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Small mothers against decapentaplegic2/3 (Smad2/3) are two signalling intermediates in the transforming growth factor beta (TGF-β) signalling pathway, which plays a critical role in gonad development. However, a systemic analysis of Smad2/3 in Monopterus albus (M. albus) has not been performed. The smad2 sequence in M. albus was characterized in our previous publication. In this study, we characterized the nucleotide sequence of smad3 and reported that smad3 is widely expressed in different tissues of M. albus. Importantly, the expression of smad3 significantly increased at the early vitellogenic stage in the ovary and decreased with oocyte maturation. Next, we aimed to identify the upstream factors that regulate Smad2/3 transcription. The 5′ flanking sequences of smad2/3 were cloned, and their core promoter regions were determined to be between −447 bp and −100 bp and between −1520 bp and −927 bp, respectively. The Jun and Foxo1 binding sites were conserved in the smad2 promoter region, and the Sp1, Bcl-6, and Nobox binding sites were conserved in the smad3 promoter region. Through dual-luciferase reporter gene experiments, we showed that Jun and Foxo1 binding sites may be involved in the regulation of smad2 transcription, whereas the Nobox binding site may be involved in the activation of the smad3 promoter.

Abstract Background Cyp19a1a is a key enzyme in the pathway that converts androgens into estrogen and is regulated by TGF-β signaling. Smad4 and FoxH1 are downstream effectors of TGF-β signaling and may play important roles in ovarian development in M. albus. Methods We investigated the expression pattern of the Smad4 and FoxH1 using qRT‒PCR and immunofluorescence, then tested the changes of smad4 and foxh1 by qRT‒PCR after ovary incubation with FSH in vitro, and analysed the regulation of cyp19a1a transcription by Smad4 and FoxH1 by dual-luciferase reporter assays. Results We found that Smad4 encoded a putative protein of 449 amino acids and harbored the three conserved domains typical of this protein family. Smad4 and foxh1 exhibited similar expression patterns during ovarian development and after FSH incubation, with Pearson’s coefficients of 0.873 and 0.63–0.81, respectively. Furthermore, Smad4, FoxH1 and Cyp19a1a colocalized in the granulosa cells and theca cells of ovaries during the mid-to-late vitellogenic stage. Smad4 repressed cyp19a1a activity via SBE1 (− 1372/−1364) and SBE2 (− 415/−407) in the cyp19a1a promoter, whereas mutating SBE1 or SBE2 restored cyp19a1a promoter activity. Co-overexpression of Smad4 and FoxH1 significantly reduced cyp19a1a promoter activity. Conclusions This study provides new insights into the potential functions of transcription factors Smad4 and FoxH1 in ovarian development and the transcriptional regulation mechanism of cyp19a1a in M. albus, which will reveal Smad4/FoxH1-mediated TGF-β signaling in reproduction and the regulation of the cyp19a1a. Plain English summary Aromatase, encoded by cyp19a1a, is involved in ovarian development and plays an important role in the quality of eggs, as well the sex ratio, of the teleost fish, M. albus. The research on the transcriptional regulation of cyp19a1a has contributed to the understanding of its role in ovarian development. In previous study, it was shown that FoxH1 inhibits cyp19a1a transcription. In the present study, Smad4 was confirmed as a cyp19a1a transcriptional repressor and Smad4 may also coordinate with FoxH1 to repress cyp19a1a transcription. At present, we provide a new perspective for the transcriptional regulation of cyp19a1a by transcription factors Smad4 and FoxH1 in teleost fish ovary. In the future, the regulatory networks of Smad4 and FoxH1 will be further studied and the gene editing technology will be applied to screen specific regulatory factors of cyp191a1a gene, so as to alter the female cycle and modulate the sex ratio of the eggs production.

