RESUMO
Aiming at the excellent killing effect of N-phenylmaleimide (N-PMI) on microorganisms, this article used structural simulation analysis, fluorescence analysis, confocal laser scanning microscope and SEM to find that the double bond in N-PMI could interact with the sulfur groups in the membrane protein, changing its conformation, rupturing the plasma membrane of the cell, leaking the contents, and ultimately causing the death of the microorganisms. Therefore, once the double bond participated in the polymerization, N-PMI lost its antimicrobial function. N-PMI could achieve azeotropic copolymerization with MMA through reactive extrusion polymerization. N-PMI with a content of 5 % can be evenly inserted into the PMMA chain segment during the copolymerization reaction, thereby increasing the Tg of pure PMMA by up to 15 °C, which provided the PMMA-co-PMI copolymer with resistance to boiling water sterilization advantageous conditions. In addition, N-PMI with a content of 5 % has little effect on the transparency of PMMA after participating in the copolymerization. Moreover, the trace amount of residual N-PMI made the material have excellent antimicrobial function, and the bacteriostatic zone is extremely small, which provided an excellent guarantee for the safety and durability of the material. As a medical biological material, the PMMA-co-PMI copolymer has a good industrialization application prospects.
Assuntos
Anti-Infecciosos , Polimetil Metacrilato , Antibacterianos/farmacologia , Maleimidas , Polímeros/química , Polímeros/farmacologia , Polimetil Metacrilato/química , Polimetil Metacrilato/farmacologiaRESUMO
We present here that easily available organic salts can stabilize/modify niobium (Nb) oxo-clusters. The as-synthesized Nb oxo-clusters have been characterized by various methods. These Nb oxo-clusters were catalytically active for the epoxidation of allylic alcohols and olefins with H2O2 as an oxidant. Notably, Nb-OC@TBAF-0.5 appeared as highly dispersed nanosized particles and showed the highest catalytic activity, which can be attributed to the following reasons on the basis of characterization. First, the strong coordination of fluorine ions with Nb sites and the steric protection with bulky organic cations led to high stabilization and dispersion of the oxo-clusters in the course of the reaction. Second, a hydrogen-bond interaction between the coordinated fluorine atom and the -OH group of allylic alcohol favored the epoxidation reaction. Third, the electron density of Nb sites decreased due to the strong electron-withdrawing ability of F- adjacent to Nb sites, thus promoting the electrophilic oxygen transfer to the CâC bond.
RESUMO
Past studies have shown that the prevalence of gestational diabetes mellitus (GDM) has been underestimated, and this can have major implications for healthcare planning. With the changes in diagnostic criteria for GDM, we wanted to assess the accuracy of the diagnosis in a private hospital setting. Using data from the hospital's obstetric database, medical records and a private pathology provider, we established the true prevalence of GDM and compared it with the NSW Perinatal Data Collection. The recorded prevalence of 6.8% was well below the real value of 15.0%.
Assuntos
Diabetes Gestacional/diagnóstico , Diabetes Gestacional/epidemiologia , Prontuários Médicos , Coleta de Dados/métodos , Bases de Dados Factuais , Feminino , Hospitais Privados , Humanos , New South Wales/epidemiologia , Gravidez , PrevalênciaRESUMO
The intestinal epithelium dynamically controls cell cycle, yet no experimental platform exists for directly analyzing cell cycle phases in non-immortalized human intestinal epithelial cells (IECs). Here, we present two reporters and a complete platform for analyzing cell cycle phases in live primary human IECs. We interrogate the transcriptional identity of IECs grown on soft collagen, develop two fluorescent cell cycle reporter IEC lines, design and 3D print a collagen press to make chamber slides for optimal imaging while supporting primary human IEC growth, live image cell cycle dynamics, then assemble a computational pipeline building upon free-to-use programs for semi-automated analysis of cell cycle phases. The PIP-FUCCI construct allows for assigning cell cycle phase from a single image of living cells, and our PIP-H2A construct allows for semi-automated direct quantification of cell cycle phase lengths using our publicly available computational pipeline. Treating PIP-FUCCI IECs with oligomycin demonstrates that inhibiting mitochondrial respiration lengthens G1 phase, and PIP-H2A cells allow us to measure that oligomycin differentially lengthens S and G2/M phases across heterogeneous IECs. These platforms provide opportunities for future studies on pharmaceutical effects on the intestinal epithelium, cell cycle regulation, and more.
