Notoginsenoside R1 protects oxygen and glucose deprivation-induced injury by upregulation of miR-21 in cardiomyocytes.

Notoginsenoside R1 (NG-R1) is a major component of Panax notoginseng, which has been used clinically for the treatment of diabetic nephropathy for centuries in China. This study aimed to reveal the functional impacts and the underlying mechanisms of NG-R1 on oxygen-glucose deprivation (OGD)-injured cardiomyocytes. Rat cardiomyocyte line H9c2 and primary cardiomyocytes were subjected to OGD with or without NG-R1 treatment. The expression levels of miR-21 and phosphatase and tensin homolog (PTEN) in the cell were altered by microRNA, vector or short-hairpin RNA transfections. Thereafter, changes in cell viability, apoptosis, and PI3K/AKT signaling were monitored. NG-R1 with low concentrations had no impact on H9c2 cells viability, but 80 µM of NG-R1 significantly reduced cell viability. NG-R1 (20 µM) protected H9c2 cells and primary cardiomyocytes against OGD-induced cell damage, as cell viability was increased, apoptotic cell rate was reduced, and Bax, cleaved caspase-3 and -9 were downregulated by addition of NG-R1. MiR-21 was low expressed in response to OGD exposure, while was highly expressed by NG-R1 treatment. PTEN was a direct target of miR-21. More interestingly, OGD-induced cell damage could be recovered by miR-21 overexpression or PTEN silence. Furthermore, PTEN silence recovered OGD-blocked PI3K/AKT signaling pathway. To conclude, this study demonstrated that NG-R1 exerted remarkable benefits in reduction of OGD-induced cardiomyocyte loss. The cardioprotective actions of NG-R1 possibly via upregulation of miR-21, repressing the expression of miR-21's target PTEN and thereby preventing the blockage of PI3K/AKT signaling pathway.

MiRNA-217 accelerates the proliferation and migration of bladder cancer via inhibiting KMT2D.

To uncover the biological function of miRNA-217 in the progression of bladder cancer and the underlying mechanism. Potential miRNAs binding KMT2D were predicted through online bioinformatics. Their expression levels in bladder cancer tissues and adjacent ones were determined. Through Pearson correlation analysis and survival analysis, the most potential miRNA candidate (miRNA-217) that targets and regulates KMT2D in bladder cancer was selected. Subsequently, expression levels of miRNA-217 and KMT2D in non-muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC) were detected. MiRNA-217 level in bladder cancer cell lines was determined as well. The interaction between KMT2D and miRNA-217 was verified by dual-luciferase reporter gene assay. Finally, regulatory effect of miRNA-217 on viability and migration in T24 and UMUC-3 cells were investigated. Five potential candidates that were upstream genes binding KMT2D were searched by bioinformatics. Among them, miRNA-217 was remarkably upregulated in bladder cancer tissues and closely linked to poor prognosis of affected patients. Moreover, dual-luciferase reporter gene assay verified the interaction between miRNA-217 and KMT2D. MiRNA-217 was able to downregulate mRNA and protein levels of KMT2D. Furthermore, knockdown of miRNA-217 attenuated viability and migration in bladder cancer cells. MiRNA-217 accelerates proliferative and migratory abilities in bladder cancer via inhibiting the level of tumor suppressor KMT2D, thereafter leading to the poor prognosis in bladder cancer patients.

The art of healing hearts: Mastering advanced RNA therapeutic techniques to shape the evolution of cardiovascular medicine in biomedical science.

Cardiovascular diseases (CVDs) are the leading cause of death worldwide and are associated with increasing financial health burden that requires research into novel therapeutic approaches. Since the early 2000s, the availability of next-generation sequencing techniques such as microRNAs, circular RNAs, and long non-coding RNAs have been proven as potential therapeutic targets for treating various CVDs. Therapeutics based on RNAs have become a viable option for addressing the intricate molecular pathways that underlie the pathophysiology of CVDs. We provide an in-depth analysis of the state of RNA therapies in the context of CVDs, emphasizing various approaches that target the various stages of the basic dogma of molecular biology to effect temporary or long-term changes. In this review, we summarize recent methodologies used to screen for novel coding and non-coding RNA candidates with diagnostic and treatment possibilities in cardiovascular diseases. These methods include single-cell sequencing techniques, functional RNA screening, and next-generation sequencing.Lastly, we highlighted the potential of using oligonucleotide-based chemical products such as modified RNA and RNA mimics/inhibitors for the treatment of CVDs. Moreover, there will be an increasing number of potential RNA diagnostic and therapeutic for CVDs that will progress to expand for years to come.

