Effect of Mn/Ag Ratio on Microstructure and Mechanical Properties of Heat-Resistant Al-Cu Alloys.

This paper mainly investigated the effect of the Mn/Ag ratio on the microstructure and room temperature and high-temperature (350 °C) tensile mechanical properties of the as-cast and heat-treated Al-6Cu-xMn-yAg (x + y = 0.8, wt.%) alloys. The as-cast alloy has α-Al, Al2Cu, and a small amount of Al7Cu2 (Fe, Mn) and Al20Cu2 (Mn, Fe)3 phases. After T6 heat treatment, a massive dispersive and fine θ'-Al2Cu phase (100~400 nm) is precipitated from the matrix. The Mn/Ag ratio influences the quantity and size of the precipitates; when the Mn/Ag ratio is 1:1, the θ'-Al2Cu precipitation quantity reaches the highest and smallest. Compared with the as-cast alloy, the tensile strength of the heat-treated alloy at room temperature and high temperature is greatly improved. The strengthening effect of the alloy is mainly attributed to the nanoparticles precipitated from the matrix. The Mn/Ag ratio also affects the high-temperature tensile mechanical properties of the alloy. The high-temperature tensile strength of the alloy with a 1:1 Mn/Ag ratio is the highest, reaching 135.89 MPa, 42.95% higher than that of the as-cast alloy. The analysis shows that a synergistic effect between Mn and Ag elements can promote the precipitation and refinement of the θ'-Al2Cu phase, and there is an optimal ratio (1:1) that obtains the lowest interfacial energy for co-segregation of Mn and Ag at the θ'/Al interface that makes θ'-Al2Cu have the best resistance to coarsening.

Is two-point method a valid and reliable method to predict 1RM? A systematic review.

This systematic review aimed to evaluate the reliability and validity of the two-point method in predicting 1RM compared to the direct method, as well as analyze the factors influencing its accuracy. A comprehensive search of PubMed, Web of Science, Scopus, and SPORTDiscus databases was conducted. Out of the 88 initially identified studies, 16 were selected for full review, and their outcome measures were analyzed. The findings of this review indicated that the two-point method slightly overestimated 1RM (effect size = 0.203 [95%CI: 0.132, 0.275]; P < 0.001); It showed that test-retest reliability was excellent as long as the test loads were chosen reasonably (Large difference between two test loads). However, the reliability of the two-point method needs to be further verified because only three studies have tested its reliability. Factors such as exercise selection, velocity measurement device, and selection of test loads were found to influence the accuracy of predicting 1RM using the two-point method. Additionally, the choice of velocity variable, 1RM determination method, velocity feedback, and state of fatigue were identified as potential influence factors. These results provide valuable insights for practitioners in resistance training and offer directions for future research on the two-point method.

Ultrasound-triggered release of miR-199a-3p from liposome nanobubbles for enhanced hepatocellular carcinoma treatment.

This study was aimed to develop an efficient tumour-targeted liposome nanobubbles (LNBs) system using ultrasound-targeted nanobubble destruction for enhanced release and transfection of miRNA-199a-3p in hepatocellular carcinoma (HCC) therapy. The prepared LNBs comprised a polyethylene glycol-modified liposome shell and a perfluoropentane (PFP) core. MiRNA-199a-3p was attached to the nanocomposite surface via electrostatic adsorption, while RGD peptide functionalized the LNBs surface for enhanced HCC cell targeting, namely PFP@miR-RGD-LNBs. The LNBs were spherical with a narrow size distribution. The gene-loaded LNBs effectively condensed miR-199a-3p and protected it from enzymatic degradation. Low-intensity focused ultrasound (LIFU) promoted a fast release of miR-199a-3p from the prepared LNBs, thereby enhancing therapeutic effects. The combined application of PFP@miR-RGD-LNBs and LIFU exhibited a more potent inhibitory effect on HepG2 cells than the other groups, potentially due to LIFU promoting rapid and efficient gene release at the target site and increasing cell membrane permeability. Quantitative reverse transcription-polymerase chain reaction analysis revealed significantly increased mRNA expression levels of key apoptosis markers (Bad, Bax, Caspase-9 and Caspase-3) in the PFP@miR-RGD-LNBs + LIFU group compared to other groups. These findings suggest that the prepared LNBs are highly likely to be promising candidates for further exploration of HCC gene delivery and therapy.

Combined application of moist exposed burn ointment and maggot therapy in wound healing.

OBJECTIVE: Hard-to-heal wounds are a global health challenge, and effective treatments are still lacking. Moist exposed burn ointment (MEBO) and maggots are traditional treatments for promoting wound healing. This study was a preliminary exploration of combined maggot therapy and MEBO in the treatment of hard-to-heal wounds. METHOD: A coexistence experiment was conducted to determine the survival rates of maggots in MEBO. The maggots were placed in two different existence conditions: one set in MEBO (MEBO group), and another set as the control group (no MEBO) to compare survival rates. Case reports describe the use of the combined application of MEBO and maggots in the treatment of patients with hard-to-heal wounds. RESULTS: The coexistence experiment indicated that maggots in the MEBO group had a higher survival rate. From the therapeutic effect of the clinical cases (n=7), the combined application was safe and effective, with all the reported wounds eventually healing. CONCLUSION: Based on the findings of this study, we believe the combined application of MEBO and maggots is a promising way of promoting wound healing. Further studies and clinical trials are needed to elucidate the mechanism of the combined application in promoting wound healing and to more persuasively clarify the therapeutic effect.