Assuntos
Ciclo Celular , Células Epiteliais , Mucosa Intestinal , Humanos , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Oligomicinas/farmacologia , Células CultivadasRESUMO
In this study, the mechanism of radical polymerization was further explored by pre-dissolving different polymers and studying the kinetics of the bulk polymerization of methyl methacrylate (MMA) under shear-free conditions. Based on the analysis of the conversion and absolute molecular weight, it was found that, contrary to the shearing effect, the inert polymer with viscosity was the key factor to preventing the mutual termination of radical active species and reducing the termination rate constant k t. Therefore, pre-dissolving the polymer could increase the polymerization rate and molecular weight of the system simultaneously, making the polymerization system enter the automatic acceleration zone faster and greatly reducing the generation of small molecular weight polymers, leading to a narrower molecular weight distribution. When the system entered the auto-acceleration zone, k t decreased rapidly and greatly and entered the second steady-state polymerization stage. Then, with the increase in the polymerization conversion, the molecular weight gradually increased, while the polymerization rate gradually decreased. In shear-free bulk polymerization systems, k t can be minimized and radical lifetimes maximized, but the polymerization system is at best a long-lived polymerization rather than a living polymerization. On this basis, by using MMA to pre-dissolve ultrahigh molecular weight PMMA and core-shell particles (CSR), the mechanical properties and heat resistance of the PMMA with pre-dissolved polymer obtained by reactive extrusion polymerization were better than for pure PMMA obtained under the same conditions. Compared with pure PMMA, the flexural strength and impact strength of PMMA with pre-dissolved CSR were up to 166.2% and 230.5%. With the same quality of CSR, the same two mechanical properties of the samples obtained by the blending method were just improved by 29.0% and 20.4%. This was closely related to the distribution of CSR in the pre-dissolved PMMA-CSR matrix with a distribution of spherical single particles 200-300 nm in diameter, which enabled PMMA-CSR to exhibit a high degree of transparency. This one-step process for realizing PMMA polymerization and high performance shows extremely high industrial application prospects.
RESUMO
A series of poly(methyl(trifluoropropyl)-diphenyl siloxane) (P(MTFPS-co-DPS)) was synthesized by polycondensation of diphenylsilanediol and methyltrifluoropropylsiloxanediol. Their chemical structures were investigated by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and differential scanning calorimeter (DSC). The effect of diphenylsiloxane (DPS) units on the thermal stability of poly[methyl(trifluoropropyl)siloxane] (PMTFPS) was studied by thermogravimetric analysis (TGA), isothermal degradation tests, and pyrolysis-gas chromatography-mass spectrometry (Py-GCMS). The results showed that the thermal stability of PMTFPS improved with the introduction of DPS units into the chain. In particular, the temperature for 5% mass loss in PMTFPS increased by 72 °C under a nitrogen atmosphere. In addition, the mechanism by which the DPS units improve the thermal stability of PMTFPS was also investigated.
