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Thermoplastic elastomers such as polyether

Bulk amorphous polymers become stretched and parallel-aligned under loading stress, and their intermolecular cooperation slows down the subsequent stress relaxation process. By means of dynamic Monte Carlo simulations, we employed the linear viscoelastic Maxwell model for stress relaxation of single polymers and investigated their intermolecular cooperation in the stress relaxation process of stretched and parallel-aligned bulk amorphous polymers. We carried out thermal fluctuation analysis on the reproduced Debye relaxation and Arrhenius fluid behaviors of bulk polymers. We found a transient state with stretch-coil coexistence among polymers in the stress relaxation process. Further structure analysis revealed a scenario of local jamming at the transient state, resulting in an entropy barrier for stretch-coil transition of partial polymers. The microscopic mechanism of intermolecular cooperation appears as unique to polymer stress relaxation, which interprets the hydrodynamic interactions as one of essential factors raising a high viscosity in bulk amorphous polymers. Our simulations set up a platform of molecular modeling in the study of polymer stress relaxation, which brought new insights into polymer dynamics and the related mechanical/rheological properties.

Parental marital satisfaction is a well-established protective factor for prosocial behavior in adolescents, yet the parental socialization of adolescent prosocial behavior is limited in Chinese culture. Furthermore, it remains unknown whether the association between parental marital satisfaction and adolescent prosocial behavior is mediated by parent–child intimacy and/or adolescent empathy. The present study examined these associations in 480 students (50.4% male, age = 12.7 ± 0.54 years) and one of their parents. Path analysis (Mplus) revealed that parental marital satisfaction was related to a high level of parent–child intimacy, which was, in turn, associated with a high level of adolescent empathy, which itself predicted adolescent prosocial behavior. The serial mediation effect differed between boys and girls. Specifically, compared with boys, girls’ parent–child intimacy was a stronger predictor of their empathy, and empathy had a stronger predictive effect on their prosocial behavior. Several implications for interventions and policies for increasing prosocial behavior in children are suggested.

Multiblock copolymers containing alternating semicrystalline and molten blocks are good thermoplastic elastomers. Their crystallization in the stretching process is however complicated by the dilution effects, prior microphase separation and contrast chain rigidity of the molten blocks. We designed our systematic investigation with three integrated steps, and herein, as the first step, we considered only the dilution effects without prior microphase separation and contrast chain rigidity. We compared two extreme situations of local dilution separately corresponding to parallel-posited and antiparallel-posited block copolymers upon strain-induced crystallization. Our dynamic Monte Carlo simulations of diblock and tetrablock copolymers demonstrated that the stretching introduces a constraint on the diffusion of locally posited crystallizable blocks along the stretching direction for crystallization and thus enhances the dilution effects to result in a higher diversity in crystal stabilities. We observed that the strain-induced crystallization of parallel-posited copolymers behaved like the melt crystallization of homopolymers; in contrast, the strain-induced crystallization of antiparallel-posited copolymers yielded crystallites near the block junction, which are relatively small and less stable due to their local dilution suppressing their melting points. Similar to the case of spider dragline silks, two contrasting stabilities of crystallites in semicrystalline multiblock copolymers explain their good toughness. Our modeling approach paves the way toward a better understanding of the structure-property relationship in the semicrystalline thermoplastic elastomers.

H9N2 avian influenza viruses (AIVs) circulate globally in poultry and have become the dominant AIV subtype in China in recent years. Previously, we demonstrated that the H9N2 virus (A/chicken/Eastern China/SDKD1/2015) naturally harbors a mammalian-adaptive molecular factor (627K) in the PB2 protein and is weakly pathogenic in mice. Here, we focused on new markers for virulence in mammals. A mouse-adapted H9N2 virus was serially passaged in mice by infecting their lungs. As expected, infected mice showed clinical symptoms and died at passage six. A comparison between the wild-type and mouse-adapted virus sequences identified amino acid substitutions in the hemagglutinin (HA) protein. H9N2 viruses with the T187P ​+ ​M227L double mutation exhibited an increased affinity to human-type (SAα2,6Gal) receptors and significantly enhanced viral attachment to mouse lung tissues, which contributed to enhancing viral replication and virulence in mice. Additionally, HA with the T187P ​+ ​M227L mutation enabled H9N2 viral transmission in guinea pigs via direct contact. AIV pathogenicity in mice is a polygenic trait. Our results demonstrated that these HA mutations might be combined with PB2-627K to significantly increase H9N2 virulence in mice, and this enhanced virulence was achieved in other H9N2 AIVs by generating the same combination of mutations. In summary, our study identified novel key elements in the HA protein that are required for H9N2 pathogenicity in mice and provided valuable insights into pandemic preparedness against emerging H9N2 strains.

