Search

As an appealing biomimetic strategy for various medical applications, cell membrane coating lacks sensitive on-demand breaking capability. Herein, we incorporated thermosensitive lipid (TSL) membrane into red blood cell (RBC) and MCF-7 cancer cell (MC) hybrid membrane ([RBC-MC]M) vesicles. The [RBC-MC-TSL]M was coated onto doxorubicin (Dox)-loaded hollow gold nanoparticles to enhance chemo-/photothermal combined tumor therapy at a mild hyperthermia temperature (≤49 °C). Double-layer coating with TSL and [RBC-MC-TSL]M as the inner and outer layer, respectively, presented better antileakage and higher NIR-responsivity than single-layer coating. The Dox release ratio upon NIR laser irradiation (≤49 °C) was 74.6%, much higher than that (33.5%) without NIR laser. The nanodrug can be efficiently and specifically taken up by MCF-7 cells. In addition, the nanodrug exhibited excellent tumor-targeting property, with 4.08- and 1.12-times Dox accumulation in MCF-7 tumors compared to free Dox and [RBC-MC]M-coated counterpart, respectively. Most importantly, TSL incorporation significantly enhanced NIR-responsive antitumor efficiency, with tumor growth inhibition ratio increased from 35.1% to 48.6% after a single dose administration. Besides, the nanodrug exhibited very good biocompatibility. Camouflaging nanoparticles with the thermosensitive biomimetic hybrid membrane provides a painless and promisingly clinical-applicable approach for effective chemo-/photothermal combined mild-hyperthermia tumor therapy.

CsPbBr3 perovskite is considered as a promising material for solar cell and light-emitting diode. Yet the application is hindered by light (or heat)-induced transition from cubic phase to orthorhom...

In the binocular vision system, the parallax image is different when the real face of the three-dimensional structure is viewed from different viewing angles, while the face in photos and videos is flat or the planar structure is the same when viewed from different angles, so it is proposed A new method that uses a manual face binocular disparity map made by a synchronized binocular visible light camera combined with a convolutional neural network (convolutional neural network, CNN) to achieve two classifications. First, the Harr cascade classifier is used to extract faces in binocular images at the same time, and the extracted partial faces are made into a data set; then, the disparity map form that meets the experimental hypothesis is proposed and analyzed; finally, the ResNet18 network is used to compare different methods Binocular live body detection solution for human face. The accuracy rate of 99.12% is achieved on the self-made data set in the laboratory, and it has a good resistance to facial attacks on photos and videos. The results show that the method has a small amount of data, low hardware cost and good robustness to human faces due to changes in light and angle.

Objectives: To investigate the diagnostic accuracy of ultrasound for evaluation of inflammatory activity in patients with Crohn’s disease (CD). Methods: Fifty-six patients with histologically proven CD (39 with active, 17 with inactive disease) and 30 healthy volunteers as a control group were enrolled in the study at WeiFang People’s Hospital, Weifang Province, China from October 2012 to December 2014. Bowel wall thickness, and vascularity pattern were measured by Doppler ultrasound. Results: There was a significant difference in flow volume of the superior mesenteric artery (585 ± 235 ml/min) in the patients with active disease, compared with those with inactive disease (401 ± 238 ml/min) and the control group (390 ± 189 ml/min, p less than 0.001). Wall thickness was 5.1 ± 1.5 mm in the active CD group, 3.3 ± 1.6 mm in the inactive disease group ( p less than 0.001) and less than 3 mm in the control group. Resistance index in the thickened bowel wall showed some differences: 0.68 ± 0.05 in the active disease group, 0.78 ± 0.08 in the inactive disease group, and 0.85 ± 0.07 in the control group ( p less than 0.05). Conclusion: Doppler ultrasound is a useful diagnostic tool in detecting CD and assessing inflammatory activity. Saudi Med J 2017; Vol. 38 (4): 391-395 doi: 10.15537/smj.2017.4.17855 How to cite this article: Na Y, Zhou J, Xiao XM, Zhang WX, Gao HL, Wang Y, et al. Assessment of Crohn's disease activity by Doppler sonography. Saudi Med J. 2017 Apr;38(4):391-395. doi: 10.15537/smj.2017.4.17855.

