Model for end-stage liver disease-dependent prognostic capacity of platelet-to-lymphocyte ratio following liver transplantation for hepatocellular carcinoma.

BACKGROUND: To improve liver organ allocation, the model for end-stage liver disease (MELD) score was adopted in candidates reflecting the severity of liver disease and the physical condition of patients. Inflammatory markers are prognostic factors for various cancers and play prognostic roles in patients after liver transplantation (LT) for hepatocellular carcinoma (HCC). Researchers focused more on pre-LT inflammatory markers, while the role of dynamic change of these inflammatory markers is still unknown. The purpose of this study was to estimate the prognostic value of pre-LT and post-LT inflammatory markers. MATERIAL AND METHODS: We collected the pre-LT complete blood count and the post-LT result with highest count of white blood cells within 48 h. Platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio, monocyte-to-lymphocyte ratio and systemic immune-inflammation index were calculated, and their prognostic roles were analyzed for their MELD scores. RESULTS: This retrospective two-center cohort study enrolled 290 patients after LT for HCC. Multivariate analysis identified pre-LT PLR as independent risk factor for recurrence-free survival (RFS) [HR (95%CI): 1.002 (1.000-1.003), p = 0.023]. A high pre-LT PLR or post-LT PLR were associated with poorer RFS (p < 0.001 and p = 0.004, respectively). Based on the MELD scores, the pre-LT PLR value was able to predict the RFS in high MELD group (p < 0.001) but had no predictive power in low MELD group (p = 0.076). On the contrary, the post-LT PLR value was better to predict the overall RFS value in low MELD group (p = 0.007) but could not predict the overall RFS value in high MELD group (p = 0.136). CONCLUSIONS: Both pre-LT PLR and post-LT PLR demonstrated prognostic value in patients following LT for HCC. Monitoring PLR values based on the MELD score can improve the predictive prognosis and more effectively guide the individual decisions for the postoperative intervention.

Circadian rhythm response and its effect on photosynthetic characteristics of the Lhcb family genes in tea plant.

BACKGROUND: The circadian clock, also known as the circadian rhythm, is responsible for predicting daily and seasonal changes in the environment, and adjusting various physiological and developmental processes to the appropriate times during plant growth and development. The circadian clock controls the expression of the Lhcb gene, which encodes the chlorophyll a/b binding protein. However, the roles of the Lhcb gene in tea plant remain unclear. RESULTS: In this study, a total of 16 CsLhcb genes were identified based on the tea plant genome, which were distributed on 8 chromosomes of the tea plant. The promoter regions of CsLhcb genes have a variety of cis-acting elements including hormonal, abiotic stress responses and light response elements. The CsLhcb family genes are involved in the light response process in tea plant. The photosynthetic parameter of tea leaves showed rhythmic changes during the two photoperiod periods (48 h). Stomata are basically open during the day and closed at night. Real-time quantitative PCR results showed that most of the CsLhcb family genes were highly expressed during the day, but were less expressed at night. CONCLUSIONS: Results indicated that CsLhcb genes were involved in the circadian clock process of tea plant, it also provided potential references for further understanding of the function of CsLhcb gene family in tea plant.

The adverse impact of perioperative body composition abnormalities on outcomes after split liver transplantation: a multi-center retrospective cohort study.

BACKGROUND: Split liver transplantation increases graft availability, but its safe and effective utilization is insufficiently documented. This study aimed to investigate the association between perioperative body composition abnormalities and outcomes in adult split liver transplantation. MATERIALS AND METHODS: 240 recipients who underwent split liver transplantation in three centers were enrolled in this retrospective cohort study. Body composition abnormalities including sarcopenia, myosteatosis, visceral obesity, and sarcopenic obesity were evaluated at baseline and one month after surgery using computed tomography. Their impact on outcomes including early allograft dysfunction, early complications, intensive care unit stay, graft regeneration rate and survival was analyzed. RESULTS: Recipients with sarcopenia or myosteatosis had a higher risk of early allograft dysfunction, higher early complication rate, and longer length of intensive care unit stay (all P<0.05), while there was no difference in graft regeneration rate. Recipient and graft survival were significantly worse for recipients with body composition abnormalities (all P<0.05). In multivariable Cox-regression analysis, sarcopenia (hazard ratio=1.765, P=0.015), myosteatosis (hazard ratio=2.066, P=0.002), and visceral obesity (hazard ratio=1.863, P=0.008) were independently associated with shorter overall survival. Piling up of the three factors increased the mortality risk stepwise (P<0.001). Recipients experienced skeletal muscle loss and muscle fat infiltration one month after surgery. Postoperative worsening sarcopenia (hazard ratio=2.359, P=0.009) and myosteatosis (hazard ratio=1.878, P=0.026) were also identified as independent risk factors for mortality. CONCLUSION: Sarcopenia, myosteatosis and their progression negatively affect outcomes including early allograft dysfunction, early complications, intensive care unit stay and survival after SLT. Systemic evaluation and dynamic monitoring of body composition are valuable.

