Search

Fractures are widely developed in lacustrine carbonate reservoirs in the Oligocene Lower Ganchaigou Formation of the western Yingxiongling area and their distribution trend is unclear. Based on well logging, formation testing, rock mechanics parameters obtained by logging interpretation, and the paleotectonic stress obtained by acoustic emission experiments, finite element numerical simulation is used to restore the tectonic stress of the typical section and target layer plane models in the late Himalayan period in the study area. The fracture distributions of the section and the plane are quantitatively predicted and their distribution trends are summarized. The results show that the tectonic compression at the end of the Neogene was strong in the study area. Under the effect of the paleotectonic stress field, the fracture development degree of the upper member of the Lower Ganchaigou Formation is generally high. Fractures mainly developed in the fault zones and their surroundings, the hanging wall of the Shizigou fault, and the abnormally high-size area of tectonic stress intensity in the northern and middle tectonic zones of the presalt carbonate reservoirs. The fracture distribution is mainly affected by faults, lithology, structural parts, and tectonic stress intensity. The predicted favorable development areas of fractures can be considered favorable exploration positions in the deep layers of the study area. This study can provide a guide for the deep oil–gas exploration in the study area and a feasible method for predicting the sweet spots of this type of tight reservoir. Using the finite element numerical simulation, the geological models for the lacustrine carbonate oil reservoirs are established. The tectonic stress field of theirs is restored. Combined with the comprehensive fracture index evaluation, the fracture development degree parameters are constructed to realize the quantitative prediction of the fracture distribution. [ABSTRACT FROM AUTHOR]

Local constraint in the lattice gauge theory provides an exotic mechanism that facilitates the disorder-free localization. However, the understanding of nonequilibrium dynamics in the non-Hermitian lattice gauge model remains limited. Here, we investigate the quench dynamics in a system of spinless fermions with nonreciprocal hopping in the Z 2 gauge field. By employing a duality mapping, we systematically explore the non-Hermitian skin effect, localization-delocalization transition, and real-complex transition. Through the identification of diverse scaling behaviors of quantum mutual information for fermions and spins, we propose that the non-Hermitian quantum disentangled liquids exist both in the localized and delocalized phases, the former originates from the Z 2 gauge field and the latter arises from the non-Hermitian skin effect. Furthermore, we demonstrate that the nonreciprocal dissipation causes the flow of quantum information. Our results provide valuable insights into the nonequilibrium dynamics in the gauge field, and may be experimentally validated using quantum simulators. Lattice gauge theory, a subset of gauge theory, has been successfully applied to a range of quantum systems allowing for the investigation of localised phenomena within these systems. Here, the authors consider a non-Hermitian lattice model observing a quantum disentangled liquid state that exists in both the localised and delocalised phases. [ABSTRACT FROM AUTHOR]

The limited electrical performance of microelectronic devices caused by low inter-particle connectivity and inferior printing quality is still the greatest hurdle to overcome for Aerosol jet printing (AJP) technology. Despite the incorporation of carbon nanotubes (CNTs) and specified solvents into functional inks can improve inter-particle connectivity and ink printability respectively, it is still challenging to consider multiple conflicting properties in mixture design simultaneously. This research proposes a novel hybrid multi-objective optimization method to determine the optimal functional ink composition to achieve low electrical resistivity and high printed line quality. In the proposed approach, silver ink, CNTs ink and ethanol are blended according to mixture design, and two response surface models (ReSMs) are developed based on the Analysis of Variance. Then a desirability function method is employed to identify a 2D optimal operating material window to balance the conflicting responses. Following that, the conflicting objectives are optimized in a more robust manner in the 3D mixture design space through the integration of a non-dominated sorting genetic algorithm III (NSGA-III) with the developed ReSMs and the corresponding statistical uncertainty. Experiments are conducted to validate the effectiveness of the proposed approach, which extends the methodology of designing materials with multi-component and multi-property in AJP technology. [ABSTRACT FROM AUTHOR]

Sampling stochastic dynamic programming (SSDP), which considers the uncertainty of streamflow, is a popular and useful method for solving release decisions of reservoirs. It is easy to implement the long-term operation for cascaded hydropower system with poor inflow prediction ability. Furthermore, SSDP describes the temporal and spatial structure of the stochastic streamflow processes implicitly through inflow scenarios instead of representing the multivariate distribution of inflow by conditional probabilities in stochastic dynamic programming (SDP). However, computation time of SSDP procedure will increase exponentially with the growth inflow scenarios. Thus, clustering algorithm is employed to reduce the number of inflow scenarios in order to improve the efficiency and operability of SSDP in practical applications. The calculation results of SSDP with inflow clustering are analyzed with different cluster numbers. The principle of how to find the least inflow scenarios to represent all inflow sequences has also been proposed. The least inflow scenarios and relevant probabilities found by clustering algorithm can approximate the empirical distribution of all streamflow scenarios used in this study without obviously decreasing the energy and exacerbating the shortage of firm power. [ABSTRACT FROM AUTHOR]

