Cell proliferation and quiescence are intimately coordinated during metazoan development. Here, we adapt a cyclin-dependent kinase (CDK) sensor to uncouple these key events of the cell cycle in
and ...zebrafish through live-cell imaging. The CDK sensor consists of a fluorescently tagged CDK substrate that steadily translocates from the nucleus to the cytoplasm in response to increasing CDK activity and consequent sensor phosphorylation. We show that the CDK sensor can distinguish cycling cells in G1 from quiescent cells in G0, revealing a possible commitment point and a cryptic stochasticity in an otherwise invariant
cell lineage. Finally, we derive a predictive model of future proliferation behavior in
based on a snapshot of CDK activity in newly born cells. Thus, we introduce a live-cell imaging tool to facilitate in vivo studies of cell-cycle control in a wide-range of developmental contexts.
Abstract
A new platform software named JUSMAR-MANS based on JASMIN was developed for the massively parallel numerical simulation on compressible multimedia multiphase flow under complex conditions. ...Different from the traditional “chimney” program research and development (r&d) pattern, the MANS who adopted the “platform” r&d pattern provides a way by which the users can rapidly and conveniently customize personalized high-credibility program of multimedium without considering in numerical discrete and parallel computing. MANS has the following advantages: 1) Decoupling of disciplines: In architecture design, physical modeling, numerical discreting, parallel computing are separated from each other and concept shielding so that the high barriers of program r&d caused by interdisciplinary are broken down. 2) Expandability: enables to easily extend new physical models and numerical schemes based on single point/element interfaces. 3) Rapid customization: enable to quickly assemble personalized program based on various models and algorithms libraries integrated by MANS. Based on MANS, it only takes serial code within a few days to obtain a well-posed large - scale multimedium simulation, which greatly reduce the complexity of software r&d for compressible multimedium flow.
The hydrogen absorption/desorption kinetics of the Mg12YNi alloy with an 18R-type long-period stacking ordered phase was investigated. It was found that the hydrogen-induced decomposition of the 18R ...phase with a grain size of 200-300nm occurs at 573K, leading to the formation of YH2 and YH3 particles with an average size of 10nm. In the subsequent hydrogen absorption/desorption process, the fine YH2 and/or YH3 particles act as catalysts that enhance remarkably the hydrogen storage kinetics.
Regenerating tissues similar to dental structure with normal function are putatively to be the aim in tooth regeneration filed. Currently, researchers preliminarily achieved tooth regeneration by ...applying dental pulp stem cells (DPSC) and stem cells from human exfoliated deciduous teeth (SHED). However, the regeneration efficiency remains unstable and needs further investigation. The development of single-cell RNA sequencing and organoid culture system provide potential of precise, targeted and controllable functional regeneration. This article reviews the current state of DPSC/SHED on tooth regeneration, and analyzes characteristics and hotspots of them, aiming to shed light on clinical translational application of stable and efficient tooth regeneration.
Pogonatherum crinitum is a promising lead (Pb) hyperaccumulator due to its high Pb tolerance and accumulation ability. However, the mechanisms that support Pb accumulation and tolerance in P. ...crinitum are not yet clearly understood.
An indoor hydroponic experiment was conducted by cultivating P. crinitum seedlings exposed to intermittent Pb stress for 60 days, divided into four stages (T1, T2, T3 and T4), with a 15‐day duration per stage. The following concentrations of Pb were used: 0, 500, 0, 500 mg·l−1 and 0, 1000, 0, 1000 mg·l−1). Antioxidant enzyme activity, Pb concentration and subcellular distribution of Pb were measured at each of the above stages.
The results showed that superoxide dismutase (SOD) activity in shoots, and SOD, peroxidase (POD) and malondialdehyde (MDA) activity in shoots and roots significantly increased from T1 (no Pb stress) to T2 (Pb stress) in both 500 mg·l−1 and 1000 mg·l−1 treatments; however, no significant difference was noted between stages T3 (no Pb stress) and T4 (Pb stress). There was no obvious effect of Pb stress on catalase (CAT) activity in shoots and roots among different stages. The Pb concentration in shoots was up to 5090.90 mg·kg−1 and 7573.57 mg·kg−1, and the bioconcentration factor (BFC) was 10.18 and 7.57 for the 500 mg·l−1 and 1000 mg·l−1 treatments, respectively, which confirmed the Pb hyperaccumulator characteristics of P. crinitum. For plants under Pb stress, most of the Pb was fixed in the cell walls, with a smaller amount in leaves and root vacuoles.
