[en] A simple and effective method for obtaining the exact soliton solutions of the coupled relativistic scalar field theory is presented. The exact solutions obtained are new and important. The method suggested here can be applied to other coupled nonlinear systems as well

[en] Production of type I collagen declines is a main characteristic during photoaging, but the mechanism is still not fully understood. Circular RNAs (circRNAs) are a class of newly identified non-coding RNAs with regulatory potency by sequestering miRNAs like a sponge. It's more stable than linear RNAs, and would be a useful tool for regulation of gene expression. However, the role of circRNAs in collagen expression during photoaging is still unclear. Here we performed deep sequencing of RNA generated from UVA irradiated and no irradiated human dermal fibroblasts (HDFs) and identified 29 significantly differentially expressed circRNAs (fold change ≥ 1.5, P < 0.05), 12 circRNAs were up-regulated and 17 circRNAs were down-regulated.3 most differentially expressed circRNAs were verified by qRT-PCR and the down-regulated circCOL3A1-859267 exhibited the most significantly altered in photoaged HDFs. Overexpression of circCOL3A1-859267 inhibited UVA-induced decrease of type I collagen expression and silencing of it reduced type I collagen intensity. Via a bioinformatic method, 44 miRNAs were predicted to binding with circCOL3A1-859267, 5 of them have been confirmed or predicted to interact with type I collagen. This study show that circCOL3A1-859267 regulate type I collagen expression in photoaged HDFs, suggesting it may be a novel target for interfering photoaging.

[en] Objective: To enhance the understanding of CT appearance in collecting duct carcinoma of the kidney. Methods: The CT features in 3 cases of collecting duct carcinoma of the kidney confirmed by pathology were reported, and the literature was reviewed. Results: 3 patients comprised 2 males and 1 female. 2 tumors located in the right kidney, 1 tumor located in the left kidney. Medulla and cortex were involved in 1 of the 3 cases. The tumor was about 8.0 cm x 8.0 cm. It was bulgy fromoutline of the kidney. The CT value was about 37-45 HU on plain CT scan, and there was high-density calcification in it. It showed inhomogeneous enhancement in arterial and venous phase after the injection of contrast material, and the CT value was about 52-107 HU. No capsule could be seen. The CT diagnosis was carcinoma of right kidney, but tuberculosis was not excluded. Medulla, cortex, and pelvis were all involved in another 2 cases. One tumor was about 7.0 x 7.5 cm and it was in the left kidney. The CT value was about 22 HU on plain CT scan. The interface between cortex and medulla was blurry in arterial phase after the injection of contrast material, and the CT value was about 70 HU. The embolism could be seen in the renal vein in venous phase. The pelvis was not displayed in excretory phase. The CT diagnosis was carcinoma of left kidney (probably collecting duct carcinoma). The other tumor located in the right kidney, it was about 8.0 cm x 14.0 cm, The CT value was about 32 HU on plain CT scan. The interface between cortex and medulla was also blurry in arterial and venous phase after the injection of contrast material, and the CT value was about 45-72 HU. The pelvis was not displayed in excretory phase. The CT diagnosis was carcinoma of right kidney, but tuberculosis was not excluded. Infiltration of perirenal fat and fascia was present in 2 of the 3 cases. Metastasis was present in focal lymph nodes in 2 cases, and metastasis was present in a costa in 1 case. Conclusion: CT is a valuable tool in the diagnosis of collecting duct carcinoma of the kidney. But the final diagnosis should be based on pathology. (authors)

[en] Objective: To study different target surface/filtration combination and exposure modes which are influence factors to digital mammography radiation dose. Methods: Phantom of breast and rectangular wave test card were exposed to Siemens MAMMOMAT NovationDR digital breast X-ray machine by different target surface/filtration combines and different exposure modes,radiation dose and line logarithms of test card was obtained. And then comparatively studied with clinical radiation does,observed the different quality of images. Results: There are significant difference between three different target surface/filtration combines and two different exposure modes at the same X-ray image quality. The radiation dose of target surface/filtration combinations of molybdenum/molybdenum, molybdenum/rhodium, and tungsten/rhodium were 2.2 mGy, 1.5 mGy, and 1.0 mGy in model test,respectively. Compared with 3 mGy of automatic exposure, manual exposure dose decreased to 1.5 mCy. The results of clinical case and model test were completely conformed. Conclusion: Manual exposure mode and tungsten/rhodium target surface/filtration combination were advised to reduce the radiation dose in clinical application. (authors)