Key message: We identified two new transposon insertions within the promoter of BnaFT.A2 in addition to an existing 288 bp MITE within the second intron. Each insertion event corresponds to a distinct BnaFT.A2 haplotype and is closely associated with established crop seasonal ecotypes. Florigen, encoded by FLOWERING LOCUS T (FT), plays key roles not only as a flowering hormone, but also a universal growth factor affecting several aspects of plant architecture. In rapeseed, BnaFT.A2 has been revealed as one of the major loci associated with flowering time and different ecotypes. However, it is unclear how allelic variations of BnaFT.A2 affect its function in flowering time regulation and beyond. In this study, we confirmed an existing 288 bp miniature inverted-repeat transposable element (MITE) insertion within the second intron and identified two new insertions within the promoter of BnaFT.A2—a 3971 bp CACTA and a 1079 bp Helitron. Each insertion event corresponds to a distinct BnaFT.A2 haplotype and is closely associated with established crop seasonal ecotypes. These alleles have similar tissue-specific expression patterns but discrete transcriptional patterns tightly associated with rapeseed flowering time and ecotype. RNAi lines and mutants of BnaFT.A2 flowered significantly later than controls. Differentially expressed genes (DEGs), identified in transcriptomic profiling of seedling leaves from two loss-of-function mutants (Bnaft.a2-L1 and Bnaft.a2-L2) compared with controls, indicated significant enrichment for hormone metabolic genes and roles related to plant cell wall synthesis and photosynthesis. Plants with loss-of-function BnaFT.A2 had smaller leaves and lower net photosynthetic rate compared to controls. These findings not only further clarify the genetic basis of flowering time variation and ecotype formation in B. napus, but also provide an additional toolbox for genetic improvement of seasonal adaptation and production. [ABSTRACT FROM AUTHOR]

In this study, the PM2.5 and PM10 concentrations from 367 cities in China were integrated with MODIS-retrieved aerosol optical depth (AOD) and Angstrom exponent (AE) data to explore the relationship between ground-measured surface particle concentrations and remote-sensing aerosol parameters. The impact of meteorological and topographical factors and seasonality were also taken into consideration and the partial least squares (PLS) regression model was adopted to evaluate the effects of surface particulate matter (PM) concentration and meteorological factors on the variation of aerosol parameters. PM concentrations and aerosol parameters all presented strong spatial disparity and seasonal patterns in China. After implementation of stringent clean air actions and policies, both the ground-measured and satellite-retrieved aerosol parameters revealed that the concentrations of suspended particles in China's cities declined dramatically from 2015 to 2018. The PM/AOD ratio showed conspicuous south–north and west–east differences. The ratio was strongly correlated to meteorological and topographic factors, and it tended to be higher in arid and less polluted regions. Moreover, the dominant factors affecting seasonal PM/AOD ratios varied among China's five regions. The correlations of daily PM-AOD were always strong in southwest China and in basin terrain (e.g., Sichuan Basin and Tarim Basin). In contrast, the PM-AOD correlation was found to be negative in some cities on the Tibetan Plateau because local relative humidity makes a greater contribution to AOD variation. Since the climate is arid and the ratio of coarse particles (e.g., PM10) is much higher, PM tended to have a significantly negative correlation with AE in northwestern cities. Whereas in many southern cities, PM was positively correlated with AE because of the area's high relative humidity and aerosol hygroscopic properties. [ABSTRACT FROM AUTHOR]

The efficiency of mine excavation has been significantly enhanced by continuing improvements in tunneling capabilities; however, this has also resulted in serious environmental pollution and greater safety risks for workers. To ensure safe production, the focus of this study is on the effect of varying the air pressure and the distance between the air pressure cylinder and the side wall settings on dust dispersion behavior and dust control in excavated tunnels. We also investigated temporal-spatial dust diffusion rules in tunnels by combining numerical simulation data with field measurement results. Through further analysis, when the pressure air volume and the exhaust air volume are both equal to 250 m3/min, the dust diffusion distance could be fitted as: L t = - 4 E - 09 t 6 + 1 E - 06 t 5 - 0.0002 t 4 + 0.0107 t 3 - 0.3219 t 2 + 5.018 t - 2.535 . When the exhaust air volume is equal to 250 m3/min, dust control effects were improved as the pressure air volume decreased, becoming optimal when the pressure air volume dropped to 150 m3/min. Under these conditions, areas of high dust pollution were contained within 16 m of the cutting face, and the dust diffusion distance satisfied the formula: L s = 2 E - 06 q 3 + 0.001 q 2 - 0.0413 q + 5.0286 . When the pressure air volume is fixed, the change of the distance between the pressure air cylinder and the side wall has little effect on the dust diffusion. When the distance is 1.5 m, the dust control effect is the best, and the high dust pollution area is controlled within 14 m of the cutting surface. This alleviated dust pollution to a certain degree, thereby enhancing the air quality and ensuring safer production. This study provides a new understanding of the environmentally sustainable development of tunnels and is of great significance for clean production. [ABSTRACT FROM AUTHOR]

