Car-following Behavior Analysis of Left-turn Vehicles at Signalized Intersections

In order to enrich the car-following theory of urban signalized intersections, and reveal the car-following characteristics of left turn at signalized intersections, the car-following behavior of left turn at signalized intersections is studied. The car-following data acquisition test which was based on high precision GPS was designed. And the car-following characteristics of left-turning vehicles at signalized intersections with different turning radii were analyzed. Based on which, the influence of radius on the car-following behavior was explained, and the New Full Velocity Difference (NFVD) model was developed. The genetic algorithm was used to calibrate the parameters of the NFVD model. The stability and accuracy of the calibrated model was further analyzed by using field data. The results showed that the average speed of the following car increases with the turning radius of the signalized intersection; the car-following speed which the highest frequency occurs under different turning radii tends to increase with the enlargement of turning radius; the larger the average headway distance between the car-following vehicles, the more intense of the driver’s response to the deceleration of the front vehicle. These findings could be used in traffic simulation and to make engineering decisions

Microtissues Enhance Smooth Muscle Differentiation and Cell Viability of hADSCs for Three Dimensional Bioprinting

Smooth muscle differentiated human adipose derived stem cells (hADSCs) provide a crucial stem cell source for urinary tissue engineering, but the induction of hADSCs for smooth muscle differentiation still has several issues to overcome, including a relatively long induction time and equipment dependence, which limits access to abundant stem cells within a short period of time for further application. Three-dimensional (3D) bioprinting holds great promise in regenerative medicine due to its controllable construction of a designed 3D structure. When evenly mixed with bioink, stem cells can be spatially distributed within a bioprinted 3D structure, thus avoiding drawbacks such as, stem cell detachment in a conventional cell-scaffold strategy. Notwithstanding the advantages mentioned above, cell viability is often compromised during 3D bioprinting, which is often due to pressure during the bioprinting process. The objective of our study was to improve the efficiency of hADSC smooth muscle differentiation and cell viability of a 3D bioprinted structure. Here, we employed the hanging-drop method to generate hADSC microtissues in a smooth muscle inductive medium containing human transforming growth factor β1 and bioprinted the induced microtissues onto a 3D structure. After 3 days of smooth muscle induction, the expression of α-smooth muscle actin and smoothelin was higher in microtissues than in their counterpart monolayer cultured hADSCs, as confirmed by immunofluorescence and western blotting analysis. The semi-quantitative assay showed that the expression of α-smooth muscle actin (α-SMA) was 0.218 ± 0.077 in MTs and 0.082 ± 0.007 in Controls; smoothelin expression was 0.319 ± 0.02 in MTs and 0.178 ± 0.06 in Controls. Induced MTs maintained their phenotype after the bioprinting process. Live/dead and cell count kit 8 assays showed that cell viability and cell proliferation in the 3D structure printed with microtissues were higher at all time points compared to the conventional single-cell bioprinting strategy (mean cell viability was 88.16 ± 3.98 vs. 61.76 ± 15% for microtissues and single-cells, respectively). These results provide a novel way to enhance the smooth muscle differentiation of hADSCs and a simple method to maintain better cell viability in 3D bioprinting

The role of ERK1/2 in colitis through regulation of NADPH oxidase and mitochondrial fission