RESUMO
OBJECTIVES: Dyspnea is a common and multidimensional experience of healthy adults and those with respiratory disorders. Due to its neural processing, it may limit or interfere with cognition, which may be examined with a dual-task paradigm. The aim of this study was to compare single-task performance of Stroop Colour and Word Test (SCWT) or inspiratory threshold loading (ITL) to their combined dual-task performance. Secondly, whether mood was related to dyspnea or cognitive performance was also evaluated. MATERIALS & METHODS: A virtual pre-post design examined single (SCWT and ITL) and dual-task (SCWT+ITL) performance. For ITL, a Threshold Trainer™ was used to elicit a "somewhat severe" rating of dyspnea. The SCWT required participants to indicate whether a colour-word was congruent or incongruent with its semantic meaning. The Depression, Anxiety and Stress Scale-21 (DASS-21) was completed to assess mood. Breathing frequency, Borg dyspnea rating, and breathing endurance time were ascertained. RESULTS: Thirty young healthy adults (15F, 15M; median age = 24, IQR [23-26] years) completed the study. SCWT+ITL had lower SCWT accuracy compared to SCWT alone (98.6%, [97.1-100.0] vs 99.5%, [98.6-100.0]; p = 0.009). Endurance time was not different between ITL and SCWT+ITL (14.5 minutes, [6.9-15.0]) vs 13.7 minutes, [6.1-15.0]; p = 0.59). DASS-21 scores positively correlated with dyspnea scores during ITL (rho = 0.583, p<0.001) and SCWT+ITL (rho = 0.592, p<0.001). CONCLUSIONS: ITL significantly reduced dual-task performance in healthy young adults. Lower mood was associated with greater perceived dyspnea during single and dual-task ITL. Considering the prevalence of dyspnea in respiratory disorders, the findings of this dual task paradigm warrant further exploration to inform dyspnea management during daily activities.
Assuntos
Dispneia , Respiração , Humanos , Adulto Jovem , AdultoRESUMO
Background and Aims: The intestinal epithelium exhibits dynamic control of cell cycle phase lengths, yet no experimental platform exists for directly analyzing cell cycle phases in living human intestinal stem cells (ISCs). Here, we develop primary human ISC lines with two different reporter constructs to provide fluorescent readouts to analyze cell cycle phases in cycling ISCs. Methods: 3D printing was used to construct a collagen press for making chamber slides that support primary human ISC growth and maintenance within the working distance of a confocal microscope objective. The PIP-FUCCI fluorescent cell cycle reporter and a variant with H2A-mScarlet that allows for automated tracking of cell cycle phases (PIP-H2A) were used in human ISCs along with live imaging and EdU pulsing. An analysis pipeline combining free-to-use programs and publicly available code was compiled to analyze live imaging results. Results: Chamber slides with soft collagen pressed to a thickness of 0.3 mm concurrently support ISC cycling and confocal imaging. PIP-FUCCI ISCs were found to be optimal for snapshot analysis wherein all nuclei are assigned to a cell cycle phase from a single image. PIP-H2A ISCs were better suited for live imaging since constant nuclear signal allowed for more automated analysis. CellPose2 and TrackMate were used together to track cycling cells. Conclusions: We present two complete platforms for analyzing cell cycle phases in living primary human ISCs. The PIP-FUCCI construct allows for cell cycle phase assignment from one image of living cells, the PIP-H2A construct allows for semi-automated direct quantification of cell cycle phase lengths in human ISCs using our computational pipeline. These platforms hold great promise for future studies on how pharmaceutical agents affect the intestinal epithelium, how cell cycle is regulated in human ISCs, and more.
RESUMO
Retinoid-related orphan receptor (RAR) gamma (RORγt)-expressing regulatory T cells (RORγt+ Tregs) play pivotal roles in preventing T cell hyperactivation and maintaining tissue homeostasis, in part by secreting the anti-inflammation cytokine interleukin-10 (IL-10). Here, we report that hypoxia-induced factor 1α (HIF1α) is the master transcription factor for Il10 in RORγt+ Tregs. This critical anti-inflammatory pathway is negatively regulated by an RNA binding protein DEAD box helicase 5 (DDX5). As a transcriptional corepressor, DDX5 restricts the expression of HIF1α and its downstream target gene Il10 in RORγt+ Tregs. T cell-specific Ddx5 knockout (DDX5ΔT) mice have augmented RORγt+ Treg suppressor activities and are better protected from intestinal inflammation. Genetic ablation or pharmacologic inhibition of HIF1α restores enteropathy susceptibility in DDX5ΔT mice. The DDX5-HIF1α-IL-10 pathway is conserved in mice and humans. These findings reveal potential therapeutic targets for intestinal inflammatory diseases.