Identification and validation of the pyroptosis-related long noncoding rna signature to predict the prognosis of patients with bladder cancer.

Bladder cancer ranked the second most frequent tumor among urological malignancies. This work investigated bladder cancer prognosis, including the relevance of pyroptosis-related long noncoding RNA (lncRNA) in it and its potential roles. The Cancer Genome Atlas database offered statistics on lncRNAs and clinical data from 411 bladder cancer patients. Pearson correlation analysis was used to evaluate pyroptosis-related lncRNAs. To explore prognosis-associated lncRNAs, we performed univariate Cox regression, least absolute shrinkage and selection operator regression analyses, as well as the Kaplan-Meier method. Multivariate Cox analysis was leveraged to establish the risk score model. Afterward, a nomogram was constructed according to the risk score and clinical variables. Finally, to investigate the potential functions of pyroptosis-related lncRNAs, gene set enrichment analysis was employed. Eleven pyroptosis-related lncRNAs were screened to be closely associated with patients prognosis. On this foundation, a risk score model was created to classify patients into high and low risk groups. The signature was shown to be an independent prognostic factor (P < .001) with an area under the curve of 0.730. Then a nomogram was established including risk scores and clinical characteristics. The nomogram prediction effect is excellent, with a concordance index of 0.86. The 11-lncRNAs signature was associated with the supervision of oxidative stress, epithelial-mesenchymal transition, cell adhesion, TGF-ß, and Wingless and INT-1 signaling pathway, according to the gene set enrichment analysis. Our findings indicate that pyroptosis-related lncRNAs, which may affect tumor pathogenesis in many ways, might be exploited to assess the prognosis of bladder cancer patients.

Design of High-Entropy Alloy Coating for Cavitation Erosion Resistance by Different Energy-Induced Dynamic Cyclic Behaviors.

The dispute over the effect of cavitation heat on material surface intensifies the fuzziness of cavitation erosion (CE) mechanism and limits the development of protective materials. Here, an anti-CE Al10Cr28Co28Ni34 high-entropy alloy (HEA) coating with single face-centered cubic (FCC), prepared by high-velocity oxy-fuel (HVOF) spraying technologies, was designed by inducing mechanical and thermal energy-induced behaviors to transform or counteract each other. The results showed that, on the one hand, this coating underwent the refinement of the average grain size from 1.22 to 1.02 µm, the increase in dislocation density from 1.28 × 10-10 to 1.83 × 10-10 m-2, and the martensitic transformation from FCC to body-centered cubic (BCC) under the cavitation load; on the other hand, cavitation heat could indeed induce grain growth and realize structural relaxation, which confirmed that cavitation heat acting on the material surface at temperatures theoretically above 1206.28 K also played a significant role in the CE mechanism. That is, the surface microstructure of this coating was always in a dynamic cycle during the CE process. Therefore, the coating achieved the simultaneous absorption of mechanical impact energy and thermal energy released by the bubble collapse while effectively avoiding the overenrichment of crystal defects and finally exhibited a CE resistance 2 times better than that of the classical AlCrCoFeNi HEA coating. This design concept of inducing different energy restraints or neutralization through the special response behaviors of surface microstructure provides a completely new way for the development of CE-resistant materials.

[Effects of age, gender and urinary diversion category on perioperative complications of radical cystectomy].