Abstract Visual information is important in final approach and landing phases for an approaching aircraft, it presents supplementary source for navigation system, and provides backup guidance when radio navigation fails, or even supports a complete vision‐based landing. Relative position and attitude can be solved from the runway features in the image. Traditional runway detection methods have high latency and low accuracy, which is unable to satisfy the requirements for a safe landing. This paper proposes a real‐time runway detection model, efficient runway feature extractor (ERFE), based on deep convolutional neural network, generating semantic segmentation and feature lines output. In order to evaluate the model's effectiveness, a benchmark is proposed to calculate the actual error between predicted feature line and ground truth one. A novel runway dataset which is based on pictures from Microsoft Flight Simulator 2020 (FS2020), is also proposed in this paper to train and test the model. The dataset will be released at https://www.kaggle.com/datasets/relufrank/fs2020‐runway‐dataset. ERFE shows excellent performance in FS2020 dataset, it gives satisfactory results even for real runway images excluded from our dataset.

Abstract Background The ricefield eel Monopterus albus undergoes a natural sex change from female to male during its life cycle, and previous studies have shown the potential mechanisms of this transition at the transcriptional and protein levels. However, the changes in protein levels have not been fully explored, especially in the intersexual stage. Results In the present study, the protein expression patterns in the gonadal tissues from five different periods, the ovary (OV), early intersexual stage gonad (IE), middle intersexual stage gonad (IM), late intersexual stage gonad (IL), and testis (TE), were determined by untargeted proteomics sequencing. A total of 5125 proteins and 394 differentially expressed proteins (DEPs) were detected in the gonadal tissues. Of the 394 DEPs, there were 136 between the OV and IE groups, 20 between the IM and IE groups, 179 between the IL and IM groups, and 59 between the TE and IL groups. Three candidate proteins, insulin-like growth factor 2 mRNA-binding protein 3 isoform X1 (Igf2bp3), triosephosphate isomerase (Tpi), and Cu-Zn superoxide dismutase isoform X1 [(Cu-Zn) Sod1], were validated by western blotting to verify the reliability of the data. Furthermore, metal metabolite-related proteins were enriched in the IL vs. IM groups and TE vs. IL groups, which had close relationships with sex change, including Cu2+-, Ca2+-, Zn2+- and Fe2+/Fe3+-related proteins. Analysis of the combined transcriptome data revealed consistent protein/mRNA expression trends for two metal metabolite-related proteins/genes [LOC109953912 and calcium Binding Protein 39 Like (cab39l)]. Notably, we detected significantly higher levels of Cu2+ during the sex change process, suggesting that Cu2+ is a male-related metal metabolite that may have an important function in male reproductive development. Conclusions In summary, we analyzed the protein profiles of ricefield eel gonadal tissues in five sexual stages (OV, IE, IM, IL, and TE) and verified the plausibility of the data. After preforming the functional enrichment of metal metabolite-related DEPs, we detected the contents of the metal metabolites Zn2+, Cu2+, Ca2+, and Fe2+/Fe3+ at these five stages and screened for (Cu-Zn) Sod1 and Mmp-9 as possible key proteins in the sex reversal process.

Abstract Background Schizothorax o’connori is an endemic fish distributed in the upper and lower reaches of the Yarlung Zangbo River in China. It has experienced a fourth round of whole gene replication events and is a good model for exploring the genetic differentiation and environmental adaptability of fish in the Qinghai-Tibet Plateau. The uplift of the Qinghai-Tibet Plateau has led to changes in the river system, thereby affecting gene exchange and population differentiation between fish populations. With the release of fish whole genome data, whole genome resequencing has been widely used in genetic evolutionary analysis and screening of selected genes in fish, which can better elucidate the genetic basis and molecular environmental adaptation mechanisms of fish. Therefore, our purpose of this study was to understand the population structure and adaptive characteristics of S. o’connori using the whole-genome resequencing method. Results The results showed that 23,602,746 SNPs were identified from seven populations, mostly distributed on chromosomes 2 and 23. There was no significant genetic differentiation between the populations, and the genetic diversity was relatively low. However, the Zangga population could be separated from the Bomi, Linzhi, and Milin populations in the cluster analysis. Based on historical dynamics analysis of the population, the size of the ancestral population of S. o’connori was affected by the late accelerated uplift of the Qinghai Tibet Plateau and the Fourth Glacial Age. The selected sites were mostly enriched in pathways related to DNA repair and energy metabolism. Conclusion Overall, the whole-genome resequencing analysis provides valuable insights into the population structure and adaptive characteristics of S. o’connori. There was no obvious genetic differentiation at the genome level between the S. o’connori populations upstream and downstream of the Yarlung Zangbo River. The current distribution pattern and genetic diversity are influenced by the late accelerated uplift of the Qinghai Tibet Plateau and the Fourth Ice Age. The selected sites of S. o’connori are enriched in the energy metabolism and DNA repair pathways to adapt to the low temperature and strong ultraviolet radiation environment at high altitude.

