Information theory-based algorithm for in silico prediction of PCR products with whole genomic sequences as templates

BACKGROUND: A new algorithm for assessing similarity between primer and template has been developed based on the hypothesis that annealing of primer to template is an information transfer process. RESULTS: Primer sequence is converted to a vector of the full potential hydrogen numbers (3 for G or C, 2 for A or T), while template sequence is converted to a vector of the actual hydrogen bond numbers formed after primer annealing. The former is considered as source information and the latter destination information. An information coefficient is calculated as a measure for fidelity of this information transfer process and thus a measure of similarity between primer and potential annealing site on template. CONCLUSION: Successful prediction of PCR products from whole genomic sequences with a computer program based on the algorithm demonstrated the potential of this new algorithm in areas like in silico PCR and gene finding

Study of unripe and inferior banana flours pre-gelatinized by four different physical methods

This study aimed to prepare the pre-gelatinized banana flours and compare the effects of four physical treatment methods (autoclaving, microwave, ultrasound, and heat-moisture) on the digestive and structural characteristics of unripe and inferior banana flours. After the four physical treatments, the resistant starch (RS) content values of unripe and inferior banana flours were decreased from 96.85% (RS2) to 28.99–48.37% (RS2 + RS3), while C∞ and k values were increased from 5.90% and 0.039 min−1 to 56.22–74.58% and 0.040–0.059 min−1, respectively. The gelatinization enthalpy (ΔHg) and I1047/1022 ratio (short-range ordered crystalline structures) were decreased from 15.19 J/g and 1.0139 to 12.01–13.72 J/g, 0.9275–0.9811, respectively. The relative crystallinity decreased from 36.25% to 21.69–26.30%, and the XRD patterns of ultrasound (UT) and heat-moisture (HMT) treatment flours maintained the C-type, but those samples pre-gelatinized by autoclave (AT) and microwave (MT) treatment were changed to C + V-type, and heat-moisture (HMT) treatment was changed to A-type. The surface of pre-gelatinized samples was rough, and MT and HMT showed large amorphous holes. The above changes in structure further confirmed the results of digestibility. According to the experimental results, UT was more suitable for processing unripe and inferior banana flours as UT had a higher RS content and thermal gelatinization temperatures, a lower degree and rate of hydrolysis, and a more crystalline structure. The study can provide a theoretical basis for developing and utilizing unripe and inferior banana flours

Exploring the influence of teachers’ motivating styles on college students’ agentic engagement in online learning: The mediating and suppressing effects of self-regulated learning ability

Abstract Online learning has gradually become the new mainstream learning norm during the post-epidemic era. To ensure college students’ online learning effectiveness, they need to be proactively engaged in their online learning, which means that they need to maintain a high level of agentic engagement. However, it is not clear what factors influence college students’ agentic engagement in online learning environments. According to self-determination theory (SDT), the teacher, as an important external factor, can influence students’ learning engagement and learning effectiveness. Meanwhile, self-regulated learning (SRL) ability is important for college students in online learning. Based on existing theoretical foundations, therefore, the current study attempts to explore the following research questions: Are there relationships between teachers’ motivating styles (including autonomy-supportive style and controlling style), college students’ online SRL ability, and college students’ online learning agentic engagement? If yes, how does the former influence college students’ online learning agentic engagement? To respond to these research questions, random sampling was used to collect a total of 681 valid data from college students with experience in online learning. Then, a pilot test, exploratory factor analysis, and confirmatory factor analysis were first conducted to confirm the reliability and validity of the data. Correlational and mediating analyses were then conducted using SPSS 21.0. According to the results, firstly, teachers’ motivating styles (autonomy-supportive style and controlling style) and college students’ online SRL ability were positively correlated with college students’ online agentic engagement. Secondly, teachers’ autonomy-supportive style was positively correlated with college students’ online SRL ability, but the controlling style was negatively correlated with their online SRL ability. What’s more, college students’ online SRL ability, as a mediating factor, acted as a partial mediation between autonomy-supportive style and college students’ online agentic engagement, and there was a suppressing effect of college students’ SRL ability between teachers’ controlling style and college students’ agentic engagement. The results imply that teachers should choose motivating styles appropriately based on students’ online learning characteristics and content, and college students should develop online SRL ability to improve their agentic engagement and ultimately achieve good online learning effectiveness

Application of excavation compensation method for constructing shallowly-buried super-large span subway tunnel