Post-transplant hepatitis B virus reactivation impacts the prognosis of patients with hepatitis B-related hepatocellular carcinoma: a dual-centre retrospective cohort study in China.

BACKGROUND: Highly active hepatitis B virus (HBV) is known to be associated with poor outcomes in patients with hepatocellular carcinoma (HCC). This study aims to investigate the relationship between HBV status and HCC recurrence after liver transplantation. METHODS: The study retrospectively analyzed HCC patients undergoing liver transplantation in two centres between January 2015 and December 2020. The authors reviewed post-transplant HBV status and its association with outcomes. RESULTS: The prognosis of recipients with hepatitis B surface antigen (HBsAg) reappearance ( n =58) was poorer than those with HBsAg persistent negative ( n =351) and positive ( n =53). In HBsAg persistent positive group, recipients with HBV DNA reappearance or greater than 10-fold increase above baseline had worse outcomes than those without ( P <0.01). HBV reactivation was defined as (a) HBsAg reappearance or (b) HBV DNA reappearance or greater than 10-fold increase above baseline. After propensity score matching, the 5-year overall survival rate and recurrence-free survival rate after liver transplantation in recipients with HBV reactivation were significantly lower than those without (32.0% vs. 62.3%; P <0.01, and 16.4% vs. 63.1%; P <0.01, respectively). Moreover, HBV reactivation was significantly related to post-transplant HCC recurrence, especially lung metastasis. Cox regression analysis revealed that beyond Milan criteria, microvascular invasion and HBsAg-positive graft were independent risk factors for post-transplant HBV reactivation, and a novel nomogram was established accordingly with a good predictive efficacy (area under the time-dependent receiver operating characteristic curve=0.78, C-index =0.73). CONCLUSIONS: Recipients with HBV reactivation had worse outcomes and higher tumour recurrence rates than those without. The nomogram could be used to evaluate the risk of post-transplant HBV reactivation effectively.

CsPAT1, a GRAS transcription factor, promotes lignin accumulation by antagonistic interacting with CsWRKY13 in tea plants.

Lignin is an important component of plant cell walls and plays crucial roles in the essential agronomic traits of tea quality and tenderness. However, the molecular mechanisms underlying the regulation of lignin biosynthesis in tea plants remain unclear. CsWRKY13 acts as a negative regulator of lignin biosynthesis in tea plants. In this study, we identified a GRAS transcription factor, phytochrome A signal transduction 1 (CsPAT1), that interacts with CsWRKY13. Silencing CsPAT1 expression in tea plants and heterologous overexpression in Arabidopsis demonstrated that CsPAT1 positively regulates lignin accumulation. Further investigation revealed that CsWRKY13 directly binds to the promoters of CsPAL and CsC4H and suppresses transcription of CsPAL and CsC4H. CsPAT1 indirectly affects the promoter activities of CsPAL and CsC4H by interacting with CsWRKY13, thereby facilitating lignin biosynthesis in tea plants. Compared with the expression of CsWRKY13 alone, the co-expression of CsPAT1 and CsWRKY13 in Oryza sativa significantly increased lignin biosynthesis. Conversely, compared with the expression of CsPAT1 alone, the co-expression of CsPAT1 and CsWRKY13 in O. sativa significantly reduced lignin accumulation. These results demonstrated the antagonistic regulation of the lignin biosynthesis pathway by CsPAT1 and CsWRKY13. These findings improve our understanding of lignin biosynthesis mechanisms in tea plants and provide insights into the role of the GRAS transcription factor family in lignin accumulation.

FGF21-mediated autophagy: Remodeling the homeostasis in response to stress in liver diseases.

