DEVELOPMENTAL AND TRANSCRIPTOMIC STUDY OF THE ZEBRAFISH SWIMBLADDER

Ph.DDOCTOR OF PHILOSOPH

Saliency-Aware Spatio-Temporal Artifact Detection for Compressed Video Quality Assessment

Compressed videos often exhibit visually annoying artifacts, known as Perceivable Encoding Artifacts (PEAs), which dramatically degrade video visual quality. Subjective and objective measures capable of identifying and quantifying various types of PEAs are critical in improving visual quality. In this paper, we investigate the influence of four spatial PEAs (i.e. blurring, blocking, bleeding, and ringing) and two temporal PEAs (i.e. flickering and floating) on video quality. For spatial artifacts, we propose a visual saliency model with a low computational cost and higher consistency with human visual perception. In terms of temporal artifacts, self-attention based TimeSFormer is improved to detect temporal artifacts. Based on the six types of PEAs, a quality metric called Saliency-Aware Spatio-Temporal Artifacts Measurement (SSTAM) is proposed. Experimental results demonstrate that the proposed method outperforms state-of-the-art metrics. We believe that SSTAM will be beneficial for optimizing video coding techniques

Isolation, Purification and Crystallization of Restriction Enzyme Bsa I and Its Preparation of Seleno-derived Derivatives

Objective: To screen and optimize the method for preparing three-dimensional structural samples of restriction endonuclease Bsa I. Methods: In this study, the Escherichia coli expression system was employed to express the Bsa I protein and its selenomethionine derivative. Firstly, a recombinant expression vector pBAD-Bsa I was constructed and transformed into Escherichia coli (E.coli) ER2566 for expression. Purification was carried out using affinity chromatography and anion exchange chromatography. Subsequently, selenomethionine derivation situation was assessed using mass spectrometry and circular dichroism spectroscopy, followed by enzyme activity determination. Lastly, preliminary crystal growth studies were conducted using the sitting-drop method. Results: Through a two-step purification approach, recombinant Bsa I and Se-Bsa I selenomethionine derivative with a purity exceeding 90% were obtained. Mass spectrometry analysis revealed that all 11 methionine residues in the recombinant Se-Bsa I protein were selenomethionine-incorporated. Circular dichroism spectroscopy and enzyme activity testing confirmed that the selenomethionine incorporation had no significant impact on the structure and activity of Bsa I protein. Crystallization experiments demonstrated that the recombinant Bsa I protein could not only form granular crystals under conditions of 0.2 mol/L magnesium acetate tetrahydrate at pH6.5, 0.1 mol/L sodium cacodylate trihydrate with 20% polyethylene glycol 8000, but also form spherical structures under conditions of 0.1 mol/L sodium acetate trihydrate at pH4.6 and 2 mol/L ammonium sulfate. Conclusion: This study successfully achieved the recombinant expression of Bsa I and Se-Bsa I selenomethionine derivative, conducted preliminary screening of protein crystal conditions, aiming to provide valuable insights for deciphering the three-dimensional structure of Bsa I protein

Maternal cobalt concentration and risk of spontaneous preterm birth: the role of fasting blood glucose and lipid profiles

