Global Existence and Blow-Up for a Chemotaxis System

In this paper we consider a Keller-Segel-type chemotaxis model with reaction term under no-flux boundary conditions, where the kinetics term of the system is power function. Assuming some growth conditions, the existence of bounded global strong solution to the parabolic-parabolic system is given. We also give the numerical test and find out that there exists a threshold. When the power frequency greater than the threshold, both global solution and blow-up solution exist

Modeling Rett Syndrome Using TALEN-Edited MECP2 Mutant Cynomolgus Monkeys

Gene-editing technologies have made it feasible to create nonhuman primate models for human genetic disorders. Here, we report detailed genotypes and phenotypes of TALEN-edited MECP2 mutant cynomolgus monkeys serving as a model for a neurodevelopmental disorder, Rett syndrome (RTT), which is caused by loss-of-function mutations in the human MECP2 gene. Male mutant monkeys were embryonic lethal, reiterating that RTT is a disease of females. Through a battery of behavioral analyses, including primate-unique eye-tracking tests, in combination with brain imaging via MRI, we found a series of physiological, behavioral, and structural abnormalities resembling clinical manifestations of RTT. Moreover, blood transcriptome profiling revealed that mutant monkeys resembled RTT patients in immune gene dysregulation. Taken together, the stark similarity in phenotype and/or endophenotype between monkeys and patients suggested that gene-edited RTT founder monkeys would be of value for disease mechanistic studies as well as development of potential therapeutic interventions for RTT

Bacterial diversity losses: A potential extracellular driving mechanism involving the molecular ecological function of hydrophobic polycyclic aromatic hydrocarbons

The DNA transformation is vital to the horizontal gene transfer (HGT). The low-efficiency transformation of bare plasmid exposed to hydrophobic polycyclic aromatic hydrocarbons (PAHs) decreases the gene transfer level, and is possibly related to the loss of bacterial diversity at present. PAHs have great affinity for bare DNA through dispersion force and π–π overlap between PAHs and bases. These noncovalent interactions between PAHs and bases reduced the transformational efficiency of plasmid into bacterial recipients. Meanwhile these low-efficiency transformations for plasmid are controlled by the ions like Ca2+ in environment, in turn, presence of 0.5 mmol L−1 Ca2+ recovered the efficiency from 3.2 (phenanthrene), 3.5 (pyrene) to about 4.45 and 4.75, respectively. The combination of Ca2+ with the POO− groups in DNA forms strong electrovalent bonds, weakening the molecular effect of DNA on PAHs and in turn promoting the gene transfer exposed to PAHs

Impact Responses and Parameters Sensitivity Analysis of Electric Wheelchairs

The shock and vibration of electric wheelchairs undergoing road irregularities is inevitable. The road excitation causes the uneven magnetic gap of the motor, and the harmful vibration decreases the recovery rate of rehabilitation patients. To effectively suppress the shock and vibration, this paper introduces the DA (dynamic absorber) to the electric wheelchair. Firstly, a vibration model of the human-wheelchair system with the DA was created. The models of the road excitation for wheelchairs going up a step and going down a step were proposed, respectively. To reasonably evaluate the impact level of the human-wheelchair system undergoing the step–road transition, evaluation indexes were given. Moreover, the created vibration model and the road–step model were validated via tests. Then, to reveal the vibration suppression performance of the DA, the impact responses and the amplitude frequency characteristics were numerically simulated and compared. Finally, a sensitivity analysis of the impact responses to the tire static radius r and the characteristic parameters was carried out. The results show that the DA can effectively suppress the shock and vibration of the human-wheelchair system. Moreover, for the electric wheelchair going up a step and going down a step, there are some differences in the vibration behaviors

Vibration Characteristics Analysis of Convalescent-Wheelchair Robots Equipped with Dynamic Absorbers

To provide a theoretical guidance for the vibration isolation design, the vibration responses characteristics for the convalescent-wheelchair robot with DA (dynamic absorber) undergoing the random road were revealed. Firstly, the vibration model of the convalescent-wheelchair system with DA was created. The frequency response functions of the road excitation velocity to the convalescent acceleration, the wheelchair body acceleration, and the tire dynamic deflection were deduced. Then, the numerical calculation method of the PSD (power spectral density) and the RMS (root mean square) responses were proposed. Thirdly, the vibration isolation performances of the wheelchair robot with DA and without DA were compared. Finally, the sensitivity analysis of the vibration responses to the mass ratios, the damping ratios, and the natural frequencies was carried out to reveal the effects of the parameters on the vibration responses. The results show that the DA can partly suppress the vibration of the convalescent and the wheelchair body, especially in the resonance area of the wheelchair body. However, the DA cannot successfully improve the tire contact behavior

