B) or a hexagonal 2H-type structure (H) and a high-temperature cubic perovskite structure (C), respectively. The present results suggest the observed abrupt changes in transport properties versus temperature are attributed to such phase transformation, which may be directly associated with the order–disorder transition of oxygen vacancies. Moreover, compared to the B/C transformation that mainly involves an order–disorder transition on the oxygen sublattice, the H/C one necessarily also involves the cooperative long-range reorganization on the cation sublattice. Therefore it occurs at a higher temperature and absorbs more heat quantity than those of B/C transformation.
Temperature dependence of oxygen permeation rates through Sr
0.9Ca
0.1Co
0.89Fe
0.11O
3−δ (SCCFO) and SrCoO
3−δ (SCO) membranes with a thickness of 1.5
mm.
Nuclear protein-1 (NUPR1), also named as p8 or Com1, has been since found overexpressed in several human malignant tumor cells, such as glioma. NUPR1 also regulates cell cycle progression, however, ...the role of NUPR1 in regulating glioma cell cycle remains poorly understood. Knockdown efficiency of U87 and U251 cells infected with the lentiviral vector was detected by quantitative real-time PCR and western blot in vitro and in vivo. Flow cytometry and western blot were used to explore a mechanism by which NUPR1 modulates cell cycle in U87 and U251 cells. Immunohistochemistry was applied to detect expression levels of P27, CDK2, and cyclin E in human glioma tissues with NUPR1 positive expression and tumorigenesis in nude mice. We confirmed that the downregulation of NUPR1 arrested the cell cycle in the G0/G1 phase in U87 and U251 cells in vitro. Furthermore, the expression level of P27 was increased, and CDK2 and cyclin E were decreased upon silencing NUPR1 expression in vitro and in vivo. In conclusion, the knockdown of NUPR1 induces cell cycle arrest in the G0/G1 phase in glioma cells via P27.
•We studied the cotton finishing with TiO2/SiO2 based on ionic cross-linking method.•The samples treated with CHTAC had lower value of whiteness.•The samples treated with BTCA achieved higher crease ...recovery angle and lower tensile strength.•The ionic cross-linking treatment (CHTAC+BTCA+TiO2/SiO2) was better than with TiO2/SiO2 sol alone.
Cotton fabric was successfully modified by 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHTAC), 1,2,3,4-butanetetracarboxylic acid (BTCA) and TiO2/SiO2 sol. Self-cleaning characteristic was investigated using a Color Measuring & Matching System with 6h sunlight irradiation. And the stability of TiO2/SiO2 coatings was explored by measuring the washing fastness and wrinkle resistance of treated cotton samples. In addition, whiteness index, crease recovery angle and tensile strength retention (%) of treated samples were evaluated. Moreover, the morphology, structure change and crystallinity of samples were observed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), respectively. The results revealed that the samples treated with CHTAC had lower value of whiteness index as compared with original cotton fabric. It was also found that samples treated with BTCA achieved higher crease recovery angle and lower tensile strength. Moreover, the treatment of CHTAC and BTCA had adverse effect on the crystallinity of cotton samples, as treated samples had lower crystallinity in comparison with raw cotton fabrics. Nevertheless, the stability of self-cleaning coatings was better for samples treated with ionic cross-linking treatment (CHTAC+BTCA+TiO2/SiO2) than samples treated with TiO2/SiO2 sol alone. Furthermore, compared with original samples the UV-blocking property of ionic cross-linking treated samples was obviously enhanced.
Effects of nitrogen incorporation on the interfacial chemical bonding states, band alignment, electrical properties and leakage current conduction mechanisms of HfGdO-based metal-oxide-semiconductor ...(MOS) capacitors has been investigated by UV–Vis transmission spectroscopy, X-ray photoemission spectroscopy (XPS), and electrical measurements. XPS results indicate that incorporation of a moderate amount of nitrogen incorporation into HfGdO gate dielectrics can effectively suppress the formation of low-k GeO2 and Hf(Gd)-Ge-O interfacial layer at the interfacial region. Meanwhile, reduction in band gap and valence band offset and increase in conduction band offset have been observed after nitrogen incorporation. Electrical measurements based on MOS capacitors have shown that MOS capacitor with HfGdON/Ge stacked gate dielectric with N2 flow rate of 3 sccm exhibits small gate leakage current (1.08 × 10−3 A/cm2 at Vg = 1 V), almost disappeared hysteresis, and large dielectric constant (29.2). The involved leakage current conduction mechanisms for MOS capacitor devices with and without nitrogen incorporation also have been discussed in detail.
