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Mixed fluid–particle flows are commonly found in nature and exhibit complex particle–particle and particle–fluid interactions. In this paper, a typical small-scale case of immersed granular collapse under the viscous regime is numerically investigated using computational fluid dynamics coupled with the discrete element method (CFD-DEM), which provide particle-scale information of the collapse. The input parameters for the coupled CFD-DEM model are carefully calibrated from experimental results, and the simulation results achieve good agreement with the experiments in terms of the front evolution and final deposition. The collapse processes for different aspect ratios exhibit similarities and propagate in a three-stage mode that includes acceleration, steady propagation, and deceleration. The propagation velocity, runout distance, and the energy evolution of both fluid and particles are presented. The final runout is linearly proportional to the densimetric Froude number in our high-column cases. The transition of particles' motion from vertical to horizontal and the drag of the fluid are found to be responsible for the constant velocity in the steady propagation stage. We also show that a small energy bump during the initial stage is the result of particle destabilization and rearrangement. [ABSTRACT FROM AUTHOR]

The evolution of energy in subaerial and subaqueous granular column collapses is studied. Employing the refractive index matching method and planar laser-induced fluorescence technique, we obtain granular and liquid images simultaneously in a single experiment of subaqueous flow. Particle image velocimetry and particle tracking velocimetry are used to process the data for the fluid and granular phase. We find stepwise decreases in the total kinetic energy of the granular material. The stage of rapidly falling energy corresponds to large transverse changes in the direction of the massive granular particles. Moreover, in this stage, a major fraction of the granular kinetic energy transferred from the granular potential energy is lost or transferred. Interestingly, compared with dry granular flow, the existence of an ambient liquid seems to reduce the total dissipated energy, which may be the reason why previous studies observed similar granular runout distances in subaqueous and dry granular collapses. [ABSTRACT FROM AUTHOR]

Microfluidic paper-based analytical devices (μPADs) have a significant potential in developing portable and disposable point-of-care testing (POCT). Herein, a facile, rapid, cost-effective and environment friendly strategy for μPADs fabrication is proposed. Specifically, the substrate paper was hydrophobized by coating with trimethoxysilane (TOS), and then the selected area was hydrophilized by treating with surfactant. The whole fabrication process was implemented within 7 min, with no need for complex pre-treatment, high-temperature and special equipment. As a proof-of-concept application, the as-prepared μPAD was applied to determination of the glucose content in human serum samples. The results agreed well with those obtained by a glucometer. We believe that the μPADs fabrication method proposed here could provide a facile, rapid and low-cost reference for other related studies. [ABSTRACT FROM AUTHOR]

Control load system is the human-felt system that provides operating force for pilots under the different environment. According to the flight control system's principle, the simulation means of the flight control system in flight simulator was presented, a digital electric control loading system was developed. First the paper introduces the working principle and the structure of the system, then establishes the mathematical model of column power, finally researches hardware and software of the control load system and designs the machine interface. This system has realized the simulation of the flight control system, and it has been successfully applied to flight simulator prototype system. The design of its components model can meet the general purpose of the control load system, and flexible applicability that the approach is fit for various simulation objects and control load features in different work pattern. For motion simulation, scenario simulation and other related to the displacement and force feedback simulation field also have certain reference significance. [ABSTRACT FROM AUTHOR]

High-quality large single crystals of Ni- and Zn-doped Bi2Sr2Ca(Cu2-xMx)O8+δ (M=Ni or Zn) have been successfully grown by the traveling solvent floating zone technique. The single crystals are characterized by compositional and structural analyses and their physical properties are investigated by magnetic susceptibility and resistivity measurements. A record high critical temperature with a Tc = 97.5K has been achieved in the annealed pristine Bi2212 single crystal. Substitution of Cu by Ni or Zn reduces the superconducting transition temperature when compared with pristine Bi2Sr2CaCu2O8+δ (Bi2212) grown under similar conditions. The successful growth of such pristine Ni- and Zn-doped Bi2212 single crystals will facilitate studies of the relationship between the magnetism and superconductivity in high-temperature cuprate superconductors [ABSTRACT FROM AUTHOR]

The characteristics of neutral chromium atoms in the standing wave field are discussed. Based on a semi-classical model, the motion equation of neutral atoms in the laser standing wave field is analyzed, and the trajectories of the atoms are obtained by simulations with the different divergence angles of the atomic beam. The simulation results show that the full width at half maximum (FWHM) of the stripe is 2.75 nm and the contrast is 38.5 : 1 when the divergence angle equals 0 mrad, the FWHM is 24.1 nm and the contrast is 6.8:1 when the divergence angle equals 0.2 mrad and the FWHMs are 58.6 and 137.8 nm, and the contrasts are 3.3 : 1 and 1.6 : 1 when the divergence angles equal 0.5 and 1.0 mrad, respectively [ABSTRACT FROM AUTHOR]

