Gemini Quaternary Ammonium Surfactants with Different Counterions-modified Montmorillonite for Efficient Removal of Methyl Orange.

Organic Na-montmorillonite (OMt-12-2-12·2Y - , Y=CH 3 CO 3 - , C 6 H 5 COO - and Br - ) modified by a series of Gemini quaternary ammonium surfactants with different counterions was prepared for enhancing the adsorption capacity of methyl orange. Compared with the initial adsorption capacity of 5.251 mg/g of Na-Mt, the adsorption effect of OMts under the optimal conditions increased by about 31~34 times. The adsorption isotherms and kinetics of all adsorption processes were respectively described by Langmuir and pseudo-second-order models. The structure, hydrophobicity and hydration of the counterions, as well as the affinity of the counterions with the long aliphatic chains, had a certain influence on the adsorption performance of OMts for methyl orange.

A Study on the Properties of Composite Modified Mortar with Styrene-Butadiene Rubber Latex and Silica Fume.

To solve the problem of the poor abrasion resistance of concrete pavement surface mortar, this study substituted cement with equal amounts of styrene-butadiene rubber (SBR) latex and silica fume (SF) to investigate the effects of organic/inorganic material composite modification on the fluidity, drying shrinkage, mechanical properties, and abrasion resistance of cement mortar. Also in this study, the microstructure, product, and pore structure characteristics of the composite modified cement mortar were investigated using scanning electron microscope (SEM), X-Ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and the Brunauer-Emmett-Teller (BET) method. This research found that the sole substitution of SF negatively impacted the mortar's fluidity and drying shrinkage yet enhanced its mechanical strength and abrasion resistance; the incorporation of SBR latex improved fluidity, reduced shrinkage, and increased flexural strength but adversely affected the compressive strength of the mortar. Additionally, the enhancement of the mortar's abrasion resistance with SBR latex was significantly greater than that with SF. When SBR latex and SF were used together as substitutes, the latex struggled to offset the negative impact of SF on mortar fluidity but effectively reduced shrinkage; SF compensated for the detrimental effect of the latex on compressive strength. Moreover, the primary role in enhancing the mortar's abrasion resistance was played by the latex. Microscopic tests showed that SBR latex and SF could increase the content of calcium silicate hydrate (C-S-H) gel, inhibit the formation of ettringite (AFt) and reduce carbonation, refine the pore size of cement mortar, and effectively improve the microstructure of mortar.

Development of radiation countermeasure agents for acute radiation syndromes.

The risk of internal and external exposure to ionizing radiation (IR) has increased alongside the development and implementation of nuclear technology. Therefore, serious security issues have emerged globally, and there has been an increase in the number of studies focusing on radiological prevention and medical countermeasures. Radioprotective drugs are particularly important components of emergency medical preparedness strategies for the clinical management of IR-induced injuries. However, a few drugs have been approved to date to treat such injuries, and the related mechanisms are not entirely understood. Thus, the aim of the present review was to provide a brief overview of the World Health Organization's updated list of essential medicines for 2023 for the proper management of national stockpiles and the treatment of radiological emergencies. This review also discusses the types of radiation-induced health injuries and the related mechanisms, as well as the development of various radioprotective agents, including Chinese herbal medicines, for which significant survival benefits have been demonstrated in animal models of acute radiation syndrome.

Preparation, Structure and Characterization of Polymer/Cement Composites.

Polymer/cement composites have gained significant attention in civil engineering due to their improved properties compared to traditional cement-based materials [...].

Screening for urinary markers predicting hematopoietic stem cell injury induced by busulfan using genetically diverse mice.

BACKGROUND: Busulfan (BU) is an alkylating agent used as a conditioning agent prior to hematopoietic stem cell (HSC) transplantation as it is known to be cytotoxic to host hematopoietic stem and progenitor cells. The susceptibility of HSCs to BU injury plays an important role in the myeloablative efficacy of BU. Different susceptibilities were demonstrated in genetically diverse (GD) mice in our preliminary research. METHODS: Three strains of GD mice with different susceptibilities to BU-induced HSC injury were used for screening biological markers of HSC injury susceptibility in urine. The urine proteins were analyzed using liquid chromatography coupled with tandem mass spectrometry to screen for differentially expressed proteins. Screening for possible biomarkers based on differences in protein expression abundance was validated using enzyme-linked immunoassay (ELISA). RESULTS: Functional analysis showed that the differential proteins were all involved in a series of biological pathways related to cellular senescence, apoptosis, and angiogenesis; whereas the differential proteins of the high-susceptible strain were enriched for the regulation of bone marrow microenvironment pathways, those of low-susceptible strain were enriched for the proapoptotic effect of GTPase pathways. Based on protein abundance differences, several urinary proteins that may be indicative of susceptibility were screened, and ELISA validation results showed that angiotensin-converting enzyme may be a potential biomarker predicting HSC susceptibility for BU conditioning. CONCLUSIONS: This study indicates that urinary protein levels can reflect differences in susceptibility to BU-induced HSC injury. Using GD mice to construct genetic difference models will provide preclinical data for screening BU-related biological markers.