Stress loss at the excavation face, stemming from underground chamber excavation, is the primary culprit behind geotechnical accidents. Implementing timely stress compensation is vital to control potential instability or failure in the surrounding rock effectively. Shallow-buried, large-span subway tunnels, characterized by complex geological conditions, significant construction challenges, and extensive engineering risks, often exceed traditional methods' capacities, resulting in excessive deformation of initial support or localized stress surpassing the overload limit during construction. This study delves into the excavation unloading effect, namely radial stress loss and tangential structural damage, offering a comprehensive understanding of rock excavation's mechanical behavior. It introduces an excavation compensation method, formulated from a mechanical perspective, specifically tailored for controlling shallow-buried, large-span tunnels. An excavation equivalent stress compensation experiment was designed, validating the substantial influence of compensation stress in controlling rock cracking, mitigating tensile stress areas in the arch, augmenting peak bearing capacity, and enhancing plastic deformation capacity. The final part of the study conducts a comparative analysis of the tensile mechanical properties and shear resistance of Negative Poisson's Ratio (NPR) anchor steel. The results reveal that NPR anchor bolt exhibits high strength, constant resistance, and substantial elongation. When compared with ordinary anchor bolt, its tensile strength and elongation surpass the latter by more than double, and its shear energy absorption is 4.37 times that of traditional Poisson's Ratio (PR) material anchors. NPR bolt demonstrates uniform deformation during tension and shearing processes, without significant necking, and prestressing can be applied to 70%− 90% of the yield strength, thus providing a material foundation for radial stress compensation and tangential structural compensation. This technology has been successfully applied to shallow-buried, large-span subway tunnels, effectively controlling the deformation and settlement of large-span tunnels and thereby demonstrating the applicability of the proposed excavation compensation methods and techniques

Application of high-spatial-resolution secondary ion mass spectrometry for nanoscale chemical mapping of lithium in an Al-Li alloy

High-spatial-resolution secondary ion mass spectrometry offers a method for mapping lithium at nanoscale lateral resolution. Practical implementation of this technique offers significant potential for revealing the distribution of Li in many materials with exceptional lateral resolution and elemental sensitivity. Here, two state-of-the-art methods are demonstrated on an aluminium-lithium alloy to visualise nanoscale Li-rich phases by mapping the 7Li+ secondary ion. NanoSIMS 50L analysis with a radio frequency O- plasma ion source enabled visualisation of needle-shaped T1 (Al2CuLi) phases as small as 75 nm in width. A compact time-of-flight secondary ion mass spectrometry detector added to a focused ion beam scanning electron microscope facilitated mapping of the T1 phases down to 45 nm in width using a Ga+ ion beam. Correlation with high resolution electron microscopy confirms the identification of T1 precipitates, their sizes and distribution observed during SIMS mapping

Self-propulsion of Janus particles in the free molecular regime

The self-propulsion of a Janus particle suspended in a dilute gas at equilibrium is investigated in the free molecular regime. The Janus particle consists of two hemispheres with different momentum accommodation factors; the particle and the surrounding gas are held at different constant temperatures. Based on the gas kinetic theory, we calculate the particle's self-propulsion and drag force. We conclude that self-propulsion occurs only under the condition that the particle is hotter/colder than the suspension gas, and the self-propulsion force is proportional to the difference of the momentum accommodation factors and directed along the symmetry axis. The drag force, instead, is corrected by a term proportional to the average of the momentum accommodation factors. Our analytical results are confirmed by numerical Monte Carlo simulations

Modulatory Effect of Polysaccharide from Artocarpus heterophyllus Lam. (Jackfruit) Pulp on Gut Microbiota in Mice

The present study aimed to investigate the modulatory effect of polysaccharide from Artocarpus heterophyllus Lam. pulp (JFP-Ps) on the diversity and structure of gut microbiota in mice. 24 male Kunming mice were randomly divided into four groups: Control group, JFP-Ps (50 mg/kg BW) group, JFP-Ps (100 mg/kg BW) group and JFP-Ps (200 mg/kg BW) group. The colonic feces of mice were collected after treating with JFP-Ps in different doses for 2 weeks. Then the DNA was extracted and the V3~V4 region of the 16S rRNA gene of the intestinal flora was amplified. The regulatory effect of JFP-Ps on the gut microbiota of mice was studied using Illumina Miseq high-throughput sequencing technology. The results showed that Bacteroidetes and Firmicutes were the dominant intestinal flora, and JFP-Ps modulated the composition of Bacteroidetes and Firmicutes in comparison with the control group. At the genus level, the abundance of SCFAs-producing bacteria, including Bacteroides, Allobaculum, Lactobacillus and Parabacteroides were significantly increased in response to JFP-Ps treatment, but a significant decrease in Prevotella. These results indicated that JFP-Ps could improve the diversity of gut microbiota by regulating the composition and structure of dominant bacteria such as Bacteroidetes and Firmicutes. This study would provide a theoretical basis for JFP-Ps in intestinal prebiotics

