In this paper, we put forward a time-delay ecological competition system with food restriction and diffusion terms under Neumann boundary conditions. For the case without delay, the conditions for ...local asymptotic stability and Turing instability are constructed. For the case with delay, the existence of Hopf bifurcation is demonstrated by analyzing the root distribution of the corresponding characteristic equations. Furthermore, by using the normal form theory and the center manifold reduction of partial functional differential equations, explicit formulas are obtained to determine the direction of bifurcations and the stability of bifurcating periodic solutions. Finally, some simulation examples are provided to substantiate our analysis.
Aberrant expression and/or activity of members of the Src family of nonreceptor protein tyrosine kinases (SFK) are commonly observed in progressive stages of human tumors. In prostate cancer, two ...SFKs (Src and Lyn) have been specifically implicated in tumor growth and progression. However, there are no data in preclinical models demonstrating potential efficacy of Src inhibitors against prostate cancer growth and/or metastasis. In this study, we used the small molecule SFK/Abl kinase inhibitor dasatinib, currently in clinical trials for solid tumors, to examine in vitro and in vivo effects of inhibiting SFKs in prostate tumor cells. In vitro, dasatinib inhibits both Src and Lyn activity, resulting in decreased cellular proliferation, migration, and invasion. In orthotopic nude mouse models, dasatinib treatment effectively inhibits expression of activated SFKs, resulting in inhibition of both tumor growth and development of lymph node metastases in both androgen-sensitive and androgen-resistant tumors. In primary tumors, SFK inhibition leads to decreased cellular proliferation (determined by immunohistochemistry for proliferating cell nuclear antigen). In vitro, small interfering RNA (siRNA)-mediated inhibition of Lyn affects cellular proliferation; siRNA inhibition of Src affects primarily cellular migration. Therefore, we conclude that SFKs are promising therapeutic targets for treatment of human prostate cancer and that Src and Lyn activities affect different cellular functions required for prostate tumor growth and progression.
Notch signaling plays a critical role in regulating cell proliferation, differentiation, and apoptosis. Our previous study showed that overexpression of Notch1 could inhibit human hepatocellular ...carcinoma (HCC) cell growth by arresting the cell cycle and inducing apoptosis. HCC cells are resistant to apoptotic induction by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), so new therapeutic approaches have been explored to sensitize HCC cells to TRAIL-induced apoptosis. We are wondering whether and how Notch1 signaling can enhance the sensitivity of HCC cells to TRAIL-induced apoptosis. In this study, we found that overexpression of ICN, the constitutive activated form of Notch1, up-regulated p53 protein expression in HCC cells by inhibiting proteasome degradation. p53 up-regulation was further observed in human primary hepatocellular carcinoma cells after activation of Notch signaling. Inhibition of the Akt/Hdm2 pathway by Notch1 signaling was responsible for the suppression of p53 proteasomal degradation, thus contributing to the Notch1 signaling-mediated up-regulation of p53 expression. Accordingly, Notch1 signaling could make HCC cells more sensitive to TRAIL-induced apoptosis, whereas Notch1 signaling lost the synergistic promotion of TRAIL-induced apoptosis in p53-silenced HepG2 HCC cells and p53-defective Hep3B HCC cells. The data suggest that enhancement of TRAIL-induced apoptosis by Notch1 signaling is dependent upon p53 up-regulation. Furthermore, Notch1 signaling could enhance DR5 expression in a p53-dependent manner. Taken together, Notch1 signaling sensitizes TRAIL-induced apoptosis in HCC cells by inhibiting Akt/Hdm2-mediated p53 degradation and up-regulating p53-dependent DR5 expression. Thus, our results suggest that activation of Notch1 signaling may be a promising approach to improve the therapeutic efficacy of TRAIL-resistant HCC.
Anthocyanins are precious industrial raw materials. Purple corn is rich in anthocyanins, with large variation in their content between organs. It is imperative to find a rapid and non-destructive ...method to determine the anthocyanin content in purple corn. To this end, a field experiment with ten purple corn hybrids was conducted, collecting plant images using a digital camera and determining the anthocyanin content of different organ types. The average values of red (R), green (G) and blue (B) in the images were extracted. The color indices derived from RGB arithmetic operations were applied in establishing a model for estimation of the anthocyanin content. The results showed that the specific color index varied with the organ type in purple corn, i.e., ACCR for the grains, BRT for the cobs, ACCB for the husks, R for the stems, ACCB for the sheaths and BRT for the laminae, respectively. Linear models of the relationship between the color indices and anthocyanin content for different organs were established with R2 falling in the range of 0.64–0.94. The predictive accuracy of the linear models, assessed according to the NRMSE, was validated using a sample size of 2:1. The average NRMSE value was 11.68% in the grains, 13.66% in the cobs, 8.90% in the husks, 27.20% in the stems, 7.90% in the sheaths and 15.83% in the laminae, respectively, all less than 30%, indicating that the accuracy and stability of the model was trustworthy and reliable. In conclusion, this study provided a new method for rapid, non-destructive prediction of anthocyanin-rich organs in purple corn.
