Enhancing the Toughness and Strength of Polymers Using Mechanically Interlocked Hydrogen Bonds.

The energy dissipative features of hydrogen bonds under conditions of mechanical strain have provided an ongoing incentive to explore hydrogen bonding units for the purpose of controlling and customizing the mechanical properties of polymeric materials. However, there remains a need for hydrogen bond units that (1) possess directionality, (2) provide selectivity, (3) dissipate energy effectively, and (4) can be incorporated readily into polymeric materials to regulate their mechanical properties. Here, we report mechanically interlocked hydrogen bond units that incorporate multiple hydrogen bonds within a [2]catenane structure. The conformational flexibility and associated spatial folding characteristics of the [2]catenane units allow for molecular scale motion under external stress, while the interlocked structure serves as a pivot that maintains the directionality and selectivity of the resultant hydrogen bonding units. When incorporated into polymers, these interlocked hydrogen bond motifs serve to strengthen and toughen the resulting materials. This study not only presents a novel hydrogen bond unit for creating polymeric materials with improved mechanical properties but also underscores the unique opportunities that mechanically interlocked hydrogen bond structures may provide across a diverse range of applications.

Adaptisorption of Nonporous Polymer Crystals.

Although our knowledge and understanding of adsorptions in natural and artificial systems has increased dramatically during the past century, adsorption associated with nonporous polymers remains something of a mystery, hampering applications. Here we demonstrate a model system for adaptisorption of nonporous polymers, wherein dative B-N bonds and host-guest binding units act as the kinetic and thermodynamic components, respectively. The coupling of these two components enables nonporous polymer crystals to adsorb molecules from solution and undergo recrystallization as thermodynamically favored crystals. Adaptisorption of nonporous polymer crystals not only extends the types of adsorption in which the sorbate molecules are integrated in a precise and orderly manner in the sorbent systems, but also provides a facile and accurate approach to the construction of polymeric materials with precise architectures and integrated functions.

Construction of slide-ring polymers based on pillar[5]arene/alkyl chain host-guest interactions.

Slide-ring polymers exhibit distinctive mechanical properties, making them highly promising for applications in emerging fields such as energy storage devices and smart sensing. However, existing slide-ring polymer systems primarily rely on hydrophilic-hydrophobic interactions to achieve ring-axle interlocking in aqueous phases. This reliance limits the construction of slide-ring networks mainly to water-soluble polymers, excluding a diverse range of lipophilic polymers. Therefore, it is crucial to introduce efficient construction strategies that facilitate interpenetration in organic solvents, enabling the development of diverse slide-ring polymers and expanding their range and applications. Herein, by utilizing the pillar[5]arene/alkyl chain host-guest interactions, we successfully facilitated the interpenetration of a pillar[5]arene and poly(caprolactone), enabling the efficient construction of two slide-ring polymer networks in organic solvents. One of these two slide-ring polymers demonstrates a unique network deformation mechanism along with outstanding mechanical properties compared with the control covalently cross-linked polymer network, including maximum stress (4.43 vs 1.98 MPa), maximum strain (1285 vs 330%), and toughness (35.4 vs 3.92 MJ/m3). More importantly, this strategy of making slide-ring polymers is highly versatile, given the wide range of macrocyclic arenes and alkyl chain-containing polymers it can accommodate.

Adaptive and Robust Vitrimers Fabricated by Synergy of Traditional and Supramolecular Polymers.

Vitrimers offer a unique combination of mechanical performance, reprocessability, and recyclability that makes them highly promising for a wide range of applications. However, achieving dynamic behavior in vitrimeric materials at their intended usage temperatures, thus combining reprocessability with adaptivity through associative dynamic covalent bonds, represents an attractive but formidable objective. Herein, we couple boron-nitrogen (B-N) dative bonds and B-O covalent bonds to generate a new class of vitrimers, boron-nitrogen vitrimers (BNVs), to endow them with dynamic features at usage temperatures. Compared with boron-ester vitrimers (BEVs) without B-N dative bonds, the BNVs with B-N dative bonds showcase enhanced mechanical performance. The excellent mechanical properties come from the synergistic effect of the dative B-N supramolecular polymer and covalent boron-ester networks. Moreover, benefiting from the associative exchange of B-O dynamic covalent bonds above their topological freezing temperature (Tv), the resultant BNVs also possess the processability. This study leveraged the structural characteristics of a boron-based vitrimer to achieve material reinforcement and toughness enhancement, simultaneously providing novel design concepts for the construction of new vitrimeric materials.