To facilitate the recovery of natural gas hydrate (NGH) deposits in the South China Sea, we have designed and developed the world's largest publicly reported experimental simulator for NGH recovery. This system can also be used to perform CO2 capture and sequestration experiments and to simulate NGH recovery using CH4/CO2 replacement. This system was used to prepare a shallow gas and hydrate reservoir, to simulate NGH recovery via depressurization with a horizontal well. A set of experimental procedures and data analysis methods were prepared for this system. By analyzing the measurements taken by each probe, we determined the temperature, pressure, and acoustic parameter trends that accompany NGH recovery. The results demonstrate that the temperature fields, pressure fields, acoustic characteristics, and electrical impedances of an NGH recovery experiment can be precisely monitored in real time using the aforementioned experimental system. Furthermore, fluid production rates can be calculated at a high level of precision. It was concluded that (1) the optimal production pressure differential ranges from 0.8 to 1.0 MPa, and the wellbore will clog if the pressure differential reaches 1.2 MPa; and (2) during NGH decomposition, strong heterogeneities will arise in the surrounding temperature and pressure fields, which will affect the shallow gas stratum.

The aim of this study was to determine the influence of four inorganic salts, KCl, NaCl, KBr and NaBr, on the thermodynamic conditions of methane hydrate formation. In order to achieve this, the vapor–liquid water-hydrate (VLWH) equilibrium conditions of methane (CH4) hydrate were measured in the temperature range of 274.15 K–282.15 K by the isothermal pressure search method. The results demonstrated that, in comparison with deionized water, the four inorganic salts exhibited a significant thermodynamic inhibition on CH4 hydrate. Furthermore, the inhibitory effect of Na+ on methane hydrate is more pronounced than that of K+, where there is no discernible difference between Cl− and Br−. The dissociation enthalpy (∆Hdiss) of CH4 hydrate in the four inorganic salt solutions is comparable to that of deionized water, indicating that the inorganic salt does not participate in the formation of hydrate crystals. The Chen–Guo hydrate model and N–NRTL–NRF activity model were employed to forecast the equilibrium conditions of CH4 hydrate in electrolyte solution. The absolute relative deviation (AARD) between the predicted and experimental values were 1.24%, 1.08%, 1.18% and 1.21%, respectively. The model demonstrated satisfactory universality and accuracy. This study presents a novel approach to elucidating the mechanism and model prediction of inorganic salt inhibition of hydrate.

The thermodynamic effect of octyl-β-D-glucopyranoside (OGP) on the formation of methane-1,3-dimethylcyclohexane (DMCH) hydrate was studied in this work. The thermodynamic equilibrium hydrate formation pressures between 275.15 K and 283.15 K were measured by the isothermal pressure search method. Different OGP aqueous solutions (0, 0.1, and 1 wt%) were used in this work. The experimental results show that OGP had no obvious thermodynamic inhibition on methane-DMCH hydrate formation when its concentration was low (0.1 wt%), whereas it had an inhibition on methane-DMCH hydrate formation when its concentration was high (1 wt%). The phase equilibrium hydrate formation pressure of the methane-DMCH-OGP system is about 0.1 MPa higher than that of the methane-DMCH system. The dissociation enthalpies of methane hydrate in different solutions remained uniform, which indicates that OGP was not involved in methane-DMCH hydrate formation. This phenomenon is explained from the perspective of the molecular structure of OGP. As a renewable and biological nonionic surfactant, the concentration of OGP in the liquid phase is low, so OGP can be added to the methane-DMCH system without significant thermodynamic inhibition.