Caprin-1 promotes HepG2 cell proliferation, invasion and migration and is associated with poor prognosis in patients with liver cancer.

The present study aimed to investigate the role of caprin-1 in liver cancer and its association with the clinicopathological features and prognosis of liver cancer, as well as the underlying mechanism of caprin-1 function. Caprin-1 expression levels in a tissue microarray containing 40 liver cancer tissues, 10 peritumoral tissues and 20 normal liver tissues were analyzed using immunohistochemistry. The clinical data of 154 patients with liver cancer were also collected from The Cancer Genome Atlas database. Kaplan-Meier analysis and a Cox proportional hazards regression model were used to assess the association between caprin-1 expression levels and survival in patients with liver cancer. The effects of caprin-1 knockdown on the mRNA levels of cyclin D1 and cyclin D2 as well as the proliferation, invasion and migration of HepG2 cells were also investigated. The expression level of caprin-1 in liver cancer tissues was significantly higher compared with normal liver tissues or cells (P<0.01). High caprin-1 expression levels were associated with advanced clinical stage (P<0.001) and enhanced tumor invasion (P<0.001). Kaplan-Meier analysis showed that the overall survival time and disease-free survival time in patients with liver cancer with high caprin-1 expression were significantly shorter compared with patients with low caprin-1 expression levels (P=0.002 and P=0.033, respectively). The Cox proportional hazards regression model showed that high caprin-1 expression levels were an independent prognostic factor for liver cancer (P<0.001). Knockdown of caprin-1 in HepG2 cells significantly downregulated mRNA expression levels of cyclin D1 and cyclin D2, inhibited cell proliferation and invasion and the cells were arrested at G0/G1 phase. In conclusion, caprin-1 may be a novel prognostic indicator for patients with liver cancer.

Anti-microRNA-21/221 and microRNA-199a transfected by ultrasound microbubbles induces the apoptosis of human hepatoma HepG2 cells.

Gene therapy, particularly microRNA (miRNA), is a promising candidate in the treatment of cancer; however, it is challenging to develop gene delivery systems. Ultrasound microbubbles have been used for gene delivery with excellent results. The present study aimed to investigate the transfection efficiency of HepG2 cells using ultrasound microbubbles. The effects of three miRNAs (miR-21, miR-221 and miR-199a) on HepG2 cells were also determined by performing ultrasound microbubble-mediated gene transfection. Three recombinant plasmids containing anti-miR-21, anti-miR-221 and miR-199a were fused with enhanced green fluorescent protein. For the transfection of genes, the type of contrast agent, the concentration of microbubble contrast agent and the exposure intensity of ultrasound were optimized. The expression of miRNAs was detected using reverse transcription-polymerase chain reaction. To determine the effect of anti-miR-21, anti-miR-221 and miR-199a on HepG2 cells, MTT, cell cycle analysis and Annexin V-PE/7-ADD apoptosis assays were performed. The optimal condition was 10% sulfur hexafluoride microbubbles at an ultrasound frequency of 2.0 MHz and mechanical index of 0.28. When cells were transfected with three recombinant plasmids using ultrasound microbubbles, there was significant downregulation of miR-21 and miR-221 and upregulation of miR-199a (P<0.05). All three treatments inhibited cell proliferation and promoted the apoptosis of cells. The present data indicated that the delivery of anti-miR-21, anti-miR-221 and miR-199a may be mediated by ultrasound microbubble contrast agents. With this approach, cell proliferation may be effectively inhibited and cell apoptosis may be induced. These are novel cancer therapy targets.

Ethanol extract of Zhongtian hawthorn lowers serum cholesterol in mice by inhibiting transcription of 3-hydroxy-3-methylglutaryl-CoA reductase via nuclear factor-kappa B signal pathway.

Hawthorn is a berry-like fruit from the species of Crataegus. In China, it has another more famous name, Shan-Zha, which has been used to improve digestion as a traditional Chinese medicine or food for thousands of years. Moreover, during the last decades, hawthorn has received more attention because of its potential to treat cardiovascular diseases. However, currently, only fruits of C. pinnatifida and C. pinnatifida var. major are included as Shan-Zha in the Chinese Pharmacopoeia. In this study, our results showed that the ethanol extract of Zhongtian hawthorn, a novel grafted cultivar of C. cuneata (wild Shan-Zha), could markedly reduce body weight and levels of serum total cholesterol, triglyceride, low-density lipoprotein cholesterol, and liver cholesterol of hyperlipidemia mice. It could suppress the stimulation effect of high-fat diet on the transcription of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) and p65, and counteract the downregulation of CYP7A1 and LDLR. In addition, the results of luciferase reporter assay and Western blot showed that the transcriptional activity of HMGCR promoter was inhibited by Zhongtian hawthorn ethanol extract in a dose-dependent manner, while overexpression of p65 could reverse this transcriptional repression effect. These results suggested that Zhongtian hawthorn could provide health benefits by counteracting the high-fat diet-induced hypercholesteolemic and hyperlipidemic effects in vivo, and the mechanism underlying this event was mainly dependent on the suppressive effect of Zhongtian hawthorn ethanol extract on the transcription of HMGCR via nuclear factor-kappa B (NF-κB) signal pathway. Therefore, this novel cultivar of hawthorn cultivar which has much bigger fruits, early bearing, high yield, cold resistance, and drought resistance, might be considered as a good alternative to Shan-Zha and has great value in the food and medicine industry. In addition, to our best knowledge, this is also the first report that the extract of Crataegus could suppress the transcription of HMGCR via NF-κB signal pathway.