The decomposition of coarse woody debris (CWD) affects the energy flow and nutrient cycling in forest ecosystems. Previous studies on CWD have focused on the input, decomposition, reserve dynamics, and CWD functions, but coarse woody debris decomposition is complex and the results from different regions vary considerably. It is not clear which factors affect decay rate (k), especially at different decomposition stages. In this study, a single-exponential decay model was used to analyze the characteristics of CWD decomposition in Larix gmelinii forests over the 33 years following a fire in the Greater Khingan Mountains. The results show that the decay rate of coarse woody debris was positively correlated to decay class. The average decomposition rate was 0.019, and 41 years and 176 years are needed for a 50% and 95% mass loss, respectively. CWD nutrient content, density, and water content could explain the variance in the decay rate (~ 42%) of the decay factors such as amount of leaching, degree of fragmentation, respiration of the debris, and biotransformation, and varied significantly between different decay classes. Using the space–time substitution method, this study arranged the coarse woody debris of different mortality times to form a 33 year chronosequence which revealed the decomposition process. It was concluded that the decay rate was mainly explained by structural component of the debris and its nitrogen and water contents. This paper quantifies the indicators affecting CWD decay to explain the decomposition process. [ABSTRACT FROM AUTHOR]

Resistivity differentiation of tight sandstone reservoirs refers to the phenomenon in which the resistivity values of some oil (gas) layers and water layers similar and the test results of reservoirs with higher resistivity are diversified. Therefore, in tight sandstone reservoirs, the geological genesis interpretation of the resistivity difference is an outstanding problem that needs to be resolved. A new interpretation method includes traditional experiments, wettability experiments and NMR experiments. High water salinity and clay mineral additional conductivity in a formation will cause changes in reservoir resistivity and certain differences in different reservoirs. The development of conductive minerals reduces the reservoir resistivity and increases differences in reservoir resistivity. The difference in pore structure and difference in wettability are the main reasons for the difference in reservoir resistivity. Based on the results of experimental research, a comparative analysis is performed on the reservoir resistivity difference between Well J8 and Well Z3. The reservoir resistivity of Well J8 is not notably different from that of the water layer. The reservoir resistivity value of Z3 is relatively large, which is a characteristic of normal gas layers. The reservoir characteristics of Well J8 are also different from those of Well Z3. In the tight sandstone reservoirs of the Shaximiao Formation of the study area, the geological genetics of the resistivity difference are obtained by comprehensive analysis. The main model of geological genetics is the difference in pore structure + difference in wettability, and the secondary model is the difference in formation water salinity + additional conductivity of clay minerals + conductive minerals. [ABSTRACT FROM AUTHOR]

Key message: Two CO paralogs in Brassica napus were confirmed and shown distinct expression pattern and function in promoting flowering and allelic variation s within BnaCO.A10 were found closely associated with ecotype divergence. CONSTANS (CO) is a key gene that responds to photoperiod and in Arabidopsis can promote flowering under long-day (LD) conditions. Brassica napus L. is a major oil crop and close relative of Arabidopsis, and arose via allopolyploidization from the diploids B. rapa (A genome) and B. oleracea (C genome). In this study, we confirmed that B. napus has two CO genes located on the A10 (BnaCO.A10) and C9 (BnaCO.C9) chromosomes. Significant differences in level and temporal pattern of transcription, as well as in protein function, of these homoeologous may have resulted from sequence variation in the promoter as well as in the coding region. Apart from two insertions of 527 bp and 2002 bp in the promoter of BnaCO.C9 that function as transcriptional enhancers, this gene is otherwise highly conserved in both promoter and coding region. However, BnaCO.A10 was classified into two haplotypes and transgene analysis in Arabidopsis and backcross analysis in rapeseed indicated that the winter-type haplotype had a greater effect in promoting flowering than the spring type. We discuss the contribution of CO alleles to species evolution, and for eco-geographic radiation following crop domestication, alongside scope for managing this locus in future breeding. [ABSTRACT FROM AUTHOR]

Design and fabrication of highly efficient and stable electrocatalysts remain key challenges in green energy technologies such as low-temperature direct liquid fuel cells. Based on in-depth theoretical calculations, here we demonstrate that surface Pd atoms with high coordination numbers (HCNs) can effectively modulate their adsorption energies for CO and OH, and thus achieve very high performance for formic acid electro-oxidation reaction (FAOR). Based on epitaxial coating Pd atomic layers onto nanoporous gold (NPG) thin membranes and a slight further decoration of Au clusters on top, the resulted core-shell structured NPG-Pd-Au electrocatalyst can demonstrate Pd intrinsic and mass activities of 8.62 mA·cm−2 and 27.25 A·mg−1 respectively at the peak potential around 0.33 V versus saturated calomel electrode toward FAOR, which are far better than those of commercial Pd/C catalysts (1.09 mA·cm−2 and 0.32 A·mg−1) tested under the same conditions. Moreover, the membrane electrode assemblies based on these low precious metal loading electrodes can achieve an anode Pd power efficiency over 10 W·mg−1 in a direct formic acid fuel cell, which is two orders of magnitude higher than that of the commercial Pd/C. These results provide new inspirations for the development of revolutionary electrodes for energy technologies in a rational manner. [ABSTRACT FROM AUTHOR]

Design of catalyst layers (CLs) with high proton conductivity in membrane electrode assemblies (MEAs) is an important issue for proton exchange membrane fuel cells (PEMFCs). Herein, an ultrathin catalyst layer was constructed based on Pt-decorated nanoporous gold (NPG-Pt) with sub-Debye-length thickness for proton transfer. In the absence of ionomer incorporation in the CLs, these integrated carbon-free electrodes can deliver maximum mass-specific power density of 198.21 and 25.91 kW·gPt−1 when serving individually as the anode and cathode, at a Pt loading of 5.6 and 22.0 µg·cm−2, respectively, comparable to the best reported nano-catalysts for PEMFCs. In-depth quantitative experimental measurements and finite-element analyses indicate that improved proton conduction plays a critical role in activation, ohmic and mass transfer polarizations. [ABSTRACT FROM AUTHOR]