A 3D Cross-Linked Metal-Organic Framework (MOF)-Derived Polymer Electrolyte for Dendrite-Free Solid-State Lithium-Ion Batteries.

Lithium metal batteries (LMBs) with high energy density have received widespread attention; however, there are usually issues with lithium dendrite growth and safety. Therefore, there is a demand for solid electrolytes with high mechanical strength, room-temperature ionic conductivity, and good interface performance. Herein, a 3D cross-linked metal-organic framework (MOF)-derived polymer solid electrolyte exhibits good mechanical and ionic conductive properties simultaneously, in which the MOF with optimized pore size and strong imidazole cation sites can restrict the migration of anions, resulting in a uniform Li+ flux and a high lithium-ion transference number (0.54). Moreover, the MOF-derived polymer solid electrolytes with the 3D cross-linked network can promote the rapid movement of Li+ and inhibit the growth of lithium dendrites. Lithium symmetric batteries assembled with the 3D MOF-derived polymer solid electrolytes are subjected to lithium plating/stripping and cycled over 2000 h at a current density of 0.1 mA cm-2 and over 800 h at a current density of 0.2 mA cm-2 . The Li/P-PETEA-MOF/LiFePO4 batteries exhibit excellent long-cycle stability and cycle reversibility.

An Asymmetric Cross-Linked Ionic Copolymer Hybrid Solid Electrolyte with Super Stretchability for Lithium-Ion Batteries.

Composite solid electrolytes are recommended to be the most promissing strategy for solid-state batteries because they combine the advantages of inorganic ceramics and polymers. However, the huge interfacial resistance between the inorganic ceramic and polymer results in low ionic conductivity, which is still the major impediment that limits their applications. Herein, a novel highly elastic and weakly coordinated ionic copolymer hybrid electrolyte with asymmetric structure based on surface-modified Li1.5 Al0.5 Ge1.5 (PO4 )3 by "in situ" polymerization is proposed to improve ionic conductivity and mechanical properties simultaneously. The all-solid hybrids electrolytes exhibit room-temperature ionic conductivity up to 2.61 × 10-4 S cm-1 and lithium-ion transference number of 0.41. The hybrids electrolytes can be repeatedly stretching-releasing-stretching, showing a super stretchability with the elongation at break up to 496%. The Li symmetrical cells assembled with the hybrid electrolytes can continuously operate for 800 h at 0.1 mA cm-2 without discernable dendrites, indicating good interfacial compatibility between the hybrid electrolytes and lithium electrodes. The Li|LiFePO4 batteries assembled with the hybrid electrolytes deliver an initial discharge specific capacity of 165.5 mAh g-1 with an initial coulombic efficiency of 94.8% and 154 mAh g-1 after 100 cycles at 0.1 C, and maintain 95.4% capacity retention after 100 cycles at 0.5 C.

Mechanically interlocked polymers based on rotaxanes.

The nature of mechanically interlocked molecules (MIMs) has continued to encourage researchers to design and construct a variety of high-performance materials. Introducing mechanically interlocked structures into polymers has led to novel polymeric materials, called mechanically interlocked polymers (MIPs). Rotaxane-based MIPs are an important class, where the mechanically interlocked characteristic retains a high degree of structural freedom and mobility of their components, such as the rotation and sliding motions of rotaxane units. Therefore, these MIP materials are known to possess a unique set of properties, including mechanical robustness, adaptability and responsiveness, which endow them with potential applications in many emerging fields, such as protective materials, intelligent actuators, and mechanisorption. In this review, we outline the synthetic strategies, structure-property relationships, and application explorations of various polyrotaxanes, including linear polyrotaxanes, polyrotaxane networks, and rotaxane dendrimers.

Positive association of nap duration with risk of non-alcoholic fatty liver disease in an occupational population in Guangdong Province, China: a cross-sectional study.

