The LEPIS-HuR-TMOD4 axis regulates hepatic cholesterol homeostasis and accelerates atherosclerosis.

BACKGROUND AND AIMS: Long noncoding RNAs (lncRNAs) play important roles in the progression of atherosclerosis. In this study, we identified an uncharacterized lncRNA, Liver Expressions by PSRC1 Induced Specifically (LEPIS). This study aimed to clarify the mechanism though which LEPIS affects atherosclerosis (AS). METHODS: The expression of LEPIS and its potential target, tropomodulin 4 (TMOD4), was increased in the livers of ApoE-/- mice fed a high-fat diet (HFD). An ApoE-/- mouse model in which LEPIS or TMOD4 was overexpressed in the liver was established. The plaque load in the aorta was assessed, plasma was collected to measure blood lipid levels, and the liver was collected to study cholesterol metabolism. RESULTS: We found that both LEPIS and TMOD4 increased the AS burden and reduced hepatic cholesterol levels. A further study revealed that LEPIS and TMOD4 affected the expression of genes related to hepatic cholesterol homeostasis, including proprotein convertase subtilisin/kexin type 9 (PCSK9) and low-density lipoprotein receptor (LDLR), which are closely related to hypercholesterolemia. Mechanistically, human antigen R (HuR), an RNA-binding protein (RBP), was shown to be critical for the regulation of TMOD4 by LEPIS. Furthermore, we found that verexpression of LEPIS promoted the shuttling of HuR from the nucleus to the cytoplasm, enhanced the stability of TMOD4 mRNA, and in turn promoted the expression of TMOD4. In addition, TMOD4 was found to affect intracellular cholesterol levels through PCSK9. CONCLUSIONS: These results suggest that the LEPIS-HuR-TMOD4 axis is a potential intervention target for dysregulated hepatic cholesterol homeostasis and AS and may provide the basis for further reductions in the circulating LDL-C concentration and arterial plaque burden.

The Potential Role and Therapeutic Relevance of Cellular Senescence in Skeletal Pathophysiology.

Biological aging profoundly impairs the homeostasis of the skeletal system. Cellular senescence, a hallmark of biological aging, plays an instrumental role in bone disease. The underlying mechanisms of cellular senescence, triggered by both intracellular and extracellular stimuli, are multifaceted and yet to be uncovered. Recent research indicates that acute cellular senescence often serves beneficial roles, such as contributing to growth, development, and tissue regeneration. By contrast, chronic cellular senescence, primarily driven by the accumulation of senescent cells (SnCs) and the release of senescence-associated secretory phenotypes (SASP), has detrimental effects on the skeletal system by irreversibly disrupting bone homeostasis and promoting age-related disorders. Furthermore, the bone marrow is rich in immune cells and their exposure to SASP often leads to immune dysfunction, resulting in unresolved chronic inflammation and compromised adaptive immunity. Until now, the impact of SnCs and SASP on the skeleton has remained elusive. Meanwhile, extensive efforts are being made to combat age-related diseases through various strategies. Among them, SnCs and SASP are the primary targets for antiaging therapeutic clearance, resulting in the development of "senolytics" and "senomorphics," respectively. In this review, we summarize and highlight the role of SnCs and SASP in skeletal pathophysiology, the mechanism of cellular senescence in affecting bone metabolism, and potential therapeutic approaches, particularly senolytics and senomorphics, in treating cellular senescence-related bone diseases.

Reducing SULT2B1 promotes the interaction of LncRNAgga3-204 with SMAD4 to inhibit the macrophage inflammatory response and delay atherosclerosis progression.

