Rheological Properties of Warm Mix Asphalt Binders and Warm Mix Asphalt Binders Containing Polyphosphoric Acid

This paper presents the laboratory investigation of properties of warm mix asphalt (WMA) binders and WMA binders containing polyphosphoric acid (PPA).Two types of warm mix additives were used to produce the WMA binders. Superpave tests were carried out on original and short-term aged binders through the rotational viscometer, the dynamic shear rheometer (DSR), and the bending beam rheometer (BBR). The results indicated that the WMA binders with different warm mix additives showed different viscosity values, however, the addition of PPA remarkably increased the viscosity values of these two kinds of WMA binders used, in the present study, to a similar level. The WMA additive type and the PPA had significant effects on the complex modulus (G*), phase angle (δ) and G∗/sinδ regardless of the binders\u27 aging state (without aging or short-term aging). In addition, two WMA binders with different additive types showed significant differences on the creep stiffness and m-value, and the addition of PPA degraded the low temperature rheological properties of the WMA binders

A Study on Public Adoption of Robo-Taxis in China

Autonomous vehicles (AVs) have been reported to improve road safety, reduce traffic congestion, and increase urban mobility. However, the high price of AVs is currently a challenge for most consumers. Robo-taxi services, with ride-sharing services and AVs, are regarded as a good approach to solving this problem. As some companies have started testing Robo-taxis on the actual road, it has become important to investigate public adoption of Robo-taxi services before they are more widely introduced to the market. This study aims to explain and predict users’ acceptance of Robo-taxis by extending the Technology Acceptance Model by including the construct of social influence. Data were collected from an online survey in China and analyzed using linear regression models. The results indicate that perceived usefulness, perceived ease of use, and social influence have significant positive correlations with people’s behavior intentions to use Robo-taxis. Perceived ease of use further has an indirect effect on intention to use via perceived usefulness. The results of this study can serve as good references for policymakers, operators, and future transport researchers. Document type: Articl

Cytoplasmic p21 is a potential predictor for cisplatin sensitivity in ovarian cancer

<p>Abstract</p> <p>Background</p> <p>P21^(WAF1/Cip1)binds to cyclin-dependent kinase complexes and inhibits their activities. It was originally described as an inhibitor of cancer cell proliferation. However, many recent studies have shown that p21 promotes tumor progression when accumulated in the cell cytoplasm. So far, little is known about the correlation between cytoplasmic p21 and drug resistance. This study was aimed to investigate the role of p21 in the cisplatin resistance of ovarian cancer.</p> <p>Methods</p> <p>RT-PCR, western blot and immunofluorescence were used to detect p21 expression and location in cisplatin-resistant ovarian cancer cell line C13* and its parental line OV2008. Regulation of cytoplasmic p21 was performed through transfection of p21 siRNA, Akt2 shRNA and Akt2 constitutively active vector in the two cell lines; their effects on cisplatin-induced apoptosis were evaluated by flow cytometry. Tumor tissue sections of clinical samples were analyzed by immunohistochemistry.</p> <p>Results</p> <p>p21 predominantly localizes to the cytoplasm in C13* compared to OV2008. Persistent exposure to low dose cisplatin in OV2008 leads to p21 translocation from nuclear to cytoplasm, while it had not impact on p21 localization in C13*. Knockdown of cytoplasmic p21 by p21 siRNA transfection in C13* notably increased cisplatin-induced apoptosis through activation of caspase 3. Inhibition of p21 translocation into the cytoplasm by transfection of Akt2 shRNA into C13* cells significantly increased cisplatin-induced apoptosis, while induction of p21 translocation into the cytoplasm by transfection of constitutively active Akt2 in OV2008 enhanced the resistance to cisplatin. Immunohistochemical analysis of clinical ovarian tumor tissues demonstrated that cytoplasmic p21 was negatively correlated with the response to cisplatin based treatment.</p> <p>Conclusions</p> <p>Cytoplasmic p21 is a novel biomarker of cisplatin resistance and it may represent a potential therapeutic target for ovarian tumors that are refractory to conventional treatment.</p