Hydrate-based CO2 sequestration is a novel approach that can not only realize permanent CO2 sequestration but can also form an artificial cap to prevent its upward migration. In this work, a self-developed large-scale 3D apparatus was employed to investigate hydrate formation characteristics in hydrate-based CO2 sequestration at a constant liquid CO2 injection rate through a vertical well for the first time. Temperature and pressure evolutions in the sediment were analyzed in detail. Key indicators, including cumulative sequestered CO2, CO2 in hydrate and liquid phases, the instantaneous hydrate conversion, and liquid CO2 retention rates, were calculated. The results show that hydrate continuously forms with increased CO2 injection and exhibits strong heterogeneity due to the variation in hydrate formation rate and quantity. Severe liquid CO2 heterogeneous figuring phenomena occur since hydrate deteriorates the effective pore structure and topology, resulting in relatively small cumulative sequestered CO2 when a large amount of CO2 is released from the outlet. Meanwhile, the instantaneous hydrate conversion and liquid CO2 retention rates have large fluctuations owing to water consumption and variation in the effective contact area between liquid CO2 and water. However, hydrate formation does not cause blockage of wellbore and formation nearby under given experimental conditions, which is beneficial for hydrate formation in deeper sediment. This study provides insights into hydrate formation and liquid CO2 immigration regularity during hydrate-based CO2 sequestration and demonstrates its feasibility at a field scale.

In order to obtain lactic acid bacteria (LAB) with a strong acid production capacity, good tolerance, and high function from persimmon vinegar broth, which is suitable for plant substrate fermentation. Using the persimmon vinegar broth naturally fermented as a source of lactic acid bacteria, five strains were isolated using MRS liquid culture medium and calcium-dissolving circle methods. The abilities of producing acid, tolerance, antioxidant and β-glucosidase production of the 5 LABs were measured, the morphology and 16S rDNA identification of the screened two LABs with stronger comprehensive performance were analyzed. Based on the results of the screening, Lactobacillus acidophilus and Lactobacillus plantarum were identified as two excellent strains of lactic acid bacteria. Both lactic acid bacteria produced acid at a rate of 2.00 and 2.24 g/100 mL, respectively. Among the pH tolerances, the lowest was 1.5, the highest was 10% for ethanol, 1% for bile salts, and 7% for NaCl. The scavenging abilities of screened two LABs on ABTS+, DPPH, O2- free radicals were 65.12% and 62.26%, 77.42% and 68.89%, 93.76% and 87.89%, respectively. The production of β-glucosidase were 26.37 and 30.27 IU/L. In this paper, the two LABs strains with strong biological properties were obtained from persimmon vinegar broth for plant substrate fermentation, which could provide strain resources for the development of probiotics.

【Objective】Sthenoteuthis oualaniensis is a mollusk with abundant resources and high development potential in the South China Sea. The study was carried out to investigate the feasibility of S. oualaniensis used as an alternative protein source of artificial compound feed for Babylonia areolata.【Method】Seven artificial compound feeds for B. areolata with different mass fractions (33.1%, 43.1%, 53.1%, 63.1%, 73.1%, 83.1%, and 100%) of S. oualaniensis were designed and fed to B. areolata larvae with initial body weight of 0.37 (± 0.03) g. The control group was fed with fish, and the experiment lasted for 90 days. The daily average weight gain and growth rate, feed coefficient, survival rate and yield per unit area were used as indexes to evaluate the breeding effect.【Result】In the treatment with 63.1% of S. oualaniensis, the daily gain of B. areolata was 0.034 g and growth rate was 9.31%, which were significantly higher than those of the control (0.029g and 7.96%); the feed coefficient was 1.33, which was significantly lower than that of the control (2.27); the yield per unit area of 3 168.6 g/m2 was higher than that of 2 856.8 g/m2 in control group, but both there were no significant differences between these two treatments. The daily gain and growth rate of B. areolata in the other groups were lower or significantly lower than that of the control. The survival rate of B. areolata in the groups with the addition of S. oualaniensis were lower than that in the control, and there were no significant differences between the treatment of adding 63.1% or more of S. oualaniensis and the control.【Conclusion】The use of the artificial compound feed for B. areolata does not require removal of residual bait or residues, which can reduce the workload of breeding and reduce the dependence on trash fish and protect offshore fishery resources. In terms of daily average weight gain, daily growth rate and feed coefficient, it is feasible to add S. oualaniensis to artificial compound feed of B. areolata, and the reference value of mass fraction is 63.1%. The application of S. oualaniensis as the main protein source can become an important direction for the development of B. areolata feed in the future.