Inflammation is a crucial pathophysiological mechanism in atherosclerosis (AS). This study aims to investigate the impact of sulfotransferase family 2b member 1 (SULT2B1) on the inflammatory response of macrophages and the progression of AS. Here, we reported that SULT2B1 expression increased with the progression of AS. In AS model mice, knockdown of Sult2b1 led to remission of AS and reduced inflammation levels. Further exploration of the downstream molecular mechanisms of SULT2B1 revealed that suppressing Sult2b1 in macrophages resulted in decreased levels of 25HC3S in the nucleus, elevated expression of Lxr, and increased the transcription of Lncgga3-204. In vivo, knockdown of Lncgga3-204 aggravated the inflammatory response and AS progression, while the simultaneous knockdown of both Sult2b1 and Lncgga3-204 exacerbated AS and the inflammatory response compared with knockdown of Sult2b1 alone. Increased binding of Lncgga3-204 to SMAD4 in response to oxidized-low density lipoprotein (ox-LDL) stimulation facilitated SMAD4 entry into the nucleus and regulated Smad7 transcription, which elevated SMAD7 expression, suppressed NF-κB entry into the nucleus, and ultimately attenuated the macrophage inflammatory response. Finally, we identified the presence of a single nucleotide polymorphism (SNP), rs2665580, in the SULT2B1 promoter region in monocytes from coronary artery disease (CAD) patients. The predominant GG/AG/AA genotypes were observed in the Asian population. Elevated SULT2B1 expression in monocytes with GG corresponded to elevated inflammatory factor levels and more unstable coronary plaques. To summarize, our study demonstrated that the critical role of SULT2B1/Lncgga3-204/SMAD4/NF-κB in AS progression. SULT2B1 serves as a novel biomarker indicating inflammatory status, thereby offering insights into potential therapeutic strategies for AS.

Effects of school myopia management measures on myopia onset and progression among Chinese primary school students.

BACKGROUND: Schools play an organizational role in managing myopia-related behavioral habits among students. We evaluated the effects of school myopia management measures on myopia onset and progression in a school-based prospective 1-year observational study. METHODS: In total, 8319 children from 26 elementary schools were included. Online questionnaire completed by a parent, in which school myopia management experience including outdoor activities in recess or physical education class, teachers' supervision, and teaching facilities. Variables were defined as implemented well or poorly, according to the Comprehensive Plan to Prevent Myopia among Children and Teenagers. Children underwent ophthalmic examinations, and the incidence and progression of myopia from 2019 to 2020 were estimated. Multilevel logistic regression models were constructed to analyze the association between school management measures and myopia development in 8,9 years and 10,11 years students. RESULTS: From 2019 to 2020, the incidence of myopia among primary school students was 36.49%; the mean difference of spherical equivalent in myopic children was - 0.29 ± 1.22 diopters. The risk of incident myopia was reduced by 20% in 8,9 years participants with well-implemented class recess compared with those with poorly implemented class recess (adjusted odds ratio [aOR]: 0.80, p = 0.032). PE outdoor time was significantly associated with myopia incidence in 10,11 years students (aOR: 0.76, p = 0.043). Compared with poorly implemented reading and writing posture, desk and chair height, 10,11 participants with well-implemented desk and chair height were less likely to have rapid myopic progression (p = 0.029, p = 0.022). CONCLUSION: In Shanghai, children's myopia is associated with better implementation of school myopia management measures. The present findings suggest that outdoor activities during class recess or PE class, providing suitable desks and chairs, and adequate instruction in reading and writing postures might protect against pathological eye growth. An age-specific myopia prevention and control programs in school is of primary importance.

Evaluation of Atlas-Based Mobile Application in Undergraduate Teaching in Oral Histopathology.

The utilization of mobile devices in education is a growing trend in various subjects. We developed the Dental and Maxillofacial Development Teaching Atlas App, and applied it to the learning process of oral histopathology. The aim of the current study was to investigate the educational effects of atlas-based mobile-assisted teaching in the field of dental medicine, and to suggest relevant improvements. The Dental and Maxillofacial Development Teaching Atlas App encompasses a wide range of atlases. It harbors various features, such as terminology definitions, student communications, and teacher-student interactions. By conducting questionnaires (70 students) and a quiz (68 students), we obtained students' feedback, to evaluate the effects and application prospects of the WeChat applet. The questionnaire results indicate that students experienced a high level of satisfaction and support. Additionally, students participated in the quiz, with the experimental group exhibiting significantly higher average scores than the control group. The fill-in-the-blank questions, image recognition questions, and the total score all demonstrated statistically significant differences, while the terminology definition questions did not. The Dental and Maxillofacial Development Teaching Atlas App facilitates students' utilization of fragmented time for learning, and demonstrates positive effects in enhancing students' learning interests and proactiveness. It also holds promising potential for applications in other disciplines in the field of dental education.

Generation of Hypoparathyroid Rats via Carbon-Nanoparticle-Assisted Parathyroidectomy.