Previous studies have identified sex differences in self-esteem and internalizing and externalizing problem behaviors. Using cross-sectional data from 483 children (67.3% males, all Han Chinese) aged 8.97 to 17.0 years in a rural China’s boarding school, this study examined whether parenting styles, teacher support and peer support mediated the effect of sex on self-esteem and problem behaviors and whether the mediation model differed between children left behind by one or both of their migrant parents and children of non-migrant families. The results indicated that peer support suppressed the relations of sex to self-esteem and internalizing problem behaviors. Low peer support mediated the relationship of being boys with more externalizing problem behaviors. The significantly different path between left-behind children and non-left-behind children was based on the association of parental refusal with self-esteem.

Background: An aging population and an increase in the proportion of disabled elderly have brought an unprecedented global challenge, especially in China. Aside lack of professional long-term care facilities, the shortage of human resource for old-age care is also a major threat. Therefore, this study tries to forecast the demand scale of nursing staff for the oldest-old in 2025 in China servicing as a reference for the development plan of human resource for elderly nursing. Methods: Based on CLHLS (Chinese Longitudinal Healthy Longevity Survey) 2011 and 2014, Logit model was used to construct the transition probability matrix of the elderly’s health status (health/mild/moderate/severe disability and death). By using the data of the elderly population aged 65 or over in the 2010 national population census, we projected the number of Chinese oldest-old population in different health status by 2025 through Markov model and projected the scale of the demand of nursing staff combined with the human population ratio method. Results: The forecast shows that the Chinese oldest-old population is about 52.6 million, among which 46.9 million are healthy, 3.7 million are mild, 0.8 million are moderate, and 1.2 million are severely disabled in 2025. Concurrently, the demand scale of nursing staff will be 5.6 million according to the low standard and 11.5 million according to the high standard. Thus, human resource supply of long-term care is worrying. Conclusion: In 2025, the population size of the Chinese oldest-old will be further expanded, and the demand of care will increase accordingly, leading to a vast gap in the nursing staff. Therefore, it is urgent to build a professional nursing staff with excellent comprehensive quality and reasonable quantity, to ensure the sustainable development of China’s elderly care service industry.

In consideration of the nucleophilic capacity of thiophenols, which could cleave sulfonamide bond under neutral conditions, a cyclometalated iridium(III) complex (probe 1) comprised 2,4-dinitrobenzenesulfonamide (DNBS) as the recognition unit was designed and synthesized to high selectivity and sensitivity detect thiophenols successfully based on internal charge transfer (ICT) mechanism. Upon addition with thiophenols to 20% DMSO/PBS solution of nearly non-fluorescent probe 1 (10 μM, pH = 7.4), fluorescent product (complex 2) was formed after cleavage of DNBS group and a significant emission enhancement at 470 nm was observed. In addition, it could be successfully applied to detect thiophenol in water samples with a high recovery, confirming its practical value in environment science.

Joint prevention and control of atmospheric pollution (JPCAP) policies play a vital role in alleviating regional pollution. Based on Latent Dirichlet Allocation (LDA) model, we construct two policy strength measures of effectiveness and number, and investigate the effects of policy strength on air pollutant emissions for four types of JPCAP policies. The results show that the effects of economic incentive policy tools and supporting policy tools on emission reduction deviate significantly from policy preferences. Economic incentive policy tools are the most effective in promoting emission reductions in SO2, NOx and dust, but their effectiveness are the lowest in reality. Supporting policy tools, with the highest strength, have little effect on emission reduction. Command-control policies and persuasion policies are both relatively high in quantity and effectiveness. In addition, policy strength plays a more important role in reducing air pollutants in key regions than in non-key regions. JPCAP policies have gradually changed from a single policy tool to multiple policy tools, and the government shifted its attention to improving the legal effectiveness of policies after 2015. Finally, we propose some policy implications to optimize JPCAP policies and address regional air pollution problem.

Stress relaxation is a common process that reduces the deformation of polymer coils against the strain-induced crystallization during the processing of polymeric materials for fibers, thinfilms and molding plastics. By introducing Maxwell model of stress relaxation into each polymer in dynamic Monte Carlo simulations, we compared stress-induced to strain-induced polymer crystallization under parallel conditions of various strain rates and temperatures. The results demonstrated the scenario of competitions among the factors of stress relaxation, strain rates and temperatures in the crystallization process. We found that, owing to fast stretching, the limited extent of stress relaxation plays the dominantly kinetic role rather than the expected thermodynamic role in the retardation of crystallization, similar to the factor of high strain rate. In addition, we observed the enhanced stress relaxation during the post-growth process of polymer crystallization, which influences the finally achieved crystallinity and crystal morphology. Our results facilitate a better understanding of polymer crystallization during the fast stretching processing.