• A novel asymmetric large mode area single mode photonic crystal fiber with ultra-low bending loss is proposed. • The proposed fiber can provide high leakage loss ratio. • The effective mode area is as large as595.02μm2 with tough bend radius of 10 cm. • The bending loss of fundamental mode is 9.884×10-5dB/m with bending radius 10 cm. A novel asymmetrical structure of Photonic Crystal Fibers (PCFs) has been proposed in this article. The first ring consists of three big air holes which can confine the propagating mode in the core region. The second ring consists of twelve doped rods with two different diameters which can decrease the difference of refractive index between the core and the cladding in order to provide the large mode area. The third ring consists of eleven air holes to help the higher-order-modes (HOMs) to leak out. The bending properties of proposed fiber are investigated by full vector finite element method with an anisotropic perfectly matched layer. The numerical results show that the effective mode area of the FM of the proposed fiber is as large as 595.02 μm2 with small bending radius of 10 cm at the wavelength of 1064nm. The bending loss of fundamental mode (FM) is 9.884×10−5dB/m, while large bending loss for the high-order mode (HOMs) is 14.685dB/m. Moreover, the loss ratio can reach 1.45×105which can realize the effective and stability single-mode operation. Therefore, the novel fiber has potential application in high-power fiber lasers. [ABSTRACT FROM AUTHOR]

To address the difficulty of estimating the indoor and outdoor depth under hazy conditions, a single hazy image depth estimation method fusing the perceptual loss function is proposed. Firstly, a two-scale network model is used to coarsely extract the hazy images that are are then locally refined by combining the underlying features. Then, in the upsampling stage, a multi-convolution kernel up-sampling method is used to obtain the haze image predition depth map. Finally, the network is trained by combining the pixel-level loss function and the perceptual loss function into a new composite loss function. The experiments are trained, tested, and validated on the indoor NYU Depth v2 dataset and the outdoor Make3D dataset. The result shows that the two-scale network model combining the multi-convolutional kernel up-sampling method and the composite loss function can better estimate the depth information of a single hazy image, improve the accuracy and quality of depth estimation under hazy condition, shorten the training time of the model, and improve the applicability and accuracy of the depth estimation of hazy images. [ABSTRACT FROM AUTHOR]

We studied the source locations and solar-cycle (SC) distribution of the major geomagnetic storms (MGSs) that occurred from 1932 to 2018. We divided the MGSs into two groups: the intense geomagnetic storms (IGSs) (− 200 nT < Dst ≤ − 100 nT ) and the great geomagnetic storms (GGSs) (Dst ≤ − 200 nT). The GGSs were split into three subgroups: GGSs-I (− 300 nT < Dst ≤ − 200 nT ), GGSs-II (− 400 nT < Dst ≤ − 300 nT ) and GGSs-III (− 600 nT < Dst ≤ − 400 nT ). The source locations of the GGSs-I and GGSs-II were distributed in the longitudinal range of [E84, W73], while the GGSs-III were distributed in the range of [E22, W14]. 90% of the GGSs were distributed in the longitudinal area of [E45, W45]. The statistical results show that 38.6%, 61.4% and 86% of the GGSs occurred in the ascending phase, the descending phase, and the period from two years before to three years after the solar maximum, respectively. 33.3%, 66.7% and 76% of the IGSs appeared in the ascending phase, the descending phase, and the period from two years to three years after the solar maximum, respectively. The number of MGSs in a SC has a good correlation with the SC size. However, the largest storm intensity in a SC has almost no relationship with the SC size, implying that the number of MGSs in a weak SC will be small. However, we cannot rule out the possibility that a weak SC may have a very strong extreme geomagnetic storm. [ABSTRACT FROM AUTHOR]