OBJECTIVE: To explore the association of age, gender and urinary diversion category with postoperative complications of radical cystectomy. METHODS: A total of 374 patients with bladder cancer undergoing modified radical cystectomy and urinary diversion between March 2000 and June 2011 were retrospectively reviewed. Their demographic, perioperative and complication data were recorded. And multivariable Logistic regression was used to investigate the predictors of perioperative complications. RESULTS: Among them, 38.8% (145/374) received ileal conduit, 47.9% (179/374) orthotopic ileal neobladder and 13.4% (50/374) orthotopic colonic neobladder. The overall perioperative complication rate was 37.4% (140/374). And 21.4% (80/374) experienced at least one complication within Day 90 postoperation while 16.3% (61/374) had the long-term complications (> Day 90). There was no significant association between patients age (P = 0.15) and perioperative complications or between gender (P = 0.16) and complication. Urinary diversion (OR = 0.26, 95%CI: 0.16 - 0.43) was the only variable significantly associated with the perioperative urinary complications. CONCLUSION: The categories of urinary diversion may be used as a single predictor for complications after radical cystectomy.

Evaluation Model of New Socialist Countryside Construction Based on a Multilayer Neural Network in a Complex Environment.

The creation of a deep neural network model with numerous hidden layers enables the layer-by-layer extraction of features from the input high-dimensional data, enabling the identification of the data's low-dimensional nested structure and the development of a more efficient and abstract high-level representation. The research on deep learning is thoroughly examined, along with the direction it needs to take going forward. Supporting the construction of new socialist rural areas as a calculated move to address the problems facing farming, rural communities, and farmers is another essential step in furthering modernization. It helps to reshape the entire rural landscape, coordinate the growth of urban and rural areas, achieve the goal of a wealthy society in every way, boost demand, and support the holistic development of people. The emergence of new socialist rural communities against the background of deep learning is the subject of significant research and analysis in this work. In the research, it is examined and studied using deep learning methods and convolutional neural networks. It is evident from the research described in this paper that deep learning backgrounds have a considerable impact on the development of new rural areas-up to 54.53%. In this essay, the foundation for the future construction of a new socialist countryside is laid forth.

A Study on the Preparation and Cavitation Erosion Mechanism of Polyether Polyurethane Coating.

Polyurethane elastomers are anticipated to be applied in the field of cavitation erosion (CE) resistance, but their protection and damage mechanisms are not clear, which greatly restricts their further development. In this article, five polyether polyurethanes (PUx) with different crosslinking densities were prepared. Their mechanical properties, thermal properties, water absorption, surface morphology and chemical structure before and after CE tests were compared with ESEM, OM, TG-DSC, FTIR and XPS in detail. The results showed that with an increase in crosslinking density, the tensile strength of PUx increased first and then decreased, elongation at break and water absorption reduced gradually and thermal decomposition temperature and adhesion strength increased steadily. During the CE process, cavitation load aggravated the degree of microphase separation and made brittle hard segments concentrate on the coating surface; meanwhile, cavitation heat accelerated hydrolysis, pyrolysis, oxidation and the fracture of molecular chains. As a result, the mechano-thermal coupling intensified the formation and propagation of fatigue cracks, which should be the fundamental reason for the CE damage of polyurethane elastomer. PU0.4 exhibited the best CE resistance among the five coatings thanks to its good comprehensive properties and may find potential applications on the surface of hydraulic components.

Bioinspired Hydroxyapatite Coating Infiltrated with a Graphene Oxide Hybrid Supramolecular Hydrogel Orchestrates Antibacterial and Self-Lubricating Performance.

Hydroxyapatite (HA) bioceramic coating has been extensively applied for the modification of metallic implants to improve their biocompatibility and service life after implantation. Unfortunately, HA coating often suffers from high friction, severe wear, and bacterial invasion, which restrict its application in artificial joints. According to a bioinspired soft/hard combination strategy, a novel HA composite coating that is infiltrated with a vancomycin-loaded graphene oxide (GO) hybrid supramolecular hydrogel is developed via vacuum infiltration and a subsequent host-guest interaction-induced self-assembly process. The holes of textured HA ceramic coating act just like a "magic pocket", offering a stable container to form and store GO hybrid hydrogels and even to recycle wear debris as well. The drug-loaded hybrid hydrogels stored in textured HA coating possess a unique shear force and/or frictional heat triggered gel-sol transition and sustained drug release behavior, acting like the extrusion of synovial fluid during articular cartilage movement, leading to a remarkable self-lubrication, anti-wear performance, and promising antibacterial property against Staphylococcus aureus. The friction coefficient and wear rate of composite coating reduced by nearly five times and three orders of magnitude compared with textured HA coating, respectively, which benefited from the synergistic lubricate effect of cyclodextrin-based pseudopolyrotaxane supramolecular hydrogel and GO lubricants.