Vegetation phenology is an indicator of vegetation response to natural environmental changes and is of great significance for the study of global climate change and its impact on terrestrial ecosystems. The normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI), extracted from the Moderate Resolution Imaging Spectrometer (MODIS), are widely used to monitor phenology by calculating land surface reflectance. However, the applicability of the vegetation index based on 'greenness' to monitor photosynthetic activity is hindered by poor observation conditions (e.g., ground shadows, snow, and clouds). Recently, satellite measurements of solar-induced chlorophyll fluorescence (SIF) from OCO-2 sensors have shown great potential for studying vegetation phenology. Here, we tested the feasibility of SIF in extracting phenological metrics in permafrost regions of the northeastern China, exploring the characteristics of SIF in the study of vegetation phenology and the differences between NDVI and EVI. The results show that NDVI has obvious SOS advance and EOS lag, and EVI is closer to SIF. The growing season length based on SIF is often the shortest, while it can represent the true phenology of vegetation because it is closely related to photosynthesis. SIF is more sensitive than the traditional remote sensing indices in monitoring seasonal changes in vegetation phenology and can compensate for the shortcomings of traditional vegetation indices. We also used the time series data of MODIS NDVI and EVI to extract phenological metrics in different permafrost regions. The results show that the length of growing season of vegetation in predominantly continuous permafrost (zone I) is longer than in permafrost with isolated taliks (zone II). Our results have certain significance for understanding the response of ecosystems in cold regions to global climate change. [ABSTRACT FROM AUTHOR]

Deqi is taken as an indispensable requirement to achieve acupuncture efficacy. This study aimed to explore the central influence of deqi on the efficacy of acupuncture for functional dyspepsia (FD). 70 FD patients were randomized to receive 20 sessions' acupuncture treatment with (n = 35) and without deqi (n = 35). In each group, 25 FD patients randomly selected underwent functional magnetic resonance imaging (fMRI) scans before and after treatment. After group re-division according to deqi response, changes of amygdala subregions-based resting-state functional connectivity (rsFC) were compared between the acupuncture with and without obvious deqi group. The clinical changes of the Nepean Dyspepsia Symptom Index (NDSI) measuring FD symptoms were also used to further assess the correlation with amygdala subregions rsFC in FD patients. The decrease in the NDSI scores (pre-pos) in the obvious deqi group was significantly greater than that in the acupuncture without obvious deqi group (p < 0.05). Compared to the without obvious deqi group, the obvious deqi group showed significantly decreased the left basolateral amygdala (BLA) rsFC with bilateral insular (INS), putamen and middle/posterior cingulate cortex (MCC/PCC), right pallidum and hippocampus (HIPP) after treatment. The changed NDSI scores(pre-post) of all 41 FD patients was significantly positively correlated with their Fisher's transformed z value of the left BLA rsFC with left INS (r = 0.376, FDR corrected p = 0.015), and rsFC with right HIPP (r = 0.394, FDR corrected p = 0.015). The changed NDSI scores(pre-post) of the obvious deqi group was significantly negatively correlated with their Fisher's transformed z value of the right centromedial amygdala (CMA) rsFC with left medial prefrontal cortex (mPFC) (r = −0.463, p = 0.035). The results tested the hypothesis that the advantage of deqi on efficacy is related to affecting the BLA and CMA rsFC. It suggested that deqi might influence the abnormal rsFC within the salience network (SN), and participate in the adaptive modulation of disrupted relationship between the SN and default mode network (DMN). [ABSTRACT FROM AUTHOR]

In order to improve the recovery of tight oil and extend the life cycle of the oilfield, in this paper, we have conducted a systematic study on the fine characterization of remaining oil distribution. A three-dimensional numerical simulation method was used to study remaining oil distribution of tight sandstones with the constraints of structure, sedimentary facies, and petrophysical properties. The results show that the distribution of remaining oil in the Chang 2 Member was affected by the structural location, sand body thickness, and petrophysical properties. The remaining oil saturation is higher in the axial parts of nose-like uplifts, the edge parts of thick sand bodies, and the positions where the monoclinic and sand bodies intersect; however, in the flanks of the nose-like uplifts, when the monoclinics are distributed nearly parallel the sand bodies, and in low-lying areas, a low oil saturation distribution often occurs. When two parameters in structure, sand body thickness, and petrophysical properties satisfy favorable conditions, this area is likely to become a favorable remaining oil enrichment area. Numerical simulation results show that improving the injection and production well pattern and increasing the number of oil production wells are important measures to improve oil recovery. The density of the well pattern can be considered as 30–50 wells per square kilometer. [ABSTRACT FROM AUTHOR]

