Characterisation of moisture migration of shiitake mushroom (Lentinula edodes) during storage and its relationship to quality deterioration

Water is a critical factor influencing the quality of mushrooms. This paper investigated the moisture migration of shiitake mushroom during storage using low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) and its relationship to quality deterioration. Three water components assigned as water in different cell compartments of cell wall, cytoplasm and vacuole were observed in shiitake mushroom matrix. As the prolonging of storage time, the right shift of immobilised water and left shift of free water led to the merge of these two peaks at the end of storage. The increase in peak area of water in cytoplasm and decrease in the peak area of water in vacuole indicated evident moisture migration from vacuole to cytoplasm. MRI images showed heterogeneous water distribution in shiitake mushroom, and the water migrated from centre to surface, then evaporated to the environment. Besides, the moisture migration might be related to the weight loss and textural softening of shiitake mushroom.     

A NEW OIL SEEPAGE IN THE OMAN MOUNTAINS AND ITS GEOLOGICAL,GEOCHEMICAL AND PETROLEUM SYSTEMS CONTEXT

A minor natural oil seepage is described from an unlikely setting in the Oman Mountains. The host rocks are fractured pelagic limestones of the lower member of the Triassic – Lower Jurassic Matbat Formation of the Hamrat Duru Group in the lower part of the allochthonous Hawasina Complex. This paper summarises Oman's established oil families and documents previously recorded oil seepages as context for describing the new seepage, its geochemistry, and possible source rock. The seep oil is different to those known from Oman's oil fields and probably derived from a poor quality, Mesozoic clastic source rock containing a mix of terrigenous and marine organic matter. The most likely source appears to be the Toarcian turbiditic upper member of the Matbat Formation, equivalent to the clastic Mafraq Formation of the Arabian Platform. The occurrence of source rocks in the allochthonous sediments of the NeoTethyan Hawasina Basin has been suspected previously, though their commercial significance remains to be established.     

Effect of Peroxiredoxin 1 on the biological function of airway epithelial cells and epithelial-mesenchymal transition

Peroxiredoxin 1 (PRDX1) participates in tumor cell proliferation, apoptosis, migration, invasion, and the epithelial-to-mesenchymal transition (EMT). This study aimed to investigate the effect of PRDX1 on the EMT of airway epithelial cells stimulated with lipopolysaccharide (LPS) and transforming growth factor-beta 1 (TGF-β1). PRDX1 overexpression significantly increased the proliferation and migration of human bronchial epithelial (BEAS-2B) cells, reduced cell apoptosis (p < 0.01), and induced EMT and collagen deposition by upregulating the expression of the matrix metallopeptidase (MMP)2, MMP9, α-smooth muscle actin (α-SMA), N-cadherin, vimentin and twist proteins and inhibiting E-cadherin expression (p < 0.05). PRDX1 overexpression promoted TGF-β1-mediated inhibition of cell proliferation and migration and significantly enhanced the TGF-β1-induced EMT and collagen synthesis (p < 0.05). Knockdown of PRDX1 inhibited cell proliferation, migration, EMT, and collagen synthesis (p < 0.01), reversed LPS-mediated inhibition of cell proliferation and migration, and significantly suppressed LPS-induced EMT and collagen synthesis (p < 0.01). The result indicating that PRDX1 may be involved in LPS/TGF-1-induced EMT and collagen synthesis in human bronchial epithelial cells.     

复频电导技术在隧洞超前探水中的应用

围岩富水带是隧道超前预报最关注的问题，目前，多使用电磁方法来预报围岩的含水性，但受到场地条件限制，面临掌子面条件、金属机具干扰、三维波场定位等诸多困难，特别是掌子面前方100 m范围内围岩的含水性预报，在国内外都是一个新的高难课题。在研究了岩体电导率与电容率复频特性的基础上，结合巴基斯坦NJ-TBM引水隧洞工程，开发了复频电导探水(CFC)技术。该技术基于电磁波反射与相干原理，选用100 kHz～10 MHz频率范围，采用电偶极子发射与阵列接收方式和偏移成像技术，突破了隧道内场地条件的限制。依据1/4相干波长确定含水体的位置，相干能量确定含水量的大小。在巴基斯坦NJ-TBM隧洞超前探水的应用，证明了该方法的可行性与有效性。      

Shear-induced migration and axial development of particles in channel flows of non-Brownian suspensions

We present an experimental study on the shear-induced migration and axial development of particles in the channel flows of non-Brownian suspensions. The suspending fluid is Newtonian. We investigate fracturing flows with a Hele-Shaw type scaling through building a unique channel setup and an advanced optical system. The local particle concentration profiles are measured via the refractive-index matching technique for a wide range of bulk volume fraction, that is, . Simultaneously, the particle image velocimetry is performed to determine the velocity profile of the particle phase. We compare our experimental results with the available two-phase continuum frameworks and show discrepancies and similarities in the fully developed and axial development of the solid volume fraction profiles. We discuss directions in which the continuum frameworks require improvements.     