Hypoparathyroidism (HypoPT) is a rare disease involving the parathyroid glands that is characterized by a reduced secretion or potency of the parathyroid hormone (PTH), which leads to high serum phosphorus levels and low serum calcium levels. HypoPT most commonly results from accidental damage to the glands or their removal during thyroid or other anterior neck surgery. Parathyroid/thyroid surgery has become more common in recent years, with a corresponding rise in the occurrence of HypoPT as a postoperative complication. There is a critical need for a HypoPT animal model to better understand the mechanisms underlying the effects of HypoPT on mineral ion homeostasis and to verify the therapeutic effectiveness of novel treatments. Here, a technique is reported to create acquired HypoPT in male rats by performing parathyroidectomy (PTX) using carbon nanoparticles. The rat model shows great promise over the mouse models of hypoparathyroidism. Importantly, the human PTH receptor binding region has an 84.2% sequence similarity with that of the rat, which is higher than the 73.7% similarity shared with mice. Moreover, the effects of estrogen, which can affect the PTH/PTHrP receptor signaling pathway, have not been fully investigated in male rats. Carbon nanoparticles are lymphatic tracers that stain the thyroid lymph nodes black without affecting their function, but they do not stain the parathyroid glands, which makes them easy to identify and remove. In this study, serum PTH levels were undetectable after PTX, and this resulted in significant hypocalcemia and hyperphosphatemia. Thus, the clinical state of postoperative HypoPT can be remarkably represented in the rat model. Carbon-nanoparticle-assisted PTX can, therefore, serve as an extraordinarily effective and readily implementable model for studying the pathogenesis, treatment, and prognosis of HypoPT.

Elucidation of the folding pathway of a circular permutant of topologically knotted YbeA by tryptophan substitutions.

CP74 is an engineered circular permutant of a deep trefoil knotted SpoU-TrmD (SPOUT) RNA methyl transferase protein YbeA from E. coli. We have previously established that the circular permutation unties the knotted topology of YbeA and CP74 forms a domain-swapped dimer with a large dimeric interface of ca. 4600 Å2. To understand the impact of domain-swapping and the newly formed hinge region joining the two folded domains on the folding and stability of CP74, the five equally spaced tryptophan residues were individually substituted into phenylalanine to monitor their conformational and stability changes by a battery of biophysical tools. Far-UV circular dichroism, intrinsic fluorescence, and small-angle X-ray scattering dictated minimal global conformational perturbations to the native structures in the tryptophan variants. The structures of the tryptophan variants also showed the conservation of the domain-swapped ternary structure with the exception that the W72F exhibited significant asymmetry in the α-helix 5. Comparative global thermal and chemical stability analyses indicated the pivotal role of W100 in the folding of CP74 followed by W19 and W72. Solution-state NMR spectroscopy and hydrogen-deuterium exchange mass spectrometry further revealed the accumulation of a native-like intermediate state in which the hinge region made important contributions to maintain the domain-swapped ternary structure of CP74.

Current Applications and Future Directions of Lasers in Endodontics: A Narrative Review.

The utilization of lasers has been regarded as a novel technique for the purposes of clinical use in the dental field. Recently, numerous studies have been conducted on the potential applications of laser therapy in endodontics. Moreover, due to their ablation, penetrability, and disinfection capabilities, lasers have performed well with respect to endodontic treatments, including root canal treatment, vital pulp therapy (pulp capping and pulpotomy), dentinal hypersensitivity treatment, and management of dental pain related to pulp and periradicular disease. In particular, the superiorities of laser-aided pulp therapy are emphasized through condensed clinical controlled trials, and histological studies, in this review. Moreover, the ingenious use of laser applications with respect to aiding in the acceleration of root development and the extraction of foreign matters (i.e., broken files and fiber posts) in canals has quickly become the cutting-edge trend of current research. This review offers a summary and discussion of the current literature on all the aforementioned laser applications. Moreover, the characteristics of laser devices, including erbium lasers, neodymium-doped lasers, CO2 lasers, and diode lasers, are detailed and discussed here, providing useful references for laser application in endodontics. We also focus on the different wavelengths with respect to the lasers that are applied in endodontics. High-power lasers perform well as operative instruments; in addition, low-level lasers lead to the regulation of pulp inflammation, and the promotion of pulp healing. This narrative review provides a summary of the advanced applications of lasers in conjunction with various devices in the practice of endodontics, and aims to inspire innovative perspectives on lasers in the context of the treatment of dental diseases, especially pulp diseases, in the future.

Creating an atlas of the bone microenvironment during oral inflammatory-related bone disease using single-cell profiling.