Comprehensive analysis of the endoplasmic reticulum stress-related long non-coding RNA in bladder cancer.

Background: Bladder cancer is ranked the second most frequent tumor among urological malignancies. The research strived to establish a prognostic model based on endoplasmic reticulum stress (ERS)-related long non-coding RNA (lncRNA) in bladder cancer. Methods: We extracted the ERS-related genes from the published research and bladder cancer data from the Cancer Genome Atlas database. ERS-related lncRNAs with prognostic significance were screened by univariate Cox regression, least absolute shrinkage and selection operator regression analysis and Kaplan-Meier method. Multivariate Cox analysis was leveraged to establish the risk score model. Moreover, an independent dataset, GSE31684, was used to validate the model's efficacy. The nomogram was constructed based on the risk score and clinical variables. Furthermore, the biological functions, gene mutations, and immune landscape were investigated to uncover the underlying mechanisms of the ERS-related signature. Finally, we employed external datasets (GSE55433 and GSE89006) and qRT-PCR to investigate the expression profile of these lncRNAs in bladder cancer tissues and cells. Results: Six ERS-related lncRNAs were identified to be closely coupled with patients' prognosis. On this foundation, a risk score model was created to generate the risk score for each patient. The ERS-related risk score was shown to be an independent prognostic factor. And the results of GSE31684 dataset also supported this conclusion. Then, a nomogram was constructed based on risk scores and clinical characteristics, and proven to have excellent predictive value. Moreover, the gene function analysis demonstrated that ERS-related lncRNAs were closely linked to fatty extracellular matrix, cytokines, cell adhesion, and tumor pathways. Further analysis revealed the association of the 6-lncRNAs signature with gene mutations and immunity in bladder cancer. Finally, the external datasets and qRT-PCR verified high expressions of the ERS-related lncRNAs in bladder cancer tissues and cells. Conclusions: Overall, our findings indicated that ERS-related lncRNAs, which may affect tumor pathogenesis in a number of ways, might be exploited to assess the prognosis of bladder cancer patients.

Primary adult intratesticular rhabdomyosarcoma: results of the treatment of six cases.

The aim of the present study was to assess the treatment outcomes in a cohort of adult patients with intratesticular rhabdomyosarcoma. Between 1999 and 2008, 296 patients underwent radical orchiectomy for intrascrotal mass. A retrospective chart review was carried out for adult patients diagnosed with intratesticular rhabdomyosarcoma. Overall, six patients (mean age 21 years, range 17-23) were included: five had embryonic rhabdomyosarcoma and one had pleomorphic rhabdomyosarcoma. Four patients underwent retroperitoneal lymph node dissection and five patients had postoperative chemotherapy. The mean length of follow up was 28 months (range 12-51 months). One patient was lost to follow up after 26 months, five cases remained alive at the end of the study. Surgical resection with chemotherapy was an effective way to achieve favorable outcomes and long-term survival in adult patients with metastases from intratesticular rhabdomyosarcoma.

[Clinical outcomes of nephron sparing surgery for T1 renal cell carcinoma].

OBJECTIVE: To investigate the safety and effect of nephron-sparing surgery (NSS) in treatment of T1a and T1b renal cell carcinoma. METHODS: Retrospective analyzed the clinical data of 101 patients with T1 renal cell carcinoma underwent NSS from November 1999 to December 2009.Including 79 male and 22 female with the mean age of 52.3 years (ranged 28 to 79 years). Based on tumor pathologic diameter, 101 patients were divided into T1a group with 62 patient and T1b group with 39 cases. Demographic, intraoperative, postoperative and follow-up data were compared between the 2 groups. RESULTS: The operation were performed successfully in all the 101 cases. The mean operation time was (151 ± 80) min in group T1a and (158 ± 50) min in group T1b with no statistical difference (P = 0.32). The mean blood loss was (322 ± 596) ml in group T1a and (308 ± 239) ml in group T1b (P = 0.45). Postoperative follow-up ranged from 8 to 102 months with a mean of 38.4 months. One patient in T1b group died of distant metastasis 36 months after operation. Others were no tumor recurred. CONCLUSION: Nephron-sparing surgery is safe and effective for the treatment of T1a and T1b renal cell carcinoma.