Liver diseases are worldwide problems closely associated with various stresses, such as endoplasmic reticulum stress. The exact interplay between stress and liver diseases remains unclear. Autophagy plays an essential role in maintaining homeostasis, and recent studies indicate tight crosstalk between stress and autophagy in liver diseases. Once the balance between damage and autophagy is broken, autophagy can no longer resist injury or maintain homeostasis. In recent years, FGF21 (fibroblast growth factor 21)-induced autophagy has attracted much attention. FGF21 is regarded as a stress hormone and can be up-regulated by an abundance of signaling pathways in response to stress. Also, increased FGF21 activates autophagy by a complicated signaling network in which mTOR plays a pivotal role. This review summarizes the mechanism of FGF21-mediated autophagy and its derived application in the defense of stress in liver diseases and offers a glimpse into its promising prospect in future clinical practice.

Differential Response of MYB Transcription Factor Gene Transcripts to Circadian Rhythm in Tea Plants (Camellia sinensis).

The circadian clock refers to the formation of a certain rule in the long-term evolution of an organism, which is an invisible 'clock' in the body of an organism. As one of the largest TF families in higher plants, the MYB transcription factor is involved in plant growth and development. MYB is also inextricably correlated with the circadian rhythm. In this study, the transcriptome data of the tea plant 'Baiyeyihao' were measured at a photoperiod interval of 4 h (24 h). A total of 25,306 unigenes were obtained, including 14,615 unigenes that were annotated across 20 functional categories within the GO classification. Additionally, 10,443 single-gene clusters were annotated to 11 sublevels of metabolic pathways using KEGG. Based on the results of gene annotation and differential gene transcript analysis, 22 genes encoding MYB transcription factors were identified. The G10 group in the phylogenetic tree had 13 members, of which 5 were related to the circadian rhythm, accounting for 39%. The G1, G2, G8, G9, G15, G16, G18, G19, G20, G21 and G23 groups had no members associated with the circadian rhythm. Among the 22 differentially expressed MYB transcription factors, 3 members of LHY, RVE1 and RVE8 were core circadian rhythm genes belonging to the G10, G12 and G10 groups, respectively. Real-time fluorescence quantitative PCR was used to detect and validate the expression of the gene transcripts encoding MYB transcription factors associated with the circadian rhythm.

Overexpressing CsPSY1 Gene of Tea Plant, Encoding a Phytoene Synthase, Improves α-Carotene and ß-Carotene Contents in Carrot.

Tea plants (Camellia sinensis (L.) O. Kuntze) belong to Theaceae family, in the section Thea. Tea plants are widely distributed in subtropical and tropical regions in the word. α-carotene and ß-carotene in the tea leaves belong to carotenoids, which are associated with the aroma and color of the tea. Phytoene synthase (PSY) is a rate-limiting enzyme in carotenoids biosynthesis. We identified three CsPSY genes in 'Shuchazao', named CsPSY1, CsPSY2, and CsPSY3. Structural analysis of three CsPSY genes showed that CsPSY1 had a longer intro structure. The cis-acting elements of CsPSYs promoter were mainly associated with light-responsiveness, abiotic stress-responsiveness, and hormone-responsiveness. CsPSY1 exhibited expression in all tissues of the tea plants, whereas CsPSY2 and CsPSY3 were trace expression levels in all tissues. The positive expression of CsPSY1 under hormonal and abiotic stresses suggested its role in plant development and defense responses. The amino acid sequence of CsPSY1 was highly conserved in eight tea cultivars. The recombinant vector pCAMBIA1301-CsPSY1 was constructed to stabilize the overexpression of CsPSY1 in carrot. The contents of α-carotene and ß-carotene in transgenic carrot callus were significantly increased. This study provides a foundational basis for further research on the function of CsPSYs and carotenoids accumulation in tea plants.

Double-negative T cells: a promising avenue of adoptive cell therapy in transplant oncology. / 双阴性Tç»†èƒžï¼šç§»æ¤è‚¿ç˜¤å­¦ä¸­ä¸€ç§é¢‡å ·å‰æ™¯çš„è¿‡ç»§ç»†èƒžç–—æ³•.

