Experimental and theoretical study of bond behaviour between FRP bar and high-volume fly ash-self-compacting concrete

The combination of fibre-reinforced polymer (FRP) and high-volume fly ash self-compacting concrete (HVFA-SCC) reinforced is expected to solve the problem of steel corrosion in traditional structures and develop sustainable infrastructures. Bond behaviour has a strong effect on serviceability of FRP reinforced concrete structures. To achieve the acceptance of this novel composite structures in practical construction and design, it is significantly important to investigate the bond behaviour of FRP reinforced HVFA-SCC. In this study, a series of pull-out tests were carried out to investigate the bond behaviour of HVFA-SCC reinforced by FRP bar, which included bond strength, bond-slip response, and failure mode. The investigated experimental variables were reinforcing materials, surface treatment of FRP bars, bar diameters and concrete materials. The test results revealed that using HVFA-SCC resulted in higher average bond strength compared to those in the normal concrete test specimens. The reinforcing materials (steel vs. GFRP) had strong effect on bond behaviour, including bond strength, bond stiffness and failure mode. The failure mechanism of bond interaction between FRP and HVFA-SCC is dependent on friction and chemical adhesion. Subsequently, theoretical models for bond strength and development length were proposed. Finally, the parameters of analytical models of bond-slip curve are calibrated for GFRP reinforced HVFA-SCC by using the experimental data

Quantum Sensing of Free Radicals in Primary Human Granulosa Cells with Nanoscale Resolution

Cumulus granulosa cells (cGCs) and mural granulosa cells (mGCs), although derived from the same precursors, are anatomically and functionally heterogeneous. They are critical for female fertility by supporting oocyte competence and follicular development. There are various techniques used to investigate the role of free radicals in mGCs and cCGs. Yet, temporospatial resolution remains a challenge. We used a quantum sensing approach to study free radical generation at nanoscale in cGCs and mGCs isolated from women undergoing oocyte retrieval during in vitro fertilization (IVF). Cells were incubated with bare fluorescent nanodiamonds (FNDs) or mitochondria targeted FNDs to detect free radicals in the cytoplasm and mitochondria. After inducing oxidative stress with menadione, we continued to detect free radical generation for 30 min. We observed an increase in free radical generation in cGCs and mGCs from 10 min on. Although cytoplasmic and mitochondrial free radical levels are indistinguishable in the physiological state in both cGCs and mGCs, the free radical changes measured in mitochondria were significantly larger in both cell types, suggesting mitochondria are sites of free radical generation. Furthermore, we observed later occurrence and a smaller percentage of cytoplasmic free radical change in cGCs, indicating that cGCs may be more resistant to oxidative stress.</p

Quantum Sensing of Free Radicals in Primary Human Granulosa Cells with Nanoscale Resolution

Cumulus granulosa cells (cGCs) and mural granulosa cells (mGCs), although derived from the same precursors, are anatomically and functionally heterogeneous. They are critical for female fertility by supporting oocyte competence and follicular development. There are various techniques used to investigate the role of free radicals in mGCs and cCGs. Yet, temporospatial resolution remains a challenge. We used a quantum sensing approach to study free radical generation at nanoscale in cGCs and mGCs isolated from women undergoing oocyte retrieval during in vitro fertilization (IVF). Cells were incubated with bare fluorescent nanodiamonds (FNDs) or mitochondria targeted FNDs to detect free radicals in the cytoplasm and mitochondria. After inducing oxidative stress with menadione, we continued to detect free radical generation for 30 min. We observed an increase in free radical generation in cGCs and mGCs from 10 min on. Although cytoplasmic and mitochondrial free radical levels are indistinguishable in the physiological state in both cGCs and mGCs, the free radical changes measured in mitochondria were significantly larger in both cell types, suggesting mitochondria are sites of free radical generation. Furthermore, we observed later occurrence and a smaller percentage of cytoplasmic free radical change in cGCs, indicating that cGCs may be more resistant to oxidative stress.</p

MIDDAG: Where Does Our News Go? Investigating Information Diffusion via Community-Level Information Pathways

We present MIDDAG, an intuitive, interactive system that visualizes the information propagation paths on social media triggered by COVID-19-related news articles accompanied by comprehensive insights, including user/community susceptibility level, as well as events and popular opinions raised by the crowd while propagating the information. Besides discovering information flow patterns among users, we construct communities among users and develop the propagation forecasting capability, enabling tracing and understanding of how information is disseminated at a higher level.Comment: To appear at AAAI'24. System demo video and more info: info-pathways.github.i

An Oxidative Stress-Related Gene Signature in Granulosa Cells Is Associated with Ovarian Aging

Ovarian aging is associated with a decrease in fecundity. Increased oxidative stress of granulosa cells (GCs) is an important contributor. We thus asked whether there is an oxidative stress-related gene signature in GCs associated with ovarian aging. Public nonhuman primate (NHP) single-cell transcriptome was processed to identify GC cluster. Then, a GC signature for ovarian aging was established based on six oxidative stress-related differentially expressed genes (MAPK1, STK24, AREG, ATG7, ANXA1, and PON2). Receiver operating characteristic (ROC) analysis confirmed good discriminating capacity in both NHP single-cell and human bulk transcriptome datasets. Gene expression levels were investigated using qPCR in the human ovarian granulosa-like tumor cell line (KGN) and mouse GCs. In an oxidative stress model, KGN cells were treated with menadione (7.5 μM, 24 h) to induce oxidative stress, after which upregulation of MAPK1, STK24, ATG7, ANXA1, and PON2 and downregulation of AREG were observed (p<0.05). In an aging model, KGN cells were continuously cultured for 3 months, leading to increased expressions of all genes (p<0.05). In GCs of reproductively aged (8-month-old) Kunming mice, upregulated expression of Mapk1, Stk24, Atg7, and Pon2 and downregulated expression of Anxa1 and Areg were observed (p<0.01). We therefore here identify a six-gene GC signature associated with oxidative stress and ovarian aging

Coupled Bionic Design of Liquid Fertilizer Deep Application Type Opener Based on Sturgeon Streamline to Enhance Opening Performance in Cold Soils of Northeast China

Liquid fertilizer has many advantages, such as low production cost and little environmental pollution. Liquid fertilizer open furrow strip application method is widely used in fertilizer application operation. The widely used core-share furrow opener has a high operational resistance, disturbing the soil, hurting the crop roots, causing the liquid fertilizer to volatilize and deteriorating the fertilization effect. In this study, based on the streamline curve of the sturgeon body, we designed several bionic sturgeon liquid fertilizer deep application openers by combining bionics and analyzed the effects of several openers under different operating speeds on open furrow resistances and soil disturbance based on the discrete element method. The mechanism of open furrow resistances reduction and efficient soil backfill of the bionic structure were verified by indoor soil bin tests. The test results show that, compared with the core-share type furrow opener, both open furrow resistances and soil disturbance of the bionic sturgeon liquid fertilizer deep application opener are smaller. This study provides theoretical and practical references for the design of liquid fertilizer deep application openers