IntroductionLimited clinical studies have been conducted on rare solid tumours, and there are few guidelines on the diagnosis and treatment, including experiences with targeted therapy and immunotherapy, of rare solid tumours in China, resulting in limited treatment options and poor outcomes. This study first proposes a definition of rare tumours and is designed to test the preliminary efficacy of targeted and immunotherapy drugs for the treatment of rare tumours.Methods and analysisThis is a phase II, open-label, non-randomised, multiarm, single-centre clinical trial in patients with advanced rare solid tumours who failed standard treatment; the study aims to evaluate the safety and efficacy of targeted drugs in patients with advanced rare solid tumours with corresponding actionable alterations, as well as the safety and efficacy of immune checkpoint (programmed death receptor inhibitor 1, PD-1) inhibitors in patients with advanced rare solid tumours without actionable alterations. Patients with advanced rare tumours who fail standardised treatment and carry actionable alterations (Epidermal growth factor receptor (EGFR) mutations, ALK gene fusions, ROS-1 gene fusions, C-MET gene amplifications/mutations, BRAF mutations, CDKN2A mutations, BRCA1/2 mutations, HER-2 mutations/overexpressions/amplifications or C-KIT mutations) will be enrolled in the targeted therapy arm and be given the corresponding targeted drugs. Patients without actionable alterations will be enrolled in the PD-1 inhibitor arm and be treated with sintilimab. After the patients treated with vemurafenib, niraparib and palbociclib acquire resistance, they will receive combination treatment with sintilimab or atezolizumab. With the use of Simon’s two-stage Minimax design, and the sample size was estimated to be 770. The primary endpoint of this study is the objective response rate. The secondary endpoints are progression-free survival in the targeted treatment group and single-agent immunotherapy group; the duration of response in the targeted therapy and single-agent immunotherapy groups; durable clinical benefit in the single-agent immunotherapy group; and the incidence of adverse events.Ethics and disseminationEthics approval was obtained from the Chinese Academy of Medical Sciences (ID: 20/132-2328). The results from this study will be actively disseminated through manuscript publications and conference presentations.Trial registration numbersNCT04423185; ChiCTR2000039310.

How the repeating-unit chemistry dominates polymer viscoelasticity remains as unclear. We employed four-set interaction parameters to represent thermodynamic and kinetic aspects of local intrachain and interchain interactions between monomers, which characterize polymer repeating-unit chemistry. We performed kinetic Monte Carlo simulations of Debye stress relaxation in stretched and parallel-aligned bulk amorphous polymers and evaluated the relative importance of each interactions in the diffusion energy derived from their Arrhenius fluid behaviors. The results demonstrated that, under the same strengths, the kinetic aspects of intrachain and interchain interactions raise much higher diffusion energies than their thermodynamic aspects. We discussed the example case of polyethylene. Our work paves the way towards the prediction of the structure-property relationship of the mechanical properties in bulk amorphous polymers.

A red-emitting cyclometalated Ir(III) complex-based phosphorescent probe 1 was designed and synthesized to selectively and sensitively detect thiophenol in 90% DMSO/PBS (0.01 M, pH = 7.4) solution with a low detection limited (LOD = 8.68 × 10−7 mol L−1). For probe 1, cyclometalated [Ir(ppy)2Phen]+ moiety acted as phosphor, 2,4-dinitrobenzenesulfonyl (DNBS) group was regarded as recognition site and phosphorescent quencher, and polyether (1-ethoxy-2-(2-methoxyethoxy)ethane) units in the C^N ligands was introduced to improve the water solubility of complex. Due to strong electro-withdrawing DNBS moiety, probe 1 exhibited very week phosphorescence at 600 nm. Upon addition with thiophenol to probe 1 and DNBS moiety left due to the cleavage of sulfonamide bond though nucleophilic elimination reaction, an obvious phosphorescence at 600 nm belong to complex 2 could be observed and the solution displayed red phosphorescent color. Meanwhile, the probe possessed a large Stokes shift (180 nm) and a relatively larger phosphorescence lifetime (τ = 5.265 μs). At the same time, the probe could be used for quantitative detection of thiophenol in actual water samples with high recovery, and detect thiophenol in human serum (100-fold dilution by PBS).

Lymphocyte homing to draining lymph nodes is critical for the initiation of immune responses. Secondary lymphoid organs of germ-free mice are underdeveloped. How gut commensal microbes remotely regulate cellularity and volume of secondary lymphoid organs remains unknown. We report here that, driven by commensal fungi, a wave of CD45(+)CD103(+)RALDH(+) cells migrates to the peripheral lymph nodes after birth. The arrival of these cells introduces high amounts of retinoic acid, mediates the neonatal to adult addressin switch on endothelial cells, and directs the homing of lymphocytes to both gut-associated lymphoid tissues and peripheral lymph nodes. In adult mice, a small number of these RALDH(+) cells might serve to maintain the volume of secondary lymphoid organs. Homing deficiency of these cells was associated with lymph node attrition in vitamin-A-deficient mice, suggesting a perpetual dependence on retinoic acid signaling for structural and functional maintenance of peripheral immune organs.