Aiming at the complexity and non-stationarity of gearbox vibration signal, a manifold semi-supervised K-means clustering algorithm based on 27-feature fusion is proposed to identify the fault of gear. Vibration signals of gear boxes under different working conditions were collected, and the time-frequency domain features, WPT (Wavelet Packet Transform) energy features and EEMD (Ensemble Empirical Mode Decomposition) energy features were fused into 27-dimensional features, semi-supervised K-means clustering algorithm based on manifold distance was used to classify fault signals. The results show that the fused features can reflect the fault features better, and the improved K-means algorithm has higher efficiency and better fault recognition effect.

The pursuit for increasing storage capacities of metal ion batteries is directly linked with the search for technologically superior next generation electrode materials. In this context, ab-initio first-principles calculations provide the means for exploring and designing novel 2D materials that can enhance energy storage capacities. In this work, we employ density functional theory calculations to draw a rationale for graphene-like B3P monolayer which shows high dynamical, thermal and mechanical stability. Our calculations predict larger cohesive energies of 2D B3P monolayer as compared to the well-known 2D boron-phosphide and recently predicted borophosphene, indicating its easy experimental synthesis as a graphene-like monolayer. Using both DFT and the thermodynamic energy decomposition scheme, we show that B3P with large lattice parameters and intrinsic metallicity is a potentially excellent 2D material for applications in energy storage devices. The results of our first-principles calculations designate B3P as a superior anode material owing to its high theoretical capacity for both Li and Na ion batteries combined with good open-circuit voltages and low metal ion migration barriers for Li and Na ions. Furthermore, sustained metallicity and thermal stability under loaded intermediate metal ion content indicates B3P monolayer to be a promising 2D material for extending battery operating cycles.

The electronic structures and thermoelectric properties of (SrO)m(SrTiO3)n superlattices have been investigated using first-principles calculations and the Boltzmann transport theory. Due to the much reduced dispersion along the c-axis, the thermoelectric properties for n-type superlattices are found to be highly anisotropic with the in-plane electrical conductivity with respect to relaxation time much higher than the out-of-plane one. The reduction of the in-plane Seebeck coefficient compared with SrTiO3 results in a slightly reduced power factor with respect to relaxation time for n-type doped (SrO)m(SrTiO3)n. However, both Seebeck coefficient and electrical conductivity with respect to relaxation time are relatively maintained for p-type doping, leading to a comparable power factor with respect to relaxation time. If the reduced thermal conductivity is taken into account, an improved ZT value can be expected for the (SrO)m(SrTiO3)n superlattice.

The polymer-coated AgZnO nanoparticles were synthesized via a one-pot process with the assistance of the triblock copolymer, poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO). The nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) including the mode of high resolution (HRTEM) and by energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible light absorbance spectrometry (UV-vis) and photoluminescence spectrophotometry (PL). It is found that the nanoparticles reveal high crystallinity, good dispersibility, and excellent optical performance both in organic and aqueous solvents. The photocatalytic behavior of the AgZnO nanoparticles was scrutinized using rhodamine B (RhB) as probe molecule. The results show that the degradation efficiency of the AgZnO nanoparticles is higher than that of the ZnO nanoparticles under both UV and sunlight irradiation, 89.5% and 66.9% for the former and 52.7% and 37.5% for the latter after 90 minute exposure, respectively. Moreover, the AgZnO nanoparticles were found to have the photocatalytic efficiency unaltered after 5 cycles of use as tested. Our results demonstrate that the nanostructured AgZnO nanoparticles exhibit enhanced photocatalytic performance and high stability. Consequently, the AgZnO nanoparticles are favorable candidates for potential application as a promising photocatalyst.

