Controllable electromechanical stability of a torsional micromirror actuator with piezoelectric composite structure under capillary force

Various types of micro/nano functional devices are being widely designed as optical switches, micro scanners, micromirrors and other core optical devices. The continuing miniaturization of the functional devices makes the size dependence of electromechanical property significant in micro/nano scale due to the sharp increase of surface interactions such as capillary force from liquid bridge, van der Waals and Casimir forces from quantum fluctuations. The surface interactions can cause the pull-in instability, adhesion between parts, and even failure of device. This work provides an active control method to avoid the pull-in instability of an electrostatically driven circular micromirror by applying voltage on a torsional piezoelectric composite structure. The influences of the three types are compared of dispersion forces on the electromechanical stability of the micromirror actuator. A comprehensive electromechanical model of a torsional piezoelectric beam was established to numerically investigate the electromechanical coupling of the micromirror. The results show that the influence of capillary force on the stability of the micromirror is as significant as van der Waals force and Casimir force. By introducing piezoelectric nanoplates into the laminated torsional structure, the micromirror stability can be controlled based on the piezoelectric effect of the torsional piezoelectric composite structure. This work can contribute to the structural optimization design and manufacture of micromirror systems.Cited as: Liu, M., Chen, Y., Cheng, W., Chen, S., Yu, T., Yang, W. Controllable electromechanical stability of a torsional micromirror actuator with piezoelectric composite structure under capillary force. Capillarity, 2022, 5(3): 51-64. https://doi.org/10.46690/capi.2022.03.0

Pyrimidine catabolism is required to prevent the accumulation of 5-methyluridine in RNA

5-Methylated cytosine is a frequent modification in eukaryotic RNA and DNA influencing mRNA stability and gene expression. Here we show that free 5-methylcytidine (5mC) and 5-methyl-2′-deoxycytidine are generated from nucleic acid turnover in Arabidopsis thaliana, and elucidate how these cytidines are degraded, which is unclear in eukaryotes. First CYTIDINE DEAMINASE produces 5-methyluridine (5mU) and thymidine which are subsequently hydrolyzed by NUCLEOSIDE HYDROLASE 1 (NSH1) to thymine and ribose or deoxyribose. Interestingly, far more thymine is generated from RNA than from DNA turnover, and most 5mU is directly released from RNA without a 5mC intermediate, since 5-methylated uridine (m5U) is an abundant RNA modification (m5U/U ∼1%) in Arabidopsis. We show that m5U is introduced mainly by tRNA-SPECIFIC METHYLTRANSFERASE 2A and 2B. Genetic disruption of 5mU degradation in the NSH1 mutant causes m5U to occur in mRNA and results in reduced seedling growth, which is aggravated by external 5mU supplementation, also leading to more m5U in all RNA species. Given the similarities between pyrimidine catabolism in plants, mammals and other eukaryotes, we hypothesize that the removal of 5mU is an important function of pyrimidine degradation in many organisms, which in plants serves to protect RNA from stochastic m5U modification

The relationship between psychological resilience and depression among the diabetes patients under the background of “dynamic zero COVID-19”: the mediating role of stigma and the moderating role of medication burden

ObjectiveDepression in diabetes patients is caused by their own disease or the surrounding social environment. How to cope with changes in mentality and adjust psychological stress responses, especially under China’s dynamic zero COVID-19 policy, is worth further discussion. The researchers constructed a moderated mediation model to test the effect of psychological resilience during dynamic zero COVID-19 on depression in diabetes patients and the mediating role of stigma and the moderating effect of medication burden.MethodFrom June to September, 2022, data were collected in Jinghu District, Wuhu City, Anhui Province, by multi-stage stratified sampling. Firstly, we selected a tertiary hospital randomly in Jinghu District. Secondly, departments are randomly chosen from the hospital. Finally, we set up survey points in each department and randomly select diabetes patients. In addition, we used the Connor-Davidson Elasticity Scale (CD-RISC) to measure psychological resilience of patients, and used the Stigma Scale for Chronic Illness (SSCI) to measure stigma, medication burden was measured by the Diabetes Treatment Burden Scale (DTBQ), and depression was assessed by the Patient Health Questionnaire-9 (PHQ-9). We used SPSS (version 23.0) and PROCESS (version 4.1) for data analysis.Results(1) Psychological resilience was negatively correlated with stigma, medication burden, and depression. Stigma was positively associated with medication burden and depression. Medication burden and depression are positively correlated, (2) The mediation analysis showed that psychological resilience had a direct predictive effect on depression, and stigma partially mediated the relationship, and (3) Medication burden moderates the direct pathway by which psychological resilience predicts depression; Medication burden moderates the first half of “psychological resilience → stigma → depression.”ConclusionUnder the mediating effect of stigma, psychological resilience can improve depression. Medication burden has a moderating effect on the relationship between psychological resilience and depression, and it also has a moderating effect on the relationship between psychological resilience and stigma. These results facilitate the understanding of the relationship mechanisms between psychological resilience and depression

Revisiting the application of molecular probe diagnostics on quantifying aqueous OH radicals in plasma–liquid systems

