Cold-mixed epoxy bitumen (CEB) has been presented as an eco-friendly paving material used for steel bridge deck pavements. This study performed an investigation on three preparation methods of CEBs, ...which includes one kind of three-component and two kinds of two-component methods. The curing process was characterized through the viscosity measurement. Meanwhile, the microstructure of CEBs was observed using fluorescence microscopy. Mechanical properties of CEBs prepared with different methods were characterized by employing direct tensile tests and dynamic mechanical analysis (DMA). Finally, thermogravimetric analysis (TGA/DTG) was conducted to feature the thermal stability of CEBs. The results indicated that the preparation methods significantly affected the performance of cured CEBs, although the same mix design was adopted. The curing temperature determined the curing rate of CEBs, while the preparation methods dominated the morphological characteristic of cured CEBs. The three-component preparation method can achieve acceptable mechanical performance for engineering requirements. As for two-component methods, the curing agent is supposed to be mixed with bitumen to obtain satisfying microstructures of CEBs.
To accurately predict the eddy current loss of silicon steel laminations over broadband frequency range, an improved parametric magneto dynamic model (IPMD) is proposed in this paper. According to ...the nonuniform distribution of magnetic field in the cross-section of the silicon steel lamination under high-frequency magnetization, the analysis area of the lamination is divided into several slices by nonlinear segmentation, wherein each slice the magnetic field distribution is regarded as uniform. Meanwhile, to accelerate the calculation speed of the IPMD model, the relationship between skin depth and slice number is deduced and verified. Furthermore, the Tellinen (TLN) hysteresis model is used when implementing the IPMD model to further increase the accuracy of eddy current loss calculation.
BRASSINAZOLE-RESISTANT (BZR) is a class of specific transcription factor (TFs) involved in brassinosteroid (BR) signal transduction. The regulatory mechanism of target genes mediated by BZR has ...become one of the key research areas in plant BR signaling networks. However, the functions of the BZR gene family in cucumber have not been well characterized.
In this study, six CsBZR gene family members were identified by analyzing the conserved domain of BES1 N in the cucumber genome. The size of CsBZR proteins ranges from 311 to 698 amino acids and are mostly located in the nucleus. Phylogenetic analysis divided CsBZR genes into three subgroups. The gene structure and conserved domain showed that the BZR genes domain in the same group was conserved. Cis-acting element analysis showed that cucumber BZR genes were mainly involved in hormone response, stress response and growth regulation. The qRT-PCR results also confirmed CsBZR response to hormones and abiotic stress.
Collectively, the CsBZR gene is involved in regulating cucumber growth and development, particularly in hormone response and response to abiotic stress. These findings provide valuable information for understanding the structure and expression patterns of BZR genes.
Cholangiocarcinoma (CCA) is the second most common hepatic malignancy. Progress and developments have also been made in the field of CCA management along with increasing scientific publications ...during the past decades, which reflect topics of general interest and suggest the future direction of studies. The purpose of this bibliometric study is to summarize scientific publications during the past 25 years in the field of CCA using a machine learning method.
Scientific publications focusing on CCA from 1995 to 2019 were searched in PubMed using the MeSH term "cholangiocarcinoma." Full associated data were downloaded in the format of PubMed and extracted in the R platform. Latent Dirichlet allocation (LDA) was adopted to identify the research topics from the abstract of each publication using Python.
A total of 8,276 publications related to CCA from the last 25 years were found and included in this study. The most type of publications remained little changed, while the proportion of clinical trials remained relatively low (7.24% as the highest) and, more significantly, with a further downward trend during the recent years (1.42% in 2019). Neoplasm staging, hepatectomy, and survival rate were the most concerning terms among those who are diagnosis-related, treatment-related, and prognosis-related. The LDA analyses showed chemotherapy, hepatectomy, and stent as the highly concerned research topics of CCA treatment. Meanwhile, conversions from basic studies to clinical therapies were suggested by a poor connection between clusters of treatment management and basic research.
