西门子双源CT评估肺癌纵隔淋巴结转移的规律分析

目的采用双源CT(DSCT)对肺癌纵隔淋巴结转移的规律进行分析。 方法选择2019年1月至2021年6月我院收治的133例行DSCT检查的肺癌患者,分析淋巴结转移情况,对比已转移与未转移患者标准化点浓度(NIC),ROC曲线分析NIC对肺癌患者纵隔淋巴结转移的预测。 结果133例肺癌患者中纵隔淋巴结转移119例(89.47%),纵膈淋巴结分区转移率最高的区域为肺叶间淋巴结(75.94%),最低的区域为肺门淋巴结(2.26%)。单纯的N1、N2、N3及N2+N3转移率低(3.76%,3.76%,5.26%,3.01%)N1+N2转移率30.83%,N1+N2+N3转移率35.34%;发生转移患者动脉期、静脉期NIC水平明显低于未发生转移患者(P<0.05)。 结论肺癌纵隔淋巴结转移遵循由近向远、自肺门至纵隔、多站、逐站转移的规律,少见孤立性、跳跃性转移。DSCT能量成像参数定量分析,可作为术前判断肺癌患者重要指标之一。     

Role of miR-511 in the Regulation of OATP1B1 Expression by Free Fatty Acid

MicroRNAs (miRNAs) are a family of non-coding RNA that are able to adjust the expression of many proteins, including ATP-binding cassette transporter and organic cation transporter. We sought to evaluate the effect of miR-511 on the regulation of OATP1B1 expression by free fatty acids. When using free fatty acids to stimulate Chang liver cells, we found that the expression of miR-511 increased significantly while the expression of OATP1B1 decreased. We also proved that SLCO1B1 is the target gene of miR-511 with a bioinformatics analysis and using the dual luciferase reporter assay. Furthermore, the expressions of SLCO1B1 and OATP1B1 decreased if transfecting Chang liver cells with miR-511, but did not increase when transfecting the inhibitors of miR-511 into steatosis cells. Our study indicates that miR-511 may play an important role in the regulation of OATP1B1 expression by free fatty acids.     

Synthesis and Evaluation of a CBZ‐AAN‐Dox Prodrug and its in vitro Effects on SiHa Cervical Cancer Cells Under Hypoxic Conditions

Although doxorubicin (Dox) is widely used in clinical treatment for solid tumors, it causes many side‐effects such as heart and kidney damage, bone marrow suppression, and drug resistance. Legumain is a lysosomal protease that is elevated and associated with an invasive and metastatic phenotype in a number of solid tumors. In this study, we designed and synthesized a Dox prodrug, N‐benzyloxycarbonyl‐Ala‐Ala‐Asn‐Doxorubicin (CBZ‐AAN‐Dox), with 94% purity. Single substrate kinetic assays demonstrated hLegumain‐specific enzymatic cleavage and activation of the prodrug in vitro, and this enzymatic cleavage of the prodrug substrate was more sensitive in acidic conditions, releasing more than 70% of Dox after 24 h. Treatment of tumor cells with our prodrug demonstrated a much higher IC₅₀ value, significantly enhanced uptake of the prodrug, and considerably less cellular toxicity compared to Dox treatment alone. Our study presents a novel prodrug, CBZ‐AAN‐Dox, to potentially increase both the safety and efficacy of clinical treatment of tumors by exploiting the tumor's innate expression of legumain.     

Universally applicable,quantitative PCR method utilizing fluorescent nucleobase analogs

We herein describe a novel quantitative PCR (qPCR) method, which operates in both signal-off and on manners, by utilizing a unique property of fluorescent nucleobase analogs. The first, signal-off method is developed by designing the primers to contain pyrrolo-dC (PdC), one of the most common fluorescent nucleobase analogs. The specially designed single-stranded primer is extended to form double-stranded DNA during PCR and the fluorescence signal from the PdCs incorporated in the primer is accordingly reduced due to its conformation-dependent fluorescence properties. In addition, the second, signal-on method is devised by designing the primers to contain 5′-overhang sequences complementary to the PdC-incorporated DNA probes. At the initial phase, the PdC-incorporated DNA probes are hybridized to the 5′-overhang sequences of the primer, exhibiting the significantly quenched fluorescence signal, but are detached by either hydrolysis or strand displacement reaction during PCR, leading to the highly enhanced fluorescence signal. This method is more advanced than the first one since it produces signal-on fluorescence response and permits the use of a single PdC-incorporated DNA probe for the detection of multiple target nucleic acids, remarkably decreasing the assay cost. With these novel qPCR methods, we successfully quantified target nucleic acids derived from sexually transmitted disease (STD) pathogens with high accuracy. Importantly, the proposed strategies overcome the major drawbacks in the current SYBR Green and TaqMan probe-based qPCR methods such as low specificity and high assay cost.