Intense particle beams generated from the interaction of ultrahigh intensity lasers with sample foils provide options in radiography, high-yield neutron sources, high-energy-density-matter generation, and ion fast ignition. An accurate understanding of beam transportation behavior in dense matter is crucial for all these applications. Here we report the experimental evidence on one order of magnitude enhancement of intense laser-accelerated proton beam stopping in dense ionized matter, in comparison with the current-widely used models describing individual ion stopping in matter. Supported by particle-in-cell (PIC) simulations, we attribute the enhancement to the strong decelerating electric field approaching 1 GV/m that can be created by the beam-driven return current. This collective effect plays the dominant role in the stopping of laser-accelerated intense proton beams in dense ionized matter. This finding is essential for the optimum design of ion driven fast ignition and inertial confinement fusion. A detailed understanding of particle stopping in matter is essential for nuclear fusion and high energy density science. Here, the authors report one order of magnitude enhancement of intense laser-accelerated proton beam stopping in dense ionized matter in comparison with currently used models describing ion stopping in matter. [ABSTRACT FROM AUTHOR]

Fractures enhance secondary porosity and permeability of tight sandstone and in turn promote fluid migration and well recovery. The developmental characteristics and dominant factors of tight sandstone reservoir fractures in the lower Permian Shanxi Formation, southern Qinshui Basin, were systematically studied by combining qualitative observations, quantitative characterizations, logging interpretations, and tectonic analysis. The results show that fractures are extensively developed in the Shanxi Formation tight sandstone. The primary factors controlling these fractures include tectonic position, proximity to faulting, rock brittleness, single sand body thickness, formation anisotropy, and diagenesis. In crest or flank portions of the anticline and the bottom or low regions or well-developed faults, the fracture density is generally greater than 2 per meter. The scale and intensity of faulting both have a significant impact on the fracture development. Near some faults, "crushed zones" or "weak zones" were observed in the cores. These areas have a moderate- to low-angle or near-horizontal dips of less than 15° and widths of less than 50 cm. The rock rupture of the crushed zone typically occurred in a certain direction. It was found that the first fractures to form in a tight sandstone reservoir are related to tensile failure or shear-tensile failure. A negative exponential correlation exists between the linear fracture density and the single sand body thickness. When the single sand body thickness is less than 3 m, the linear fracture density is generally higher than 4 per meter; when the single sand body thickness is greater than 6 m, the fracture density is generally lower than 2 m−1. The influence of fracture density on rock anisotropy is stronger than that of the geostress. Minerals with unstable chemical properties, such as carbonate cements and feldspar, provide favorable conditions for the migration of acidic fluids and the formation of dissolution fractures. [ABSTRACT FROM AUTHOR]

Across the globe, the formation of large oil and gas fields is always associated with a wide range of anhydrite cap rocks. Thus, an accurate analysis of the dynamic and static mechanical properties of anhydrite rocks is required. A deep thick anhydrite cap rock is developed in the Paleogene formation of the southwestern Tarim Basin, NW China. In this paper, we designed mechanical and acoustic synchronization tests and acquired the corresponding parameters. The effects of stress and mineral composition on the dynamic and static mechanical properties of the anhydrite rock were analyzed systematically. The results indicate that under uniaxial conditions, the anhydrite rock showed obvious brittle rupture characteristics, while under triaxial conditions, the shear rupture characteristics were obvious. The stress–strain curves of the anhydrite rocks under triaxial conditions can be divided into five stages: initial compression stage, linear elasticity stage, nonlinear steady extension stage, nonlinear unsteady extension and failure stage and post-peak stress stage. An increase in the anhydrite content can delay the weakening time of the anhydrite rocks, greatly improving the rock strength. Under high-stress conditions, the anhydrite mineral particles can accumulate large amounts of energy, exhibit a long period of creep behavior and produce significant additional stresses. The anhydrite composition can improve the strength and rigidity of the anhydrite rocks. However, anhydrite rock with a high anhydrite content will also have strong plasticity. The greater the stress environment that the anhydrite rock bears, the stronger its plasticity will be. The anhydrite component can improve the ability of the anhydrite rocks to resist shear rupture. Compared to the anhydrite mudrocks (AMR), argillaceous anhydrite rocks (AR) have higher VP, VS and VP/VS values. There is a very good positive correlation between VP/VS and the anhydrite content. A regression model of the longitudinal and shear wave time differences of the anhydrite rocks is obtained, which can be used for the prediction of the shear wave time difference. The dynamic Young's modulus, Poisson's ratio and shear modulus of the AR are higher than those of the AMR. The regression models of dynamic and static mechanical parameters of the anhydrite rocks are also obtained. These models will be valuable in the evaluation of mechanical characteristics for similar types of anhydrite rocks worldwide. [ABSTRACT FROM AUTHOR]

Background: Radiotherapy remains one of the cornerstones to improve the outcome of colorectal cancer (CRC) patients. Radiotherapy of the CRC not only help to destroy cancer cells but also remodel the tumour microenvironment by enhancing tumour-specific tropism of bone marrow-derived mesenchymal stromal cell (BM-MSC) from the peripheral circulation. However, the role of local MSCs and recruited BM-MSC under radiation were not well defined. Indeed, the functions of BM-MSC without irradiation intervention remained controversial in tumour progression: BM-MSC was previously shown to modulate the immune function of major immune cells, resulting in an impaired immunological sensitivity and to induce an increased risk of tumour recurrence. In contrast, it could also secrete various cytokines and possess anticancer effect.Methods: Three co-cultivation modules, 3D culture modules, and cancer organoids were established. The induction of cytokines secretion in hBM-MSCs after irradiation was analysed by ELISA array and flow cytometry. AutoMac separator was used to separate hBM-MSC and CRC automatically. Cells from the co-cultured group and the control group were then irradiated by UV-C lamp and X-ray. Proliferation assay and viability assay were performed.Results: In this study, we show that BM-MSCs can induce the EMT progression of CRC cells in vitro. When irradiated with low doses of ultraviolet radiation and X-rays, BM-MSCs show an anti-tumour effect by secreting certain cytokine (TNF-α, IFN-γ) that lead to the inhibition of proliferation and induction of apoptosis of CRC cells. This was further verified in a 3D culture model of a CRC cell in vitro. Furthermore, irradiation on the co-culture system induced the cleavage of caspase3, and attenuated the phosphorylation of phosphatidylinositol 3-kinase (PI3K)/AKT and extracellular signal-regulated kinase in cancer cells. The signal pathways above might contribute to the cancer cell death.Conclusions: Taken together, we show that BM-MSC can potentially promote the effect of radiotherapy in CRC. [ABSTRACT FROM AUTHOR]