Background: Mesenchymal stem cells (MSCs) have been proved to drive castration resistant prostate cancer (CRPC). In this study, we aim to investigate the contribution of MSCs to the development of docetaxel resistance in CRPC cells and its potential mechanisms. Methods: The effect of MSCs on CRPC cells resistance to docetaxel was determined using in vivo and in vitro approaches. CCK8 and PI/Annexin V-FITC assay were used to examined the cell viability and apoptosis. The concentration of transforming growth factor-β1 was measured by enzyme-linked immunosorbent assay and small interfering RNA was used for functional analyses. Results: MSCs significantly reduced the sensitivity of CRPC cells to docetaxel-induced proliferation inhibition and apoptosis promotion in vivo and in vitro. CRPC cells cocultured with MSCs under docetaxel administration have an increased autophagy activation, while autophagy inhibitor could effectively reversed MSCs-induced resistance to docetaxel. Additionally, MSCs-induced CRPC cell autophagy increase under docetaxel administration depends on MSCs secreting TGF-β1 and inhibition of TGF-β1 secretion in MSCs could consequently increase the sensitivity of CRPC cells to docetaxel. Conclusions: These results suggest that docetaxel administrated CRPC cells may elicit MSCs secreting TGF-β1 increase, which desensitizes CRPC to docetaxel chemotherapy accelerating chemoresistance occurrence via inducing cell autophagy. [ABSTRACT FROM AUTHOR]

Os acromiale is a developmental defect which results from the lack of an osseous union between the ossification centers of the acromion, leading to the fibrocartilaginous tissue connection. The prevalence of os acromiale is 1% to 15%, and is quite common in the African American population. Os acromiale in adults is easily diagnosed by symptoms and X‐ray, particularly on the axillary view; however, the differential diagnosis of adolescents may require MRI or SPECT–CT. Generally, nonoperative therapy for symptomatic os acromiale should be started, including physiotherapy, nonsteroidal anti‐inflammatory drugs, and injections. Surgical treatment is indicated after failed conservative treatment. In symptomatic patients with fixable acromiale, the tension band technique should be used to make the anterior aspect of the acromion elevated from the humerus head. In patients with small fragments which are unsuitable for reattachment, excision might be the best therapeutic option and lead to good outcomes. Whether using internal fixation or resection, the arthroscopic technique results in a better outcome and fewer complications, especially in older patients or athletes with overhead movement, because of the high incidence of shoulder impingement or rotator cuff tears which can be treated concurrently. [ABSTRACT FROM AUTHOR]

Impingement, tibial erosions, and "painful hardware" caused by a lag screw used for malleolar fracture stabilization are rare occurrences. We report a case of a symptomatic lag screw, used to fix a distal fibular fracture, that impinged on the distal tibial and causing symptoms. Awareness of the condition and early diagnosis based on thoughtful review of CT images are key to symptom alleviation. A review of the published data on the complication of "painful hardware" following ankle fracture fixation is also presented. [ABSTRACT FROM AUTHOR]

Intramuscular hemangioma is a rare but challenging cause of pain in the lower extremities. When nonsurgical approaches have a certain possibility of post-procedural recurrence or incomplete success, surgery is a good choice. An open excision forms a long scar but allows for a wider surgical scope. Excision by arthroscopy may be a possible method for the treatment of intramuscular hemangioma with overall better results. The purpose of this study was to evaluate and compare the clinical outcomes of arthroscopic and open excisions for the treatment of intramuscular hemangioma of a lower extremity. Fifty-two patients with intramuscular hemangioma were divided into either the arthroscopic or open excision groups. Each group was compared by operative time, Lysholm score, length of the scar, the numbness of the surgery area, satisfaction of appearance, recurrence, and infection. Compared with the open excision group, the Lysholm scores mean ± standard error between the arthroscopic and open excision groups were 96.2 ± 3.7 to 93.2 ± 4.2 (P < 0.05), the scar lengths were 0.61 ± 0.17 cm to 10.04 ± 5.31 cm (P < 0.01), numbness scores were 1.08 ± 0.74 to 2.19 ± 1.02 (P < 0.01), and satisfaction with appearance scores were 8.42 ± 1.27 to 5.27 ± 1.48 (P < 0.01). The clinical results were comparable between the arthroscopic and open excision groups, suggesting that an arthroscopic excision on the intramuscular hemangioma can achieve better function, a shorter scar, and a higher satisfaction with appearance. [ABSTRACT FROM AUTHOR]

An green and convenient approach to the synthesis of 3,6,9-aryl-1,8-dioxo-1,2,3,4,5,6,7,8-octahydroxanthene derivatives from appropriate aromatic aldehydes and 5-aryl-1,3-cyclo-hexanedione in the presence of two drops of concentrated H2SO4 as a catalyst in water is described. This method provides several advantages such as environmental friendliness, low cost, excellent yields, and simple workup procedure. [ABSTRACT FROM AUTHOR]