The bismuth nanoparticles are synthesized via a solvothermal reduction method based on the chemical reduction of Bi3+ by ethylene glycol acting as the solvent and the reducing agent. The structural and morphological properties of the bismuth nanoparticles are investigated by X-ray diffraction and scanning electron microscope. The results demonstrate that the synthesized powders has a rhombohedral crystalline structure and their diameters are in the range of 75-103 nm under the condition of the different initial bismuth nitrate concentrations with the reduction temperature of 200°C, indicating that the thermal reduction temperature and the initial bismuth nitrate concentrations are key factors for phase composition as well as crystal size.

Based on stream of variation theory, parametric state space model of multi-station assembly process was built up. For problems of system-level evaluation index, the sensitivity evaluation index, soundness index as three methods of assembly system performance evaluation, the comprehensive stability index was presented. Parametric state space model was as a tool and the comprehensive stability index was as evaluation index to optimize the assembly lines, reduce the geometric deviation of product, improve the quality of product. Experiment verified comprehensive stability index can accurately evaluate the performance of assembly systems, improve the efficiency of optimizing assembly lines.

The title ligand (H2L) and its complex [CdL(py)2]py (L= C12H9N3OS dianionic) have been synthesized and characterized. The complex structure determination indicates that Cd( II ) atom has a distorted octahedral coordination geometry. As an unusual tetradentate ligand, one L2 chelates one Cd( II ) atom using the O, S atoms and one N atom of the hydrazino group while its another N atom links to the neighbouring Cd atom. The bridging hydrazono groups extend the compound into a catena chain. The naphthoxy rings of each neighboring unit are alternatively arranged at opposite sides of the chain, and the ring planes on the same side are parallel.

This paper attempts to study the feasibility of cloud base height (cloud base height–CBH) remote sensing by ground-based sky thermal infrared brightness temperature (thermal infrared brightness temperature-Tb) observation and the quantitative effects of aerosol layer on it. Using MODTRAN4.0 model simulation, the variations of Tb with zenith angle of observation for different types of aerosol and different visibilities (visibility-VIS) under clear and cloudy sky conditions were systematically investigated. Based on the simulated results, the statistic equations for clear and cloudy sky Tb calculation were obtained respectively, and then a preliminary method of CBH estimation was developed. The results of simulation and preliminary experiments show that for low and middle clouds, the sky Tb observed on the ground is very sensitive to the change of CBH, therefore it can be used to estimate CBH. The influence of aerosol (VIS and aerosol types) above the ground on the sky Tb cannot be neglected, it must be corrected. Because the regularity of aerosol's influence on Tb at different zenith angles is fairly clear, it can be corrected well.

A Ti–6Al–4V particulate (TAp) reinforced magnesium matrix composite was fabricated using a powder metallurgy route. Tensile strength of the composite was markedly higher than that of the unreinforced magnesium alloy, and TAp seemed to be more beneficial for the ductility of magnesium matrix composites than SiC particles.

A novel Ti–6Al–4V particle (TCp) reinforced MB15 magnesium matrix composite, TCp/MB15, was fabricated using powder metallurgy route. Microstructural characterization revealed that a uniform distribution of TCp, good interfacial bond between TCp and the matrix, and a smaller grain-size compared to the unreinforced MB15 were achieved in the composite. Mechanical properties investigation showed the ultimate tensile strength, 0.2% yield strength and elastic modulus of MB15 were markedly increased by the addition of TCp, and the strengthening effect of TCp was better than that of SiC particles. The primary aim of this work was to compare the microstructural and mechanical properties of TCp/MB15 with those of MB15 alloy.