Mesenchymal stem cells as carriers and amplifiers in CRAd delivery to tumors

<p>Abstract</p> <p>Background</p> <p>Mesenchymal stem cells (MSCs) have been considered to be the attractive vehicles for delivering therapeutic agents toward various tumor diseases. This study was to explore the distribution pattern, kinetic delivery of adenovirus, and therapeutic efficacy of the MSC loading of E1A mutant conditionally replicative adenovirus Adv-Stat3(-) which selectively replicated and expressed high levels of anti-sense Stat3 complementary DNA in breast cancer and melanoma cells.</p> <p>Methods</p> <p>We assessed the release ability of conditionally replicative adenovirus (CRAd) from MSC using crystal violet staining, TCID₅₀assay, and quantitative PCR. In vitro killing competence of MSCs carrying Adv-Stat3(-) toward breast cancer and melanoma was performed using co-culture system of transwell plates. We examined tumor tropism of MSC by Prussian blue staining and immunofluorescence. In vivo killing competence of MSCs carrying Adv-Stat3(-) toward breast tumor was analyzed by comparison of tumor volumes and survival periods.</p> <p>Results</p> <p>Adv-Stat3(-) amplified in MSCs and were released 4 days after infection. MSCs carrying Adv-Stat3(-) caused viral amplification, depletion of Stat3 and its downstream proteins, and led to significant apoptosis in breast cancer and melanoma cell lines. In vivo experiments confirmed the preferential localization of MSCs in the tumor periphery 24 hours after tail vein injection, and this localization was mainly detected in the tumor parenchyma after 72 hours. Intravenous injection of MSCs carrying Adv-Stat3(-) suppressed the Stat3 pathway, down-regulated Ki67 expression, and recruited CD11b-positive cells in the local tumor, inhibiting tumor growth and increasing the survival of tumor-bearing mice.</p> <p>Conclusions</p> <p>These results indicate that MSCs migrate to the tumor site in a time-dependent manner and could be an effective platform for the targeted delivery of CRAd and the amplification of tumor killing effects.</p

Comprehensive analysis of the association between inflammation indexes and complications in patients undergoing pancreaticoduodenectomy

BackgroundDuring clinical practice, routine blood tests are commonly performed following pancreaticoduodenectomy (PD). However, the relationship between blood cell counts, inflammation-related indices, and postoperative complications remains unclear.MethodWe conducted a retrospective study, including patients who underwent PD from October 2018 to July 2023 at the First Hospital of Chongqing Medical University, and compared baseline characteristics and clinical outcomes among different groups. Neutrophil count (NC), platelet count (PLT), lymphocyte count (LC), systemic immune-inflammation index (SII), platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), and the product of platelet count and neutrophil count (PPN) were derived from postoperative blood test results. We investigated the association between these indicators and outcomes using multivariable logistic regression and restricted cubic spline analysis. The predictive performance of these indicators was assessed by the area under the curve (AUC) of the receiver operating characteristic (ROC) curve and decision curve analysis (DCA).ResultA total of 232 patients were included in this study. Multivariate logistic regression and restricted cubic spline analysis showed that all indicators, except for PLT, were associated with clinical postoperative pancreatic fistula (POPF). SII, NLR, and NC were linked to surgical site infection (SSI), while SII, NLR, and PLR were correlated with CD3 complication. PLT levels were related to postoperative hemorrhage. SII (AUC: 0.729), NLR (AUC: 0.713), and NC (AUC: 0.706) effectively predicted clinical POPF.ConclusionIn patients undergoing PD, postoperative inflammation-related indices and blood cell counts are associated with various complications. NLR and PLT can serve as primary indicators post-surgery for monitoring complications

