A locally active discrete memristor model and its application in a hyperchaotic map

© 2022 Springer Nature Switzerland AG. Part of Springer Nature. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1007/s11071-021-07132-5The continuous memristor is a popular topic of research in recent years, however, there is rare discussion about the discrete memristor model, especially the locally active discrete memristor model. This paper proposes a locally active discrete memristor model for the first time and proves the three fingerprints characteristics of this model according to the definition of generalized memristor. A novel hyperchaotic map is constructed by coupling the discrete memristor with a two-dimensional generalized square map. The dynamical behaviors are analyzed with attractor phase diagram, bifurcation diagram, Lyapunov exponent spectrum, and dynamic behavior distribution diagram. Numerical simulation analysis shows that there is significant improvement in the hyperchaotic area, the quasi-periodic area and the chaotic complexity of the two-dimensional map when applying the locally active discrete memristor. In addition, antimonotonicity and transient chaos behaviors of system are reported. In particular, the coexisting attractors can be observed in this discrete memristive system, resulting from the different initial values of the memristor. Results of theoretical analysis are well verified with hardware experimental measurements. This paper lays a great foundation for future analysis and engineering application of the discrete memristor and relevant the study of other hyperchaotic maps.Peer reviewedFinal Accepted Versio

Determinants of Nam8-dependent splicing of meiotic pre-mRNAs

Nam8, a component of yeast U1 snRNP, is optional for mitotic growth but required during meiosis, because Nam8 collaborates with Mer1 to promote splicing of essential meiotic mRNAs AMA1, MER2 and MER3. Here, we identify SPO22 and PCH2 as novel targets of Nam8-dependent meiotic splicing. Whereas SPO22 splicing is co-dependent on Mer1, PCH2 is not. The SPO22 intron has a non-consensus 5′ splice site (5′SS) that dictates its Nam8/Mer1-dependence. SPO22 splicing relies on Mer1 recognition, via its KH domain, of an intronic enhancer 5′-AYACCCUY. Mutagenesis of KH and the enhancer highlights Arg214 and Gln243 and the CCC triplet as essential for Mer1 activity. The Nam8-dependent PCH2 pre-mRNA has a consensus 5′SS and lacks a Mer1 enhancer. For PCH2, a long 5′ exon and a non-consensus intron branchpoint dictate Nam8-dependence. Our results implicate Nam8 in two distinct meiotic splicing regulons. Nam8 is composed of three RRM domains, flanked by N-terminal leader and C-terminal tail segments. The leader, tail and RRM1 are dispensable for splicing meiotic targets and unnecessary for vegetative Nam8 function in multiple synthetic lethal genetic backgrounds. Nam8 activity is enfeebled by alanine mutations in the putative RNA binding sites of the RRM2 and RRM3 domains

Vaccination against coronavirus disease 2019 in patients with pulmonary hypertension: a national prospective cohort study

Background: Coronavirus disease 2019 (COVID-19) has potential risks for both clinically worsening pulmonary hypertension (PH) and increasing mortality. However, the data regarding the protective role of vaccination in this population are still lacking. This study aimed to assess the safety of approved vaccination for patients with PH. Methods: In this national prospective cohort study, patients diagnosed with PH (World Health Organization [WHO] groups 1 and 4) were enrolled from October 2021 to April 2022. The primary outcome was the composite of PH-related major adverse events. We used an inverse probability weighting (IPW) approach to control for possible confounding factors in the baseline characteristics of patients. Results: In total, 706 patients with PH participated in this study (mean age, 40.3 years; mean duration after diagnosis of PH, 8.2 years). All patients received standardized treatment for PH in accordance with guidelines for the diagnosis and treatment of PH in China. Among them, 278 patients did not receive vaccination, whereas 428 patients completed the vaccination series. None of the participants were infected with COVID-19 during our study period. Overall, 398 patients received inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine, whereas 30 received recombinant protein subunit vaccine. After adjusting for baseline covariates using the IPW approach, the odds of any adverse events due to PH in the vaccinated group did not statistically significantly increase (27/428 [6.3%] vs. 24/278 [8.6%], odds ratio = 0.72, P = 0.302). Approximately half of the vaccinated patients reported at least one post-vaccination side effects, most of which were mild, including pain at the injection site (159/428, 37.1%), fever (11/428, 2.6%), and fatigue (26/428, 6.1%). Conclusions: COVID-19 vaccination did not significantly augment the PH-related major adverse events for patients with WHO groups 1 and 4 PH, although there were some tolerable side effects. A large-scale randomized controlled trial is warranted to confirm this finding. The final approval of the COVID-19 vaccination for patients with PH as a public health strategy is promising

An Overview of Recent Development in Composite Catalysts from Porous Materials for Various Reactions and Processes

Catalysts are important to the chemical industry and environmental remediation due to their effective conversion of one chemical into another. Among them, composite catalysts have attracted continuous attention during the past decades. Nowadays, composite catalysts are being used more and more to meet the practical catalytic performance requirements in the chemical industry of high activity, high selectivity and good stability. In this paper, we reviewed our recent work on development of composite catalysts, mainly focusing on the composite catalysts obtained from porous materials such as zeolites, mesoporous materials, carbon nanotubes (CNT), etc. Six types of porous composite catalysts are discussed, including amorphous oxide modified zeolite composite catalysts, zeolite composites prepared by co-crystallization or overgrowth, hierarchical porous catalysts, host-guest porous composites, inorganic and organic mesoporous composite catalysts, and polymer/CNT composite catalysts

The prognostic factors and nomogram for patients with high-grade gliomas

The evaluation on prognosis of glioma patients is critical for the individualized treatment. Despite of the widely used mRNA expression level and methylation status of prognostic genes in predicting the patients’ prognosis, the clinical application of high-throughput sequencing technology is still limited. Thus, this study aimed to construct a visual and reliable nomogram based on the common clinicopathological parameters for predicting the prognosis of patients diagnosed with high grade glioma (HGG). Notably, age, histopathology, IDH status, 1p/19q status, radiotherapy status, chemotherapy status, and tumor recurrence were identified as seven independent prognostic factors for HGG patients. A comprehensive nomogram based on the seven identified factors was subsequently constructed with the remarkable C-index of 0.732. Calibrations for nomogram showed great consistency between the predictive values and the actual values in 1-, 3-, and 5-year survival rates. Besides, the areas under the ROC curve (AUC) for predicting 1-, 3-, and 5-year survival rates of patients had the values of 0.796 (95% CI: 0.759-0.833), 0.809 (95% CI: 0.770-0.848), and 0.820 (95% CI: 0.771-0.869), respectively. Furthermore, an external cohort (n=89) was used to validate the nomogram. In conclusion, age, histopathology, IDH status, 1p/19q status, radiotherapy status, chemotherapy status, and tumor progression were identified as independent prognostic factors, on which a visual predictive model was constructed with powerful predictive value