The nanocrystalline Cu 2 O was successfully prepared by calcining the precursor synthesized by a ball-milling step using Cu 2 (OH) 2 CO 3 and H 2 C 2 O 4 ·2H 2 O as initial reactants without any other additives. The as-synthesized precursor and the resulting calcined product are characterized by XRD and TG/DTA. The result shows that the reaction between Cu 2 (OH) 2 CO 3 and H 2 C 2 O 4 ·2H 2 O is complete after 15 min of milling and the precursors are of the crystalline sizes between 17 and 37 nm. The Cu 2 O is obtained with crystallite sizes of 15–21 nm after the ball-milled precursors is calcined at 310 °C for a certain time. The XRD also shows that the ball-milling time and the calcining time influence the crystallite sizes of the products to a certain extent. The average crystallite sizes of Cu 2 O decreases gradually with the increase of ball milling time, while they increase gradually with the increase of calcining time. In addition, the prepared Cu 2 O exhibits a high catalytic activity for the photodegradation of methyl orange under visible light irradiation, and the photocatalytic degradation ratio of methyl orange reaches to 88.7% after 2 h of irradiation.

The tungsten heavy alloy with the composition of 76.6W–17.3Ni–6.1Fe in atom percent was mechanically alloyed (MA) from the elemental powders of W, Ni and Fe. Nanocrystalline supersaturated solid solutions and amorphous phase were obtained during MA. Phase evolution, grain size and lattice distortion of these powders were determined and discussed. A thermodynamic model was developed based on semi-experimental theory of Miedema to calculate the driving force for phase evolution. The thermodynamic analysis showed that there is no chemical driving force to form the solid solution and the amorphous phase. The effect of the work of milling on the amorphization during MA was discussed and the model of multilayer amorphization during MA was applied to illustrate the feasibility of amorphization of powder with neither ΔHmix⪡0 nor DB⪢DA. The driving force for amorphization is provided not by the negative heat of mixing or the stored energy in the grain boundaries but by the sharp concentration gradients in this system. Amorphization is mechanically driven and not by the negative heat of mixing. Crystallization is suppressed by sharp concentration gradients.

Bi-phase dispersible Cu-ZnO hybrid nanoparticles were synthesized by one-pot non-aqueous nanoemulsion with the use of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The transmission electron microscopy (TEM) and X-ray diffraction (XRD) show high crystallinity of the Cu-ZnO hybrid nanoparticles and an average particle size of ~19.4 nm. The ultraviolet-visible light absorbance spectrometry (UV-vis) and photoluminescence spectrophotometry (PL) demonstrate well dispersibility and excellent optical performance of Cu-ZnO hybrid nanoparticles both in organic and aqueous solvent. The X-ray photoelectron spectroscopy (XPS) confirms Cu(1+) and Cu(2+) in ZnO. The observation using Sudan red (III) as probe molecule reveals that the Cu-ZnO hybrid nanoparticles possess enhanced photocatalytic activity and stability which are promising for potential applications in photocatalysis.

The title complex with formally heptadentate dinucleating ligands L, [Ni2L2](py)2(H2O)2 (L=C31H28N2O7 dianion), was synthesized, characterized by elemental analyses and IR spectroscopy, and structurally determined by X-ray diffraction technique. In the center-symmetric unit [Ni2L2], two phenolates and two Schiff-base imino groups of each L, as a practical tetradentate ligand, bond two Ni atoms to form square-distortionally tetrahedral coordination geometries, D2d symmetry. This nickel(II) complex and its homologue [Cu2L2](py)2(H2O)2 were both studied by TG–DTG technique under non-isothermal conditions. The relationship between weight loss and coordinations of L in each complex was inferred in the thermal decomposition processes. The most probable kinetic mechanism, Zhuralev–Lesokin–Tempelman equition, was determined by using the combined differential and integral methods, and the related values of activation energy E and pre-exponential factor A were calculated, respectively, for each complex.