Effect of spermidine on radiation-induced long-term bone marrow cell injury.

OBJECTIVE: Spermidine, a natural polyamine, possesses anti-oxidant, autophagy-regulation, and anti-aging properties. Elevated levels of oxidative stress, which was mediated the senescence of hematopoietic stem cells (HSCs) induced by radiation exposure, may further contribute to long-term myelosuppression. Therefore, this study investigated the protective effect of spermidine on the long-term damage of the hematopoietic system caused by radiation exposure. METHODS: In vitro experiments, bone marrow mononuclear cells (BMMNCs) of C57BL/6 mice were isolated and incubated with 5 mM spermidine for 30 min, then irradiated by 2 Gy X ray. The survival rate, proliferation, and differentiation ability of BMMNCs were detected. In vivo experiment, mice received 4 Gy total body irradiation (TBI), 3 mM spermidine were administered in the drinking water every day for 14 days prior to irradiation and then continued for 30 days after irradiation. Peripheral blood, bone marrow cell typing, level of reactive oxygen species (ROS), colony-forming ability of HSC, and transplantation-reconstitution capability were detected. RESULTS: In vitro experiments, spermidine significantly improved the survival rate of BMMNCs as well as the proliferation and differentiation ability of HSCs exposure to ionizing radiation (IR). In vivo, spermidine reduced levels of ROS in HSCs; spermidine attenuated long-term myeloid differentiation deviation induced by TBI. Spermidine promoted the proliferation and differentiation ability of stem cells, but failed to ameliorate the decreased engraftment capacity of bone marrow cells in mice exposed to TBI. CONCLUSION: This study demonstrated that spermidine could promote the recovery of IR-induced inhibition of proliferation and differentiation ability of HSCs, partly through antioxidant effects. Whether combining spermidine with other radioprotectants could further increase protective efficacy and reduce the long-term bone marrow injury needs further investigation.

Morphine analgesia in male inbred genetic diversity mice recapitulates the among-individual variance in response to morphine in humans.

Morphine is a widely used analgesic, but its use in clinical precision medicine is limited by the variance in response among individuals. Although previous studies have shown that individual differences in morphine can be explained in terms of pharmacodynamics and pharmacokinetics, genetic polymorphisms also play an important role. However, the genetic basis of different sensitivity and tolerance susceptibility to morphine remains ambiguous. Using 15 strains of inbred Genetic Diversity (GD) mice, a new resource with wide genetic and phenotypic variation, we demonstrated great variance in sensitivity to morphine analgesia and susceptibility to morphine tolerance between different GD strains. Among-individual variance in response to morphine analgesia in the population can be modeled in GD mice. Two loci respectively may be associated with the among-individual variance in morphine sensitivity and tolerance, confirming the role of genetic factors in among-individual different responses to morphine. These results indicate that GD mice may be a potential tool for the identification of new biomarkers to improve the clinical administration of morphine.

Effects of Fly Ash and Hexadecyltrimethoxysilane on the Compressive Properties and Water Resistance of Magnesium Oxychloride Cement.

The application of magnesium oxychloride cement (MOC) is promising, but its poor water resistance seriously hinders its development and application. In this paper, we describe a new type of MOC with excellent water resistance, prepared using fly ash and hexadecyltrimethoxysilane (HDTMS). SEM, XRD, FTIR, TG/DSC, and other microscopic-scale studies were conducted to investigate the mechanism underlying the water-resistance enhancement of the new MOC. It was found that adding 20% fly ash and 3% HDTMS can strengthen the water resistance of MOC while retaining high mechanical properties. In particular, the residual coefficient remained at 0.91 after 7 days of immersion. This is because these two additives, when used together, can increase the content of the gelling 5-phase of MOC, as well as optimize the pore structure of MOC.

Potential role of senescent macrophages in radiation-induced pulmonary fibrosis.

Radiation-induced pulmonary fibrosis (RIPF) is a late toxicity of therapeutic radiation in clinic with poor prognosis and limited therapeutic options. Previous results have shown that senescent cells, such as fibroblast and type II airway epithelial cell, are strongly implicated in pathology of RIPF. However, the role of senescent macrophages in the development RIPF is still unknown. In this study, we report that ionizing radiation (IR) increase cellular senescence with higher expression of senescence-associated ß-galactosidase (SA-ß-Gal) and senescence-specific genes (p16, p21, Bcl-2, and Bcl-xl) in irradiated bone marrow-derived monocytes/macrophages (BMMs). Besides, there's a significant increase in the expression of pro-fibrogenic factors (TGF-ß1 and Arg-1), senescence-associated secretory phenotype (SASP) proinflammatory factors (Il-1α, Il-6, and Tnf-α), SASP chemokines (Ccl2, Cxcl10, and Ccl17), and SASP matrix metalloproteinases (Mmp2, Mmp9 and Mmp12) in BMMs exposed to 10 Gy IR. In addition, the percentages of SA-ß-Gal+ senescent macrophages are significantly increased in the macrophages of murine irradiated lung tissue. Moreover, robustly elevated expression of p16, SASP chemokines (Ccl2, Cxcl10, and Ccl17) and SASP matrix metalloproteinases (Mmp2, Mmp9, and Mmp12) is observed in the macrophages of irradiated lung, which might stimulate a fibrotic phenotype in pulmonary fibroblasts. In summary, irradiation can induce macrophage senescence, and increase the secretion of SASP in senescent macrophages. Our findings provide important evidence that senescent macrophages might be the target for prevention and treatment of RIPF.