A novel quantitative PCR (qPCR) method was developed by utilizing a unique property of fluorescent nucleobase analogs (PdCs).     

Effects of Maillard-type caseinate glycation on the preventive action of caseinate digests in acrylamide-induced intestinal barrier dysfunction in IEC-6 cells

Dietary acrylamide has attracted widespread concern due to its toxic effects; however, its adverse impact on the intestines is less assessed. Protein glycation of the Maillard-type is widely used for property modification, but its potential effect on preventive efficacy of protein digest against the acrylamide-induced intestinal barrier dysfunction is quite unknown. Caseinate was thus glycated with lactose. Two tryptic digests from the glycated caseinate and untreated caseinate (namely GCN digest and CN digest) were then assessed for their protective effects against acrylamide-induced intestinal barrier dysfunction in the IEC-6 cell model. The results showed that acrylamide at 1.25–10 mmol L⁻¹ dose-dependently had cytotoxic effects on IEC-6 cells, leading to decreased cell viability and increased lactate dehydrogenase release. Acrylamide also brought about barrier dysfunction, including decreased trans-epithelial electrical resistance (TEER) value and increased epithelial permeability. However, the two digests at 12.5–100 μg mL⁻¹ could alleviate this dysfunction via enhancing cell viability by 70.2–83.9%, partly restoring TEER values, and decreasing epithelial permeability from 100% to 76.6–94.1%. The two digests at 25 μg mL⁻¹ strengthened the tight junctions via increasing tight junction proteins ZO-1, occludin, and claudin-1 expression by 11.5–68.6%. However, the results also suggested that the GCN digest always showed lower protective efficacy than the CN digest in the cells. It is concluded that Maillard-type caseinate glycation with lactose endows the resultant tryptic digest with impaired preventive effect against acrylamide-induced intestinal barrier dysfunction, highlighting another adverse effect of the Maillard reaction on food proteins.

Glycated caseinate digest of the Maillard-type has lower protective action than caseinate digest against acrylamide-induced barrier dysfunction in IEC-6 cells.     

A Non-Geodesic Trajectory Design Method and Its Post-Processing for Robotic Filament Winding of Composite Tee Pipes

With the advantages of high specific strength and well corrosion resistance, polymer-matrix composite tee pipes are widely used in aerospace and civilian fields. The robotic filament winding technology is suitable for forming complex shape parts. This paper aims to provide a novel non-geodesic trajectory design method to get a continuous trajectory for tee pipe winding. Furthermore, post-processing methods are proposed for realizing the full coverage of tee pipes by robotic filament winding. The CAD/CAM software is then designed to simulate the winding process and realize the cover of the whole tee pipe. Finally, experiments of winding a tee pipe with a desktop winding machine and a six-axis winding robot are carried out. The results show that the tee pipe is fully covered, verifying the accuracy of the design method and post-processing methods.     

Evaluation of Micro-Mechanism and High- and Low-Temperature Rheological Properties of Disintegrated High Volume Crumb Rubber Asphalt (DHVRA)

The aims of this paper are to prepare disintegrated high volume crumb rubber asphalt (DHVRA) with low viscosity, good workability and low-temperature performance by adding disintegrating agent (DA) in the preparation process, and to further analyze the disintegrating mechanism and evaluated high-temperature and low-temperature rheological properties. To obtain DHVRA with excellent comprehensive performance, the optimum DA dosage was determined. Based on long-term disintegrating tests and the Fluorescence Microscopy (FM) method, the correlations between key indexes and crumb rubber (CR) particle diameter was analyzed, and the evaluation indicator and disintegrating stage division standard were put forward. Furthermore, Fourier transform infrared spectroscopy (FT-IR) and Gel Permeation Chromatography (GPC) was used to reveal the reaction mechanism, and the contact angle test method was adopted to evaluate the surface free energy (SFE). In addition, the high-temperature and low-temperature rheological properties were measured, and the optimum CR content was proposed. Results indicated that the optimum DA dosage was 7.5‰, and the addition of DA promoted the melt decomposition of CR, reduced the viscosity and improved the storage stability. The 135 °C rotational viscosity (RV) of DHVRA from mixing for 3 h could be reduced to 1.475 Pa·s, and the softening point difference was even less than 2 °C. The linear correlation between 135 °C RV and the diameter of CR particle in rubber asphalt system was as high as 0.968, and the viscosity decay rate (VDR) was used as the standard to divide the disintegrating process into a fast disintegrating stage, stable disintegrating stage and slight disintegrating stage. Compared to common rubber asphalt (CRA), DHVRA has an absorption peak at 960 cm⁻¹ caused by trans olefin = C-H, and higher molecular weight and polar component of surface energy. Compared with CRA, although the high-temperature performance of DHVRA decreases slightly, the low-temperature relaxation ability can be greatly improved.