The Vilsmeier reaction of nickel(II) chlorin P6 trimethyl ester with 3-dimethyl-aminoacrolein yielded nickel(II) chlorin P6 20-(2-formylvinyl) trimethyl ester and nickel(II) chlorin P6 3-(1-hydroxyethyl)-3-devinyl-20-(2-formylvinyl) trimethyl ester. Also, the outgrowths of nickel(II) chlorin P6 20-(2-formyl) trimethyl ester and nickel(II) chlorin P6 3-(2-formylvinyl)-3-devinyl-20-(2-formyl) trimethyl ester were obtained by Vilsmeier reaction with dimethylformamide. By treating the derivatives of nickel(II) 20-(2-formyl)-chlorin and nickel(II) 3-(2-formylvinyl)-20-(2-formyl)-chlorin with trifluoracetic acid, the removal of the central nickel(II) ion was accomplished. The derivatives of 20-(2-formyl)-chlorin and 3-(2-formylvinyl)-20-(2-formyl)-chlorin demonstrated considerable bathochromic shift of the major absorption band in the red region of the optical spectrum. [ABSTRACT FROM AUTHOR]

Novel 9-amino-3-substituted-1,2,3,4-acridin-1-one derivatives and 9,14-diamino-7-substituted-7,8-dihydroquinolino[2,3-a]acridine derivatives were synthesized by the condensation reaction of 5-substituted-1,3-cyclohexanedione with 2-aminobenzonitrile and substituted 2-aminobenzonitrile using p-toluenesulfonic acid, K2CO3, and Cu2Cl2 as catalysts. The structures of all compounds were characterized by elemental analysis, infrared, mass spectrometry, and 1H and 13C NMR spectra. The crystal and molecular structures of 6, 14-diamino-3,4,11,12-tetramethoxy-7-phenyl-7,8-dihydroquinolino[2,3-a]acridine 5a have been determined by single-crystal x-ray diffraction analysis. The crystal of compound 5a belongs to triclinic with space group P-1, a = 1.06168(15) nm, b = 1.16951(17) nm, c = 1.6020(2) nm, α = 71.380(3)°, β = 77.686(3)°, γ = 66.743(3)°, Z = 2, V = 1.7231(4) nm3, R1 = 0.1060, and wR2 = 0.2192. [ABSTRACT FROM AUTHOR]

Trombe wall is an effective method for passively absorbing solar energy and providing heat to buildings. This paper conducts a comparative experiment between Trombe wall buildings and glass curtain wall buildings during the winter season in Songpan County, western Sichuan. The climate characteristics of the western Sichuan plateau are analyzed, and the potential applications of these two building types in the region are investigated. To further understand the heat transfer mechanism of Trombe wall buildings, numerical simulations are carried out to analyze the indoor thermal environment of buildings with varying air channel thicknesses. The results show that Trombe wall buildings are more effective at delaying heat loss compared to glass curtain wall buildings, due to the thermal storage of the Trombe wall providing heat at night. This makes Trombe wall buildings well-suited for regions with strong solar radiation and large temperature differences between day and night, such as the alpine region. However, excessively small air channel thickness can lead to excessive air flow speed during the day, causing more heat loss and weaker insulation at night. Conversely, excessively large air channel thickness reduces air flow temperature difference and diminishes the heat brought into the room. Among different air channels, a thickness of 100 mm performs best with a temperature difference between the inlet and outlet of about 45 °C. At 13:00 o 'clock, the maximum airflow rate of approximately 5.8 L/s is achieved for a thickness of 100 mm, whereas for thicknesses of 150 mm and 50 mm, the corresponding values are 4.9 L/s and 4.1 L/s, respectively. It is important to note that blindly increasing air channel thickness to raise indoor temperature is not a practical or reasonable engineering solution. The measured and numerical results can provide valuable reference value for the improvement and development of Trombe wall buildings in the future. [ABSTRACT FROM AUTHOR]

In order to observe and ascertain the properties of a sub-group of T cells in the lymph node (LN) from seven patients who did not suffer from T cell lymphoproliferative disorders (T-LPDs), the expression levels of several pan-T markers were evaluated by multiparameter flow cytometry (FC) and the clonality of these T-cells was evaluated by both FC analysis and PCR assessment. It turned out that multiple pan-T-cell markers such as CD2, CD5 and CD7 were found to be lost in these T cells. The majority of them were positive for TCRαβ, only a minority of them being positive for TCRγδ. A subset of these T-cells were positive for CD4 or CD8 or dual-negative for CD4 and CD8. Oligoclonality was detected in one case by FC, while clonalTCRrearrangement was detected in three cases. Absence of multiple pan-T-cell markers could be found in benign T cells in LNs. [ABSTRACT FROM AUTHOR]