Water-land ecotone is a core area of wetlands which play an important role in ecological function. The information of vegetation type on the water-land ecotone is important for detecting the health of the wetland, and its protection. Seasonal flooding is a key factor in controlling the environment in water-land ecotone. Even preventing direct detection of the flooded vegetation with satellites, seasonal flooding has effects on the distribution of plants, which may provide potential information on vegetation classification with satellites. Therefore, the study induces flooding index in vegetation mapping in water-land ecotone with satellites. We applied Sentinel-1 and Sentinel-2 images to map vegetation in the Dongting Lake with random forest method. The Sentinel-1 SAR images were used to obtain the flooding index (i.e. inundation frequency), and Sentinel-2 images were applied to acquire the optical characteristic of vegetation. A comparative experiment based on whether the flooding index was added or not during vegetation mapping in the Dongting Lake was carried out to explore the role of flooding index in vegetation mapping. The results concluded that (1) seasonal flooding will hinder vegetation mapping using a single phase of optical information; (2) the classification accuracy of single phase scenario was significantly improved with the aid of flooding index especially in wet season; (3) the classification accuracy can be somewhat improved by adding flooding index for the multi-temporal scenario. The study implies that inundation frequency information can be used for vegetation mapping in water-land ecotone, especially for complex regions with insufficient cloud-free satellite images.

Wild marine pearl oyster shells have rich colors, and the color and gloss of pearls cultivated by pearl oysters are closely related to the pearl layer color of the mantle. Therefore, in this study, four important wild marine pearl oyster species (Pinctada maxima, Pteria penguin, Pinctada margaritifera, and Pinctada fucata) were collected from the South China Sea, and a colorimeter was used to measure the color of their inner and outer shells. We analyzed the color range of their shells and the correlation between the color parameters; additionally, we observed the microstructure of their shells using a scanning electron microscope. The results showed that the color distribution and brightness of the inner shells of the four species were wider than that of the outer shells. In addition, the color distribution range of the outer and inner shells of the four pearl oyster species were P. fucata > P. margaritifera > P. maxima > Pt. penguin and Pt. penguin > P. fucata > P. margaritifera > P. maxima, respectively. Concerning the microstructures of the four pearl oysters, the shell structures of P. maxima, P. margaritifera and P. fucata had a honeycomb arrangement, whereas Pt. penguin had an irregular polygon structure. The P. maxima and P. margaritifera with a strong nacre secretion ability that area and thickness of the single crystal particles were larger than those of Pt. penguin and P. fucata.

Acute salinity stress can impact many physiological processes of marine shellfish. The responses of Pinctada maxima to salinity stress, especially the osmotic pressure regulation and immune response, are of great significance to health. To investigate the molecular changes in response to acute salinity stress, the pearl oysters were transferred from 30 ppt (C) to 40 ppt (HS) and 20 ppt (LS) for 12 h, and the transcriptome analysis was conducted on the gills. Compared to the control, there were 6613 (3253 up-regulated and 3360 down-regulated) differentially expressed genes (DEGs), 4395 (2180 up-regulated and 2215 down-regulated) DEGs observed in HS and LS, respectively. The related molecular biological processes and potential functions were explored from enrichment analysis. A total of 332 KEGG pathways (including 1514 genes) and 308 KEGG pathways (including 731 genes) were enriched in C vs. HS and C vs. LS, respectively. In addition, there are 1559 DEGs shared by C vs. HS group and C vs. LS group, and the results of the KEGG function annotation showed that 7 DEGs were involved in membrane transport, and 34 DEGs were involved in the immune system. The correlation network for expression of genes shows that the expression of 3 genes was significantly correlated with each other in membrane transport, and there were significant correlations between the expression of 27 genes in immune response. The results of this study will be of great value in understanding the molecular basis of salinity stress adaptation in the pearl oyster P. maxima.