Oral inflammatory diseases such as apical periodontitis are common bacterial infectious diseases that may affect the periapical alveolar bone tissues. A protective process occurs simultaneously with the inflammatory tissue destruction, in which mesenchymal stem cells (MSCs) play a primary role. However, a systematic and precise description of the cellular and molecular composition of the microenvironment of bone affected by inflammation is lacking. In this study, we created a single-cell atlas of cell populations that compose alveolar bone in healthy and inflammatory disease states. We investigated changes in expression frequency and patterns related to apical periodontitis, as well as the interactions between MSCs and immunocytes. Our results highlight an enhanced self-supporting network and osteogenic potential within MSCs during apical periodontitis-associated inflammation. MSCs not only differentiated toward osteoblast lineage cells but also expressed higher levels of osteogenic-related markers, including Sparc and Col1a1. This was confirmed by lineage tracing in transgenic mouse models and human samples from oral inflammatory-related alveolar bone lesions. In summary, the current study provides an in-depth description of the microenvironment of MSCs and immunocytes in both healthy and disease states. We also identified key apical periodontitis-associated MSC subclusters and their biomarkers, which could further our understanding of the protective process and the underlying mechanisms of oral inflammatory-related bone disease. Taken together, these results enhance our understanding of heterogeneity and cellular interactions of alveolar bone cells under pathogenic and inflammatory conditions. We provide these data as a tool for investigators not only to better appreciate the repertoire of progenitors that are stress responsive but importantly to help design new therapeutic targets to restore bone lesions caused by apical periodontitis and other inflammatory-related bone diseases.

PW06 Triggered Fas-FADD to Induce Apoptotic Cell Death In Human Pancreatic Carcinoma MIA PaCa-2 Cells through the Activation of the Caspase-Mediated Pathway.

Pancreatic cancer has higher incidence and mortality rates worldwide. PW06 [(E)-3-(9-ethyl-9H-carbazol-3-yl)-1-(2,5-dimethoxyphenyl) prop-2-en-1-one] is a carbazole derivative containing chalcone moiety which was designed for inhibiting tumorigenesis in human pancreatic cancer. This study is aimed at investigating PW06-induced anticancer effects in human pancreatic cancer MIA PaCa-2 cells in vitro. The results showed PW06 potent antiproliferative/cytotoxic activities and induced cell morphological changes in a human pancreatic cancer cell line (MIA PaCa-2), and these effects are concentration-dependent (IC50 is 0.43 µM). Annexin V and DAPI staining assays indicated that PW06 induced apoptotic cell death and DNA condensation. Western blotting indicated that PW06 increased the proapoptotic proteins such as Bak and Bad but decreased the antiapoptotic protein such as Bcl-2 and Bcl-xL. Moreover, PW06 increased the active form of caspase-8, caspase-9, and caspase-3, PARP, releasing cytochrome c, AIF, and Endo G from mitochondria in MIA PaCa-2 cells. Confocal laser microscopy assay also confirmed that PW06 increased Bak and decreased Bcl-xL. Also, the cells were pretreated with inhibitors of caspase-3, caspase-8, and caspase-9 and then were treated with PW06, resulting in increased viable cell number compared to PW06 treated only. Furthermore, PW06 showed a potent binding ability with hydrophobic interactions in the core site of the Fas-Fas death domains (FADD). In conclusion, PW06 can potent binding ability to the Fas-FADD which led to antiproliferative, cytotoxic activities, and apoptosis induction accompanied by the caspase-dependent and mitochondria-dependent pathways in human pancreatic cancer MIA PaCa-2 cells.

A single-cell transcriptional atlas reveals resident progenitor cell niche functions in TMJ disc development and injury.

The biological characteristics of the temporomandibular joint disc involve complex cellular network in cell identity and extracellular matrix composition to modulate jaw function. The lack of a detailed characterization of the network severely limits the development of targeted therapies for temporomandibular joint-related diseases. Here we profiled single-cell transcriptomes of disc cells from mice at different postnatal stages, finding that the fibroblast population could be divided into chondrogenic and non-chondrogenic clusters. We also find that the resident mural cell population is the source of disc progenitors, characterized by ubiquitously active expression of the NOTCH3 and THY1 pathways. Lineage tracing reveals that Myh11+ mural cells coordinate angiogenesis during disc injury but lost their progenitor characteristics and ultimately become Sfrp2+ non-chondrogenic fibroblasts instead of Chad+ chondrogenic fibroblasts. Overall, we reveal multiple insights into the coordinated development of disc cells and are the first to describe the resident mural cell progenitor during disc injury.