Assuntos
Interleucina-10 , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares , Humanos , Camundongos , Animais , Interleucina-10/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Regulação da Expressão Gênica , Fatores de Transcrição/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Ligação ProteicaRESUMO
Using the method of bulk reactive extrusion radical copolymerization, N-phenyl maleimide (N-PMI) and styrene (St) and methyl methacrylate (MMA) were copolymerized. Through multi-detection gel permeation chromatography, bulk copolymerization kinetic analysis, UV-Vis spectroscopy, elemental analysis, and 1H NMR and 13C NMR analysis, it was found that, contrary to the classical free radical copolymerization theory, N-PMI and MMA could not only achieve copolymerization, but could even reach the level of azeotropic copolymerization. The factor that caused this change turned out to be the viscosity of the system. Secondly, through DSC, TG and GC-MS analysis, it was found that N-PMI units were randomly inserted into the molecular chain of PMMA, which greatly improved the stiffness of its molecular segments and the T g of the copolymer; at the same time, the insertion of N-PMI units also very effectively blocked the zipper-style de-end group degradation that often occurs in PMMA. When the mass content of the N-PMI copolymer reached 10%, the T g, initial degradation temperature and semi-degradation temperature of the copolymer increased by 19 °C, 58 °C and 47 °C, respectively. In addition, St, N-PMI can also significantly improve the processing fluidity of the PMMA copolymer, and after St participates were introduced in the copolymerization, the melt flow rate can be increased by 3.5 times. Furthermore, the copolymer not only had good mechanical properties and transparency, but also had excellent antibacterial properties against E. coli and S. aureus with only the effect of trace residual N-PMI in the copolymer. This provides an excellent reference for the preparation of antibacterial PMMA with high heat resistance, good mechanical properties and high transparency.
RESUMO
Introduction: Research suggests that narcotic pain medications are dramatically overprescribed. We hypothesize that narcotics are unnecessary for postoperative pain control in most infants undergoing robotic pyeloplasty. In this series, we report our experience combining caudal blocks with a non-narcotic postoperative pathway as a means of eliminating postoperative narcotics after infant robotic pyeloplasty. Methods: We reviewed 24 consecutive patients who underwent robotic pyeloplasty by a single surgeon treated with an end-procedure caudal block followed by a non-narcotic postoperative pain pathway treated between May 2017 and May 2021. The standardized postoperative pathway consisted of an end-procedure caudal block followed by alternating intravenous acetaminophen and ketorolac. We reviewed demographics, outcomes, and unscheduled health care encounters within 30 postoperative days. Results: Sixty-three percent (15/24) of patients were male and average age was 12.1 months (range 4-34 months). Fifty-eight percent (9/15) underwent surgery on the left, and 16.7% (4/24) of patients received a single postoperative dose of narcotics in the postanesthesia care unit. No patient required narcotic prescriptions at discharge or anytime thereafter. The average length of stay was 1.13 days. There was no pain-related unscheduled visits or phone calls after discharge. Conclusions: This series shows that a non-narcotic standardized pain management strategy is a viable option for infants undergoing robotic pyeloplasty. Postprocedure caudal block is a good addition to a non-narcotic pathway. In the future, we intend to expand these findings to other pediatric urologic procedures in the hope of eliminating unnecessary narcotic use.
Assuntos
Anestesia Caudal , Procedimentos Cirúrgicos Robóticos , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Entorpecentes/uso terapêutico , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/etiologia , Estudos Retrospectivos , Resultado do Tratamento , Procedimentos Cirúrgicos Urológicos/métodosRESUMO
Immobilizing poly(butyl acrylate) (PBA) on cellulose microfibrils (CMFs) by atom transfer radical polymerization (ATRP) of butyl acrylate (BA) on the surface of 2-bromoisobutyryl-functionalized CMF generated highly hydrophobic microfibrils (CMF-PBA) with a hard core and a soft-shell structure. TGA and static water contact angle results suggested that the surfaces of the modified CMF samples were not completely covered by PBA chains until the molecular weight of grafts became sufficiently long. The GPC results indicated that the grafts with low molecular weight showed controlled/"living" characteristics of the surface-initiated ATRP; however, there existed more side reactions with the increase in molecular weights. Biocomposites consisting of polypropylene (PP) and CMF-PBA samples exhibited significantly improved compatibility, interface adhesion, and mechanical properties with the increase in PBA graft length. The findings confirmed that the longer grafts facilitated the better entanglement of PBA grafts with PP macromolecules and thus further improved the mechanical properties.