Purpose: Pancreatic cancer 3D in vitro models including multicellular tumor spheroid (MCTS), single cell-derived tumor spheroid (SCTS), tissue-derived tumor spheroid, and organotypic models provided powerful platforms to mimic in vivo tumor. Recent work supports that circulating tumor cell (CTC) clusters are more efficient in metastasis seeding than single CTCs. The purpose of this study is to establish 3D culture models which can mimic single CTC, monoclonal CTC clusters, and the expansion of macrometastases. Methods: Seven pancreatic ductal adenocarcinoma cell lines were used to establish MCTS and SCTS using hanging drop and ultra-low attachment plates. Spheroid immunofluorescence staining, spheroid formation assay, immunoblotting, and literature review were performed to investigate molecular biomarkers and the morphological characteristics of pancreatic tumor spheroids. Results: Single cells experienced different growth patterns to form SCTS, like signet ring-like cells, blastula-like structures, and solid core spheroids. However, golf ball-like hollow spheroids could also be detected, especially when DanG and Capan-1 cells were cultivated with fibroblast-conditioned medium ( p < 0.05). The size of golf ball-like hollow spheroids hardly grew after getting matured. Only DanG and Capan-1 could establish SCTS- and MCTS-derived hollow spheroids using hanging drop plates and ultra-low attachment plates. Other PDA cell lines could also establish tumor spheroid with hanging drop plates by adding methylated cellulose. Tumor spheroids derived from pancreatic cancer cell line DanG possessed asymmetrically distributed proliferation center, immune-checkpoint properties. ß-catenin, Ki-67, and F-actin were active surrounding the crater-like structure distributing on the inner layer of viable rim cover of the spheroids, which was relevant to well-differentiated tumor cells. Conclusions: It is possible to establish 3D CTC cluster models from homogenous PDA cell lines using hanging drop and ultra-low attachment plates. PDA cell line displays its own intrinsic properties or heterogeneity. The mechanism of formation of the crater-like structure as well as golf ball-like structure needs further exploration. [ABSTRACT FROM AUTHOR]

Rice is the second largest staple crop in the world and therefore plays an important role in food security. As a thermophilic crop, rice is sensitive to temperature changes. Thus, research on the chilling damage of rice is essential. The Sanjiang Plain is an emerging rice production area and is located at high latitudes in China, the world's largest rice-producing country. Landsat data were used to extract rice-planting area from 1985 to 2015. MODIS 13Q1, which was uniformly distributed during the growing period of rice, was used to obtain NDVI values of paddies during 2002-2015. Dynamic Identification Index of sterile-type chilling damage and monitoring standard of delayed-type chilling damage were the proposed methods used in this paper, which were used to judge the chilling damage of rice. The results show that in the study region, the rice-planting area in 2015 is nearly 12 times larger than that in 1985. Delayed-type chilling damage occurred in 2002 and 2009, while sterile-type chilling damage occurred in 2005, 2006, 2009, 2010, 2014, and 2015. Comparing with the prevalent meteorological standards, the results indicate that the index and standards proposed in this paper are precise, applicable, and more sensitive than them. The method is a macroscopic and accurate method to identify chilling damage in rice and can also provide a scientific basis to ensuring the stability of rice yield. [ABSTRACT FROM AUTHOR]

A halophilic archaeal strain, YJ-18-S1, was isolated from Yangjiang marine solar saltern, Guangxi Province, China. Cells were pleomorphic, stained Gram-negative and formed red-pigmented colonies on agar plates. Strain YJ-18-S1 was able to grow at 20-55 °C (optimum 37 °C), at 0.9-4.8 M NaCl (optimum 2.6 M NaCl), at 0.005-1.0 M MgCl (optimum 0.3 MgCl) and at pH 5.5-8.5 (optimum pH 7.0). The cells were lysed in distilled water, and the minimal NaCl concentration to prevent cell lysis was found to be 5 % (w/v). The major polar lipids of the strain were phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and sulfated mannosyl glucosyl diether. The 16S rRNA gene and rpoB′ gene of strain YJ-18-S1 were phylogenetically related to the corresponding genes of Halorubrum members (94.3-98.0 and 86.7-96.1 % similarities, respectively). The DNA G+C content of strain YJ-18-S1 was 66.2 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YJ-18-S1 (=CGMCC 1.12554 = JCM 30030) represents a new species of Halorubrum, for which the name Halorubrum rutilum sp. nov. is proposed. [ABSTRACT FROM AUTHOR]

