Poly(ethylene-co-vinyl acetate) (PEVAc) nanocomposites containing exfoliated α-zirconium phosphate (ZrP) have been prepared using a simple solution mixing method to improve their barrier and ...mechanical properties. ZrP was pre-exfoliated with a surfactant, followed by additional targeted surface functionalization and surfactant exchange to allow for hydrogen bonding of ZrP with the acetate functionality on PEVAc and to improve ZrP surface hydrophobicity. The solvent is found to play an important role in stabilizing ZrP exfoliation in the presence of PEVAc to retain full exfoliation and homogeneous dispersion upon the removal of the solvent. The PEVAc/ZrP nanocomposite exhibits greatly improved oxygen barrier, melt strength, and mechanical properties. The usefulness of the present study for the preparation of olefinic polymer nanocomposites is discussed.
As one of the main gynecological cancers, ovarian cancer (OC) has an unfavourable outcomes owing to its high recurrence and metastasis rate. Our previous studies have revealed that LINC01296 ...functions as an oncogene in OC, but the underlying mechanism has not been explored. The aim of this paper was to further investigate that how LINC01296 plays a role in OC. Through online software prediction, miR-29c-3p has been discriminated as the target miRNA of LINC01296 for further research, and subsequent luciferase assay confirmed bioinformatics prediction. Then the data obtained from the two databases (GSE119055 and GSE83693) were analyzed by GEO2R for differential gene analysis. The results indicated that the miR-29c-3p was lowly expressed in OC tissues than that in normal ovarian tissues, and its expression in recurrent OC tissues was lower than that in primary OC tissues. Simultaneously, Kaplan-Meier survival analysis illustrated that the lower expression of miR-29c-3p was interrelated to unfavourable outcomes of OC. Further, the qRT-PCR data revealed that the miR-29c-3p expression in OC cell lines (SKOV-3 and OVCAR-3) was markedly declined than that in normal control cells (IOSE80). Subsequently, the functional experiments, such as CCK8, colony formation and Transwell assays, prompted that inhibition of miR-29c-3p can obviously increase the proliferation, invasion and migration of OVCAR3 and SKOV3 cells compared with control group, while downregulation of LINC01296 showed an opposite result. It is worth noting that downregulation of LINC01296 can reverse the effect of miR-29c-3p suppression on OC cells. Finally, we detected the changes of EMT-related proteins by western blot experiment, and reached a similar conclusion that knockdown of LINC01296 reversed the EMT caused by miR-29c-3p inhibition. In sum up, the cancer-promoting function of LINC01296 was achieved by regulating the expression of miR-29c-3p, and LINC01296/miR-29c-3p axis mediates the mechanical regulation of EMT in OC cells, hoping to provide the novel biomarkers and possibilities for OC therapy.
Flexible porous materials generally switch their structures in response to guest removal or incorporation. However, the design of porous materials with empty shape-switchable pores remains a ...formidable challenge. Here, we demonstrate that the structural transition between an empty orthorhombic phase and an empty tetragonal phase in a flexible porous dodecatuple intercatenated supramolecular organic framework can be controlled cooperatively through guest incorporation and thermal treatment, thus inducing empty shape-memory nanopores. Moreover, the empty orthorhombic phase was observed to exhibit superior thermoelasticity, and the molecular-scale structural mobility could be transmitted to a macroscopic crystal shape change. The driving force of the shape-memory behaviour was elucidated in terms of potential energy. These two interconvertible empty phases with different pore shapes, that is, the orthorhombic phase with rectangular pores and the tetragonal phase with square pores, completely reject or weakly adsorb N2 at 77 K, respectively.
Hydrothermal synthesis has afforded five divalent zinc coordination polymers containing 4-(4-carboxyphenyl)-2,2':6',2''-terpyridine (HL1) or its isomer 4-(4-carboxyphenyl)-2,2':4',4''-terpyridine ...(HL2), with or without the addition of auxiliary ligands, 1,3,5-benzenetricarboxylic acid (H3btc) and 1,4-benzenedicarboxylic acid (H2bdc). Their structures have been characterized by single crystal X-ray analyses and further characterized by infrared spectra, elemental analyses, powder X-ray diffraction, thermogravimetric analyses and photoluminescent spectra. Across this series, the π···π interactions have a dramatic impact on the self-assembly of these entanglement structures, in either case it can exert an important structure-directing role. In addition, the disposition of pyridine nitrogen atoms in ligands also plays a large role in structure direction in this system. Complex 1 is a 2D + 2D→3D inclined polycatenated coordination polymer based on the resulting array of 2D (6,3) layers constructed by 1D→2D π···π directed self-assembly. Complex 2 is assembled into a 3D framework by means of 1D + 1D→3D mutual interdigitation based on 1D→1D self-assembly driven by π···π stacking interactions. Complex 3 shows a 2D + 2D→3D interdigital network involving 2D + 2D→2D parallel interpenetrated and 2D + 2D→2D interdigital (4,4) layer motifs. Complex 4 displays a 2D + 2D→3D polythreaded framework based on a 2D (4,4) network comprised of alternating rings and rods. Complex 5 is a (3,4)-connected 3D framework with topology (4.8(2).10(3))(4.8(2)). In comparison with covalently connected entanglements, such π···π directing self-assembly of entanglements are far less explored, especially, polycatenane based on 1D chain motifs and polythread based on 2D layer motifs are rarely reported. Furthermore, the luminescent properties of complexes 1-5 at room temperature have also been studied in detail herein.
