Friction injury of the central vein caused by catheter for hemodialysis: an in vitro study.

Vascular injury such as central venous stenosis (CVS) is a common complication in hemodialysis patients with central venous catheters (CVCs), yet the impact of the microstructure and partial physic characteristics of catheter surface on the chronic injury of central vein has not been elucidated. In this study, the microscopic morphology of tips and bodies of six different brands of polyurethane CVCs was observed and their roughness was assessed. Subsequently, an in vitro model was established to measure the coefficients of friction (COF) between CVCs (tips and bodies) and the vena cava intima of Japanese rabbits under the same condition in a linear reciprocating mode, and changes in the intima of vessels after friction were observed. The study found that there was a significant variation in surface roughness among different brands of CVCs (tips P < 0.001, bodies P = 0.02), and the COF was positively correlated with the catheter surface roughness (tips P = 0.005, R = 0.945, bodies P = 0.01, R = 0.909). Besides, the endovascular roughness increased after friction. These findings suggest that the high roughness surface of CVCs may cause chronic mechanical friction injury to the central venous intima, which is one of the potential factors leading to CVS or occlusion. This provides a breakthrough for reducing complications, improving patient prognosis, and advancing catheter surface lubrication technology.

High-Resolution Mapping of Material Stocks in Belgian Road Infrastructure: Material Efficiency Patterns, Material Recycling Potentials, and Greenhouse Gas Emissions Reduction Opportunities.

Road infrastructure is an integral part of built environment stocks, as it delivers essential social and economic services. While previous work has assessed material stocks, flows, and embodied emissions, spatially refined mapping of materials accumulated in road infrastructure can highlight hitherto underappreciated synergies between improved spatial planning, material stock efficiency, and urban mining. In this study, we mapped the materials stocked in road infrastructure across Belgium, explored the patterns of material stock efficiency and the recyclability of end-of-life road materials, and examined the greenhouse gas (GHG) emissions reductions of improving stock efficiency and recycling. We assembled data scattered across various governmental sources and crowdsourced platforms and developed a comprehensive database to warehouse locational information on road typology, layer geometry and thickness, material characteristics, traffic volume, climatic conditions, and soil conditions. Our results reveal a strong but nonlinear correlation between material stock efficiency and population density, indicating that spatial planning can reduce the required road stocks and associated GHG emissions. Urban mining potentials in road infrastructure hinge on multiple factors, such as the proximity to recycling facilities and the degradation of pavements during use. Our counterfactual analysis shows that urban road planning and reusing recycled asphalt can cut GHG emissions by up to 53 and 70%, respectively. Therefore, material-efficient road planning and improved material recycling can help realize circular economy potentials and mitigate GHG emissions moving forward.

Expression of VEGFR-2 and Meis1 in the early stage of kidney cancers and its clinical significance. / Meis1与VEGFR-2åœ¨æ—©æœŸè‚¾ç™Œç»„ç»‡ä¸­çš„è¡¨è¾¾åŠå ¶ä¸´åºŠæ„ä¹‰.

OBJECTIVES: To evaluate the expression of myeloid ecotropic viral integration site 1 (Meis1) and vascular endothelial growth factor receptor 2 (VEGFR-2) in early-stage kidney cancers and the clinical significance. METHODS: The cancer tissues and the matched adjacent normal tissues in patients with kidney cancer, who received surgical treatment from April 2005 to September 2018 in the Haikou Hospital Affiliated to Xiangya School of Medicine, Central South University, were collected. The samples included 80 pairs of paraffin specimen, 15 pairs of fresh cancer and the matched adjacent normal tissues from these patients. Real-time PCR and immunohistochemical method were used to detect the expression levels of Meis1 and VEGFR-2 mRNA and protein in kidney tissues and adjacent normal tissues, and the correlation of clinical pathology parameters and the prognosis were analyzed in the patients. RESULTS: The expression levels of Meis1 and VEGFR-2 mRNA and protein in the renal carcinoma tissues were lower than those in the matched adjacent normal tissues (both P<0.01), and the expression levels of Meis1 were positively correlated with that of VEGFR-2 (r=0.681, P<0.01). The analysis of relevant clinical-pathological parameters in the patients showed that: the expression positive rate of Meis1 was significantly related with the pathological type of renal cancer (P<0.01), while the positive rate of Meis1 and VEGFR-2 expression was not related with the gender, age, T stage of patients (all P>0.05), but it was significantly related with the prognosis in the patients (P<0.05). Cox regression analysis showed that: Meis1 was an independent factor for the prognosis of patients (P<0.05). CONCLUSIONS: The mRNA and protein expression levels of Meis1 and VEGFR-2 in the early-stage kidney cancer tissues are significantly decreased compared with those in the adjacent normal tissues. Meis1 may be served as a tumor suppressor to affect the occurrence and development of kidney cancer. Therefore, Meis1 may be used as a biomarker to predict the prognosis of patients with kidney cancer.

Decreased expression of apoptosis-inducing factor in renal cell carcinoma is associated with poor prognosis and reduced postoperative survival.