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•Sputtering-derived HfGdO gate dielectrics have been deposited on Ge substrates.•Nitrogen incorporation can effectively suppress the formation of interfacial layer.•Reduction in band gap and valence band offset have been observed after nitrogen incorporation.•HfGdO/Ge gate stack with N2 flow rate of 3 sccm displays excellent performance.
Various enzymes are encapsulated in ordered mesoporous silica analogous to a fish in a net, where the enzymes are entrapped in macroporous cages that are connected by uniform mesoporous channels (see ...Figure). Most importantly, these encapsulated enzymes act as nanoreactors, showing not only comparable activities with native enzymes, but also excellent long‐term recycling stabilities.
Abstract Using (27.12 ± 0.14) × 108 ψ(3686) events collected with the BESIII detector at BEPCII, the decay of ψ(3686) → Ω − K + Ξ ¯ 0 $$ {\varOmega}^{-}{K}^{+}{\overline{\Xi}}^0 $$ + c.c. is observed ...for the first time. The branching fraction of this decay is measured to be B ψ 3686 → Ω − K + Ξ ¯ 0 + c . c . $$ {\mathcal{B}}_{\psi (3686)\to {\varOmega}^{-}{K}^{+}{\overline{\Xi}}^0+\textrm{c}.\textrm{c}.} $$ = (2.78 ± 0.40 ± 0.18) × 10 −6, where the first uncertainty is statistical and the second is systematic. Possible baryon excited states are searched for in this decay, but no evident intermediate state is observed with the current sample size.
Carbon nanotube (CNT)-reinforced 6061Al (CNT/6061Al) composites with directionally aligned CNT were fabricated, and their wear behavior was investigated. The results indicate that the wear properties ...of CNT/6061Al composites exhibited a significant anisotropy. A certain CNT concentrations (1 wt% and 2 wt%) could effectively improve the wear resistance of CNT/6061Al composites along the CNT circumferential and CNT radial directions for the load transfer, grain refinement and self-lubrication effect of CNT. The Brass {011} < 211 > and {112} < 110 > textures inhibited the load transfer effect of CNT along the CNT radial direction, resulting in a better wear resistance along CNT circumferential direction than CNT radial direction. Along the CNT axial direction, the weak deformability of composites caused by the intensifying < 111 > fiber texture was the main reasons for the poor wear resistance of CNT/6061Al composites with increasing CNT concentration.
This paper presents a displacement based back-analysis method for the determination of rock mass modulus (
E) and the horizontal in situ stress (
P) perpendicular to the axis line of the tunnel ...excavation in hard and intact rock masses. The rock mass is assumed to respond in an isotropic and linear elastic manner. Essentially, the method is a best-fit solution of back-analysis by comparing the measured displacements near a tunnel face during excavation with those calculated using a three-dimensional finite element method. The method can be applied efficiently and effectively by iterative algorithms such as direct search technique and damping least square technique. In particular, a three-dimensional finite element pattern technique (3-D FEPT) is used to compute the theoretical displacements for saving computation time. The method is further illustrated with a case study. The case study deals with a test adit at Zhanghewan Pumped Storage Power Station in Hebei Province, North China. It is shown that the back-analyzed results of
E and
P are reliable and representative for the actual rock masses.
We report on the quasi-linear in field intrachain magnetoresistance in the normal state of a quasi-one-dimensional superconductor Ta4Pd3Te16 ( K). Both the longitudinal and transverse in-chain ...magnetoresistance shows a power-law dependence, B, with the exponent close to 1 over a wide temperature and field range. The magnetoresistance shows no sign of saturation up to 50 T studied. The linear magnetoresistance observed in Ta4Pd3Te16 is found to be overall inconsistent with the interpretations based on the Dirac fermions in the quantum limit, charge conductivity fluctuations as well as quantum electron-electron interference. Moreover, it is observed that the Kohler's rule, regardless of the field orientations, is violated in its normal state. This result suggests the loss of charge carriers in the normal state of this chain-containing compound, due presumably to the charge-density-wave fluctuations.
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