Statistical applications to cardiovascular disease research

Cardiovascular disease (CVD) is the most frequent cause of deaths worldwide [1]. Scien-tists have done and are stilling doing a high volume of research on this area, hoping to help people who are already suffering from the disease and also to prevent those at high risk of getting CVD. Statistical applications play a very important role in most of these research activities and a better utilization of the right statistical methodology for a specif-ic study would definitely make the research outcomes more reliable and eventually being beneficial to the human kind. This dissertation studies several scenarios in cardiovascular disease research where traditional statistical methods may not be applicable. And we pro-posed corresponding practical solutions or modifications to existing methods to better fit the problems case by case. In the first part, we are focusing on using the gain in life expectancy to assess the treat-ment effect of an antihypertensive therapy for stroke. We first propose a framework for estimating this quantity by calculating the area between estimated survival curves given by two comparative treatments. And then, in order to better assess the variability of our estimate especially with small sample size, we propose a new bootstrap method for ob-taining confidence interval for this quantity. We also propose the corresponding bootstrap testing procedure to test the null hypothesis. The second part of the dissertation is about meta-analysis in CVD research. We discover the non-normal behavior of the test statistics when sample size in each study of the meta-analysis is small. We use t distribution to approximate the underlying distribution and propose a simple formula to calculate the degree of freedom of the t distribution based on the sample size in each study as well as the number of studies. Finally, we modify a new clinical design called Simultaneous Global Drug Development Program (SGDDP) which can be more efficient for evaluating the treatment effect on diseases such as CVD where ethnicity have a potential impact. We add an additional as-sumption to the original test to make it unbiased. We also show the performance of the program after the modification.Ph. D.Includes bibliographical referencesby Kezhen Li

Rheological Characteristics of Polyphosphoric Acid-Modified Asphalt Mastic

In this study, a dynamic shear rheometer (DSR) and bending beam rheometer (BBR) were employed to characterize the rheological properties of asphalt modified with polyphosphoric acid (PPA) and containing different mineral fillers, forming a material referred to as asphalt mastic. Pulverized limestone filler (PLF), portland cement (PC), and hydrated lime (HL) were selected as mineral fillers. Filler-to-binder (F/A) ratios of 0.6, 0.9, 1.2, and 1.5 were chosen, which are defined as the weight ratio of filler and asphalt binder. The effects of F/A ratio and filler type on the complex shear modulus, phase angle, rutting parameter, fatigue parameter, m-value, and creep stiffness of various PPA-modified asphalt mastics were studied. Regression functions were built to express the relations between rutting parameter, fatigue parameter, creep stiffness, and F/A. The results indicated that the F/A significantly affected the stiffness of the modified asphalt mastic regardless of testing temperature, but had little effect on m-value at low temperatures. The modified asphalt mastics with different fillers showed different stiffness values but almost the same phase angle at the identical testing temperature

Effects of Prescribed Fire on Meadow Soil Chemical Properties in Nanwenghe Nature Reserve

The Nanwenghe Nature Reserve is located in the Daxing’anling forest region, which is abundant meadow resource which is prone to fire in fire season every year. In this paper, the change in the soil chemical properties of burned stands was emphasized. The results showed that: (1) Soil organic matter (SOM) concentration in burned stands showed an extremely significant difference from that in the control stands (p p p > 0.05). (3) Available K, total N, total P and total K concentration showed no significant difference from June to September. The pH values increased with a variance of 8%, and pH values in July, August and September were significantly different from those in June. SOM concentrations obtained in July, August and September increased significantly, compared to the concentrations in June (p < 0.05). Alkali-hydrolysable N showed a decreasing trend for all conditions

A Study on the Transmission Line Transient Protection Containing Static Synchronous Compensator

This paper focuses on the transient protection of transmission line with FACTS Devices; the principle and mathematical model of static synchronous compensator (STATCOM) has been analyzed. And feasible control strategy has been pro-posed considering the voltage source inverter (VSI) as a core part of the FACTS components. The simulation results verify the rightness using electromagnetic transient simulation software PSCAD/EMTDC to set up electromagnetic transient model