Endothelial dysfunction resulting from oxidative stress and inflammation plays a dominant role in hyperglycemia-induced vasculopathy. While double-stranded RNA (dsRNA) accumulates in redox and inflammatory conditions, its precise role in hyperglycemia-associated endothelial dysfunction remains unclear. This study aimed to investigate whether and how endogenous dsRNA contributes to endothelial dysfunction via oxidative stress. We used a dsRNA-specific antibody J2 to detect and immunoprecipitate cellular dsRNA. Acquired dsRNA was recognized by cDNA library construction and DNA sequencing. Quantitative PCR, ELISA and immunoassays were performed to identify changes induced by acquired dsRNA in primary human umbilical vein endothelial cells (HUVEC). Our data showed that endogenous dsRNA homologous to Alu Sc subfamily accumulated in hyperglycemic HUVEC. Comparing Alu -transfected HUVEC with high-glucose treated HUVEC, we found that Alu RNA elicited the production of reactive oxygen species (ROS) and up-regulated interleukin-1β (IL-1β) expression and secretion in a similar manner as high-glucose treatment. Moreover, Alu RNA impeded the expression of endothelial nitric oxide synthase (eNOS) and superoxide dismutase 2 (SOD2), increased ROS production and activated nuclear factor NFκB by chemically scavenging ROS and inactivation of NFκB. The repressed expression of eNOS and SOD2 resulted from Alu RNA-mediated negative regulatory mechanisms. Our study uncovered endogenous Alu RNA accumulation in hyperglycemic endothelial cells that provoked endothelial oxidative stress and dysfunction by suppressing SOD2 and eNOS expression at both transcription and translation levels via NFκB signaling pathway. These findings suggest a novel regulatory mechanism that involves endogenous dsRNA in endothelial oxidative stress and dysfunction. [ABSTRACT FROM AUTHOR]

Age estimation by third molar mineralization has been developed for a period of time. Recent studies showed that impaction status has an influence on the rate of the third molar mineralization in Europids and male Black African populations. In this regard, the present study was conducted to determine whether the impaction status could delay the chronological process of third molar mineralization in northwestern Chinese population too. A total of 3,512 digital orthopantomograms of 1,255 male and 2,257 female northwestern Chinese subjects aged from 11 to 26 years were assessed based on the formation stages described by Demirjian et al. with two modifications. Mineralization stage and impaction status were determined for all third molars. Statistical measures were calculated at stages C-H in the male and female gender for both impacted and non-impacted third molars. It was ascertained that the mean ages with impacted third molars at stages C-H were 0.02-1.42 years higher in males and 0.04-1.52 years higher in females than those with non-impacted third molars, but statistical differences were only found at stages C, D, and E in males and stages D and E in females. The probabilities of being under 14, 16, or 18 years of age with non-impacted third molars were all higher than those with impacted third molars. The results prove that impacted third molars show significant slower mineralization than non-impacted ones at stages D and E in both males and females of northwestern Chinese population. It is recommended to consider the influence of impaction on the rate of third molar mineralization for dental age estimation. [ABSTRACT FROM AUTHOR]

Noble metal nanoantenna could effectively enhance light absorption and increase detection sensitivity. In this paper, we propose a periodic Ag diamond nanoantenna array to increase the absorption of thin-film solar cells and to improve the detection sensitivity via localized surface plasmon resonance. The effect of nanoantenna arrays on the absorption enhancement is theoretically investigated using the finite difference time domain (FDTD) method with manipulating the spectral response by geometrical parameters of nanoantennas. A maximum absorption enhancement factor of 1.51 has been achieved in this study. In addition, the relation between resonant wavelength (intensity reflectivity) and refractive index is discussed in detail. When detecting the environmental index using resonant wavelengths, a maximum detection sensitivity of about 837 nm/RIU (refractive index unit) and a resolution of about 10−3 RIU can be achieved. Moreover, when using the reflectivity, the sensitivity can be as high as 0.93 AU/RIU. Furthermore, we also have theoretically studied the effectiveness of nanoantennas in distinguishing chemical reagents, solution concentrations, and solution allocation ratios by detecting refractive index. From the results presented in this paper, we conclude that this work might be useful for biosensor detection and other types of detections. [ABSTRACT FROM AUTHOR]