Genome-wide profiling of BK polyomavirus integration in bladder cancer of kidney transplant recipients reveals mechanisms of the integration at the nucleotide level.

Chronic BK polyomavirus (BKPyV) infection is recognized as a potential oncogenic factor of urothelial carcinoma (UC) in renal transplant recipients. Recent studies have reported a positive correlation among BKPyV integration, persistent overexpression of viral large T antigen (TAg), and malignancy, yet little is known about the specific integration mechanisms and the impacts of viral integration. Here, we performed whole-genome sequencing (WGS) and viral capture-based sequencing on high-grade immunohistochemically TAg-positive UCs in two renal transplant recipients. A total of 181 integration sites, including the three found by WGS, were identified by viral capture-based sequencing, indicating its enhanced sensitivity and ability in identifying low-read integration sites in subpopulations of the tumor cells. The microhomologies between human and BKPyV genomes were significantly enriched in the flanking regions of 84.5% the integration sites, with a median length of 7 bp. Notably, 75 human genes formed fusion sequences due to viral insertional integration. Among them, the expression of 15 genes were statistically associated with UC based on GEO2R expression analysis. Our results indicated a multisite and multifragment linear integration pattern and a potential microhomology or nonhomologous end joining integration mechanism at the single-nucleotide level. We put forward a potential selection mechanism driven by immunity and centered on viral integration in the carcinogenesis of BKPyV.

Dynamic Model of Polished Stone Value Attenuation in Coarse Aggregate.

The polished stone value (PSV) of coarse aggregate is closely related to pavement skid resistance and traffic safety. However, the determination of the PSV of coarse aggregate is conventionally a time- and energy-intensive process. To facilitate the test process of PSV in materials selection and pavement design and for the prediction of the service life of aggregate materials in practical service, here a new mathematical model of PSV attenuation in coarse aggregate, which employs a physical polishing process analysis, is proposed. The PSVs of four types of coarse aggregates (calcined bauxite, granite, basalt, and limestone) were analyzed through a polishing experiment, and the corresponding mechanism was investigated via scanning electron microscopy analysis. The modeling results are in good agreement with experimental results. The aggregate PSV is affected by both the macrotexture and microtexture of the aggregate surface. The PSV due to the macrotexture exhibits a strong negative correlation with the Vickers hardness of the aggregates and decreases exponentially as the polishing time increases. The attenuation rate decreases as the fractal box dimension in the aggregate surface morphology increases. The primary factor influencing the macrotexture service life and the half-life is the aggregate surface morphology. The PSV due to the microtexture exhibits a strong positive correlation with the Vickers hardness of the aggregates, whereas there is a poor correlation with the aggregate surface morphology and polishing time. The proportion of the aggregate PSV due to the microtexture increases as the aggregate hardness increases. These results highlight the effectiveness of a new modeling approach that may potentially assist in predicting the anti-slip performance and durability of coarse aggregates.

Investigation of Voids Characteristics in an Asphalt Mixture Exposed to Salt Erosion Based on CT Images.

The performance of an asphalt mixture will deteriorate under the condition of salt erosion, but there are different opinions on the mechanism of deterioration. Few studies have focused on the relation between the change of void characteristics and performance deterioration of an asphalt mixture exposed to salt erosion. To explore the relation between the air voids characteristics of an asphalt mixture and mechanical damage under salt erosion, the mechanical damage in an asphalt mixture was measured by splitting strength. The asphalt mixture specimens, immersion solutions, asphalt mortar, and aggregate were scanned with CT technology. To segment the voids, the Otsu method was used over asphalt mortar and solution range of CT values. A three-dimensional reconstruction of the CT image was performed with Mimics 20 software to calculate the asphalt mixture's void characteristics. On this basis, the relationships between the change in void characteristics and splitting strength were analyzed. The results showed that the ideal calculated void fraction can be obtained by threshold segmentation of the image void/asphalt mortar interface with the local CT value Otsu method. Under the salt corrosion environment, the increase of open voids of an asphalt mixture is linearly correlated with the decrease of splitting strength, while salts' crystallization in the open voids produces crystallization pressure, accelerating the volume growth of open voids. The early damage of an asphalt mixture suffered from the salt may be mainly physical damage. These results can provide a useful reference for the performance of damage research on asphalt mixtures in salt enrichment areas.