IntroductionSpontaneous preterm birth (SPB) is a significant cause of neonatal mortality, yet its etiology remains unclear. Cobalt, an essential trace element, might be a risk factor for SPB. This study aims to investigate the relationship between maternal serum cobalt concentration and SPB, and to clarify the role of blood lipids and fasting blood glucose (FBG) in this relationship.MethodsWe conducted a nested case-control study within the Beijing Birth Cohort Study. Serum samples were obtained from 222 pregnant women with SPB and 224 controls during the first (7–13 weeks of pregnancy) and third trimesters (32–42 weeks of pregnancy). Serum cobalt concentration was determined using inductively coupled plasma mass spectrometry (ICP-MS). Fasting blood glucose and lipids levels were detected using a fully automated biochemical immunoassay instrument. Logistic regression models and linear regression models were established to explore the association between serum cobalt concentration and the risk of SPB in pregnant women, and to test the mediating effect of fasting blood glucose (FBG) and lipids.ResultsWe found that the serum cobalt concentration in mothers with SPB and controls was similar in the first trimester, with values of 0.79 (0.58–1.10) ng/mL and 0.75 (0.51–1.07) ng/mL, respectively. However, in the third trimester, the cobalt concentration increased to 0.88 (0.59–1.14) ng/mL and 0.84 (0.52–1.19) ng/mL, respectively. In the logistic regression model, when considering the third trimester of pregnancy, after adjusting for ethnicity, pre-pregnancy body mass index (BMI), maternal age, education, income, and parity, it was observed that the medium level of cobalt concentration (0.63–1.07 ng/ml) had a negative correlation with the risk of SPB. The odds ratio (OR) was 0.56, with a 95% confidence interval of 0.34–0.90 ng/mL and a p-value of 0.02. This suggests that cobalt in this concentration range played a protective role against SPB. Additionally, it was found that FBG in the third trimester of pregnancy had a partial intermediary role, accounting for 9.12% of the association. However, no relationship between cobalt and SPB risk was found in the first trimester.ConclusionDuring the third trimester, intermediate levels of maternal cobalt appear to offer protection against SPB, with FBG playing a partial mediating role. To further clarify the optimal cobalt concentrations during pregnancy for different populations, a multi-center study with a larger sample size is necessary. Additionally, exploring the specific mechanism of FBG’s mediating role could provide valuable insights for improving the prevention of SPB

Seasonal variations in carbon, nitrogen and phosphorus concentrations and C:N:P stoichiometry in different organs of a Larix principis-rupprechtii Mayr. plantation in the Qinling Mountains, China

Understanding how concentrations of elements and their stoichiometry change with plant growth and age is critical for predicting plant community responses to environmental change. Weusedlong-term field experiments to explore how the leaf, stem and root carbon (C), nitrogen (N) and phosphorous (P) concentrations and their stoichiometry changed with growth and stand age in a L.principis-rupprechtii Mayr. plantation from 2012–2015 in the Qinling Mountains, China. Our results showed that the C, N and P concentrations and stoichiometric ratios in different tissues of larch stands were affected by stand age, organ type andsampling month and displayed multiple correlations with increased stand age in different growing seasons. Generally, leaf C and N concentrations were greatest in the fast-growing season, but leaf P concentrations were greatest in the early growing season. However, no clear seasonal tendencies in the stem and root C, N and P concentrations were observed with growth. In contrast to N and P, few differences were found in organ-specific C concentrations. Leaf N:P was greatest in the fast-growing season, while C:N and C:P were greatest in the late-growing season. No clear variations were observed in stem and root C:N, C:P andN:Pthroughout the entire growing season, but leaf N:P was less than 14, suggesting that the growth of larch stands was limited by N in our study region. Compared to global plant element concentrations and stoichiometry, the leaves of larch stands had higher C, P, C:NandC:PbutlowerNandN:P,andtherootshadgreater PandC:NbutlowerN,C:Pand N:P. Our study provides baseline information for describing the changes in nutritional elements with plant growth, which will facilitates plantation forest management and restoration, and makes avaluable contribution to the global data pool on leaf nutrition and stoichiometry

Transcriptomic Analyses of Sexual Dimorphism of the Zebrafish Liver and the Effect of Sex Hormones

10.1371/journal.pone.0053562PLoS ONE81

Comparative transcriptome analyses indicate molecular homology of zebrafish swimbladder and mammalian lung

10.1371/journal.pone.0024019PLoS ONE68

Mechanics of shaft-loaded blister test for thin film suspended on compliant substrate

AbstractBased on the von Kármán plate theory, the mechanics of a shaft-loaded blister test for thin film/substrate systems is studied by considering elastic substrate deformations and residual stresses in these films. In testing, films are attached to a substrate provided with a circular hole, through which loading is applied to the film by a flat-ended shaft of circular cross-section. The effect of substrate deformation on the deflection of the loaded film is taken into account by using a line spring model. For small deflections, an analytical solution is derived, while for large deflections a numerical solution is obtained using the shooting method. The resulting load-shaft displacement relation, which is essential in blister tests, compares favorably with finite element analysis