BACKGROUND: A lack of sleep or disorder in sleep-wake cycles has been associated with metabolic impairments. However, few studies have investigated the association between daytime napping duration and the risk of non-alcoholic fatty liver disease. This study aimed to investigate the association of daytime napping duration with the risk of non-alcoholic fatty liver disease in a Chinese population. METHODS: This cross-sectional study analyzed data from the Health Management Center of Nanfang Hospital, Guangdong Province. A total of 3363 participants aged 20-79 years were recruited and admitted from January 20, 2018, to October 16, 2020. Non-alcoholic fatty liver disease was diagnosed using abdominal ultrasonography. The outcome was the association between daytime sleep duration and the risk of non-alcoholic fatty liver disease. RESULTS: Compared with non-nappers, long daytime nappers (≥ 60 min) were associated with a higher risk of non-alcoholic fatty liver disease in the crude model (odds ratio 2.138; 95% confidence interval 1.88-2.61, P < 0.05) and in the multivariable adjustment model (odds ratio 2.211; 95% confidence interval 1.042-4.690, P < 0.05) after adjusting for demographic, educational, and metabolic risk factors. The association was moderately enhanced with additional adjustments for night sleep duration and socioeconomic or other factors (odds ratio 2.253; 95% confidence interval 1.061-4.786, P = 0.035). CONCLUSION: In this cross-sectional study, daytime napping duration of ≥ 60 min was positively associated with the risk of non-alcoholic fatty liver disease in an occupational population of Guangdong Province after multivariable adjustment.

[Evaluation of the Nurses' Utilization of the Pain Management Information System Based on the Information System Success Model].

BACKGROUND: Pain records provide important data to medical teams to guide their provision of pain management interventions. Incomplete records and records that do not integrate pain data will affect patient safety. Use of information technology helps facilitate communication within the medical team and improve quality of care. PURPOSE: This study was designed to evaluate the effectiveness of a pain management information system. METHODS: The questionnaire survey method was employed in this study. The system-evaluation questionnaire was designed based on the six dimensions of the information system success model (ISSM), including system quality, information quality, service quality, intention to use, user satisfaction, and net benefits. Three months after the pain management system was implemented, the opinions of 282 nurses from a medical center in central Taiwan were collected. Research data were analyzed using descriptive and inferential statistical methods. RESULTS: Of the six dimensions, "information quality" received the highest average score (4.71). The two dimensions of "intention to use" and "user satisfaction" had the highest correlation with "net benefits". "User satisfaction" was found to have the highest predictive power for the "net benefits" of the system, with an explanatory power of about 81.2%. CONCLUSIONS: The pain management system considered in this study was shown to provide complete and accurate pain management information, which is an important factor affecting nurses' intention to use and satisfaction. The evaluation results based on the ISSM show the pain management system to be a good information system that generates accurate information and has a high intention-to-use rate and high rate of user satisfaction.

miR-144 suppresses cell proliferation and migration in colorectal cancer by targeting NRAS.

Colorectal cancer (CRC) is a type of malignant cancer that has become particularly prevalent worldwide. It is of crucial importance to CRC treatment that the underlying molecular mechanism of CRC progression is determined. The NRAS gene is an important small G protein that is involved in various biological processes, including cancers. NRAS is an oncogene in many neoplasms but its function and regulation in CRC have seldom been investigated. In this study, it was uncovered that the NRAS protein was significantly upregulated in CRC tissues. According to a bioinformatics prediction, we identified that miR-144 may target NRAS to suppress its expression. In vitro experiments indicated that miR-144 decreased NRAS expression in different CRC cell lines (SW480, LoVo, and Caco2). By inhibiting NRAS, miR-144 repress SW480 cell proliferation and migration. Moreover, miR-144 decelerated the growth of SW480 xenograft tumors in vivo by targeting NRAS. In summary, our results identified a novel miR-144-NRAS axis in CRC that could promote the research and treatment of CRC.

New Constituents from the Low Polar Fraction of the Fruits of Crataegus dahurica and Their Anti-Inflammatory Activity in RAW264.7 Cells.