Identification of circRNAs and circRNA-miRNA-mRNA regulatory network in radiation-induced heart disease.

OBJECTIVE: Radiation-induced heart disease (RIHD) is one of the most common and serious long-term adverse effect after thoracic radiotherapy. Our aim was to investigate the potential molecular mechanism underlying RIHD using RNA-sequencing (RNA-seq) and bioinformatics methods. MATERIALS AND METHODS: An RIHD rat model was established and transcription profiles were identified using RNA-seq. Differentially expressed circRNAs, miRNAs and mRNAs were identified. Enrichment of functions and signaling pathways analysis were performed based on GO and the KEGG database. Potential circRNA-miRNA-mRNA regulatory network underlying RIHD was established. qRT-PCR was used to validate the associated genes. RESULTS: In total, 21 circRNAs, 26 miRNAs, and 178 mRNA transcripts were differentially expressed in RIHD. GO and KEGG pathway analyses identified that differentially expressed mRNAs were most enriched in pathways referring to endothelial function and vascular pathological processes. Nine circRNAs, 10 miRNAs, and 6 mRNA transcripts were most likely involved in vascular function and a candidate competitive endogenous RNA (ceRNA) network of circRNA-miRNA-mRNA was established, which were further validated by qRT-PCR. CONCLUSIONS: Our study revealed that vascular pathology plays an important role in the early stage of RIHD. Furthermore, a circRNA-miRNA-mRNA ceRNA network was found that may be involved in the regulation of vascular function and RIHD.

Degradation of 1-alkyl-3-methylimidazolium tetrafluoroborate in an ultrasonic zero-valent zinc and activated carbon micro-electrolysis system.

Increased attention has been given to the removal of ionic liquids (ILs) from natural water environments. In this work, 5 kinds of 1-alkyl-3-methylimidazoliumtetrafluoroborate ([Cnmim][BF4] (n = 2, 4, 6, 8, 10)) ILs were degraded in an ultrasonic zero-valent zinc (ZVZ) and activated carbon (AC) micro-electrolysis system. Optimization of degradation conditions and the degradation levels were studied by high performance liquid chromatography, the surface morphology of the ZVZ and AC changed before and after the reaction were observed by scanning electron microscope. The degradation intermediates were detected by gas chromatography- mass spectrometry and ion chromatography, and inferred the degradation pathway. The degradation effect of [C4mim][BF4] was best with ultrasonic assistance, pH 3 and an AC/ZVZ ratio of 1:1. The degradation of [Cnmim][BF4] in aqueous solution exceeded 91.7% in 120 min, and the mineralization level exceeded 88.9%. The surface of smooth and dense ZVZ particles became loose flocculent and the porous surface of AC became larger and rougher after reaction. The degradation pathway suggested that the imidazolium ring was sulfurized or oxidized, and then the ring was opened to form N-alkyl formamide and N-methyl formamide. ZVZ/AC micro-electrolysis combined with ultrasonic irradiation is an effective method to remove ILs, which provides new insight into IL degradation.

Purification performance from bypass ecological treatment systems treating WWTPs effluents and improvement of water quality in receiving rivers: A case study in southern China.

Effluents from wastewater treatment plants (WWTPs) is the main source of pollution in rivers in developing countries. In this case study, three bypass ecological treatment systems along urban rivers achieved high removal efficiencies for chemical oxygen demand (COD; 55.7-64.0%), ammonium N (NH4+-N; 63.1-89.4%) and total phosphorous (TP; 27.6-76.7%). 16 S rRNA gene sequencing analysis confirmed that Proteobacteria was the main bacterial phylum (44.4%) in the ecological treatment system, and members were enriched significantly in the non-aeration area (59.3%). The relative abundance of Nitrospirae was highest in the inflow area (25.0%), but restrained in the non-aeration area (5.7%). 18 S rRNA gene annotation results indicated that phylum Rotifer was gradually inhibited with the direction of water flow and diffusion, while phylum Rhodophyta displayed the opposite trend. After implementation of bypass ecological treatment systems, receiving rivers were improved significantly from Grade Ⅴ to Ⅳ, and the biodiversity of zooplankton, zoobenthos and fish communities was greatly improved.

SeqCP: A sequence-based algorithm for searching circularly permuted proteins.