[en] The position of the magnetic dipole can be estimated by measuring the magnetic field of the magnetic dipole and processing the measurement information. The main problem in locating a ferromagnetic target is to eliminate the interference of the geomagnetic field. In recent years, there has been a lot of research to eliminate geomagnetic interference by processing measurement results. For an object with an alternating current signal, the interference of geomagnetic field can be eliminated through a simple band-pass filter. However, there are still other causes of localization errors. The measurement error of the sensor has different effects on different positioning systems. This paper compares the influence of measurement error on localization systems with different structures. The simulation results show that when the measurement error is at a reasonable level, some localization systems perform better than others. (paper)

[en] The integration of topology optimization(TO) and additive manufacturing(AM) has the huge potential to expand the design freedom of parts. However, traditional topology optimization approaches are not tailored to the particular characteristics of AM processes, resulting in a large number of overhangs in these designs, which lead to use of sacrificial support structures and increase the manufacturing cost. This paper presents an AM-restrained topology optimization approach based on the overhang sensitivity analysis. The overhangs can be explicitly expressed by the design variable and considered to be a minimization goal of the optimization process, in which the overhang sensitivity is combined with other performance sensitivities to update design variables. The effectivity and robustness of the proposed method is demonstrated by the typical cantilever beam and the MBB beam, then validated through the fused deposition modelling(FDM) 3D printing. (paper)

[en] Highlights: • The model of exergy analysis for low temperature combustion engine is established. • The irreversibility mainly happen in low and high temperature reaction zones. • The N₂ component in EGR gas has the greatest influence on the distribution of exergy. -- Abstract: Low temperature combustion (LTC) is a new mode for efficient and clean combustion in engines, and the process is mainly controlled by chemical reaction kinetics of fuel. In this paper, the numerical model of exergy analysis for LTC engine was established. The temperature, pressure and species concentration were obtained by using the homogeneous charge compression ignition (HCCI) engine model of Chemkin-Pro software with the simplified mechanism of toluene reference fuel (TRF). The exergy items were further calculated to explore the effect of different intake conditions on exergy destruction in LTC process. It was found that the irreversibility related to the combustion proceeding mainly happened in low temperature and high temperature reaction zones. With the increase of exhaust gas recirculation (EGR) rate, the proportion of working exergy increases but the irreversibility destruction of combustion decreases. Besides, N₂ component concentration in EGR gas has the greatest influence on the distribution of exergy.

[en] Through analysis of the results of a verified high-fidelity numerical model, the intra-seasonal variations (ISVs) in the depth of the 22°C isotherm (D22) in the South China Sea (SCS) basin are investigated. The results show that the ISVs in the D22 exhibit distinct seasonality in the SCS. The ISVs in the D22 are quite significant, especially within a band along the northwestern boundary of the basin and at the southern end of the basin during boreal winter. In these areas, the ratio of the standard deviations (STDs) of intra-seasonal band to the STDs of total data could exceed 0.6. Although the ISVs in the D22 are detectable in the area affected by the Vietnam Offshore Current during boreal summer and autumn, these variations are sometimes overwhelmed by oscillations with other frequencies. An analysis of the causes of the ISVs in the D22 in the SCS indicates that sea surface fluxes and wind stirring are not the dominant external driving mechanisms of the phenomena described above. The ISVs in the D22 are thought to be induced mainly by the thermodynamic adjustment of the ocean itself and the associated instabilities. The energy of the northern and southern bands that display strong ISVs in the D22 may be derived from eddy kinetic energy, rather than eddy available potential energy. The diversity of the propagation of the ISVs in the D22 is very conspicuous within these two bands.

[en] We propose a vectorial optical field generation system based on two-dimensional blazed grating to high-efficiently generate structured optical fields with prescribed amplitude, phase, and polarization. In this system, an optimized blazed grating hologram is written on a spatial light modulator (SLM) and can diffract the majority of the incident light into the first-order diffractions of the x and y directions, which then serve as base vectors for synthesizing desired vector beams. Compared with the conventional cosine grating used in the previous work, the proposed two-dimensional, blazed grating has a much higher efficiency. Both computer simulation and optical experiment validate that a conversion efficiency up to 5 times that of the former work is achieved. Our method can facilitate applications of the optical field manipulation. (special topic)

[en] Against the technical defects of universally applicable beam tube monitoring system at present, such as air suction in the beam tube, line clogging, long sampling time, etc., the paper analyzes the current situation of the spontaneous combustion fire disaster forecast of mine in our country and these defects one by one. On this basis, the paper proposes a research thought that improving the positive pressure beam tube so as to substitute the negative pressure beam tube. Then, the paper introduces the beam tube monitoring system based on positive pressure technology through theoretical analysis and experiment. In the comparison with negative pressure beam tube, the paper concludes the advantage of the new system and draws the conclusion that the positive pressure beam tube is superior to the negative pressure beam tube system both in test result and test time. At last, the paper proposes prospect of the beam tube monitoring system based on positive pressure technology. (paper)