Halophilic archaeal strain YC89 was isolated from Yuncheng salt lake in Shanxi, China. Cells from strain YC89 were short rods, lysed in distilled water, stained Gram-negative and formed red-pigmented colonies on agar plate. Strain YC89 was able to grow at 25-50 °C (optimum 37 °C), at 1.4-4.8 M NaCl (optimum 2.6-3.1 M), at 0-1.0 M MgCl (optimum 0.3 M) and at pH 6.0-9.5 (optimum pH 7.5). The major polar lipids are phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, sulfated mannosyl glucosyl diether and two unknown glycolipids. 16S rRNA gene analysis revealed that strain YC89 was phylogenetically related to Halorientalis persicus D108 (95.6 % nucleotide identity) and H. regularis TNN28 (95.3 % nucleotide identity). The rpoB′ gene similarities between strain YC89 and H. persicus IBRC-M 10043 and H. regularis TNN28 were 88.1 and 88.0 %, respectively. The DNA G+C content of strain YC89 was determined to be 61.3 mol%. The phenotypic, chemotaxonomic and phylogenetic properties suggested that strain YC89 (=CGMCC 1.12125 = JCM 18366) represents a new species of Halorientalis, for which the name H. brevis sp. nov. is proposed. [ABSTRACT FROM AUTHOR]

A halophilic archaeal strain, YGH94, was isolated from the Yinggehai marine solar saltern near the Shanya city of Hainan Province, China. Cells of the strain were observed to be short rods, stain Gram-negative and to form red-pigmented colonies on solid media. Strain YGH94 was found to grow at 25-50 °C (optimum 40 °C), at 0.9-4.8 M NaCl (optimum 3.1 M), at 0-1.0 M MgCl (optimum 0.05 M) and at pH 5.0-9.0 (optimum pH 7.5). The cells were found to lyse in distilled water and the minimal NaCl concentration to prevent cell-lysis was determined to be 5 % (w/v). The major polar lipids were identified as phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and four major glycolipids (disulfated mannosyl glucosyl diether, sulfated mannosyl glucosyl diether and two unidentified glycolipids chromatographically identical to glycolipids in Halosimplex carlsbadense JCM 11222). Strain YGH94 was found to possess two heterogeneous 16S rRNA genes ( rrnA and rrnB) and both are related to those of Hsx. carlsbadense JCM 11222 (92.7-98.6 % similarities), Halosimplex pelagicum R2 (94.6-99.2 % similarities) and Halosimplex rubrum R27 (92.9-98.8 % similarities). The rpoB′ gene similarity between strain YGH94 and Hsx. carlsbadense JCM 11222, Hsx. pelagicum R2 and Hsx. rubrum R27 are 95.4, 94.9 and 95.1 %, respectively. The DNA G+C content of strain YGH94 was determined to be 64.0 mol%. Strain YGH94 showed low DNA-DNA relatedness (35-39 %) with the current three members of the genus Halosimplex. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strain YGH94 (=CGMCC 1.12235 = JCM 18647) represents a new species of the genus Halosimplex, for which the name Halosimplex litoreum sp. nov. is proposed. [ABSTRACT FROM AUTHOR]

The thermal-decomposition characteristics and kinetics of Spartina alterniflora (smooth cordgrass; SC) pretreated with thermo-lime and hot water were investigated by thermogravimetric analysis. Results showed that pretreatment changed the thermal-decomposition behavior of pretreated biomass, as shown in the change of the volatile-matter yield, the thermal-decomposition temperature for a given conversion and the mass-loss rate, because of the breakage of lignocellulosic structure. The activation energy of SC ranged from 40.8 to 55.8 kJ mol for conversion ratios between 0.15 and 0.8. Pretreatment increased the activation energy of thermal-decomposition reaction, indicating the increment of the thermal stability of biomass. Compared with thermo-lime pretreatment, hot-water pretreatment increased the volatile-matter yield, activation energy, and mass-loss rate of the sample. Structure changes were further investigated by X-ray and Fourier-transform infrared (FTIR) spectroscopy analysis to determine the effect of pretreatment on thermal decomposition. FTIR analyses revealed the depolymerization of lignocellulosic structure and the disruption of carboxyl carbons attached to the lignin side chain. X-ray and FTIR results also showed that thermo-lime and hot-water pretreatment broke the crystalline structure of cellulose by disrupting hydrogen bonding and removing amorphous matter. Compared with hot water, thermo-lime pretreatment resulted in many modifications of lignocellulosic structure and composition. Furthermore, structure breakage and composition removal changed thermal-decomposition characteristics of pretreated samples. [ABSTRACT FROM AUTHOR]

Flexible aerogel was successfully supported onto 4-layer-aligned glass fibers through impregnation, followed by drying at atmospheric pressure. The prepared nanocomposites can achieve a low thermal conductivity of 0.026 W/(m·K), which holds great promising for their use in thermal insulation applications. By choosing different designs of the four fiber layers, in the terms of LLLL, LTLL, LLTT, LTLT, LTTL and LTTT, the laminated structures of aerogel composites can be accordingly controlled. Further microstructure characterization of the composites revealed the homogeneous dispersion of nanoporous structure through the aerogel matrix, as well as highly-aligned fibers to reinforce the structure. Detailed investigation on the thermal and mechanical properties of the prepared fiber-aerogel composites showed that their performances were highly related to the laminated design of fiber layers. The introduction of fibers as the backbone of the aerogel and the suitable design of their laminated structure can greatly improve the mechanical properties of the aerogel composites while maintaining a low thermal conductivity. [ABSTRACT FROM AUTHOR]