Supramolecular hydrogel-infiltrated ceramics composite coating with combined antibacterial and self-lubricating performance.

Inspired by the structure and dynamic weeping lubricating mechanism of articular cartilage, a novel composite coating composed of a textured Y2O3-stabilized ZrO2 (YSZ) ceramics reservoir and silver nanoparticles (AgNPs) hybrid supramolecular hydrogel was developed on the basis of a soft/hard combination strategy. The precursor solution including the poly(ethylene glycol) (PEG)-modified AgNPs and α-cyclodextrins (α-CDs) could be infiltrated deep into (50-60 µm) the pores of a textured YSZ ceramics substrate by a vacuum infiltration method, in situ forming a supramolecular hydrogel within the pores through host-guest inclusion between α-CDs and PEG chains distributed onto the surface of AgNPs. The AgNPs hybrid hydrogel showed thixotropic and thermoresponsive gel-sol transition behavior, low cytotoxicity, and excellent drug-loading capacity, as well as significant antibacterial properties. The textured YSZ ceramics not only provided a hard supporting skeleton and stable reservoir to protect the supramolecular hydrogel from destruction under load-bearing or shear condition, but also allowed retaining the stimuli-responsive gel-sol transition property and drug-release capability of the infiltrated hydrogel, endowing the composite coating with excellent antibacterial properties, and self-lubrication and wear-resistance performance. The composite coating in this work brings a new insight into the design of antibacterial and self-lubricating ceramic coatings for artificial joint applications.

Benign pathological findings in 303 Chinese patients undergoing surgery for presumed localized renal cell carcinoma.

OBJECTIVE: To analyze the incidence of benign lesions in Chinese patients undergoing nephrectomies for renal masses identified as localized renal cell carcinoma (RCC) in preoperative imaging. METHODS: Between 1999 and 2007, 303 patients (112 female, 191 male) with presumed localized RCC underwent nephrectomy (234 radical nephrectomies and 69 partial nephrectomies). Preoperative computed tomography images and pathological findings were reviewed and analyzed. RESULTS: Pathological examinations revealed 31 (10.2%) benign lesions in the 303 patients. Among these 31 benign lesions, 15 (5.0%) were angiomyolipomas (AML) and only four (1.3%) were oncocytomas. Significantly, 20 (17.9%) of the 112 female patients had benign lesions compared with 11 (5.8%; P = 0.001) male patients. Benign renal lesions were found in five (25.0%) of the 20 patients with renal masses smaller than 2 cm, 13 (13.0%) of the 100 patients with renal masses 2-4 cm in size and 13 (7.1%) of the 183 patients with renal masses larger than 4 cm. CONCLUSIONS: Patients in the present study population show a low incidence of benign renal lesions, approximately half of them being AML. Female patients and patients with renal masses smaller than 4 cm are more likely to have benign renal lesions.

Oncological outcome of surgical treatment in 336 patients with renal cell carcinoma.

