Arctigenin-induced reversal of drug resistance in cisplastin-resistant cell line A549/DDP, and the mechanism involved

Purpose: To investigate the drug resistance reversal effect of arctigenin (ARG) on cisplatin-insensitive A549/DDP cancer cells, and to elucidate the underlying mechanism(s). Methods: Four groups of cells: control, DDP, ARG and ADP were used. The degrees of inhibition of proliferation, drug resistance and apoptotic changes were measured using MTT assay, CCK-8 assay and flow cytometry, respectively. Expressions of PTEN and STAT3 proteins were determined by Western blotting. Results: At ARG concentration of 5 μmol/L, A549/DDP cells were significantly inhibited (p < 0.05). The combination therapy was more effective in reversing A549/DDP cells resistance than the single therapy. The expression level of PTEN protein increased with increase in ARG concentration, while STAT3 protein expression decreased with increase in ARG concentration. ADP group up-regulated PTEN but decreased STAT3 expression levels. Conclusion: ARG regulates drug resistance in A549/DDP cells, possibly via a mechanism involving reduction of A549/DDP cell sensitivity to DDP, thereby regulating the stress pathways associated with PTEN and STAT3. The combination of ARG and DDP effectively reduces A549/DDP cells resistance

Behaviour of a FRP anchor for seismic strengthening of clay brick masonry walls

Fibre reinforced polymer (FRP) anchors made from rolled or folded fibres have been shown to be an effective technology for delaying or even preventing premature debonding failure in concrete structures strengthened with externally bonded FRP. It would naturally be expected that the use of FRP anchors can improve the earthquakeresistance of FRP strengthened structures by increasing its loading capacity and ductility especially the latter. This study explores the application of FRP anchors in seismic strengthening of clay brick walls. One unique feature of such a system is that the brick unit has smaller dimensions compared to common concrete specimens. This paper reports an experimental pull out study of these FRP anchors. Test parameters included anchor construction, the diameter of the anchor, and the size of predrilled holes in clay brick. The experimental results indicate that FRP anchors can be designed to achieve high loading capacities and hence can be effectively used to prevent or delay FRP debonding failure. The results also indicate that the geometry of the anchor system has a significant effect on its loading capacity

The Hydrodynamic Characteristics Induced by Multiple Layouts of Typical Artificial M-Type Reefs with Sea Currents Typical of Liaodong Bay, Bohai Sea

Artificial reefs are effective measures to improve the marine ecological environment and increase fishery production. However, there are several geometries being investigated nowadays and their setup, including the spacing between groups of them, can provide dissimilar effects on hydrodynamics. To enhance the understanding of this topic, in this paper, the focus is mainly on M-Type artificial reefs that will be adopted in Juehua Island, Liaodong Bay, China. An experimental campaign was carried out in order to simulate the influence that M-Type unit reef groups may have on the local flow field and the Particle Image Velocimetry (PIV) technique has been implemented to provide velocity maps. The results showed that with the increase of velocity’s current approaching the artificial reef, the height, length and area of the upwelling and the back vortex rise with the increase of spacing between the artificial reefs. Furthermore, when comparing different geometrical configurations with similar currents approaching the artificial reef, the maximum values of both upwelling and back vortex were obtained when the spacing between unit reefs was 1.25 L. Finally, the entropy method was used to evaluate the effects on the flow field under four kinds of spacing based on the hydrodynamic characteristics and the economic cost. The comprehensive score obtained for all the configurations followed the order 1.25 L > 1.50 L > 0.75 L > 1.00 L. Therefore, it is suggested that the original design spacing should be increased by 25% when the M-type unit reef is put into practice. Additionally, after having completed a comparative analysis, it is recommended to further change the reef group into four reef monocases. By executing this adjustment, the unit reef cost was reduced by 10%, and the influence range on the flow field increased by 10%, and this result can consequently achieve greater ecological benefits with less economic input. The results of this study provide a preliminary reference for the construction of artificial reefs M-Type from the perspective of theory and practice

Observations of aerosol optical properties at a coastal site in Hong Kong, South China