The number of publications of CCA has increased rapidly during the past 25 years. Survival analysis, differential diagnosis, and microRNA expression are the most concerned topics in CCA studies. Besides, there is an urgent need for high-quality clinical trials and conversions from basic studies to clinical therapies.
The wet carbonation process of steel slag (SS) is envisaged to be an effective way to sequestrate CO
and improve the properties of SS as a supplementary cementitious material. However, the ...carbonation process still struggles with having a low carbonation efficiency. This paper studied the effect of glycine on the accelerated carbonation of SS. The phase composition change of carbonated SS was analyzed via XRD, FT-IR, and TG-DTG. The carbonation process of SS is facilitated by the assistance of glycine, with which the carbonation degree is increased. After 60 min of carbonation, SS with glycine obtained a CO
sequestration rate of 9.42%. Meanwhile, the carbonation reaction could decrease the content of free calcium oxide in SS. This significantly improves the soundness of SS-cement cementitious material, and the compressive strength of cementitious materials that contain carbonated SS with glycine is improved. Additionally, the cycling performance of glycine in the successive wet carbonation process of SS was investigated. Multicycle experiments via solvent recovery demonstrated that although the promotion effect of glycine was reduced after each cycle, compared with the SS-water system, the carbonation process could still be facilitated, demonstrating that successive wet carbonation via solvent recovery has considerable potential. Herein, we provide a new idea to facilitate the wet carbonation process of SS and improve the properties of SS-cement cementitious material.
Silica nanoparticles (SiNPs) with a chemically modified surface typically have a complicated chemical composition, which can significantly differ from their intended design. In this study, we ...systematically studied the effects of two surface modification methods on active-targeting of intracellular organelles of SiNPs: (1) the widely used step-by-step approach, which involves modifying SiNPs in two steps, i.e., the outer surface of SiNPs was firstly modified with amino groups and then these amino groups were linked with targeting groups, and (2) a newly developed one-step approach in which the ligand–silane complex is initially synthesized, followed by chemically immobilizing the complex on the surface of SiNPs. In the one-step approach, the molar ratio of reactants was precisely tuned so that there are no reactive groups left on the outer surface of SiNPs. Two essential organelles, mitochondria and the nucleus, were selected to compare the targeting performances of SiNPs synthesized via these two approaches. By characterizing physicochemical properties, including structural properties, the number of amino groups, surface charge, polydispersity, and cell colocalization, we demonstrated that SiNPs synthesized via the one-step approach with no residual linkage groups on their surface showed significantly improved mitochondria- and nucleus-targeting performances. This precise control of surface properties allows for optimized biological behavior and active-targeting efficiency of SiNPs. We anticipate that such simple and efficient synthetic strategies will enable the synthesis of effective SiNPs for active-targeting organelles in various biological applications.
Graphical abstract
Lignin accounts for approximately 30% of the weight of herbaceous biomass. Utilizing lignin in asphalt pavement industry could enhance the performance of pavement while balancing the construction ...cost. This study aims to evaluate the feasibility of utilizing lignin as a bitumen performance improver. For this purpose, lignin derived from aspen wood chips (labeled as KL) and corn stalk residues (labeled as CL) were selected to prepare the lignin modified bituminous binder. The properties of the lignin modified binder were investigated through rheological, mechanical and chemical tests. The multiple stress creep recovery (MSCR) test results indicated that adding lignin decreased the J
of based binder by a range of 8% to 23% depending on the stress and lignin type. Lignin showed a positive effect on the low temperature performance of asphalt binder, because at -18 °C, KL and CL were able to reduce the stiffness of base binder from 441 MPa to 369 MPa and 378 MPa, respectively. However, lignin was found to deteriorate the fatigue life and workability of base binder up to 30% and 126%. With bituminous mixture, application of lignin modifiers improved the Marshall Stability and moisture resistance of base mixture up to 21% and 13%, respectively. Although, adding lignin modifiers decreased the molecular weight of asphalt binder according to the gel permeation chromatography (GPC) test results. The Fourier-transform infrared spectroscopy (FTIR) test results did not report detectable changes in functional group of based binder.