Bioactivity and influence on colonic microbiota of polyphenols from noni (Morinda citrifolia L.) fruit under simulated gastrointestinal digestion

Noni (Morinda citrifolia L.) is a tropical fruit rich in bioactive compounds. Little is known about its polyphenol composition at different ripeness levels and digestive characteristics. Here, we studied changes in polyphenols and antioxidant activity as noni ripened. Rutin and kaempferol-3-O-rutinoside were found in high amounts in noni, with antioxidant capacity increasing as it ripened. Under simulated digestion, polyphenols were gradually released from the oral to gastrointestinal phases, partially decomposing in the small intestine due to their instability. Conversely, fiber-bound phenols were released during colonic fermentation, leading to high bioaccessible antioxidant activity. Additionally, noni consumption affected the intestinal microbiome by reducing the Firmicutes/Bacteroidetes ratio and increasing bacteria with prebiotic properties like Prevotella and Ruminococcus. These findings demonstrate that polyphenols significantly contribute to the health benefits of noni fruit by providing absorbable antioxidants and improving the structure of the intestinal microbiome

Tunable chiral-selective electromagnetically induced transparency-like effect in VO

A chiral metamaterial based on vanadium dioxide (VO2) is proposed to realize the ultrafast active control of an electromagnetically induced transparency-like (EIT-like) effect. The design of the tunable metamaterial is based on the heat-induced insulator-to-metal transition of VO2 and a tunable transmission peak with circular polarization selectivity is achieved. For the right circular polarization (RCP) laser incidence, the sharp EIT-like peak is generated and rises with the increasing signal powers, which has not happened in the left circular polarization (LCP) incident condition. The spin-dependent phenomenon in time domain is also observed and the slow light effect in the metamaterial yields a tunable time delay up to 4 ns. Therefore, the tunable EIT-like effect with chiral selectivity is presented and highlights its practical applications in programmable metamaterial regions and slow light devices, etc

High-Throughput Color Imaging Hg2+ Sensing via Amalgamation-Mediated Shape Transition of Concave Cube Au Nanoparticles

Mercury, as one type of toxic heavy metal, represents a great threat to environmental and biological metabolic systems. Thus, reliable and sensitive quantitative detection of mercury levels is particularly meaningful for environmental protection and human health. We proposed a high-throughput single-particle color imaging strategy under dark-field microscopy (DFM) for mercury ions (Hg2+) detection by using individual concave cube Au nanoparticles as optical probes. In the presence of ascorbic acid (AA), Hg2+ was reduced to Hg which forms Au–Hg amalgamate with Au nanoparticles, altering their localized surface plasmon resonance (LSPR). Transmission electron microscopy (TEM) images demonstrated that the concave cube Au nanoparticles were approaching to sphere upon increasing the concentration of Hg2+. The nanoparticles underwent an obvious color change from red to yellow, green, and finally blue under DFM due to the shape-evolution and LSPR changes. In addition, we demonstrated for the first time that the LSPR of Au–Hg amalgamated below 400 nm. Inspired by the above-mentioned results, single-particle color variations were digitalized by converting the color image into RGB channels to obtain (green+blue)/red intensity ratios [(G+B)/R]. The concentration-dependence change was quantified by statistically analyzing the (G+B)/R ratios of a large number of particles. A linear range from 10 to 2000 nM (R2 = 0.972) and a limit of detection (LOD) of 1.857 nM were acquired. Furthermore, many other metal ions, like Cu2+, Cr3+, etc., did not interfere with Hg2+ detection. More importantly, Hg2+ content in industrial wastewater samples and in the inner regions of human HepG2 cells was determined, showing great potential for developing a single-particle color imaging sensor in complex biological samples using concave cube Au nanoparticles as optical probes