Temporal variations in aerosol optical properties were investigated at a coastal station in Hong Kong based on the field observation from February 2012 to February 2015. At 550 nm, the average light-scattering (151 +/- 100Mm(-1) / and absorption coefficients (8.3 +/- 6.1Mm(-1) / were lower than most of other rural sites in eastern China, while the single-scattering albedo (SSA = 0.93 +/- 0.05) was relatively higher compared with other rural sites in the Pearl River Delta (PRD) region. Correlation analysis confirmed that the darkest aerosols were smaller in particle size and showed strong scattering wavelength dependencies, indicating possible sources from fresh emissions close to the measurement site. Particles with D-p of 200-800 nm were less in number, yet contributed the most to the light-scattering coefficients among submicron particles. In summer, both Delta BC / Delta CO and SO2 / BC peaked, indicating the impact of nearby combustion sources on this site. Multi-year backward Lagrangian particle dispersion modeling (LPDM) and potential source contribution (PSC) analysis revealed that these particles were mainly from the air masses that moved southward over Shenzhen and urban Hong Kong and the polluted marine air containing ship exhausts. These fresh emission sources led to low SSA during summer months. For winter and autumn months, contrarily, Delta BC / Delta CO and SO2 / BC were relatively low, showing that the site was more under influence of well-mixed air masses from long-range transport including from South China, East China coastal regions, and aged aerosol transported over the Pacific Ocean and Taiwan, causing stronger abilities of light extinction and larger variability of aerosol optical properties. Our results showed that ship emissions in the vicinity of Hong Kong could have visible impact on the light-scattering and absorption abilities as well as SSA at Hok Tsui.Peer reviewe

Frost and high-temperature resistance performance of a novel dual-phase change material flat plate solar collector

In order to overcome the freezing and overheating problems of solar collectors, a novel dual-phase change material (PCM) flat plate collector was proposed in this research. There were two layers of PCMs in the solar collector, one layer material with a phase change temperature of 70 °C and another with a phase change temperature of 15 °C, respectively. They were placed in the space under the absorber plate in the dual-PCM collector. Frost and High-temperature resistance performance of the novel dual-phase change material solar collector was tested systematically in a laboratory. The experimental results showed that the time taken for the temperature of the absorber plate to increase from 60 °C to 78 °C could be prolonged by 1.6 h under high temperature conditions. Furthermore, the low-melting point PCM can substantially slow the temperature decrease of the collector by solidifying and releasing heat under the low-temperature conditions. And the time taken for the temperature of the absorber plate to decrease from 19 °C to 10 °C could be prolonged by 6.4 h and 3.1 h when low-melting PCM placed below high-melting PCM and the high-melting PCM placed below low-melting PCM. Thus it can be seen that the dual-PCM collector can be used to overcome the phenomenon of overheating and freezing. In addition, compared with an ordinary flat plate collector, the efficiency of the dual-PCM collector was increased by 24.1% and 19.6% when placing low-melting PCM below high-melting PCM and in the opposite condition respectively

Comprehensive analysis of transcriptomics and metabolomics to understand tail-suspension-induced myocardial injury in rat

Background/AimsThe effect and underlying mechanism of microgravity on myocardium still poorly understood. The present study aims to reveal the effect and underlying mechanism of tail-suspension-induced microgravity on myocardium of rats.MethodsTail-suspension was conducted to simulate microgravity in rats. Echocardiography assay was used to detect cardiac function. The cardiac weight index was measured. Hematoxylin and eosin (HE) staining and transmission electron microscopy assay were conducted to observe the structure of the tissues. RNA sequencing and non-targeted metabolomics was employed to obtain transcriptome and metabolic signatures of heart from tail-suspension-induced microgravity and control rats.ResultsMicrogravity induced myocardial atrophy and decreased cardiac function in rats. Structure and ultrastructure changes were observed in myocardium of rats stimulated with microgravity. RNA sequencing for protein coding genes was performed and identified a total of 605 genes were differentially expressed in myocardium of rats with tail suspension, with 250 upregulated and 355 downregulated (P < 0.05 and | log2fold change| > 1). A total of 55 differentially expressed metabolites were identified between the two groups (VIP > 1 and P < 0.05) by the metabolic profiles of heart tissues from microgravity groups and control. Several major pathways altered aberrantly at both transcriptional and metabolic levels, including FoxO signaling pathway, Amyotrophic lateral sclerosis, Histidine metabolism, Arginine and proline metabolism.ConclusionMicrogravity can induce myocardial atrophy and decreases cardiac function in rats and the molecular alterations at the metabolic and transcriptomic levels was observed, which indicated major altered pathways in rats with tail suspension. The differentially expressed genes and metabolites-involved in the pathways maybe potential biomarkers for microgravity-induced myocardial atrophy

Glomerular capillary C3 deposition as a risk factor for unfavorable renal outcome in pediatric primary focal segmental glomerular sclerosis