Tumor recurrence is one of the major life-threatening complications after liver transplantation for liver cancer. In addition to the common mechanisms underlying tumor recurrence, another unavoidable problem is that the immunosuppressive therapeutic regimen after transplantation could promote tumor recurrence and metastasis. Transplant oncology is an emerging field that addresses oncological challenges in transplantation. In this context, a comprehensive therapeutic management approach is required to balance the anti-tumor treatment and immunosuppressive status of recipients. Double-negative T cells (DNTs) are a cluster of heterogeneous cells mainly consisting of two subsets stratified by T cell receptor (TCR) type. Among them, TCRαß+ DNTs are considered to induce immune suppression in immune-mediated diseases, while TCRγδ+ DNTs are widely recognized as tumor killers. As a composite cell therapy, healthy donor-derived DNTs can be propagated to therapeutic numbers in vitro and applied for the treatment of several malignancies without impairing normal tissues or being rejected by the host. In this work, we summarized the biological characteristics and functions of DNTs in oncology, immunology, and transplantation. Based on the multiple roles of DNTs, we propose that a new balance could be achieved in liver transplant oncology using them as an off-the-shelf adoptive cell therapy (ACT).

Molecular markers in tea plant (Camellia sinensis): Applications to evolution, genetic identification, and molecular breeding.

Tea plants have a long cultivation history in the world, and the beverage (tea) made from its leaves is well known in the world. Due to the characteristics of self-incompatibility, long-term natural and artificial hybridization, tea plants have a very complex genetic background, which make the classification of tea plants unclear. Molecular marker, one type of genetic markers, has the advantages of stable inheritance, large amount of information, and high reliability. The development of molecular marker has facilitated the understanding of complex tea germplasm resources. So far, molecular markers had played important roles in the study of the origin and evolution, the preservation and identification of tea germplasms, and the excellent cultivars breeding of tea plants. However, the information is scattered, making it difficult to understand the advance of molecular markers in tea plants. In this paper, we summarized the development process and types of molecular markers in tea plants. In addition, the application advance of these molecular markers in tea plants was reviewed. Perspectives of molecular markers in tea plants were also systematically provided and discussed. The elaboration of molecular markers in this paper should help us to renew understanding of its application in tea plants.

TNFR2 is a potent prognostic biomarker for post-transplant lung metastasis in patients with hepatocellular carcinoma.

Objective: Lung metastasis is a common and fatal complication of liver transplantation for hepatocellular carcinoma (HCC). The precise prediction of post-transplant lung metastasis in the early phase is of great value. Methods: The mRNA profiles of primary and paired lung metastatic lesions were analyzed to determine key signaling pathways. We enrolled 241 HCC patients who underwent liver transplantation from three centers. Tissue microarrays were used to evaluate the prognostic capacity of tumor necrosis factor (TNF), tumor necrosis factor receptor 1 (TNFR1), and TNFR2, particularly for post-transplant lung metastasis. Results: Comparison of primary and lung metastatic lesions revealed that the TNF-dependent signaling pathway was related to lung metastasis of HCC. The expression of TNF was degraded in comparison to that in para-tumor tissues (P<0.001). The expression of key receptors in the TNF-dependent signaling pathway, TNFR1 and TNFR2, was higher in HCC tissues than in para-tumor tissues (P<0.001). TNF and TNFR1 showed no relationship with patients' outcomes, whereas elevated TNFR2 in tumor tissue was significantly associated with worse overall survival (OS) and increased recurrence risk (5-year OS rate: 31.9% vs. 62.5%, P<0.001). Notably, elevated TNFR2 levels were also associated with an increased risk of post-transplant lung metastasis (hazard ratio: 1.146; P<0.001). Cox regression analysis revealed that TNFR2, Hangzhou criteria, age, and hepatitis B surface antigen were independent risk factors for post-transplant lung metastasis, and a novel nomogram was established accordingly. The nomogram achieved excellent prognostic efficiency (area under time-dependent receiver operating characteristic =0.755, concordance-index =0.779) and was superior to conventional models, such as the Milan criteria. Conclusions: TNFR2 is a potent prognostic biomarker for predicting post-transplant lung metastasis in patients with HCC. A nomogram incorporating TNFR2 deserves to be a helpful prognostic tool in liver transplantation for HCC.

Con-AAE: contrastive cycle adversarial autoencoders for single-cell multi-omics alignment and integration.