The fruit of Crataegus dahurica Koehne was used to treat the disease of infantile indigestion and dyspepsia as an ethnic medicine and food. As a continuous work on finding the active constituents from the edible herbs, four new biphenyl derivatives (1-4), together with two known compounds (5 and 6), were obtained from the petroleum ether fraction of the fruits of C. dahurica. Their structures were determined by the extensive 1D and 2D NMR spectra and HR-MS spectrometry. Furthermore, the anti-inflammatory activities of all the isolated compounds were investigated, in which compound 4 showed moderately inhibitory effects on NO production in RAW264.7 cells without inducing cytotoxicity.

Rapamycin attenuates liver injury caused by vinyl chloride metabolite chloroethanol and lipopolysaccharide in mice.

Vinyl chloride (VC) is a prevalent environmental toxicant that is rapidly metabolized within the liver. Its metabolites have been shown to directly cause hepatic injury at high exposure levels. We have previously reported that VC metabolite, chloroethanol (CE), potentiates liver injury caused by lipopolysaccharide (LPS). Importantly, that study showed that CE alone, while not causing damage per se, was sufficient to alter hepatic metabolism and increase mTOR phosphorylation in mice, suggesting a possible role for the mTOR pathway. Here, we explored the effect of an mTOR inhibitor, rapamycin, in this model. C57BL/6 J mice were administered CE, followed by rapamycin 1 h and LPS 24 h later. As observed previously, the combination of CE and LPS significantly enhanced liver injury, inflammation, oxidative stress, and metabolic dysregulation. Rapamycin attenuated not only inflammation, but also restored the metabolic phenotype and protected against CE + LPS-induced oxidative stress. Importantly, rapamycin protected against mitochondrial damage and subsequent production of reactive oxygen species (ROS). The protective effect on mitochondrial function by rapamycin was mediated, by restoring the integrity of the electron transport chain at least in part, by blunting the deactivation of mitochondrial c-src, which is involved mitochondrial ROS production by electron transport chain leakage. Taken together, these results further demonstrate a significant role of mTOR-mediated pathways in VC-metabolite induced liver injury and provide further insight into VC-associated hepatic damage. As mTOR mediated pathways are very complex and rapamycin is a more global inhibitor, more specific mTOR (i.e. mTORC1) inhibitors should be considered in future studies.

Exposure to Vinyl Chloride and Its Influence on Western Diet-Induced Cardiac Remodeling.

Obesity, usually caused by high fat diets (HFD), is a major public health issue worldwide, causing obesity associated cardiomyopathy. Moreover, the environmental toxicant vinyl chloride (VC) can exacerbate HFD-induced fatty liver disease. However, whether VC serves to enhance obesity-associated cardiomyopathy remains unclear. This study aims to investigate the interaction of western diet (WD) containing relatively low fat (42%) with VC on cardiac remodeling and its underling mechanisms. Adult male C57BL/6J mice were exposed to WD coinhalation of low-dose VC (<1 ppm/d) for 12 weeks. Results showed that WD feeding for 12 weeks caused slight cardiac systolic dysfunction without significant hypertrophy or fibrosis, even with VC. Nevertheless, WD upregulated NF-κB function and expression of IL-1ß and PAI-1, while VC showed no significant impact on these effects. In contrast, WD together with VC significantly increased the expression of CHOP and TGF-ß1, key markers for endoplasmic reticulum stress and profibrotic cytokine, respectively. In summary, exposure to low-dose of environmental toxicant VC while a WD is consumed for a relatively short time does not have significant impact on cardiac remodeling except for a mild systolic dysfunction of the heart.

Immobilization of Sphingomonas sp. GY2B in polyvinyl alcohol-alginate-kaolin beads for efficient degradation of phenol against unfavorable environmental factors.