Fatigue performance is one of the most important properties that affect the service life of asphalt mixture. Many fatigue test methods have been developed to evaluate the fatigue performance in the ...lab. Although these methods have contributed a lot to the fatigue performance evaluation and the development of fatigue related theory and model, their limitations should not be ignored. This paper starts by characterizing the stress state in asphalt pavement under a rolling wheel load. After that, a literature survey focusing on the experimental methods for fatigue performance evaluation is conducted. The working mechanism, applications, benefits, and limitations of each method are summarized. The literature survey results reveal that most of the lab test methods primarily focus on the fatigue performance of asphalt mixture on a material level without considering the effects of pavement structure. In addition, the stress state in the lab samples and the loading speed differ from those of asphalt mixture under rolling wheel tire load. To address these limitations, this paper proposes the concept of an innovative lab fatigue test device named Accelerated Repeated Rolling Wheel Load Simulator (ARROWS). The motivation, concept, and working mechanism of the ARROWS are introduced later in this paper. The ARROWS, which is under construction, is expected to be a feasible and effective method to simulate the repeated roll wheel load in the laboratory.
Practicing in unprecedented working environment and fighting against the COVID-19 crisis influenced the image of nursing in the general population, as well as among nurses themselves. This study ...aimed to describe the sense of professional identity among Chinese nursing students during the COVID-19 outbreak and to explore the relationship between psychological resilience and the sense of professional identity in this cohort. A nationwide online cross-sectional survey was conducted. Nursing students were recruited from 18 Chinese universities. The 10-item Connor-Davidson resilience scale (CD-RISC-10) evaluated psychological resilience and professional identity was assessed by the Professional Identity Questionnaire for Nursing Students (PIQNS). A total of 6348 respondents had a moderate level of professional identity to nursing (average PIQNS score at 62.02 ± 12.02). About 86% of respondents attributed the response to the COVID-19 pandemic in elevating the nursing image. Psychological resilience was the strongest contributor to professional identity (β = 0.371, P < 0.001). There was a high level of professional identity among Chinese nursing students during the COVID-19 crisis. Policy support and courses to enhance psychological resilience are critical to sustain professional identity among nursing students.
•First study on nursing students’ professional identity during COVID-19.•Students attributed the response to COVID-19 in elevating the nursing image.•Students presented high level of professional identity.•Strategies to ensure an inspired and a proud future nursing workforce are crucial.
Along with the boost of drugs’ exploitation, drug delivery has been a common concern among researchers and patients. As an emerging strategy, the micro- and nano-needle (MNN) is a single or an array ...of micro/nanoneedles, and promises to be a robust technology for efficient, noninvasive and convenient drug delivery. Compared with the conventional injection, MNN can pierce the bio-membranes to transfer cargos without any damage of tissue or nerves. And regarding the topical drug release, MNN is more efficient than oral administration and topical cream. More specifically, microneedle, a powerful technique, has been widely applied in different diseases such as diabetes, anti-obesity and contraception through skin and ocular surface. Correspondingly, many novel microneedles and optimization methods have been developed recently to improve the drug delivery efficacy. Nanoneedle, much smaller than microneedle, can minimize the skin damages caused by the repeated use of microneedles. Nanoneedles with nanoscaled size are usually used to penetrate the cell membrane. And recently many stimulus-aided methods like electrical and magnetic force have been invented to deepen penetration and improve transfer effects. The aim of this review is to introduce the recent advances of MNN-based drug delivery, including their types, application locations and diseases, optimization of delivery strategies and future development prospects.
Schematic diagram of micro- and nano-needles. Display omitted
I•The latest developments of micro- and nano-needles for advanced drug delivery and applications in various diseases are summarized.•Emerging improvements of stimuli-responsive MNN, including exogenous (heat, force and electricity) and endogenous (glucose and thrombin) stimuli are discussed.•Future challenges of micro- and nano-needles in accurate drug delivery and clinic transition are proposed.
PDF