MOTIVATION: We have entered the multi-omics era and can measure cells from different aspects. Hence, we can get a more comprehensive view by integrating or matching data from different spaces corresponding to the same object. However, it is particularly challenging in the single-cell multi-omics scenario because such data are very sparse with extremely high dimensions. Though some techniques can be used to measure scATAC-seq and scRNA-seq simultaneously, the data are usually highly noisy due to the limitations of the experimental environment. RESULTS: To promote single-cell multi-omics research, we overcome the above challenges, proposing a novel framework, contrastive cycle adversarial autoencoders, which can align and integrate single-cell RNA-seq data and single-cell ATAC-seq data. Con-AAE can efficiently map the above data with high sparsity and noise from different spaces to a coordinated subspace, where alignment and integration tasks can be easier. We demonstrate its advantages on several datasets. AVAILABILITY AND IMPLEMENTATION: Zenodo link: https://zenodo.org/badge/latestdoi/368779433. github: https://github.com/kakarotcq/Con-AAE.

Metabolomic biomarkers for the diagnosis and post-transplant outcomes of AFP negative hepatocellular carcinoma.

Background: Early diagnosis for α-fetoprotein (AFP) negative hepatocellular carcinoma (HCC) remains a critical problem. Metabolomics is prevalently involved in the identification of novel biomarkers. This study aims to identify new and effective markers for AFP negative HCC. Methods: In total, 147 patients undergoing liver transplantation were enrolled from our hospital, including liver cirrhosis patients (LC, n=25), AFP negative HCC patients (NEG, n=44) and HCC patients with AFP over 20 ng/mL (POS, n=78). 52 Healthy volunteers (HC) were also recruited in this study. Metabolomic profiling was performed on the plasma of those patients and healthy volunteers to select candidate metabolomic biomarkers. A novel diagnostic model for AFP negative HCC was established based on Random forest analysis, and prognostic biomarkers were also identified. Results: 15 differential metabolites were identified being able to distinguish NEG group from both LC and HC group. Random forest analysis and subsequent Logistic regression analysis showed that PC(16:0/16:0), PC(18:2/18:2) and SM(d18:1/18:1) are independent risk factor for AFP negative HCC. A three-marker model of Metabolites-Score was established for the diagnosis of AFP negative HCC patients with an area under the time-dependent receiver operating characteristic curve (AUROC) of 0.913, and a nomogram was then established as well. When the cut-off value of the score was set at 1.2895, the sensitivity and specificity for the model were 0.727 and 0.92, respectively. This model was also applicable to distinguish HCC from cirrhosis. Notably, the Metabolites-Score was not correlated to tumor or body nutrition parameters, but difference of the score was statistically significant between different neutrophil-lymphocyte ratio (NLR) groups (≤5 vs. >5, P=0.012). Moreover, MG(18:2/0:0/0:0) was the only prognostic biomarker among 15 metabolites, which is significantly associated with tumor-free survival of AFP negative HCC patients (HR=1.160, 95%CI 1.012-1.330, P=0.033). Conclusion: The established three-marker model and nomogram based on metabolomic profiling can be potential non-invasive tool for the diagnosis of AFP negative HCC. The level of MG(18:2/0:0/0:0) exhibits good prognosis prediction performance for AFP negative HCC.

Exogenous methyl jasmonate and cytokinin antagonistically regulate lignin biosynthesis by mediating CsHCT expression in Camellia sinensis.

Tea plant, an important beverage crop, is cultivated worldwide. Lignification can improve the hardness of tea plant, which is of great significance for tea quality. Jasmonates (JAs) and cytokinin are plant hormones that control processes of plant development and secondary metabolite accumulation. Hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HCT) is primarily involved in lignin biosynthesis. The effects of exogenous application of JAs and cytokinin on lignin biosynthesis and related HCT gene expression profiles in tea plants are still unclear. In order to investigate the effects of exogenous JAs and cytokinin on lignin accumulation, anatomical structures, and CsHCT gene profiles in tea plants, we treated tea plants with methyl jasmonate (MeJA) and cytokinin (6-BA). MeJA and 6-BA treatments triggered the lignification at 6 and 12 d in tea leaves. The combined treatment resulted in an increase in lignin content at 6 d, which was 1.32 times of that at 0 d for 'Mengshan 9.' The CsHCTs in clade 2 (CsHCT5, CsHCT6, CsHCT7, and CsHCT8) were mainly expressed in leaves. We found that exogenous MeJA and cytokinin might be able to antagonistically regulate tea plant lignin accumulation through the mediation of CsHCT expression. This study revealed that HCTs play potential important roles involved in lignin biosynthesis of tea plant development and hormonal stimuli.

