Description of the impact damage of dams subjected to projectile penetration objectively is a significant but difficult issue. To take the advantages of bond-based peridynamics (BB PD) in analyzing ...multiple crack growth and fragmentation, a modified conjugated BB PD model with two micro-moduli is established for analyzing the quasi-static deformation and the projectile impact damage of a typical concrete gravity dam. The nonlocal interaction force in the conjugated BB PD is not only related to the relative normal stretch of a bond, but also related to a series of relative rotation angle of a pair of conjugated bonds. This model can be regarded as considering the tensile spring and the rotation spring together, so that it can break through the fixed Poisson’s ratio limitation of the original BB PD model due to the central pairwise interaction. Furthermore, compared with the original conjugated BB PD model, the definitions of tangent bond force and rotation strain energy density are distinctly different, which will not varied with different geometry discretization; also an attenuation kernel function related to the bond length is incorporated to reflect the decreasing long-range force with the increasing distance between material points. Finally, the failure analysis of a dam subjected to high-velocity projectile impacting at the center of dam crest demonstrates the effectiveness of the PD method for simulating the projectile impact failure.
Summary
Spray‐induced gene silencing (SIGS) is an innovative strategy for crop protection. However, the mechanism of SIGS is not known. Here, we first demonstrate that secondary small interfering RNA ...(siRNA) amplification limits the application of SIGS. A myosin5 gene (Myo5) was chosen as the target of SIGS in an agronomically important pathogen—Fusarium asiaticum. Five segments corresponding to the different regions of the Myo5 gene were found to efficiently silence Myo5, resulting in cell wall defects, life cycle disruption and virulence reduction. Myo5‐8 (one of the Myo5 segments) induced sequence‐specific RNA interference (RNAi) activity in F. asiaticum, F. graminearum, F. tricinctum and F. oxysporum, but not in other fungi, in vitro. Remarkably, the silencing of Myo5 lasted for only 9 h unless the double‐stranded RNA (dsRNA) was continuously supplied, because F. asiaticum is unable to maintain siRNA amplification. After spraying on plants, dsRNAs were more efficiently taken up via the wounded surface. The antifungal activity of dsRNAs taken up by plant cells was higher and longer lasting than that dried onto the plant surface. In contrast with dsRNAs in fungi, dsRNAs in plant cells could efficiently turn into substantial siRNAs via secondary amplification machinery. Our findings provide new implications to develop SIGS as a mainstream disease control strategy against Fusarium and other fungi.
The design of highly efficient, stable, and noble‐metal‐free bifunctional electrocatalysts for overall water splitting is critical but challenging. Herein, a facile and controllable synthesis ...strategy for nickel–cobalt bimetal phosphide nanotubes as highly efficient electrocatalysts for overall water splitting via low‐temperature phosphorization from a bimetallic metal‐organic framework (MOF‐74) precursor is reported. By optimizing the molar ratio of Co/Ni atoms in MOF‐74, a series of CoxNiyP catalysts are synthesized, and the obtained Co4Ni1P has a rare form of nanotubes that possess similar morphology to the MOF precursor and exhibit perfect dispersal of the active sites. The nanotubes show remarkable hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalytic performance in an alkaline electrolyte, affording a current density of 10 mA cm−2 at overpotentials of 129 mV for HER and 245 mV for OER, respectively. An electrolyzer with Co4Ni1P nanotubes as both the cathode and anode catalyst in alkaline solutions achieves a current density of 10 mA cm−2 at a voltage of 1.59 V, which is comparable to the integrated Pt/C and RuO2 counterparts and ranks among the best of the metal‐phosphide electrocatalysts reported to date.
An unusual nanotube of nickel–cobalt bimetal phosphides is produced via a facile and controllable low‐temperature phosphorization from a bimetallic metal‐organic framework (MOF‐74) by optimizing the molar ratio of Co/Ni atoms in MOF precursor. It shows remarkable hydrogen evolution reaction and oxygen evolution reaction catalytic performance in an alkaline electrolyte and can be used as a highly efficient electrocatalyst for overall water splitting.
A probe mediated SERS-based strategy is developed to selectively detect hydrazine with superb sensitivity. Ortho-phthaldialdehyde, a simple probe, reacts specifically with hydrazine to form ...phthalazine, a molecule that possesses a larger Raman cross section and better affinity toward the SERS substrate. We observed a limit of detection of 8.5 × 10(-11) M. Our method shows both qualitative and quantitative measurement of hydrazine with high sensitivity, low cost, and fast analysis time.
Nanofluidics derived from low‐dimensional nanosheets and protein nanochannels are crucial for advanced catalysis, sensing, and separation. However, polymer nanofluidics is halted by complicated ...preparation and miniaturized sizes. This work reports the bottom‐up synthesis of modular nanofluidics by confined growth of ultrathin metal–organic frameworks (MOFs) in a polymer membrane consisting of zwitterionic dopamine nanoparticles (ZNPs). The confined growth of the MOFs on the ZNPs reduces the chain entanglement between the ZNPs, leading to stiff interfacial channels enhancing the nanofluidic transport of water molecules through the membrane. As such, the water permeability and solute selectivity of MOF@ZNPM are one magnitude improved, leading to a record‐high performance among all polymer nanofiltration membranes. Both the experimental work and the molecular dynamics simulations confirm that the water transport is shifted from high‐friction‐resistance conventional viscous flow to ultrafast nanofluidic flow as a result of rigid and continuous nanochannels in MOF@ZNPM.