BACKGROUND AND OBJECTIVE: The most effective therapy against renal cell carcinoma (RCC) is surgical treatment; however, there have been few large-scale studies that focused on the oncological outcome of this disease in China. The aim of the current study was to report the clinicopathological results and cancer-specific survival (CSS) rate in RCC patients after surgical treatment in our center. METHODS: We retrospectively analyzed the clinicopathological data of 336 RCC patients who underwent radical or partial nephrectomy between 1999 and 2006. Of the 336 patients, 226 were male and 110 were female; the median age was 51 years. Univariate and multivariate analyses were conducted to identify the independent prognostic predictors for this cohort of RCC patients. RESULTS: During follow-up, the overall 5-year CSS rate was 81.4%. The 5-year CSS rates for patients with stage-I, -II, -III, and -IV RCC were 94.7%, 88.9%, 68.8%, and 19.3%, respectively. The patients with T1N0M0 (T1) and T2N0M0 (T2) tumors had similar survival curves. For patients with T1 category tumor, the survival rate did not differ significantly between the radical nephrectomy and nephron-sparing surgery groups. For the 21 patients with metastasis confined to the local lymph nodes, the 5-year survival rate was 31.6% after radical nephrectomy and lymph node dissection. For the 15 patients with vena caval tumor thrombus, the 5-year survival rate was 52.5% after radical nephrectomy and tumor thrombus extirpation. Multivariate Cox regression showed that stage was an independent predictor for CSS (hazard ratio, 3.359; P < 0.001). CONCLUSIONS: For localized RCC, the oncological outcome of this cohort is comparable to that reported in the Western literature. For some patients with locally advanced RCC, aggressive surgical treatment can lead to better long-term survival. However, the prognosis of the patients with metastasis still needs to be improved.

[Experience of the treatment for clinical Stage-1 seminoma over a period of 10 years].

BACKGROUND AND OBJECTIVE: Patients with clinical stage I seminoma accounts for 70%-80% of patients with this disease. This study was to analyze the relationship between different therapeutic methods and the prognosis of this disease. METHODS: The data of all patients with clinical Stage I seminoma treated by multi-disciplinary approach from 1999 to 2008 in Sun Yat-sen University Cancer Center were analyzed. The patients were divided into 3 groups based on the treatment they received after orchiectomy: 30 patients treated with chemotherapy, 8 with radiotherapy, and 20 under surveillance. The prognosis of different treatment groups was evaluated. RESULTS: Among the 58 patients with stage I seminoma, 57 were followed up successfully. The median follow-up time was 50 months (range, 8-115 months). No relapse or metastasis was seen in the chemotherapy group. One patient relapsed in the radiotherapy group. Four patients had metastasis of retroperitoneal lymph node in the surveillance group. The disease-free survival was higher in the chemotherapy group than that in the surveillance group (P=0.005). There was no significant difference in the relapse-free survival between the surveillance group and the radiotherapy group (P=0.364). CONCLUSIONS: Chemotherapy is a safe and effective treatment for patients with Stage-1 seminoma after radical orchidectomy.

The Effect of Single-port Transvesical Laparoscopic Radical Prostatectomy on Erectile Function and Urinary Continence Compared to Intrafascial Endoscopic Extraperitoneal Radical Prostatectomy.

PURPOSE: To compare the erectile function and urinary continence of patients after single-port transvesical laparoscopic radical prostatectomy (STLRP) with intrafascial endoscopic extraperitoneal radical prostatectomy (IEERP). MATERIALS AND METHODS: Patients treated with STLRP (35) or IEERP (52) were recruited from September 2013 to June 2017. At baseline preoperatively and 2-year follow-up postoperatively, sex and continence assessments were performed by International Index of Erectile Function-6 (IIEF-6) and daily pads, respectively. RESULTS: The sexual function at 3 months after RP declined obviously. 71.4% (STLRP) and 38.5% (IEERP) patients recovered potency at 6 months postoperatively (P < .01). 82.9% (STLRP) and 59.6% (IEERP) patients recovered potency at 2 years postoperatively (P < .05). 97.1% (STLRP) and 75.0% (IEERP) patients recovered continence (0 pad/day) at 3 months postoperatively (P < .01). Continence achieved 100.0% at 2 years after RP in both groups. CONCLUSION: Patients receiving STLRP may obtain better and faster postoperative functional recovery than the ones receiving IEERP. As an exploratory research, STLRP may be another effective treatment for organ-confined prostate cancer.

Electroacupuncture Inhibits Atherosclerosis through Regulating Intestinal Flora and Host Metabolites in Rabbit.