Circular permutation (CP) is a protein sequence rearrangement in which the amino- and carboxyl-termini of a protein can be created in different positions along the imaginary circularized sequence. Circularly permutated proteins usually exhibit conserved three-dimensional structures and functions. By comparing the structures of circular permutants (CPMs), protein research and bioengineering applications can be approached in ways that are difficult to achieve by traditional mutagenesis. Most current CP detection algorithms depend on structural information. Because there is a vast number of proteins with unknown structures, many CP pairs may remain unidentified. An efficient sequence-based CP detector will help identify more CP pairs and advance many protein studies. For instance, some hypothetical proteins may have CPMs with known functions and structures that are informative for functional annotation, but existing structure-based CP search methods cannot be applied when those hypothetical proteins lack structural information. Despite the considerable potential for applications, sequence-based CP search methods have not been well developed. We present a sequence-based method, SeqCP, which analyzes normal and duplicated sequence alignments to identify CPMs and determine candidate CP sites for proteins. SeqCP was trained by data obtained from the Circular Permutation Database and tested with nonredundant datasets from the Protein Data Bank. It shows high reliability in CP identification and achieves an AUC of 0.9. SeqCP has been implemented into a web server available at: http://pcnas.life.nthu.edu.tw/SeqCP/.

Protective Actions in Apical Periodontitis: The Regenerative Bioactivities Led by Mesenchymal Stem Cells.

Resulting from bacterial infection, apical periodontitis (AP) is a common inflammatory disease of the periapical region of the tooth. The regeneration of the destroyed periapical alveolar bone and the surrounding periodontium tissues has long been a difficult task in clinical practice. These lesions are closely related to pathogen invasion and an overreactive immune response. It is worth noting that the protective healing process occurs simultaneously, in which mesenchymal stem cells (MSCs) have a crucial function in mediating the immune system and promoting regeneration. Here, we review the recent studies related to AP, with a focus on the regulatory network of MSCs. We also discuss the potential therapeutic approaches of MSCs in inflammatory diseases to provide a basis for promoting tissue regeneration and modulating inflammation in AP. A deeper understanding of the protective action of MSCs and the regulatory networks will help to delineate the underlying mechanisms of AP and pave the way for stem-cell-based regenerative medicine in the future.

Neural Regeneration in Regenerative Endodontic Treatment: An Overview and Current Trends.

Pulpal and periapical diseases are the most common dental diseases. The traditional treatment is root canal therapy, which achieves satisfactory therapeutic outcomes-especially for mature permanent teeth. Apexification, pulpotomy, and pulp revascularization are common techniques used for immature permanent teeth to accelerate the development of the root. However, there are obstacles to achieving functional pulp regeneration. Recently, two methods have been proposed based on tissue engineering: stem cell transplantation, and cell homing. One of the goals of functional pulp regeneration is to achieve innervation. Nerves play a vital role in dentin formation, nutrition, sensation, and defense in the pulp. Successful neural regeneration faces tough challenges in both animal studies and clinical trials. Investigation of the regeneration and repair of the nerves in the pulp has become a serious undertaking. In this review, we summarize the current understanding of the key stem cells, signaling molecules, and biomaterials that could promote neural regeneration as part of pulp regeneration. We also discuss the challenges in preclinical or clinical neural regeneration applications to guide deep research in the future.

Composites Filled with Metal Organic Frameworks and Their Derivatives: Recent Developments in Flame Retardants.

Polymer matrix is vulnerable to fire hazards and needs to add flame retardants to enhance its performance and make its application scenarios more extensive. At this stage, it is more necessary to add multiple flame-retardant elements and build a multi-component synergistic system. Metal organic frameworks (MOFs) have been studied for nearly three decades since their introduction. MOFs are known for their structural advantages but have only been applied to flame-retardant polymers for a relatively short period of time. In this paper, we review the development of MOFs utilized as flame retardants and analyze the flame-retardant mechanisms in the gas phase and condensed phase from the original MOF materials, modified MOF composites, and MOF-derived composites as flame retardants, respectively. The effects of carbon-based materials, phosphorus-based materials, nitrogen-based materials, and biomass on the flame-retardant properties of polymers are discussed in the context of MOFs. The construction of MOF multi-structured flame retardants is also introduced, and a variety of MOF-based flame retardants with different morphologies are shown to broaden the ideas for subsequent research.