Objective To investigate the role of extracellular signal regulated kinase 1/2 （ERK1/2） in colitis through the regulation of NADPH oxidase and mitochondrial fission. Methods Mice models of acute colitis were induced by 3% dextran sulfate sodium （DSS）. Thirty C57BL/6J mice were randomly divided into six groups by random number table method： control group， 3%DSS group，1% dimethyl sulfoxide （DMSO） group， ERK1/2 inhibitor（PD98059） group， 3%DSS+1%DMSO group and 3%DSS+PD98059 group， with five mice in each group. The changes of body weight， colonic length， disease activity index and colonic histopathological changes of mice in the control and 3%DSS groups were evaluated， and the expression levels of ERK1/2， p-ERK1/2， Nicotinamide adenine dinucleotide phosphate oxidase 1 （Nox1） and Nox2 in colonic mucosa of mice were detected. Mice in 1%DMSO and 3%DSS+1%DMSO groups were intraperitoneally injected with 1%DMSO. Mice in the PD98059 and 3%DSS+PD98059 groups were intraperitoneally injected with PD98059. The colonic histopathological changes were evaluated among four groups， and the expression levels of Nox1， Nox2， Dynamin related protein 1 （DRP1）， p-DRP1-S616 and p-DRP1-S637 mitochondrial fission related proteins were detected. Mitochondrial fission of colonic epithelial cells in the control and 3%DSS groups was observed by transmission electron microscopy. The co-localization of Nox2 and mitochondrial outer membrane translocator enzyme TOM complex （TOMM20） in colonic mucosa of mice in two groups was analyzed by double-immunofluorescence staining. The correlation between relative expression levels of DRP1 and Nox2 mRNA in mouse colonic mucosa was analyzed in two groups. Results Compared with the control group， mice in the 3%DSS group exhibited body weight loss， shortened colonic length， increased disease activity index and increased colonic histopathological score. The expression levels of p-ERK1/2， Nox1， Nox2 in colonic mucosa of mice were significantly up-regulated in the 3%DSS group （all P < 0.05）. In mice with colitis， mitochondrial fission in colonic epithelial cells was increased， and the colonic mucosa co-localization of DRP1 and Nox2 was elevated， and the relative mRNA expression levels of both target genes were positively correlated （r = 0.678， P < 0.05）. ERK1/2 inhibitor PD98059 improved colonic histopathological changes in mice with colitis， and down-regulated the expression levels of Nox1， Nox2， DRP1， p-DRP1-S616 in colonic mucosa. Conclusion Inhibition of ERK1/2 may ameliorate colitis by down-regulating NADPH oxidase expression and alleviating mitochondrial fission

Study protocol of a phase II clinical trial evaluating the efficacy of neoadjuvant intraperitoneal and systemic albumin-bound paclitaxel combined with camrelizumab and S-1 in the treatment of patients with exfoliative cell-positive gastric cancer

BackgroundCurrently, gastric cancer with positive lavage cytology without gross peritoneal dissemination (GC-CY1) is a special type of metastatic form with poor prognosis. Consensus guidelines on treatment strategies for patients with GC-CY1 have not been established. This study involves a single-arm, prospective, phase II clinical trial to examine the efficacy and safety of neoadjuvant intraperitoneal and systemic (NIPS) albumin-bound paclitaxel combined with Camrelizumab and S-1 in the treatment of GC-CY1 patients.Methods/designThis is a prospective single-center exploratory study, and the primary endpoints of the trial are R0 resection rate and conversion rate of abdominal free cancer cells (FCCs), with secondary endpoints of 3-year progression-free survival (PFS); 3-year overall survival (OS); objective remission rate (ORR); disease control rate (DCR); safety and TRG classification.DiscussionThis study is the first to apply NIPS albumin-bound paclitaxel combined with Camrelizumab and S-1 to the conversion therapy of GC-CY1 patients. It is speculated that this combination of regimens will increase the negative conversion rate of FCCs by 20%, which will provide innovative insights into conversion treatment ideas for GC-CY1 patients to be managed in a more comprehensive and optimized manner.Clinical trial registrationhttp://clinicaltrials.gov/, identifier NCT05410847

Long-term effect of transurethral partial cystectomy with a 2-micrometer continuous-wave laser for non-muscle-invasive bladder cancer

PurposeWe have reported the efficacy and safety of 2-micrometer continuous-wave laser cystectomy of non-muscle invasive bladder tumor (NMIBC) (J Urol. 2009;182:66–9). In this study, we evaluated the long-term outcomes of patients with NMIBC who underwent transurethral partial cystectomy with a 2-micrometer continuous-wave laser, and explored the risk factors for tumor recurrence.MethodsThis was a retrospective study of patients with NMIBC planned to undergo transurethral partial cystectomy with a 2-micrometer continuous-wave laser at the Fourth Medical Center of the PLA General Hospital between January 2012 and December 2014. The primary outcome was bladder cancer recurrence.ResultsA total of 75 patients were enrolled. Sixty-two (82.7%) were male. The patients were 59.8 ± 12.9 years of age. The mean operation time was 38.7 ± 20.4 min. No Clavien grade >2 complications occurred. The duration of catheter indwelling was 3.6 ± 1.8 days. The hospital stay was 6.0 ± 2.3 days. The median follow-up was 80 months. A total of 17 patients had a recurrence during follow-up, and the recurrence-free survival (RFS) rate was 77.3%. In the multivariable analysis, the tumor risk group were independently associated with the recurrence of NMIBC (p = 0.026).ConclusionsAfter TURBT with a 2-micrometer continuous-wave laser, RFS was 77.3% at the median follow-up of 80 months. All complications were mild. Only tumor risk group was independently associated with the recurrence of NMIBC