降雨强度对植被过滤带中胶体迁移过程的影响

通过人工降雨条件下胶体在10 m长度植被过滤带中的运移试验，建立耦合降雨的胶体迁移模型，以探究降雨强度对植被过滤带中胶体运移过程的影响。结果表明:不同降雨强度下，胶体在植被过滤带中的沉积吸附效率系数随运移距离呈幂指数下降趋势，并在6 m左右趋于稳定；随着降雨强度的增大，胶体在植被过滤带中的沉积吸附效率系数增大，在较大降雨强度下的去除效果更好。     

中中新世以来南海南部前隆的迁移:来自北康盆地的证据

利用二维地震资料探讨南海南部北康前隆的迁移现象及其对形成油气圈闭的影响。在南沙海域，早中新世不整合（EMU）是一个区域性不整合面，EMU之上的地层可以简单归结为披覆层系和水平层系。披覆层系直接覆盖在EMU上，具有连续薄层的平行地震反射特征，向南东方向加厚，属于悬浮沉积；而水平层系同期充填在低凹处，不断上超和覆盖早期的披覆层系，厚层状，呈不连续或弱反射特征，属于浊积物与悬浮物的混合沉积。通过上超反射终止的迁移和披覆层系的加厚两个特征判断，中中新世以来北康前隆在向上隆升的同时不断向南东方向迁移，反映了南沙海域减薄的陆壳有一个强烈挠曲和均衡反弹过程。前隆的迁移留下了一系列的古潜山，披覆层系和水平层系是很好的盖层，有利于圈闭的形成。     

Pre-stack elastic reverse time migration in tunnels based on cylindrical coordinates

Seismic forward-prospecting in tunnels is an important step to ensure excavation safety. Nowadays, most advanced imaging techniques in seismic exploration involve calculating the solution of elastic wave equation in a certain coordinate system. However, considering the cylindrical geometry of common tunnel body, Cartesian coordinate system seemingly has limited applicability in tunnel seismic forward-prospecting. To accurately simulate the seismic signal received in tunnels, previous imaging method using decoupled non-conversion elastic wave equation is extended from Cartesian coordinates to cylindrical coordinates. The proposed method preserves the general finite-difference time-domain (FDTD) scheme in Cartesian coordinates, except for a novel wavefield calculation strategy addressing the singularity issue inherited at the cylindrical axis. Moreover, the procedure of cylindrical elastic reverse time migration (CERTM) in tunnels is introduced based on the decoupled non-conversion elastic wavefield. Its imaging effect is further validated via numerical experiments on typical tunnel models. As indicated in the synthetic examples, both the PP- and SS-images could clearly show the geological structure in front of the tunnel face without obvious crosstalk artifacts. Migration imaging using PP-waves can present satisfactory results with higher resolution information supplemented by the SS-images. The potential of applying the proposed method in real-world cases is demonstrated in a water diversion tunnel. In the end, we share our insights regarding the singularity treatment and further improvement of the proposed method.     

Numerical study of microscopic particle arrangement of suspension flow in a narrow channel for the estimation of macroscopic rheological properties

In a narrow channel, the apparent relative viscosity of a suspension with finite-size particles is strongly dependent on its microscopic particle arrangement. Relative viscosity increases when suspended particles flow near the channel wall; thus, a suspension in a narrow channel does not always exhibit the same rheological properties even if the concentration is the same. In this study, we focus on the inertia and concentration of particles in a narrow channel and consider their effects on the microscopic particle arrangement and macroscopic suspension rheology. Two-dimensional pressure-driven suspension flow simulations were performed using a two-way coupling scheme, and normalized particle density distribution (PDD) were implemented to consider their particle arrangements. The results demonstrated that the velocity profiles for the particle suspension were changed by the Reynolds number and particle concentration because of the interactions between particles according to the power-law index. These changes affected the particle equilibrium positions in the channel, and the subsequent changes in solvent layer thickness caused changes in the macroscopic apparent viscosity. The behavior of microscopic particles played important roles in determining macroscopic rheology. Thus, we have confirmed that a normalized PDD can be used to estimate and assess the macroscopic rheology of a suspension.