China is in the midst of history's largest flow of rural-urban migration in the world; a flow that includes growing numbers of children and adolescents. Their health status is an important public ...health issue. This study compares self-rated physical and mental health of migrant and local adolescents in China, and examines to what extent layered social connections account for health outcomes.
In 2010, we conducted a cross-sectional study among middle school students in Pudong New Area, Shanghai. Information about health status, social connections, and demographic factors were collected using a questionnaire survey. After controlling for sociodemographic factors, we used the t-test, Chi-square analysis, and a series of regression models to compare differences in health outcomes and explore the effects of social connections.
Migrant adolescents reported significantly higher rates of good physical health. However, they also had significantly fewer social connections, lower self-esteem, and higher levels of depression than their native peers. Family cohesion was associated with depressive symptoms and low self-esteem among all adolescents; peer association and social cohesion played major roles in migrants' well-being. Gender, age, and socioeconomic (SES) factors also affected adolescents' self-rated physical and mental health.
Self-rated data suggest that migrant adolescents enjoy a physical health advantage and a mental health disadvantage. Layered social connections, such as peer association and social cohesion, may be particularly important for migrants. A public health effort is required to improve the health status of migrant youth.
The Beijing Daxing International Airport is a newly opened airport, and a comprehensive emission inventory of air pollution sources has not yet been established. The lack of basic inventory data will ...cause difficulties in controlling the air quality (AQ) in and around the airport. Based on actual flight data, we established a comprehensive emission inventory (carbon monoxide (CO), nitrogen oxides (NOX), hydrocarbons (HC), sulfur dioxide (SO2), particulate matter (PM), and carbon dioxide (CO2)) at Beijing Daxing International Airport. Furthermore, we evaluated the impact of airport emissions on the AQ of the surrounding areas using the ADMS-Airport model. The results showed that Beijing Daxing International Airport emitted 1.15 E+03, 1.76 E+03, 1.38 E+02, 1.16 E+02, 3.53 E+01, and 3.75 E+05 t of CO, NOX, HC, SO2, PM, and CO2, respectively, from July 1, 2020, to June 30, 2021. Engine exhaust emissions (landing and takeoff LTO cycles) dominated all airport pollutant emissions except for PM from the power plant. Among all aircraft types, B738 emitted the most CO2, as it accounted for almost half of all the flights. The AQ simulations showed that the air pollutant diffusion range was concentrated within 15 km of the airport and the surrounding areas. The contribution of airport emissions to NOX concentrations was most apparent under the most unfavorable meteorological conditions. Based on the average pollutant concentration during the study period, the Gu'an Li Hu Primary School station was the most affected. In particular, NOX concentrations at this station were approximately 50% higher in winter than in summer. Currently, the airport's contribution to pollution in the surrounding areas is insignificant. However, with the continuous increase in the number of flights at the airport, its impact on the AQ in the surrounding areas must be addressed in the future.
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•An emission inventory including all airport-related sources was established.•The airport emissions made the most obvious contribution to NOX concentration.•Airport contributed more pollutant concentrations in clean weather than in polluted day.•The airport emissions have the most significant impact on the surrounding 5 km area.
A digital technique is presented that records peri-implant soft tissue contours and the emergence profile. The architecture of interim restorations and adjacent teeth, the position of the implant, ...and the emergence profile of interim prostheses are scanned and registered to design a zirconia frame and to form a digital cast.
To explore the significance of the resistance to polymyxin resistance of the extensively drug resistant
(XDRAB) lipopolysaccharide (LPS)
,
,
and to screen appropriate combination therapy.
In the past ...two years, 72 XDRAB in the secretions of our patients were selected as the research object. According to the minimum inhibitory concentration (MIC) of the XDRAB strain on polymyxin, they were included in the drug resistance group and the sensitive group. The gene sequences of strains
,
,
were compared with the standard strains to analyze gene mutations and compared the mutation rates in the drug resistant group and the sensitive group. The efficacy of the combination drugs was evaluated by microcheckerboard dilution method, including polymyxin+imipenem group, polymyxin+meropenem group, polymyxin+cefoperazone/sulbactam group, polymyxin+levofloxacin group, and polymyxin+fosfomycin group. Calculated the fractional inhibitory concentration (FIC) index of the combined medication regimen and compared the percentage of
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