Apoptosis-inducing factor (AIF) serves a crucial role in cell death and is involved in several types of cancer, including kidney cancer. The present study aimed to explore the association between AIF expression and patient survival based on tumor grades. AIF expression in 96 patients with renal cell carcinoma (RCC) was investigated using immunohistochemistry. Negative AIF expression was determined in 80 patients (83.3%). mRNA expression of AIF was analyzed in RCC and adjacent tissue samples from 15 patients. AIF mRNA expression in RCC tissues were significantly lower compared with that in adjacent tissues. Analysis of histopathological grades revealed that AIF expression was negatively associated with RCC grade, with AIF expression in Grade II tumors being lower than Grade I types, but higher than Grade III. Finally, 68 patients were followed up for 6-118 months, and it was revealed that the overall postoperative survival rate of patients with negative AIF expression was significantly lower compared with those those with positive AIF expression. These results suggest that decreased AIF expression could be associated with worsening RCC grade. Therefore, reduced AIF expression may potentially help diagnose RCC and distinguish tumor grades.

Bacterial Adhesion to Ultrafiltration Membranes: Role of Hydrophilicity, Natural Organic Matter, and Cell-Surface Macromolecules.

Insight into the mechanisms underlying bacterial adhesion is critical to the formulation of membrane biofouling control strategies. Using AFM-based single-cell force spectroscopy, we investigated the interaction between Pseudomonas fluorescens, a biofilm-forming bacterium, and polysulfone (PSF) ultrafiltration (UF) membranes to unravel the mechanisms underlying early stage membrane biofouling. We show that hydrophilic polydopamine (PDA) coatings decrease bacterial adhesion forces at short bacterium-membrane contact times. Further, we find that adhesion forces are weakened by the presence of natural organic matter (NOM) conditioning films, owing to the hydrophilicity of NOM. Investigation of the effect of adhesion contact time revealed that PDA coatings are less effective at preventing bioadhesion when the contact time is prolonged to 2-5 s, or when the membranes are exposed to bacterial suspensions under stirring. These results therefore challenge the notion that simple hydrophilic surface coatings are effective as a biofouling control strategy. Finally, we present evidence that adhesion to the UF membrane surface is mediated by cell-surface macromolecules (likely to be outer membrane proteins and pili) which, upon contacting the membrane, undergo surface-induced unfolding.

Rapid determination of 88 veterinary drug residues in milk using automated TurborFlow online clean-up mode coupled to liquid chromatography-tandem mass spectrometry.

A novel method based on TurborFlow online solid phase extraction (SPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been established for simultaneous screening and confirmation of 88 wide-range veterinary drugs belonging to eight families (20 sulfonamides, 7 macrolides, 15 quinolones, 8 penicillins, 13 benzimidazoles, 4 tetracyclines, 2 sedatives, and 19 hormones) in milk. The preparation method consists of sample dilution and ultrasonic extraction, followed by an automated turbulent flow cyclone chromatography sample clean-up system. The detection was achieved in selected reaction monitoring mode (SRM). The total run time was within 39 min, including automated extraction, analytical chromatography and re-equilibration of the turboflow system. The optimization of different experimental parameters including extraction, purification, separation, and detection were evaluated separately in this study. The developed method was validated and good performing characteristics were obtained. The linear regression coefficients (R(2)) of matrix-match calibration standard curves established for quantification were higher than 0.9930. The limits of detection (LOD) were in the range of 0.2-2.0 µg/kg given by signal-noise ratio ≥3 (S/N) and the limits of quantification (LOQ, S/N≥10) ranged between 0.5 µg/kg and 10 µg/kg. Average recoveries of spiked target compounds with different levels were between 63.1% and 117.4%, with percentage relative standard deviations (RSD) in the range of 3.3-17.6%. The results indicated that the developed method has great potential for the routine laboratory analysis of large numbers of samples on measuring different classes of compounds. In comparison to traditional procedures, the automated sample clean-up ensures rapid, effective, sensitive analyses of veterinary drugs in milk.

Ultra-broadband near-infrared excitable upconversion core/shell nanocrystals.

Monodisperse Er(3+):NaGdF(4)@Ho(3+):NaGdF(4)@NaGdF(4) active-core/active-shell/inert-shell nanocrystals, which can extend the near-infrared wavelength excitable range for upconversion (UC) emissions, were successfully fabricated for the first time. Importantly, doping of Er(3+) and Ho(3+) into the core and shell respectively suppresses adverse energy transfers between them, resulting in intense UC emissions for both Er(3+) and Ho(3+) dopants.

Monodisperse upconversion Er3+/Yb3+:MFCl (M = Ca, Sr, Ba) nanocrystals synthesized via a seed-based chlorination route.

Monodisperse Yb(3+)/Er(3+):MFCl nanocrystals were fabricated via a simple and effective seed-based chlorination route for the first time. Remarkably, their upconversion emissions are found to be greatly intensified compared with those of the well-reported Er(3+)/Yb(3+):SrF(2) with the same size and shape.