Soil erosion often leads to land degradation, agricultural production reduction, and environmental deterioration, which seriously restricts the sustainable development of regions. Clarifying the ...driving factors of soil erosion is the premise of preventing soil erosion. Given the lack of current research on the driving factors/force changes of soil erosion in different regions or under different erosion intensity grades, this paper pioneered to use machine learning methods to address this problem. Firstly, the widely used (Revised) Universal Soil Loss Equation ((R)USLE) framework was applied to simulate the spatial distribution of soil erosion. Then, the K-fold algorithm was used to evaluate the accuracy and stability of five machine learning algorithms for fitting soil erosion. The random forest (RF) method performed best, with average accuracy reaching 86.35%. Then, the Permutation Importance (PI) and the Partial Dependence Plot (PDP) methods based on RF were introduced to quantitatively analyze the main driving factors under different geological conditions and the driving force changes of each factor under different erosion intensity grades, respectively. Results showed that the main drivers of soil erosion in Chongqing and Guizhou were cover management factors (PI: 0.4672, 0.4788), while that in Sichuan was slope length and slope factor (PI: 0.6165). Under different erosion intensity grades, the driving force of each factor shows nonlinear and complex inhibitory or promoting effects with factor value changing. These findings can provide scientific guidance for the refined management of soil erosion, which is significant for halting or reversing land degradation and achieving sustainable use of land resources.
Liver diseases are a major health issue, and prolonged liver injury always progresses. Advanced liver disorders impair liver regeneration. Millions of patients die yearly worldwide, even with the ...available treatments of liver transplantation and artificial liver support system. With its abundant cell resources and significant differentiative potential, stem cell therapy is a viable treatment for various disorders and offers hope to patients waiting for orthotopic liver transplantation. Considering such plight, stem cell therapeutic strategies deliver hope to the patients. Moreover, we conclude intrinsic and acquired perspectives based on stem cell sources. The properties and therapeutic uses of these stem cells' specific types or sources were then reviewed. Owing to the recent investigations of the above cells, a safe and effective therapy will emerge for advanced liver diseases soon.
A wave of Omicron infections rapidly emerged in China in 2022, but large-scale data concerning the safety profile of vaccines and Coronavirus disease 2019 (COVID-19) infection features in liver ...transplant (LT) recipients have not been collected. Therefore, the aim of this study was to assess the protectiveness and safety profile of the inactivated vaccines in LT patients against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infections. A multi-centre retrospective study was conducted in a cohort with a history of liver transplantation. A total of 1881 participants (487 vaccinated and 1394 unvaccinated patients) were enrolled from seven centres in China. Fourteen of the participants were infected by Omicron, and 50% patients had over 14 days of viral shedding duration. The protection rate of COVID-19 vaccinations to Omicron was 2.59%. The three breakthrough infections occurred more than 6 months after fully vaccinated. A total of 96 (19.7%) vaccinated patients had adverse events, including fatigue, myalgia, liver dysfunction, swelling, and scleroma. There were more Grade 3 adverse events in the preoperative vaccination group than those in the postoperative vaccination group. Inactivated whole-virion SARS-CoV-2 vaccines are safe in patients with post-liver transplantation. The efficacy of inactivated vaccines decreases after 6 months of vaccination, it is recommended that liver transplant patients get boosted vaccinations as early as possible even when they are fully vaccinated. Although clinical manifestations of Omicron infections were mild in LT patients, unvaccinated patients might have a higher risk of liver dysfunction during infections.
Sex-specific differences are observed in various liver diseases, but the influence of sex on the outcomes of hepatocellular carcinoma (HCC) after liver transplantation (LT) remains to be determined. ...This study is the first Chinese nationwide investigation of the role of sex in post-LT outcomes in patients with HCC.
Data for recipients with HCC registered in the China Liver Transplant Registry between January 2015 and December 2020 were analyzed. The associations between donor, recipient, or donor-recipient transplant patterns by sex and the post-LT outcomes were studied with propensity score matching (PSM). The survival associated with different sex-based donor-recipient transplant patterns was further studied.
Among 3,769 patients enrolled in this study, the 1-, 3-, and 5-year overall survival (OS) rates of patients with HCC after LT were 96.1%, 86.4%, and 78.5%, respectively, in female recipients, and 95.8%, 79.0%, and 70.7%, respectively, in male recipients after PSM (
= 0.009). However, the OS was comparable between recipients with female donors and male donors. Multivariate analysis indicated that male recipient sex was a risk factor for post-LT survival (HR = 1.381,
= 0.046). Among the donor-recipient transplant patterns, the male-male donor-recipient transplant pattern was associated with the poorest post-LT survival (
< 0.05).
Our findings highlighted that the post-LT outcomes of female recipients were significantly superior to those of male recipients, and the male-male donor-recipient transplant pattern was associated with the poorest post-LT survival. Livers from male donors may provide the most benefit to female recipients. Our results indicate that sex should be considered as a critical factor in organ allocation.
This paper investigates robust and global exponential synchronizations in an array of nonidentical neural networks with leakage delays and impulsive coupling subject to parametric uncertainties. Some ...simpler sufficient conditions for synchronization are obtained when uncertainties vanish. A numerical example is given to illustrate the effectiveness of the theoretical results.
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