Establishment and evaluation of a prediction model for acute gastrointestinal injury in patients with prolonged disorder of consciousness.

OBJECTIVE: To establish a prediction model for acute gastrointestinal injury (AGI) in patients with prolonged disorder of consciousness (pDOC) and to evaluate and apply the prediction model.  METHODS: The clinical data of 165 patients with pDOC admitted to the hyperbaric oxygen department from January 2021 to December 2021 were retrospectively reviewed, and the patients were divided into an AGI group (n = 91) and an N-AGI group (n = 74) according to whether AGI occurred. A prediction model was built by fitting multiple independent influencing factors through logistic regression. The receiver operating characteristic (ROC) curve was used to evaluate the predictive value of the model, the Hosmer-Lemeshow (H-L) test was used to evaluate the goodness-of-fit of the model, and the ROC curve and calibration curve were drawn to evaluate the predictive performance. A nomogram was plotted to visualize the prediction model. RESULTS: According to the multivariate logistic regression analysis results, the prediction model was finally constructed with the CRS-R score, DAO, PCT, ALB, and I-FABP, and a nomogram was generated. The area under the ROC curve (AUC) of the prediction model was 0.931, the sensitivity was 83.5%, and the specificity was 93.2%. The data were divided into 5 groups for the H-L test (χ2 = 2.54, P = 0.468 > 0.05) and into 10 groups for the H-L test (χ2 = 9.98, P = 0.267 > 0.05). A calibration curve was drawn based on the test results, indicating that the prediction model has a good goodness-of-fit and good prediction stability. CONCLUSION: The prediction model for AGI in pDOC patients constructed in this study can be used in clinical practice and is helpful to predict the occurrence of AGI in pDOC patients.

Self-supervised contrastive learning for integrative single cell RNA-seq data analysis.

We present a novel self-supervised Contrastive LEArning framework for single-cell ribonucleic acid (RNA)-sequencing (CLEAR) data representation and the downstream analysis. Compared with current methods, CLEAR overcomes the heterogeneity of the experimental data with a specifically designed representation learning task and thus can handle batch effects and dropout events simultaneously. It achieves superior performance on a broad range of fundamental tasks, including clustering, visualization, dropout correction, batch effect removal, and pseudo-time inference. The proposed method successfully identifies and illustrates inflammatory-related mechanisms in a COVID-19 disease study with 43 695 single cells from peripheral blood mononuclear cells.

One Shoot, Two Birds: Alleviating Inflammation Caused by Ischemia/Reperfusion Injury to Reduce the Recurrence of Hepatocellular Carcinoma.

Inflammation is crucial to tumorigenesis and the development of metastasis. Hepatic ischemia/reperfusion injury (IRI) is an unresolved problem in liver resection and transplantation which often establishes and remodels the inflammatory microenvironment in liver. More and more experimental and clinical evidence unmasks the role of hepatic IRI and associated inflammation in promoting the recurrence of hepatocellular carcinoma (HCC). Meanwhile, approaches aimed at alleviating hepatic IRI, such as machine perfusion, regulating the gut-liver axis, and targeting key inflammatory components, have been proved to prevent HCC recurrence. This review article highlights the underlying mechanisms and promising therapeutic strategies to reduce tumor recurrence through alleviating inflammation induced by hepatic IRI.

A New Index of Energy Dissipation Considering Time Factor under the Impact Loads.

Rock failure phenomena are accompanied by abundant energy variation, and the energy dissipation can explain the dynamic mechanical characteristics of the rock. In this study, a series of granite specimens (a total of 60) with different aspect ratios were dynamically loaded by a split Hopkinson pressure bar (SHPB) to explain the energy dissipation and the rock-crushing degree under dynamic load. A new index, namely energy time density (wtd), is proposed to evaluate the energy dissipation considering the time factor. The relationships between strain rate, energy time density, and specific energy absorption are analyzed. A metric (Ku) is defined to describe the degree of rock fragmentation quantitatively. The correlations of fractal dimension and Ku with different impact pressures are compared. It was concluded that there is a noticeable peak point in the energy time density curve. The energy time density of the stress equilibrium point is three times that of the peak point. The energy time density declines after the peak point, then the energy consumption density tends to be stable. The linear relationship between strain rate and peak point energy time density is stronger. The new index can describe energy dissipation well under dynamic loading. In addition, the experimental results indicate that the degree of crush Ku can describe the degree of crush, and the effect of fractal dimension to quantify the fracture characteristics of the rocks is less good in this test. The crushing degree of rocks increases with the increase of strain rate. Furthermore, the prediction effect of energy time density is better than that of strain rate about Ku.