In this study, batch experiments were carried out to evaluate the biodegradation of phenol by Sphingomonas sp. GY2B, which were immobilized in polyvinyl alcohol (PVA)-sodium alginate-kaolin beads under different conditions. The optimal degradation performance was achieved by GY2B immobilized in beads containing 1.0% (w/v) of kaolin, 10% (w/v) of PVA, 0.3% (w/v) of sodium alginate, 10% (v/v) of biomass dosage, and exposed to an initial phenol concentration of 100 mg/L. The experimental results indicated that PVA-sodium alginate-kaolin beads can accelerate the degradation rate of phenol by reducing the degradation time and also improve degradation rate. The biodegradation rate of phenol by immobilized cells (16.79 ±â€¯0.81 mg/(L·h)) was significantly higher than that of free cells (11.49 ±â€¯1.29 mg/(L·h)) under the above optimal conditions. GY2B immobilized on beads was more competent than free GY2B in degradation under conditions with high phenol concentrations (up to 300 mg/L) and in strong acidic (pH = 1) and alkaline (pH = 12) environments. Higher phenol concentrations inhibit the biomass and reduce the biodegradation rate, while the lower biodegradation rate at low initial phenol concentrations is attributed to mass transfer limitations. The Haldane inhibitory model was in agreement with the experimental data well, revealing that phenol showed a considerable inhibitory effect on the biodegradation by Sphingomonas sp. GY2B, especially at concentrations higher than 90 mg/L. Intra-particle diffusion model analysis suggests that adsorption of phenol by immobilized beads was controlled by both rapid surface adsorption as well as pore diffusion mechanism. It's worth noting that the presence of 1 mg/L Cr(VI) enhanced the biodegradation of phenol by free cells, while Cr(VI) showed no obvious impact on the removal of phenol by immobilized cells. In addition, immobilized cells were reused 16 times and removed 99.5% phenol, and when stored at 4 °C for 90 days, more than 99% phenol was removed. These results showed that immobilized cells can significantly improve the microbial degradation performance, and protect microorganisms against unfavorable environment. It is implied that PVA -sodium alginate-kaolin beads have great potential to be applied in a practical and economical phenolic wastewater treatment system.

Human epididymal protein 4 and its combined detection show good diagnostic value in lung cancer: A retrospective study.

OBJECTIVES: This study aimed to assess the diagnostic value of human epididymal protein 4 (HE4), a potential novel biomarker for lung cancer, and its combined detection with five other conventional biomarkers in lung cancer diagnosis and subtyping. METHODS: In this retrospective study, 115 lung cancer patients, 50 patients with benign pulmonary disease, and 50 healthy controls were included. Serum HE4, progastrin-releasing peptide (ProGRP), squamous cell carcinoma (SCC) antigen, cytokeratin-19 fragment (CYFRA21-1), neuron-specific enolase (NSE), and carcinoembryonic antigen (CEA) were analyzed using the electrochemiluminescence immunoassay and chemiluminescence immunoassay. The receiver operating characteristic curve was performed to analyze the diagnostic efficacy of individual biomarkers in identifying both lung cancer and its histologic subtypes. RESULTS: All six biomarkers showed significantly elevated levels in the lung cancer group compared to both benign pulmonary disease and control groups (P < 0.05). Among the biomarkers evaluated, HE4 exhibited the highest diagnostic performance for lung cancer, lung adenocarcinoma, and lung squamous cell carcinoma with area under the curve (AUC) values of 0.921, 0.891, and 0.937, respectively. ProGRP was the optimal biomarker for small cell lung cancer with an AUC of 0.973. The combination of all six biomarkers yielded the largest AUCs in the diagnosis of lung cancer subtypes (0.937 for lung adenocarcinoma, 0.998 for lung squamous cell carcinoma, and 0.985 for small cell lung cancer). Furthermore, specific combinations, such as HE4 + CEA, HE4 + SCC, and ProGRP + HE4 + NSE, showed strong diagnostic performance in lung cancer. CONCLUSIONS: HE4 and its combined detection held substantial clinical significance in the diagnosis of lung cancer and its histologic subtyping, especially for lung adenocarcinoma and lung squamous cell carcinoma.

Bioaccumulation and transferreing for impacts on Cd and Pb by aphid consumption of the broad bean, Vicia faba L, in soil heavy metal pollution.