Cost-effectiveness analysis of introducing rotavirus vaccine into immunization program in Zhejiang province, China: A decision tree-Markov model study

Two RV vaccines have been licensed in Zhejiang province, China, including the pentavalent RotaTeq (RV5) and the monovalent RV vaccine (RV1). This study aimed to evaluate the cost-effectiveness of RV1 and RV5 to inform the prioritization of provincial immunization program. A decision tree-Markov model was applied to assess the cost-effectiveness of RV1 or RV5 vaccination, compared to no RV vaccination in a 5-year period. The incremental health cost per disability-adjusted life year (DALY) is averted when each kind of RV vaccine included in the immunization program was estimated. It was also compared to the willingness-to-pay (WTP) threshold of 1 time of the Gross Domestic Product (GDP) per capita of Zhejiang province in 2021 (16865.70US$). The uncertainties of these results were assessed through the one-way sensitivity analysis and probabilistic sensitivity analysis. In the base-case scenario, RV5 was the least costly RV vaccine with a cost-effectiveness ratio of 510 US$ per DALY averted. The other RV1 vaccines provided equivalent benefits but at higher costs, with a cost-effectiveness ratio of 4600 US$ per DALY averted. Compared to no vaccination, the probabilities of being cost-effective were 72.3% for RV1 and 88.4% for RV5, at a WTP threshold of 1 time of the GDP per capita. An RV vaccination program using any of the two China-licensed RV vaccines compared to no vaccination would avert 30–70% of outpatient visits, hospitalizations, and deaths from RVGE. RV5 was currently estimated to be the most cost-effective

Benefits of prompting students to generate summaries during pauses in segmented multimedia lessons

Background: How to improve learning with online multimedia lessons has attracted widespread concern. Prior studies have attempted to help students learn by breaking a video lesson into several segments. However, there has been a debate about whether learners can use pause time effectively and whether prompting them to engage in different types of generative learning activities during pauses can better facilitate learning. Objectives: This study aimed to explore how to maximize learning by asking students to engage in generative processing activities during pauses in segmented narrated video lessons. Methods: Three experiments explored the effectiveness of segmenting, and whether adding summaries between segments can improve learning performance. In Experiment 1, participants were asked to view a segmented video or a continuous video. In Experiment 2, we examined whether adding summarizing activities during pauses can improve the effects of segmenting. In Experiment 3, we further investigated the effects of adding different types of summarizing activities during pauses. Results and Conclusions: In Experiment 1, segmenting improved performance on retention tests, but not on transfer tests. In Experiment 2, the effects of segmenting on the retention and transfer tests were enhanced when learners were asked to produce written summaries during the pauses. In Experiment 3, asking participants to imagine or write summaries during the pauses in segmented lessons improved retention and transfer test performance, but providing a summary only helped on retention. Takeaways: Adding generative learning activities (i.e., summarizing) during pauses prompted learners to learn the material more deeply. Results are consistent with the ICAP framework and the cognitive theory of multimedia learning

Mineralogical Characteristics of Baima Vanadium Titanomagnetite during Magnetic Separation Upgrading

The Baima vanadium titanomagnetite deposit, located in the Panzhihua-Xichang (Panxi) metallogenic belt in China, is one of the super-large deposits in the region. The titanomagnetite upgrading process involves grinding the raw ore followed by magnetic separation. To determine the processing characteristics of the ore and assess the upgrading process, this study employs various methods and techniques, including the X-ray fluorescence spectrometer (XRF), chemical element analysis, the electron probe microanalyzer (EPMA), and the advanced mineral identification and characterization system (AMICS). The results show that the Fe grades in the upgraded raw ore, upgraded concentrate, and upgraded tailings are 55.68%, 57.89%, and 15.62%, respectively. After upgrading, the titanomagnetite content increased from 77.41% to 82.10%, and the Fe distribution in titanomagnetite also increased from 91.05% to 93.14%. In the upgraded raw ore, titanomagnetite particles followed a normal distribution, with 50.44% in the 38–74 μm range. In the upgraded concentrate, titanomagnetite was concentrated in the 19–38 μm range. Based on EPMA data, the theoretical Fe grade in titanomagnetite was calculated to be 65.08%, indicating the potential for further improvement through the upgrading process. This study elucidates the mineralogical characteristics during the vanadium titanomagnetite upgrading, providing a theoretical basis to further enhance the Fe recovery rate