Comparative analysis morphology, anatomical structure and transcriptional regulatory network of chlorophyll biosynthesis in Oryza longistaminata, O. sativa and their F1 generation.

Oryza longistaminata, a perennial wild species, is widely distributed in the African continent. It has strong tolerance to biotic and abiotic stresses, and high biomass production on poor soils. Chlorophyll biosynthesis is important for photosynthesis in rice. However, the chlorophyll biosynthesis and related gene profiles of O. longistaminata and its descendants remained unclear. Here, the F1 generation of O. sativa and O. longistaminata were obtained. Then, the comparative analysis morphology, anatomical structure, and transcriptional regulatory networks of chlorophyll biosynthesis were detected and analyzed. Results showed that the F1 generation has obvious long awn, similar with that of the male parent. The purple color of the long awn is different from that of the male parent. Microstructural results showed that the flag leaves of F1 have large mesophyll cell gaps in the upper- and lower-positions, small mesophyll cell gaps in the middle position, and more chloroplasts. Increased chlorophyll content was also observed in the F1 generation. In the lower-position flag leaves, the total chlorophyll contents of F1 were 1.55 and 1.5 times those of O. sativa and O. longistaminata, respectively. POR, MgCH and HEMA1 showed higher expression levels than the other related genes selected in the chlorophyll biosynthesis pathway. The HEMA1 expression level in the middle-position flag leaves of O. longistaminata was the highest, and it was 2.83 and 2.51 times that of O. sativa and F1, respectively. The expression level of DVR gene in lower-position flag leaves of F1 were 93.16% and 95.06% lower than those of O. sativa and O. longistaminata, respectively. This study provided a potential reference for studying the photosynthesis and heterosis utilization of O. longistaminata.

Attenuation of the Na/K­ATPase/Src/ROS amplification signaling pathway by astaxanthin ameliorates myocardial cell oxidative stress injury.

The 3S, 3'S­ASTaxanthin (3S, 3'S­AST) isomer has strong antioxidant activity; however, its protective roles and potential mechanisms against oxidative stress damage in cardiomyocytes have not been investigated. Na+/K+­ATPase (NKA)/Src signal activation has an important role in increasing reactive oxygen species (ROS) production. The aim of the present study was to investigate the protective effects and mechanism of 3S, 3'S­AST on hydrogen peroxide (H2O2)­induced oxidative stress injury in H9c2 myocardial cells. The protective effects of 3S, 3'S­AST on H2O2­induced H9c2 cell injury was observed by measuring lactate dehydrogenase and creatine kinase myocardial band content, cell viability and nuclear morphology. The antioxidant effect was investigated by analyzing ROS accumulation and malondialdehyde, glutathione (GSH) peroxidase, GSH and glutathione reductase activity levels. The protein expression levels of Bax, Bcl­2, caspase­3 and cleaved caspase­3 were analyzed using western blotting to determine cardiomyocyte apoptosis. Western blot analysis of the phosphorylation levels of Src and Erk1/2 were also performed to elucidate the molecular mechanism involved. The results showed that 3S, 3'S­AST reduced the release of LDH and promoted cell viability, and attenuated ROS accumulation and cell apoptosis induced by H2O2. Furthermore, 3S, 3'S­AST also restored apoptosis­related Bax and Bcl­2 protein expression levels in H2O2­treated H9c2 cells. The phosphorylation levels of Src and Erk1/2 were significantly higher in the H2O2 treatment group, whereas 3S, 3'S­AST pretreatment significantly decreased the levels of phosphorylated (p)­Src and p­ERK1/2. The results provided evidence that 3S, 3'S­AST exhibited a cardioprotective effect against oxidative stress injury by attenuating NKA/Src/Erk1/2­modulated ROS amplification.