Assuntos
Acrilatos/síntese química , Materiais Biocompatíveis/síntese química , Celulose/química , Microfibrilas/química , Acrilatos/análise , Materiais Biocompatíveis/análise , Interações Hidrofóbicas e Hidrofílicas , Espectroscopia de Ressonância Magnética , Microfibrilas/ultraestrutura , Microscopia Eletrônica de Varredura , Estrutura Molecular , Peso Molecular , Polimerização , Polipropilenos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Temperatura , Resistência à Tração , Água , MolhabilidadeRESUMO
Four synthesized biocidal guanidine hydrochloride polymers with different alkyl chain length, including polyhexamethylene guanidine hydrochloride and its three new analogs, were used to investigate their interactions with phospholipids vesicles mimicking bacterial membrane. Characterization was conducted by using fluorescence dye leakage, isothermal titration calorimetry, and differential scanning calorimetry. The results showed that the gradually lengthened alkyl chain of the polymer increased the biocidal activity, accompanied with the increased dye leakage rate and the increased binding constant and energy change value of polymer-membrane interaction. The polymer-membrane interaction induced the change of pretransition and main phase transition (decreased temperature and increased width) of phospholipids vesicles, suggesting the conformational change in the phospholipids headgroups and disordering in the hydrophobic regions of lipid membranes. The above information revealed that the membrane disruption actions of guanidine hydrochloride polymers are the results of the polymer's strong binding to the phospholipids membrane and the subsequent perturbations of the polar headgroups and hydrophobic core region of the phospholipids membrane. The alkyl chain structure significantly affects the binding constant and energy change value of the polymer-membrane interactions and the perturbation extent of the phospholipids membrane, which lead to the different biocidal activity of the polymer analogs. This work provides important information about the membrane disruption action mechanism of biocidal guanidine hydrochloride polymers.
Assuntos
Anti-Infecciosos/química , Guanidinas/química , Bicamadas Lipídicas/química , Fosfolipídeos/química , Anti-Infecciosos/síntese química , Anti-Infecciosos/farmacologia , Fenômenos Biofísicos , Calorimetria , Candida albicans/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Guanidina/química , Guanidinas/síntese química , Guanidinas/farmacologia , Testes de Sensibilidade Microbiana , Modelos Químicos , Estrutura Molecular , Fosfatidiletanolaminas/química , Fosfatidilgliceróis/química , Polímeros/síntese química , Polímeros/química , Polímeros/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacosRESUMO
Biofouling is one of the major obstacles in the application of poly(vinylidene fluoride) (PVDF) membrane in water and wastewater treatment. Developing antimicrobial PVDF could kill the attached microbe in the initial stage, thus theoretically inhibiting the formation of biofilm and delaying the occurrence of biofouling. However, the leaching of the antimicrobial component and deterioration of antimicrobial properties remain a concern. In this work, an antimicrobial PVDF (PVDF-g-AGE-PHMG) was developed by chemical bonding PVDF with poly(hexamethylene guanidine hydrochloride) (PHMG). The obtained PVDF-g-AGE-PHMG was blended with pristine PVDF to prepare an antimicrobial PVDF membrane. The results of Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) confirmed that PHMG was successfully grafted into the PVDF membrane. The morphologies, membrane porosity, water contact angles, antimicrobial properties, mechanical properties, and thermostability of the as-prepared membranes were investigated. When the content of PVDF-g-AGE-PHMG reached 10.0 wt %, the inhibition rates of both antimicrobial PVDF membrane against Escherichia coli and Staphylococcus aureus were above 99.99%. Due to the increased hydrophilicity, excellent antimicrobial activity, nonleaching of antimicrobial component, good mechanical properties, and thermostability, the as-prepared PVDF membrane has promising applications in the field of water treatment.