AbstractWe revisit one of the most used techniques for quantifying the aqueous OH radicals (OHaq) in plasma–liquid systems, the molecular probe method which obtains the [OHaq] by measuring a stable material formed through a rapid reaction between the molecular probe and the OHaq. In this study, we used disodium terephthalate (NaTA) as the molecular probe; the experimental results with a theoretical analysis suggest that to obtain the correct OHaq concentration, the concentration of the molecular probe should be greater than a certain value, which depends on the types of the plasma–liquid systems. However, this is not the case in most of the existing reports in which the NaTA is often much less than the requisite value.</jats:p

The Relationship between Gene Polymorphism of miRNAs Regulating FGA and Schizophrenia

AIM: To investigate the relationship between the polymorphism of related gene loci of miRNAs regulated fibrinopeptide A and schizophrenia. Lay the foundation for the aetiology of schizophrenia. METHODS: Adapt to the phase match of sex and age case-control study, a total of 513 Chinese Han patients with schizophrenia were selected as the case group, 513 normal healthy persons as a control group. Obtaining SNPs information of the FGA gene by querying the dbSNP database, and reference HapMap database included SNPs site frequency information for screening. The frequency distributions of SNPs were genotyped by iMLDR® SNP detection technology. Two SNPs (pre-hsa-miR-605rs2043556 T&gt;C, pre-hsa-miR-499a/pre-hsa-miR-499brs4909237 T &lt; C) were analyzed to demonstrate their association with susceptibility to schizophrenia. RESULTS: There were no significant differences between patients and controls in genotype and allele distribution of SNPs（rs2043556 and rs4909237）in the precursor region of hsa-miR-605 and pre-hsa-miR-499a/pre-hsa-miR-499b. Their gene-gene interaction, which suggests that the polymorphisms of miRNA genes might not contribute to schizophrenia susceptibility in the Han Chinese population. CONCLUSION: No significant difference existed between schizophrenic patients and controls in SNP (rs2043556 and rs4909237) in the precursor region of hsa-miR-605 and pre-hsa-miR-499a/pre-hsa-miR-499b. There may not regulate FGA gene expression. Thus, hsa-miR-605 and pre-hsa-miR-499a/pre-hsa-miR-499b may not influence the risks of schizophrenia

Purification and Characterization of a Novel Hypersensitive Response-Inducing Elicitor from Magnaporthe oryzae that Triggers Defense Response in Rice

<div><h3>Background</h3><p><em>Magnaporthe oryzae</em>, the rice blast fungus, might secrete certain proteins related to plant-fungal pathogen interactions.</p> <h3>Methodology/Principal Findings</h3><p>In this study, we report the purification, characterization, and gene cloning of a novel hypersensitive response-inducing protein elicitor (MoHrip1) secreted by <em>M. oryzae</em>. The protein fraction was purified and identified by de novo sequencing, and the sequence matched the genomic sequence of a putative protein from <em>M. oryzae</em> strain 70-15 (GenBank accession No. XP_366602.1). The elicitor-encoding gene <em>mohrip1</em> was isolated; it consisted of a 429 bp cDNA, which encodes a polypeptide of 142 amino acids with a molecular weight of 14.322 kDa and a pI of 4.53. The deduced protein, MoHrip1, was expressed in <em>E. coli</em>. And the expression protein collected from bacterium also forms necrotic lesions in tobacco. MoHrip1 could induce the early events of the defense response, including hydrogen peroxide production, callose deposition, and alkalization of the extracellular medium, in tobacco. Moreover, MoHrip1-treated rice seedlings possessed significantly enhanced systemic resistance to <em>M. oryzae</em> compared to the control seedlings. The real-time PCR results indicated that the expression of some pathogenesis-related genes and genes involved in signal transduction could also be induced by MoHrip1.</p> <h3>Conclusion/Significance</h3><p>The results demonstrate that MoHrip1 triggers defense responses in rice and could be used for controlling rice blast disease.</p> </div

Genomic analysis of NF-kappa B signaling pathway reveals its complexity in Crassostrea gigas

NF-kappa B signaling pathway is an evolutionarily conserved pathway that plays highly important roles in several developmental, cellular and immune response processes. With the recent release of the draft Pacific oyster (Crassostra gigas) genome sequence, we have sought to identify the various components of the NF-kappa B signaling pathway in these mollusks and investigate their gene structure. We further constructed phylogenetic trees to establish the evolutionary relationship of the oyster proteins with their homologues in vertebrates and invertebrates using BLASTX and neighbor-joining method. We report the presence of two classic NF-kappa B/Rel homologues in the pacific oyster namely Cgp100 and CgRel, which possess characteristic RHD domain and a consensus nuclear localization signal, similar to mammalian homologues and an additional CgRel-like protein, unique to C. gigas. Further, in addition to two classical I kappa B homologues, CgI kappa B1 and CgI kappa B2, we have identified three atypical I kappa B family members namely CgI kappa 133, CgI kappa B4 and CgBCL3 which lack the I kappa B degradation motif and consist of only one exon that might have arisen by retrotransposition from CgI kappa Bl. Finally, we report the presence of three IKKs and one NEMO genes in oyster genome, named CgIKK1, CgIKK2, CgIKK3 and CgNEMO, respectively. While CgIKK1 and CgIKK3 domain structure is similar to their mammalian homologues, CgIKK2 was found to lack the HLH and NBD domains. Overall, the high conservation of the NF-kappa B/Rel, I kappa B and IKK family components in the pacific oyster and their structural similarity to the vertebrate and invertebrate homologues underline the functional importance of this pathway in regulation of critical cellular processes across species