A rigid‐scaffold‐reinforced polymeric nanoparticles’ interfacial channel strategy is proposed for fabricating nanofluidic membranes that exhibit water permeance and dye/salt selectivity that are 1–2 orders of magnitude higher than conventional polymeric membranes. The unprecedented separation performance is due to the paradigm shift of water transport from conventional viscous flow to ultrafast nanofluidic flow in the membrane nanofluidics.
The COVID-19 pandemic has seen the rapid but sometimes controversial take-up of 'online examination proctoring' systems by universities keen to maintain their assessment schedules during times of ...campus closure. Following the theoretical tradition of media 'domestication', this article examines the mainstream adoption of different online proctoring systems in Australian higher education during the first year of the pandemic. Through analysis of interviews, documents, news, social media and marketing materials, the article examines the 'appropriation', 'objectification', incorporation' and 'conversion' of proctoring technology from the perspective of commercial providers, university authorities, university staff and student groups. This raises a number of critical issues underpinning the adoption of this exam surveillance technology - not least the surrender of control to commercial providers, the hidden labour required to sustain 'automated' systems and the increased vulnerabilities of 'remote' studying.
With more than 600,000 mortalities each year, colorectal cancer (CRC) is the third most commonly diagnosed type of cancer worldwide. Recently, mechanisms involving noncoding RNAs have been implicated ...in the development of CRC.
We examined expression levels of lncRNA CRNDE and miR-181a-5p in 64 cases of CRC tissues and cell lines by qRT-PCR. Gain-of-function and loss-of-function assays were performed to examine the effect of CRNDE and miR-181a-5p on proliferation and chemoresistance of CRC cells. Using fluorescence reporter and western blot assays, we also explored the possible mechanisms of CRNDE in CRC cells.
In this study, we found that the expression levels of the CRNDE were upregulated in CRC clinical tissue samples. We identified microRNA miR-181a-5p as an inhibitory target of CRNDE. Both CRNDE knockdown and miR-181a-5p overexpression in CRC cell lines led to inhibited cell proliferation and reduced chemoresistance. We also determined that β-catenin and TCF4 were inhibitory targets of miR-181a-5p, and that Wnt/β-catenin signaling was inhibited by both CRNDE knockdown and miR-181a-5p overexpression. Significantly, we found that the repression of cell proliferation, the reduction of chemoresistance, and the inhibition of Wnt/β-catenin signaling induced by CRNDE knockdown would require the increased expression of miR-181a-5p.
Our study demonstrated that the lncRNA CRNDE could regulate the progression and chemoresistance of CRC via modulating the expression levels of miR-181a-5p and the activity of Wnt/β-catenin signaling.
Abstract
With an increasing aging society, China is the world’s fastest growing markets for oral implants. Compared with traditional oral implants, immediate implants cause marginal bone resorption ...and increase the failure rate of osseointegration, but the mechanism is still unknown. Therefore, it is important to further study mechanisms of tension stimulus on osteoblasts and osteoclasts at the early stage of osseointegration to promote rapid osseointegration around oral implants. The results showed that exosomes containing circ_0008542 from MC3T3-E1 cells with prolonged tensile stimulation promoted osteoclast differentiation and bone resorption. Circ_0008542 upregulated Tnfrsf11a (RANK) gene expression by acting as a miR-185-5p sponge. Meanwhile, the circ_0008542 1916-1992 bp segment exhibited increased m6A methylation levels. Inhibiting the RNA methyltransferase METTL3 or overexpressing the RNA demethylase ALKBH5 reversed osteoclast differentiation and bone resorption induced by circ_0008542. Injection of circ_0008542 + ALKBH5 into the tail vein of mice reversed the same effects in vivo. Site-directed mutagenesis study demonstrated that 1956 bp on circ_0008542 is the m6A functional site with the abovementioned biological functions. In conclusion, the RNA methylase METTL3 acts on the m6A functional site of 1956 bp in circ_0008542, promoting competitive binding of miRNA-185-5p by circ_0008542, and leading to an increase in the target gene RANK and the initiation of osteoclast bone absorption. In contrast, the RNA demethylase ALKBH5 inhibits the binding of circ_0008542 with miRNA-185-5p to correct the bone resorption process. The potential value of this study provides methods to enhance the resistance of immediate implants through use of exosomes releasing ALKBH5.
Skeletal muscle plays important roles in normal biological activities and whole-body energy homeostasis in humans. The growth and development of skeletal muscle also directly influence meat ...production and meat quality in animal production. Therefore, regulating the development and homeostasis of skeletal muscle is crucial for human health and animal production. Adipose tissue, which includes white adipose tissue (WAT) and brown adipose tissue (BAT), not only functions as an energy reserve but also has attracted substantial attention because of its role as an endocrine organ. The novel signalling molecules known as “adipokines” and “lipokines” that are secreted by adipose tissue were identified through the secretomic technique, which broadened our understanding of the previously unknown crosstalk between adipose tissue and skeletal muscle. In this review, we summarize and discuss the secretory role of adipose tissues, both WAT and BAT, as well as the regulatory roles of various adipokines and lipokines in skeletal muscle development and homeostasis. We suggest that adipokines and lipokines have potential as drug candidates for the treatment of skeletal muscle dysfunction and related metabolic diseases and as promising nutrients for improving animal production.
Display omitted
•Adipokines and lipokines mediate crosstalk between adipose and skeletal muscle.•Adipokines and lipokines regulate skeletal muscle development and homeostasis.•Adipokines and lipokines may have potential in human health and animal production.
PDF