Evaluating the vaccination coverage: validity of household-hold vaccination booklet and caregiver’s recall

Background We compared results from household data sources to medical record sources by using data from a vaccination coverage survey. Methods Vaccination coverage (VC) was calculated based on parental recall, household vaccination booklet, and Zhejiang provincial immunization information system (ZJIIS). We evaluated the accuracy of VC based on household sources (vaccination booklet and recall) assuming the medical record was accurate. Concordance, sensitivity, specificity, positive predictive value, and negative predictive value were estimated as well as the Kappa statistic was also used to evaluate the agreement between data sources. Results Among the 1,800 children identified in the household survey, all were registered in ZJIIS. VC estimated using the vaccination booklet alone was substantially lower than that based on medical records (net bias 3.4–16.7% in different age groups). VC based on parental recall ranged from 2.5% below (among children aged 1 year) to 16.7% points above (among children aged 6 years) than those based on medical records. Concordance was lowest for card estimates (32.5–45.5%). Sensitivity was 75%, while negative predictive value was <50%, for all household sources. Kappa statistics generally indicated poor agreement between household and medical record sources. Conclusions Household-retained vaccination booklets and parental recall were insufficient sources for evaluating the VC. Our findings emphasized the importance of taking interventions to make the vaccination booklet more consistent with the records from medical resource

Exosomal microRNA-342-5p secreted from adipose-derived mesenchymal stem cells mitigates acute kidney injury in sepsis mice by inhibiting TLR9

Abstract Background Sepsis-related acute kidney injury (AKI) is an inflammatory disease associated with extremely high mortality and health burden. This study explored the possibility of exosomes secreted by adipose-derived mesenchymal stem cells (AMSCs) serving as a carrier for microRNA (miR)-342-5p to alleviate sepsis-related AKI and investigated the possible mechanism. Methods Serum was obtained from 30 patients with sepsis-associated AKI and 30 healthy volunteers for the measurement of miR-342-5p, blood urea nitrogen (BUN), and serum creatinine (SCr) levels. For in vitro experiments, AMSCs were transfected with LV-miR-342-5p or LV-miR-67 to acquire miR-342-5p-modified AMSCs and miR-67-modified AMSCs, from which the exosomes (AMSC-Exo-342 and AMSC-Exo-67) were isolated. The human renal proximal tubular epithelial cell line HK-2 was induced by lipopolysaccharide (LPS) to construct a cellular model of sepsis. The expression of Toll-like receptor 9 (TLR9) was also detected in AKI cells and mouse models. The interaction between miR-342-5p and TLR9 was predicted by dual luciferase reporter gene assay. Results Detection on clinical serum samples showed that BUN, SCr, and TLR9 were elevated and miR-342-5p level was suppressed in the serum of patients with sepsis-associated AKI. Transfection with LV-miR-342-5p reinforced miR-342-5p expression in AMSCs and AMSC-secreted exosomes. miR-342-5p negatively targeted TLR9. LPS treatment enhanced TLR9 expression, reduced miR-342-5p levels, suppressed autophagy, and increased inflammation in HK-2 cells, while the opposite trends were observed in LPS-induced HK-2 cells exposed to AMSC-Exo-342, Rapa, miR-342-5p mimic, or si-TLR9. Additionally, the effects of AMSC-Exo-342 on autophagy and inflammation in LPS-induced cells could be weakened by 3-MA or pcDNA3.1-TLR9 treatment. Injection of AMSC-Exo-342 enhanced autophagy, mitigated kidney injury, suppressed inflammation, and reduced BUN and SCr levels in sepsis-related AKI mouse models. Conclusion miR-342-5p transferred by exosomes from miR-342-5p-modified AMSCs ameliorated AKI by inhibiting TLR9 to accelerate autophagy. Graphical Abstrac