METHODS: In this study, general rabbit conditions, vascular histology, metabolites, and intestinal flora structures were analyzed. Integrated analysis of metabolomics and 16S rRNA sequencing were performed. All the rabbits were randomly divided into four groups. The rabbit model of atherosclerosis was established. The histopathological change in the common carotid artery was assessed by HE staining and the structural change in the flora by 16S rRNA sequencing. HPLC-TOF-MS and Agilent MPP 12.1 were integrated to identify and screen out differential metabolites. Correlational analyses of every differential metabolite with intestinal flora were integrated on Omicshare platform. RESULTS: Atherosclerotic rabbits showed obvious changes in general conditions, significant fibrous cap and necrotic center on carotid artery, abnormal intestinal bacteria structure, and metabolites levels. Electroacupuncture improved the conditions, reduced lipid deposition on the carotid artery wall, diversified intestinal flora, and normalized host metabolism. Integrated analysis showed that 149 altered metabolites were related to 22 intestinal flora, among which eight intestinal floras and 21 metabolites have relationships with atherosclerosis. CONCLUSION: Electroacupuncture can effectively reverse atherosclerosis through manipulating the structural feature of intestinal flora to influence the host metabolites. The possible mechanisms involved activating signal pathways through host metabolites or affecting the activity of cardiovascular-related enzymes, or regulating host lipid metabolism directly.

Cavitation erosion mechanisms in Co-based coatings exposed to seawater.

The cavitation erosion (CE) of most materials in seawater is more serious than in fresh water due to the onset of corrosion; however, in a previous study we reported results that contradict this widely accepted trend. In this research our objective is to provide fundamental insight into the mechanisms that may be responsible for these earlier results. To accomplish this objective, two types of Co-based coatings, prepared by high velocity oxygen fuel (HVOF) spraying system, were used to further investigate the underlying corrosion-mitigating CE mechanism in seawater. Accordingly, the influence of spraying parameters on microstructure, composition and mechanical properties of the coatings was analyzed on the basis of SEM, XRD, Raman spectroscopy, Vicker's hardness and nano-indentation results. Electrochemical corrosion tests were used to evaluate the corrosion behavior of the Co-based coatings. Their CE performances in seawater and deionized water were comparatively studied by a vibratory apparatus. Results demonstrated that a higher flame temperature facilitated the oxides formation with associated improvements in compactness, hardness and toughness of the coatings. The presence of alumina in combination with the oxides formed in-situ facilitated the formation of an oxidation film on surfaces, and effectively enhanced the charge transfer resistance of the coating, thereby significantly improving the corrosion resistance in seawater. Metallic Co was not only more easily oxidized but also more readily corroded than the alloyed Co. Compactness was identified as an important factor affecting CE resistance of coatings in deionized water, because defects facilitate the nucleation and eventual collapse of bubbles. Moreover, bubble collapse produced a transient high temperature spike in excess of 600 °C that also caused Co and Cr elements to oxidize. Because the CE tests were carried out in seawater, additional Co3O4 and Cr2O3 were generated owing to corrosion that more effectively increased the surface compactness and mechanical properties of the coatings. This behavior was particular notable for coatings with metallic Co and Cr, which should be why seawater corrosion could weaken the CE of Co-based coatings.

Effect of substrate preheating treatment on the microstructure and ultrasonic cavitation erosion behavior of plasma-sprayed YSZ coatings.

Inconel 718 was used as the substrate and preheated at different temperatures to deposit yttrium stabilized zirconia (denoted as YSZ) coatings by atmospheric plasma spraying. The microstructure of the as-deposited YSZ coatings and those after cavitation-erosion tests were characterized by field emission scanning electron microscopy, Raman spectroscopy, and their hardness and toughness as well as cavitation-erosion resistance were evaluated in relation to the effect of substrate preheating temperature. Results indicate that the as-deposited YSZ coatings exhibit typical layered structure and consist of columnar crystals. With the increase of the substrate preheating temperature, the compactness and cohesion strength of coatings are obviously enhanced, which result in the increases in the hardness, elastic modulus and toughness as well as cavitation-erosion resistance of the ceramic coatings therewith. Particularly, the YSZ coating deposited at a substrate preheating temperature of 800 °C exhibits the highest hardness and toughness as well as the strongest lamellar interfacial bonding and cavitation-erosion resistance (its cavitation-erosion life is as much as 8 times than that of deposited at room temperature).