This study was conducted to understand the changes of physiological and biochemical indexes of black and red shell Pinctada fucata under acute high and low salt stress. In this study, the salinity of 35‰ was used as the control, while the salinities of 20 and 50% salinity were used as the low and high salt treatment groups, respectively. The osmotic pressure (OSM) and ion concentration in the hemolymph, Na+-K+ -ATPase (NKA) activity and respiratory metabolism in gills, and antioxidant and immune (non) enzymes in the hepatopancreas of P. fucata with two shell colors were compared and analyzed at the time periods of 1.5 and 3 h post-salinity stress. The results showed that the OSM and inorganic ion (Na+, Ca2+, and Cl–) concentration in the hemolymph of the black and red P. fucata increased significantly with the increase of salinity after the time periods of 1.5 and 3 h. At 3 h, the black P. fucata NKA activity decreased significantly with the increase of salinity, while red P. fucata reached the highest value at high salinity. The succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH) activities of red P. fucata showed U-shaped and inverted U-shaped distributions with the increase of salinity after 1.5 h, respectively. With the increase of salinity, the phenoloxidase (POX) activity of red and black P. fucata showed inverted U-shaped and U-shaped distributions, respectively. The contents of glutathione (GSH) and vitamin C (VC) in black P. fucata decreased significantly with the increase of salinity at 1.5 and 3 h. Red P. fucata GSH and VC reached their maximum value in the 1.5-h low salinity group and 3-h high salinity group. The vitamin E (VE) content in black P. fucata increased significantly with the increase of salinity at 1.5 h, and reached the maximum at 3 h in the control group. Red P. fucata VE reached the maximum at 1.5 and 3 h in the control group. The results obtained from the present study revealed that the sensitivity of P. fucata to salinity varied in shell color. Compared to black P. fucata, red P. fucata responds more quickly to sharp salinity changes, thereby reducing more likely damage. Compared with a high salt environment, P. fucata was more adaptable to the changes of acute low salt environment. The results obtained from the present study provide the physical references for subsequent selective breeding of this species.

Understanding different fluids flow behavior confined in microscales has tremendous significance in the development of tight oil reservoirs. In this article, a novel semiempirical model for different confined fluid flow based on the concept of boundary layer thickness, caused by the fluid–solid interaction, is proposed. Micro-tube experiments are carried out to verify the novel model. After the validation, the viscosity effect on the flow rate and Poiseuille number considering the fluid–solid interaction is investigated. Furthermore, the novel model is incorporated into unstructured networks with anisotropy to study the viscosity effect on pore-scale flow in tight formations under the conditions of different displacement pressure gradients, different aspect ratios (ratio of the pore radius to the connecting throat radius), and different coordination numbers. Results show that the viscosity effect on the flow rate and Poiseuille number after considering the fluid–solid interaction induces a great deviation from that in conventional fluid flow. The absolute permeability is not only a parameter related to pore structures but also depends on fluid viscosity. The study provides an effective model for modeling different confined fluid flow in microscales and lays a good foundation for studying fluid flow in tight formations.

In this study, effects of different temperatures (20 ℃, 25 ℃, and 30 ℃) air exposure (12 h) on the survival rate and biochemical indexes of four shell color stains of Pinctada fucata were studied. The survival rates of P. fucata after 72 h′ re-watering period, and the activities of 11 biochemical indexes of P. fucata were measured. 11 biochemical indexes included as follows: digestive enzymes (lipase (LPS), amylase (AMS) and cellulase (CL)), antioxidant related indicators (superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), anti-superoxide anion free radical (ASAFR), peroxidase (POD), total antioxidant capacity (T-AOC)) and hydrolytic enzymes (acid phosphatase (ACP) and Alkaline phosphatase (ALP)). The results showed that 12 h′ air exposure at 30 ℃ significantly reduced the survival rate of P. fucata (P