Heavy metal pollution threatens human and ecological health. Heavy metals can exist in the soil for a long time and migrate to organisms along the food chain. However, only a few studies have investigated the effects of a single stress on broad beans. Here, we aimed to characterize Cd and Pb bioaccumulation, at varying concentrations, in the broad bean, Vicia faba L. We also determined how the bioaccumulated metals are impacted by aphids that consume the plant. No significant difference was noted in the germination rates of broad beans at the early stage of planting (after 8 days), but eventually, the germination rates of broad beans at all time points first decreased and then increased, and the highest inhibition efficiency was observed in the T3 group (12.5 mg/L Cd2+ + 50 mg/L Pb2+). Fourteen days after planting, there was no significant difference in seedling height between the T5 (50 mg/L Cd2+ + 200 mg/L Pb2+) and control groups; however, that in the other groups decreased significantly and there was no dependence between stress concentration and inhibition efficiency. In addition, both Cd and Pb in the soil could be transferred to broad beans, and the concentration of Pb in the roots of broad beans was greater than that of Cd, whereas the opposite was observed in the stems and leaves. Notably, under mixed stress, aphids could significantly reduce the content of Cd in broad beans; similarly, the Pb content in the roots and stems of broad beans decreased significantly after being infested with aphids but increased significantly in the leaves. Further, the aphid infestation decreased the Pb content in the soil and the soil Cd content in the highest concentration group (T5 group) (50 mg/L Cd2+ + 200 mg/L Pb2+). These results highlight the necessity of focusing on the effect of insects on heavy metal remediation in plants and provide a new perspective for reducing plant Cd toxicity.

Single crystals of purely organic free-standing two-dimensional woven polymer networks.

The aesthetic and practicality of macroscopic fabrics continue to encourage chemists to weave molecules into interlaced patterns with the aim of providing emergent physical and chemical properties when compared with their starting materials. Weaving purely organic molecular threads into flawless two-dimensional patterns remains a formidable challenge, even though its feasibility has been proposed on several occasions. Herein we describe the synthesis of a flawless, purely organic, free-standing two-dimensional woven polymer network driven by dative B-N bonds. Single crystals of this woven polymer network were obtained and its well-defined woven topology was revealed by X-ray diffraction analysis. Free-standing two-dimensional monolayer nanosheets of the woven polymer network were exfoliated from the layered crystals using Scotch Magic Tape. The surface features of the nanosheets were investigated by integrated low-dose and cryogenic electron microscopy imaging techniques. These findings demonstrate the precise construction of purely organic woven polymer networks and highlight the unique opportunities for the application of woven topologies in two-dimensional organic materials.

Improvement of obesity-induced fatty liver disease by intermittent hypoxia exposure in a murine model.

Background: The high prevalence of non-alcoholic fatty liver disease (NAFLD) in the world raises an important concern for human health. The western diet containing high fat and fructose is the risk factor for NAFLD development. Intermittent hypoxia (IH), known as the basis of obstructive sleep apnea (OSA), normally is correlated with impaired liver function. However, the role of IH in liver injury prevention has been revealed by many other studies based on the different IH paradigms. The current study, therefore, tests the impact of IH on the liver of high-fat and high-fructose diet (HFHFD) fed mice. Material and Method: Mice were exposed to IH (2 min cycle, FiO2 8% for 20 s, FiO2 20.9% for 100 s; 12 h/day) or intermittent air (FiO2 20.9%) for 15 weeks, with normal diet (ND) or high-fat and high-fructose diet (HFHFD). Indices of liver injury and metabolism were measured. Results: IH causes no overt liver injury in mice fed an ND. However, HFHFD-induced lipid accumulation, lipid peroxidation, neutrophil infiltration, and apoptotic process were significantly attenuated by IH exposure. Importantly, IH exposure altered bile acids composition and shifted the hepatic bile acids towards FXR agonism, which was involved in the protection of IH against HFHFD. Conclusion: These results support that the IH pattern in our model prevents liver injury from HFHFD in experimental NAFLD.

Applications of macrocycle-based solid-state host-guest chemistry.

Macrocyclic molecules have been used in various fields owing to their guest binding properties. Macrocycle-based host-guest chemistry in solution can allow for precise control of complex formation. Although solution-phase host-guest complexes are easily prepared, their limited stability and processability prevent widespread application. Extending host-guest chemistry from solution to the solid state results in complexes that are generally more robust, enabling easier processing and broadened applications. Macrocyclic compounds in the solid state can encapsulate guests with larger affinities than their soluble counterparts. This is crucial for use in applications such as separation science and devices. In this Review, we summarize recent progress in macrocycle-based solid-state host-guest chemistry and discuss the basic physical chemistry of these complexes. Representative macrocycles and their solid-state complexes are explored, as well as potential applications. Finally, perspectives and challenges are discussed.