IntroductionSome patients with primary focal segmental sclerosis (FSGS) demonstrate complement 3 (C3) deposition in glomerular capillary loops (Cap-C3) and/or mesangial area (Mes-C3). The clinicopathological and prognostic significance of C3 deposition remains incompletely investigated, especially in the pediatric cohort.MethodsWe retrospectively analyzed 264 children of biopsy-proven primary FSGS between January 2003 and December 2020. The correlation between Cap-C3 and renal outcome was evaluated by the Kaplan-Meier method and Cox multivariate regression analysis. Renal end-point event was defined as the development of end-stage renal disease, death for renal disease, or an estimated glomerular filtration rate reduction by at least 50% from baseline.ResultsAmong the 264 patients, 30 (11.4%) had Cap-C3. Kaplan-Meier analysis showed that patients with Cap-C3 had significantly lower renal survival rates than patients without Cap-C3 (60.17% vs. 84.71% at 5 years, 39.49% vs. 65.55% at 10 years, P < 0.01). Cox multivariate regression analysis showed that Cap-C3 was an independent risk factor for poor renal outcome (HR 3.53, 95% CI 1.22–10.19, P = 0.02).ConclusionGlomerular capillary C3 deposition was an independent risk factor for unfavorable renal outcome in children with primary FSGS

3-Phosphoinositide–Dependent Kinase 1 Potentiates Upstream Lesions on the Phosphatidylinositol 3-Kinase Pathway in Breast Carcinoma

Lesions of ERBB2, PTEN, and PIK3CA activate the phosphati- dylinositol 3-kinase (PI3K) pathway during cancer development by increasing levels of phosphatidylinositol-3,4,5-triphosphate (PIP3). 3-Phosphoinositide-dependent kinase 1 (PDK1) is the first node of the PI3K signal output and is required for activation of AKT. PIP3 recruits PDK1 and AKT to the cell membrane through interactions with their pleckstrin homology domains, allowing PDK1 to activate AKT by phosphorylating it at residue threonine-308. We show that total PDK1 protein and mRNA were overexpressed in a majority of human breast cancers and that 21% of tumors had five or more copies of the gene encoding PDK1, PDPK1. We found that increased PDPK1 copy number was associated with upstream pathway lesions (ERBB2 amplification, PTEN loss, or PIK3CA mutation), as well as patient survival. Examination of an independent set of breast cancers and tumor cell lines derived from multiple forms of human cancers also found increased PDK1 protein levels associated with such upstream pathway lesions. In human mammary cells, PDK1 enhanced the ability of upstream lesions to signal to AKT, stimulate cell growth and migration, and rendered cells more resistant to PDK1 and PI3K inhibition. After orthotopic transplantation, PDK1 overexpression was not oncogenic but dramatically enhanced the ability of ERBB2 to form tumors. Our studies argue that PDK1 overexpression and increased PDPK1 copy number are common occurrences in cancer that potentiate the oncogenic effect of upstream lesions on the PI3K pathway. Therefore, we conclude that alteration of PDK1 is a critical component of oncogenic PI3K signaling in breast cancer

Enhanced Oil Recovery and CO₂ Storage Performance in Continental Shale Oil Reservoirs Using CO₂ Pre-Injection Fracturing

CO2 pre-injection fracturing is a promising technique for the recovery of continental shale oil. It has multiple advantages, such as oil recovery enhancement, CO2 geological storage and water consumption reduction. Compared with conventional CO2 huff and puff and flooding, CO2 pre-injection features higher injection rates and pressures, leading to EOR and improved CO2 storage performance. Combining physical experiments and numerical simulation, this research systematically investigated the EOR and storage performance of CO2 pre-injection in continental shale reservoirs. The results showed that CO2 pre-injection greatly improved the oil recovery; after seven cycles of soaking, the average oil recovery factor was 39.27%, representing a relative increase of 31.6% compared with that of the conventional CO2 huff and puff. With the increasing pressure, the CO2 solubility grew in both the oil and water, and so did the CO2 adsorption in shale. Numerical simulation indicated that the average CO2 storage ratio of the production stage was 76.46%, which validated the effectiveness of CO2 pre-injection in terms of CO2 geological storage

Evaluation for climates adaptive capability of traditional Tuzhang dwelling

Present study is concentrated on evaluating the climate adaptive capability of Tuzhang dwellings. The comparisons to different thermal physical properties such as thermal resistance R0, thermal inertia index data D, reduction coefficient of thermal wave transferring V0 and thermal transferring delaying time ξ0 have been performed between Tuzhang dwelling and normal brick house. Comparing results show that Tuzhang dwelling has much better thermal properties than normal brick house. Therefore, regarding to climate adaptive capability, traditional Tuzhang dwelling is vastly superior to brick house