The title Schiff base ligand, H2L, and its complex [CuL] have been prepared and characterized by elemental analysis and i.r. spectroscopy. The electrochemical properties of the single crystal [CuL]·0.5C2H4Cl2 have been investigated by cyclic voltammetry (c.v.). Upon scanning at negative and positive potentials, two reduction and two oxidation waves were observed at E1/20 = −0.47 and −0.77 V and E1/20 = 1.10 and 1.39 V, respectively. Two Kcom values for the reduction and oxidation process are 1.2×105 and 8.0×104, respectively, and indicate that the deprotonated ligand, L, has the ability to stabilize the mixed valent states of both CuIICuI and CuIICuIII. The crystal structure has been solved by X-ray diffraction, with a final R = 0.0653. Wound around a copper atom, the effectively tetradentate chain ligand, L, coordinates only via its two imino and two phenolate groups at both ends of the chain. The geometry, D2d symmetry, is best described as trans 'N2O2' square-planar with slight tetrahedral distortion. The reason, why the mononuclear [CuL] unit can display two c.v. waves in each process, has been explained on the basis of configuration interchange between mono- and dinuclear units in c.v. electrolyte solution.

The complex Ni 2 L(ClO 4 ) 2 was obtained by the reaction of Ni(ClO 4 ) 2 and the macrocyclic ligand H 2 L, where L 2− is the dinucleating macrocycle with two 2,6-di(aminomethyl)-4-methyl phenolate entities combined by the same two lateral chains –(CH 2 ) 2 –NH–(CH 2 ) 2 –, at the amino nitrogens. The crystal structure of complex Ni 2 L(ClO 4 ) 2 was determined by X-ray diffraction. The macrocycle adopts a twisted configuration and the geometry about each nickel atom is square pyramidal with the N 3 O 2 donor sets of the macrocycle. The nickel–nickel separation bridged by the two phenolic oxygens is 3.092 A and the Ni–O–Ni angle is 100.7(2)°. The two Ni–O (phenolate) bond lengths are 2.001(3) and 2.016(3) A, respectively. The three Ni–N bond distances are 2.055(4), 2.060(5) and 2.063(4) A. The cyclic voltammogram of the complex shows two reversible one electron oxidation steps ( E 1/2 =0.835, 1.05 V, versus SCE, Pt/MeCN) with the formation of Ni(II)–Ni(III) and Ni(III)–Ni(III) species.

A new ligand, 1,3-di[o-(o-vanillideneimino)phenoxo]-2-propanol, H2L, has been prepared stepwise and identified by elemental analyses (EA), IR and 1H NMR spectra. The title complex [Cu2L2](py)2(H2O)2 has been synthesized by reaction of H2L and Cu(OAc)2H2O, and characterized by EA and IR. The redox properties of the dinuclear complex have been investigated by cyclic voltammetry. Two successive, one-electron, quasi-reversible processes indicate an interaction between two copper centers. The title complex structure is solved by X-ray diffraction. In the centro-symmetric unit [Cu2L2], only phenolic and imino groups bind Cu atoms to form two distortional square coordination geometries, parallel to each other; and the Cu · · · Cu separation is 9.87 A.

The adsorption of DNA bases on a magnetic probe composed of Fe atoms and graphene is studied by using first-principles calculations. The stability of geometry, the electronic structure and magnetic property are investigated. The results indicate that four DNA bases, i.e., adenine, thymine, cytosine and guanine, can all be adsorbed on the probe solidly. However, the magnetic moments of the composite structure can be observed only when adenine adsorbs on the probe. In the cases of the adsorption of the other three bases, the magnetic moments of the composite structure are zero. Based on the significant change of magnetic moment of the composite structure, adenine can be distinguished conveniently from thymine, cytosine and guanine. This work may provide a new way to detect DNA bases.

This paper reports the progress in D-band CW silicon IMPATT diode. The small-signal. computer simulation of a diode has been performed. The preliminary experiments of the single-drift IMPATT diode show a aw output power of 73 mW at 116.7GHz and 34mW at 126GHz, respectively.