The Fengfeng Coalfield is an important coal production base in the Hebei Province of North China. It has been reported that higher coal-bed methane (CBM) contents exist in this area showing good prospects for the exploration of CBM. However, there are few studies on CBM investigation in Fengfeng Coalfield. In order to better understand the geological controls on CBM in the Fengfeng Coalfield, geological surveys and laboratory experiments were conducted that included coal petrology analysis, proximate analysis, mercury intrusion, low-temperature liquid nitrogen adsorption, coal permeability analysis, and methane adsorption/desorption. The results show that the organic compositions are dominated by vitrinites, followed by inertinites, and minor liptinites. The CBM contents are range between 0.83 and 11.52 m3/t, with an average of 4.72 m3/t. The moisture contents are range from 0.76 to 2.54%, with an average of 1.21%, and the ash yields are range from 11.46 to 24.5%, with an average of 17.07%. Low-temperature nitrogen gas adsorption indicates the micropores provide most of the pore specific surface and the pore volume is mainly determined by small pores and mesopores. The geologic structures, coal-bearing strata, and the coal depositional environments were studied through field geological research and laboratory tests. The coals were deposited in a river-dominated shallow delta environment to form the mudstones or siltstones of the coal roof and floor that were used to seal the CBM. The CBM were mainly generated during stages of the Hercynian–Indosinian and the Early-Middle Yanshanian orogeny. Underground water flowed to the Dashucun Mine and its adjacent mines in the northeast of the Gushan Anticline to form a semi-closed hydrodynamic system that created the CBM emission and preservation. The coal rank increases from the southern to the northern areas. Then, it can be speculated that the CBM formation and preservation conditions in the north are better than in the south. The best prospective targets for CBM are in the northern areas. The results of this study may be useful for CBM exploration in North China. [ABSTRACT FROM AUTHOR]

The original publication of the article does not indicate the second affiliation of the author Shuai Yin [ABSTRACT FROM AUTHOR]

The Qinshui Basin was an active residual basin in the Mesozoic and Cenozoic periods and is located inside the North China Plate. The Upper Paleozoic strata in the basin have been strongly deformed and have developed a large number of strike-slip faults. The Qinshui Basin has been influenced by compressive stress from the northeast direction since the Himalayan period, and the faults have a dextral strike-slip property. Under the action of such a stress field, the right-slip, right-order faults indicate an extension region, and the right-slip, left-order faults indicate a compression region. Based on this principle, the extension and the compression areas were divided. From northwest to southeast direction in the study area, two types of regions have interactive distribution characteristics. For the Fanzhuang block in the eastern part of the study area, the fault distribution has an ‘S-type’ trend from north to south, and the middle extension region is the ‘elbow’ or the ‘hinge zone’ of the ‘S-type’ area, which can also be called the ‘stress transition zone’. The tectonic stress field of the stress transition zone is complex, and tensile fractures are usually extremely developed with extension tectonics. Gas wells with higher capacity are mainly distributed in the extension zone, while the capacity of the gas wells in the compression area is usually lower. The study showed that the distribution of the gas well capacity is consistent with the tectonic extension and compression analysis, indicating that the tectonic analysis method in this study is reliable. The Upper Paleozoic coal measure strata in the Qinshui Basin represent a whole gas-bearing and stress-bearing system, the tectonic analysis method in this study is also applicable to other types of tight reservoirs for this set of depositional systems. [ABSTRACT FROM AUTHOR]

Accurate assessment of irrigation water resources to meet the sustainable development needs of agriculture relies on the study of the spatial and temporal patterns of change in crop water requirements or evapotranspiration (ETc). In this study, we derived the rice crop coefficient (Kc) curves from lysimeter experiments at 21 experimental stations for a total of 349 experimental years from 1952 to 2002 in Heilongjiang Province and then further refined the assessment of the spatiotemporal variation characteristics of ETc, effective precipitation (Pe), irrigation water requirements (IWR) and irrigation water requirement index (IRI) for each growth stage of rice from 1960 to 2015. The results showed that Kc varied throughout the whole growing season at the different experiment stations, and the average Kc values of each station at the initial, mid-season and end of the late season stages were 1.01 ± 0.15, 1.29 ± 0.15, and 0.69 ± 0.23, respectively. In addition, the trends in ETc (− 0.78 to − 0.02 mm year−1) and IWR (− 0.07 to 0.17 mm year−1) varied widely among the 4 irrigation zones. The region with higher IWRs was primarily located in the eastern and western plains of the study area. The negative trend in IWR in the west was due to a significant decrease in ETc, however, the positive trend in IWR in the east was due to a significant decrease in Pe. The high and increasing IWR in the east required additional water conservation measures or supplemental irrigation to cope with possible agricultural water shortages. This study highlights the fine estimation of ETc using lysimeter experiment data and provides a basis for water deployment and related agricultural strategies in the region under climate change. [ABSTRACT FROM AUTHOR]