This is the first detailed report of embryonic and larval development, larval morphological changes, movement, and feeding behavior of Antigona lamellaris, and to provide references for seed breeding. Nine microalgal species (Chlorella vulgaris, Nannochloropsis oculata, Dunaliella salina, Platymonas subcordiformis, Pavlova viridis, Dicrateria zhanjianggensis, Isochrysis galbana, Chaetoceros muelleri, and Phaeodactylum tricornutum) were tested for ingestion and digestion in A. lamellaris larvae using optical microscopy to choose an appropriate diet. Fertilized eggs of A. lamellaris hatched into D-larvae after 22 h and 10 min, the larvae began to ingest microalgae after 24 h and 30 min, and the larvae developed to metamorphosis stage at 8 days post hatch (dph). The growth model of shell length is decelerating positive growth, and the growth model of shell height is accelerating positive growth. As for the nine microalgal species fed, larvae could ingest C. vulgaris, N. oculata, D. salina, P. viridis, D. zhanjianggensis and I. galbana at 1 dph, P. subcordiformis and C. muelleri at 2 dph, and P. tricornutum could not be ingested during the planktonic period. It was difficult for the larvae to digest C. vulgaris and N. oculata. A. lamellaris newly hatched larvae are relatively large and have a short time in planktonic larval cultivation. There are a widely variety of microalgal species that can be used for feeding as the larval cultivation. A. lamellaris is a valuable species with huge aquaculture potential.

This study compares salinity tolerance between red and black shell Pinctada fucata salinity stress of 20 and 50‰, while 35‰ was used as a control. The hemolymph osmotic pressure, inorganic ion concentration, the activities of Na+-K+ -ATPase, respiratory metabolism related enzymes and liver tissue antioxidant related enzymes were measured at 12 and 24 h after salinity stress. The osmotic pressure and inorganic ion concentration of hemolymph of two strains P. fucata increased significantly with the increase of salinity. The activity of Na+-K+ -ATPase of red P. fucata only decreased under low salinity at 24 h, and was significantly higher than that the control under low salinity at 12 h and high salinity at 12 and 24 h. The succinate dehydrogenase (SDH) activities of the P. fucata treatment groups were significantly higher than those the control at 12 h. The lactate dehydrogenase (LDH) activity increased significantly with salinity at 12 h. and the black P. fucata LDH activity was significantly higher than the control at 24 h, while the LDH activity of red P. fucata was significantly lower than that the control in 50‰ salinity. The superoxide dismutase (SOD) activity of black P. fucata was significantly lower than that the control, while that of red P. fucata was significantly higher than that the control within 24. At 12 h, the catalase (CAT) activity of red P. fucata increased significantly with salinity, but decreased significantly with salinity at 24 h. The CAT activity of black P. fucata was highest at 24 h under low salinity. Glutathione peroxidase (GSH-Px) and alkaline phosphatase (AKP) activities of red P. fucata were significantly higher than those the control under low or high salinity. At high salinity for 24 h, the GSH-Px activity was lowest in black P. fucata, AKP activity was highest. The present study indicates that the physical responses of P. fucata to the salinity stress vary with shell colors. The red P. fucata can quickly respond positively to the change of environmental salinity and reduce the damage caused by the change of environmental salinity.

The quantitative assessment of the location and size of myocardial infarction has important implications for the diagnosis and treatment of ischemic cardiac diseases. In particular, the tasks of optical flow estimation are of increasing interest in the motion analysis in the field of computer vision. In this paper, we propose a deep learning constrained framework, integrating optical flow features for the classification and localization of myocardial infarction from medical image sequences. The framework is composed of two stages. In the first stage, a stacked denoising autoencoder allows for the extraction of the intensity and motion characteristics from images. Thereafter, a support vector machine model is employed to predict the anomaly scores of each input. Initial experiments are performed with two-dimensional cardiac MRI sequences.

The purpose of this study was to investigate the effects of microwave power and additives on the microwave-assisted pyrolysis of cotton stalk. Pyrolysis temperature profiles, product yields, and bio-oil components were analyzed. The results indicated that as the microwave power increased, so did the final temperature and heating rate. When microwave power increased from 800 to 1200 W, the yield of the solid residue decreased and gas yield increased, but the maximum bio-oil yield of 26.7% was achieved under a microwave power of 1000 W. All three of the additives (NaOH, Na2CO3, and H3PO4) increased the yields of solid residue and gas, while the yield of the bio-oil decreased. Gas chromatography-mass spectrometry (GC-MS) analysis indicated that the main components of bio-oil from microwave-assisted pyrolysis of pure sample were acetol, furfural, 2-methoxy-phenol, and 4-methyl-2-methoxy-phenol. Sodium hydroxide and sodium carbonate (NaOH and Na2CO3) greatly favor the formation of acetol. Phosphoric acid (H3PO4) remarkably promoted the formation of furfural and 4-methyl-2-methoxy-phenol, while H3PO4 inhibited the formation of acetol.