Phthalate acid esters and polycyclic aromatic hydrocarbons concentrations with their determining factors among Chinese pregnant women: A focus on dietary patterns.

BACKGROUND: Pregnant women are susceptible to adverse health effects associated with phthalate acid esters (PAEs) and polycyclic aromatic hydrocarbons (PAHs), and diet is a significant exposure source. Little is known about the contributions of dietary patterns during pregnancy to the exposure variability of these environmental contaminants. OBJECTIVES: To identify dietary patterns in relation to PAEs and PAHs exposure in the Chinese pregnant population. METHODS: Dietary data and urinary concentrations of environmental pollutants were obtained from 1190 pregnant women in the Tongji Birth Cohort (TJBC). PAEs and PAHs were measured in spot urine samples. Food intake was assessed using a food-frequency questionnaire. Dietary patterns were constructed by principal component analysis (PCA). Through PCA, we also extracted three chemical mixture scores that represent different co-exposure patterns of PAEs and PAHs. Multiple linear regression models were adopted to identify predictors of PAEs and PAHs exposure. RESULTS: Four dietary patterns were identified by PCA that explained 44.9 % of the total variance of food intake. We found egg-dairy products pattern, whole grain-tuber crop pattern, and meat-aquatic products pattern were positively associated with specific pollutants exposure. In contrast, fruit-nut-vegetable pattern was negatively correlated with PAEs and PAHs exposure. Every SD increase in this pattern score was associated with 14.36 % reduced mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) (95 % CI: -24.50 ~ -2.96, p-trend = 0.01), 10.86 % reduced 2-hydroxynaphthalene (2-OHNap) (95 % CI: -20.07 ~ -0.60, p-trend = 0.04), 19.35 % reduced 9-hydroxyphenanthrene (9-OHPhe) (95 % CI: -34.49 ~ -0.70, p-trend = 0.01), and 8.33 % reduced scores of PAHs group (95 % CI: -15.97 ~ -0.10, p-trend = 0.02). In addition, disposable tableware usage and passive smoking were suggested as potentially modifiable sources of PAEs and PAHs exposure, respectively. CONCLUSION: Adhering to egg-dairy products pattern, whole grain-tuber crop pattern, and meat-aquatic products pattern may be related to increased PAEs and PAHs exposure, while following fruit-nut-vegetable pattern seems to correlate with a lower burden of such exposure.

Study of Blast Mitigation Performance and Fracture Mechanism of Polyurea under Contact Explosion.

In order to further study the blast mitigation performance of polyurea and to investigate the protection mechanism and damage characteristics of polyurea-protected structures under contact explosion loads, based on earlier work, this paper investigated the response and energy absorption performance of polyurea under various frequency loads. Qtech T26 blast mitigation polyurea (T26 polyurea) was adopted to protect the reinforced concrete (RC) slab and damage analysis of the post-explosion specimens was carried out at micro and macro levels. The response and energy absorption capacity of the material towards different frequency loads were investigated by dynamic mechanical analysis (DMA). Protective performance of T26 polyurea on RC slab was examined with a 10 kg TNT contact explosion test. Scanning electron microscopy (SEM) was employed to analyze the microscopic fracture morphology of the typical areas of the coating after the explosion. The chemical structure changes of the blast-face coating before and after the explosion were compared by Fourier transform infrared spectroscopy (FTIR). The results show that the glass transition region of T26 polyurea is -40 °C to 10 °C, which is a large temperature range, and the microphase separation of T26 polyurea is low. It is significantly influenced by the ambient temperature and loading frequency. The energy absorption of T26 polyurea is realized through the interaction between the hard and soft segments. When the frequency is between 102 Hz and 106 Hz, the loss factor of T26 polyurea is between 0.20 and 0.31, which exhibits a good energy dissipation performance. In the contact explosion of 10 kg TNT, the fragmentation rate of the coated specimen decreased significantly compared with that of the unprotected specimen, realizing the zero fragmentation protection effect on the back-blast face. The maximum deformation area and the main energy absorption area of T26 polyurea under contact explosion is the ring area outside the longitudinal deformation area. The chemical structure of T26 polyurea changed significantly after the explosion; typically the N-H bonds, etc., were broken and the percentage of hydrogen bonding was reduced. T26 polyurea has realized the protection effect of zero fragmentation of large-equivalent contact explosion, which has a high application value for blast mitigation and blast-fragmentation prevention in actual engineering.