Both SOD and POD scavenging of reactive oxygen radicals and fixing and compartmentalisation of Pb in the cell wall might play important roles in detoxification of P. crinitum seedlings in response to Pb stress. There was no phased response of P. crinitum to intermittent Pb stress and the physiological response to Pb stress may be contiguous.
To analyze the epidemiological characteristics and clinical features of pertussis cases reported in Shandong Province of China.
Data on pertussis cases in Shandong Province from 2007 to 2022 were ...collected from China Information System for Disease Control and Prevention. At the same time, some case information was collected from the database of notifiable pertussis in Shandong Province from 2007 to 2022. The distribution characteristics and clinical features of pertussis were analyzed. A spatial distribution map of pertussis cases in Shandong Province was drawn.
A total of 26 122 pertussis cases were reported in Shandong Province during 2007-2022, with an annual incidence rate ranging from 0.11 to 5.77 cases per 100 000 people. Cases occurred throughout the whole year, with a seasonal peak occurring in spring and summer, especially in July and August. In recent years, reported cases were mainly distributed in the central and western regions of Shandong Province, with fewer cases in the eastern region. The hot
Transformation optics represents a new paradigm for designing light-manipulating devices, such as cloaks and field concentrators, through the engineering of electromagnetic space using materials with ...spatially variable parameters. Here we analyse liquid flowing in an optofluidic waveguide as a new type of controllable transformation optics medium. We show that a laminar liquid flow in an optofluidic channel exhibits spatially variable dielectric properties that support novel wave-focussing and interference phenomena, which are distinctively different from the discrete diffraction observed in solid waveguide arrays. Our work provides new insight into the unique optical properties of optofluidic waveguides and their potential applications.
•Light focusing in optofluidic waveguides is used as the detection signal for chemical reaction monitoring.•The optimized operating conditions of r and Pe are obtained for better sensitivity.•The ...method has broad applications in microreactors, chemical synthesis, and quantification of biomolecular interactions.
This paper studies the light focusing phenomenon in optofluidic waveguides and uses it to monitor chemical reactions. Firstly, the relationship between the light focusing pattern and its contributing factors is investigated experimentally. Next, a characterization experiment is conducted to validate the use of light focusing pattern as an indicator of diffusion properties. The sensitivity and the limit-of-detection (LOD) are measured to be 1.54 μm/(μm2/s) and 3.93 × 10−12 m2/s in the over-mixed region, respectively. Then, the sucrose hydrolysis reaction is monitored using the proposed optofluidic method as a demonstration. The initial hydrolysis rate of this reaction is measured to be 19.62 μM/min, which agrees reasonably well with the reported value. Lastly, this method is extended to determine the diffusion coefficient of binary solutions. The diffusion coefficients of ethylene glycol and glycerol in water are measured to be 5.56 ± 0.12 × 10-10 and 7.01 ± 0.20 × 10-10 m2/s, respectively. This study demonstrates a new method for potential integrated biochemical sensing and paves the way for a broad range of sensing applications in microreactors, chemical synthesis, and quantification of biomolecular interactions.
The breach of a steel column target (Steel 45, 120 mm in diameter) by an inward-cutting circular shaped charge is considered. The jet penetration process is simulated by a 3D model run in the ...ANSYS/LS-DYNA program. The results are compared with actual tests, where photographs of the jet penetration process allowed observation of detonation forms, timing of the jets arising at the cross section of the detonation points, and detonation wave collision points. Different penetration effects are observed with 2-, 4-, or 8-point symmetrical synchronous initiation of detonation. With 2-point initiation, the circular-shaped charge can basically cut off the steel column target, but 4- and 8-point initiation is more effective. A greater number of detonation points provides more detonation wave collision points, higher jet velocity, earlier jet-target contact, greater penetration depth, and more rapid cutting of the target.
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