There are multiporosity media in tight oil reservoirs after stimulated reservoir volume (SRV) fracturing. Moreover, multiscale flowing states exist throughout the development process. The fluid flowing characteristic is different from that of conventional reservoirs. In terms of those attributes of tight oil reservoirs, considering the flowing feature of the dual-porosity property and the fracture network system based on the discrete-fracture model (DFM), a mathematical flow model of an SRV-fractured horizontal well with multiporosity and multipermeability media was established. The numerical solution was solved by the finite element method and verified by a comparison with the analytical solution and field data. The differences of flow regimes between triple-porosity, dual-permeability (TPDP) and triple-porosity, triple-permeability (TPTP) models were identified. Moreover, the productivity contribution degree of multimedium was analyzed. The results showed that for the multiporosity flowing states, the well bottomhole pressure drop became slower, the linear flow no longer arose, and the pressure wave arrived quickly at the closed reservoir boundary. The contribution ratio of the matrix system, natural fracture system, and network fracture system during SRV-fractured horizontal well production were 7.85%, 43.67%, and 48.48%, respectively in the first year, 14.60%, 49.23%, and 36.17%, respectively in the fifth year, and 20.49%, 46.79%, and 32.72%, respectively in the 10th year. This study provides a theoretical contribution to a better understanding of multiscale flow mechanisms in unconventional reservoirs.

In this paper, the nuclear magnetic resonance (NMR) technique is applied to exploring the spontaneous imbibition mechanism in tight sandstones under all face open (AFO) boundary conditions, which will benefit a better understanding of spontaneous imbibition during the development of oil & gas in tight formations. The advantages of nuclear magnetic resonance imaging (NMRI) and NMR T2 are used to define the distribution of remaining oil, evaluate the effect of micro structures on imbibition and predict imbibition recovery. NMR T2 results show that pore size distributions around two peaks are not only the main oil distributions under saturated condition but also fall within the main imbibition distributions range. Spontaneous imbibition mainly occurs in the first 6 h and then slows down and even ceases. The oil signals in tiny pores stabilize during the early stage of imbibition while the oil signal in large pores keeps fluctuating during the late stage of imbibition. NMRI results demonstrate that spontaneous imbibition is a replacement process starting slowly from the boundaries to the center under AFO and ending with oil-water mixing. Furthermore, the wetting phase can invade the whole core in the first 6 h, which is identical with the main period of imbibition occurring according to NMR T2 results. Factors influencing the history of oil distribution and saturation differ at different periods, while it is dominated by capillary imbibition at the early stage and allocated by diffusion at later time. Two imbibition recovery curves calculated by NMRI and NMR T2 are basically consistent, while there still exists some deviations between them as a result of the resolutions of NMRI and NMR T2. In addition, the heterogeneity of pore size distributions in the two samples aggravates this discrepancy. The work in this paper should prove of great help to better understand the process of the spontaneous imbibition, not only at the macroscopic level but also at the microscopic level, which is significant for oil/gas recovery in tight formations.

Due to micro-nanopores in tight formation, fluid-solid interaction effects on fluid flow in porous media cannot be ignored. In this paper, a novel model which can characterize micro-fluid flow in micro scales is proposed. This novel model has a more definite physical meaning compared with other empirical models. And it is validated by micro tube experiments. In addition, the application range of the model is rigorously analyzed from a mathematical view, which indicates a wider application scope. Based on the novel model, the velocity profile, the average flow velocity and flow resistance in consideration of fluid-solid interaction are obtained. Furthermore, the novel model is incorporated into a representative pore scale network model to study fluid-solid interactions on fluid flow in porous media. Results show that due to fluid-solid interaction in micro scales, the change rules of the velocity profile, the average flow velocity and flow resistance generate obvious deviations from traditional Hagen-Poiseuille’s law. The smaller the radius and the lower the displacement pressure gradient (∇P), the more obvious the deviations will be. Moreover, the apparent permeability in consideration of fluid-solid interaction is no longer a constant, it increases with the increase of ∇P and non-linear flow appears at low ∇P. This study lays a good foundation for studying fluid flow in tight formation.