A novel cyclometalated iridium(III) complex 1oo including two photochromic diarylethene (DTE) units and 2,4-dinitrobenzenesulfonyl (DNBS) group was designed and synthesized as a probe for thiophenol. Due to the intramolecular charge transfer (ICT) mechanism, probe 1oo displayed almost non-fluorescence. After nucleophilic elimination reaction occurred triggered by thiophenol a fluorescence complex 2oo was generated, the ICT process was blocked and obvious fluorescence enhancement centred at ca. 450 nm was observed. Moreover, during the detection process, fluorescent behavior of probe 1oo could be modulated upon alternate irradiations of UV and Vis light, ascribed to photochromic diarylethene molecules in the C^N ligands could play the part of fluorescent switch. Probe 1oo exhibited excellent sensitivity (LOD: 2.43 μM), selectivity and rapid response (15 min) to thiophenol.

Vibration-based energy harvesting using piezoelectric circular diaphragms (PCDs) has drawn many attentions in the recent decades, in which a structure with the central mass (C-mass) configuration was widely employed. In this work, we propose a new configuration with the annular proof mass (A-mass) where an improved energy harvesting is promised. Combining the numerical analysis using the circuit-coupled piezoelectric simulation and experimental validation using the even-width annular the PCDs via modifying the mass configurations as well as the parameters piv1 and piv2 which indicates the ratio between the inner boundary radius and the piezoelectric ceramic radius and the ratio between outer boundary radius and the substrate radius, respectively. The impedance-matched output power of full-electrode PCDs was also collected with varying structural parameters and some distinct improvement was measured on certain structural parameters. The power increases from 14.1mW to 19.0mW after changing the configuration of samples from C-mass to A-mass with the same parameters (piv1, piv2)=(0.16,0.9), showing the considerable improvement in energy harvesting by using A-mass configuration.

BACKGROUND: The pathophysiology of pelvic floor dysfunction resulting in stress urinary incontinence (SUI) in women is complex. Evidence suggests that there is also a genetic predisposition towards SUI. We sought to identify differentially expressed genes involved in extracellular matrix (ECM) metabolism in vaginal tissues from women with SUI in the secretory phase of menses compared with asymptomatic women. METHODS: Tissue samples were taken from the periurethral vaginal wall of five pairs of premenopausal, age-matched SUI and continent women and subjected to microarray analysis using the GeneChip Human Genome U133 oligonucleotide chip set. RESULTS: Extensive statistical analyses generated a list of 79 differentially expressed genes. Elafin, keratin 16, collagen type XVII and plakophilin 1 were consistently identified as up-regulated ECM genes. Elafin, a serine protease inhibitor involved in the elastin degradation pathway and wound healing, was expressed in pelvic fibroblasts and confirmed by Western blot, quantitative competitive PCR and immunofluorescence cell staining. CONCLUSIONS: Genes involved in elastin metabolism were differentially expressed in vaginal tissue from women with SUI, suggesting that elastin remodelling may be important in the molecular aetiology of SUI.

In this paper, we introduce a modified version of linear discriminant analysis, called the "shrunken centroids regularized discriminant analysis" (SCRDA). This method generalizes the idea of the "nearest shrunken centroids" (NSC) (Tibshirani and others, 2003) into the classical discriminant analysis. The SCRDA method is specially designed for classification problems in high dimension low sample size situations, for example, microarray data. Through both simulated data and real life data, it is shown that this method performs very well in multivariate classification problems, often outperforms the PAM method (using the NSC algorithm) and can be as competitive as the support vector machines classifiers. It is also suitable for feature elimination purpose and can be used as gene selection method. The open source R package for this method (named "rda") is available on CRAN (http://www.r-project.org) for download and testing.

Circulating T cells from many cancer patients are known to be dysfunctional and undergo spontaneous apoptosis. We used microarray technology to determine whether gene expression differences exist in T cells from melanoma patients versus healthy subjects, which may underlie these abnormalities. To maximize the resolution of our data, we sort purified CD8+ subsets and amplified the extracted RNA for microarray analysis. These analyses show subtle but statistically significant expression differences for 10 genes in T cells from melanoma patients versus healthy controls, which were additionally confirmed by quantitative real-time PCR analysis. Whereas none of these genes are members of the classical apoptosis pathways, several may be linked to apoptosis. To additionally investigate the significance of these 10 genes, we combined them into a classifier and found that they provide a much better discrimination between melanoma and healthy T cells as compared with a classifier built uniquely with classical apoptosis-related genes. These results suggest the possible engagement of an alternative apoptosis pathway in circulating T cells from cancer patients.