RESUMO
A controlled synthesis method of alkyl methacrylate block copolymers such as poly(methyl methacrylate)-b-poly(ethyl methacrylate) (PMMA-b-PEMA), poly(methyl methacrylate)-b-poly(butyl methacrylate) (PMMA-b-PBMA) and poly(ethyl methacrylate)-b-poly(butyl methacrylate) (PEMA-b-PBMA) via living anionic polymerization was innovated with potassium tert-butoxide (t-BuOK) as initiator in tetrahydrofuran(THF) solvent. The sequential anionic copolymerization could be smoothly conducted at 0 °C and the conversion of all monomers reached up to almost 100%. The copolymers were characterized by gel permeation chromatography (GPC), proton nuclear magnetic resonance (1H-NMR), fourier transform infrared spectroscopy (FTIR) and dynamic mechanical analysis (DMA). It was found that all block copolymers were in a narrow MWD while M w and weight ratio of each block were coincided with the theoretical values and feed ratio. DMA measurement indicated that all the block copolymers have two glass transition temperatures which have proved the certain microphase separation and the partial compatibility of the blocks. The similar results were achieved after changing feed order or addition amount. Furthermore, the reactivity ratio was also studied and confirmed that reactivity ratio of MMA was the largest among alkyl methacrylate. Based on these results, the anionic block copolymerization containing polar alkyl methacrylate monomers at a commercial scale starts to become possible.
RESUMO
Antimicrobial cotton fabrics received much attention for the demand of health and hygiene fields. In this work, an antimicrobial copolymer was prepared via a reaction between polyhexamethylene guanidine hydrochloride and polypropylene glycol diglycidyl ether. The copolymer has amphiphilic characteristic and excellent antimicrobial properties. When the copolymer was adhered onto cotton fabrics through physical adsorption and chemical bonding using dipping-drying method, the resultant cotton fabrics had excellent and durable antimicrobial properties. The antimicrobial rates against Escherichia coli and Staphylococcus aureus were higher than 99.99% when the adsorption amount of the copolymer was above 35.5mg/g. The antimicrobial cotton fabrics remained the excellent antimicrobial properties even after laundered with detergent solution.
Assuntos
Anti-Infecciosos/química , Fibra de Algodão , Éteres/química , Guanidina/análogos & derivados , Polietilenoglicóis/química , Éteres/síntese química , Polietilenoglicóis/síntese química , Tensoativos/químicaRESUMO
The combination of transparency, antimicrobial activities, nonleaching of antimicrobial component and green preparation for poly(vinyl alcohol) (PVA) films is of importance for practical applications in industry. However, until now it remains a challenge. Herein, a facile antimicrobial PVA films containing polyhexamethylene guanidine (PHMG) is reported via a green solution casting method. Such PVA films show high transparency of 91%, above 99.99% of antimicrobial rates against Escherichia coli and Staphylococcus aureus, and nonleaching characteristic of PHMG due to the hydrogen-bond (H-bond) interaction between PHMG and PVA. The thermal stability and mechanical properties of the PVA films are further improved compared to neat PVA film. These antimicrobial films are expected to find promising applications in tissue engineering and packaging fields, which opens up a methodology to prepare nonleaching antimicrobial polymeric materials via H-bond.
Assuntos
Anti-Infecciosos/química , Guanidinas/química , Ligação de Hidrogênio , Álcool de Polivinil/química , Varredura Diferencial de Calorimetria , Escherichia coli/efeitos dos fármacos , Temperatura Alta , Teste de Materiais , Microscopia Eletrônica de Varredura , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Estresse Mecânico , Resistência à TraçãoRESUMO
BACKGROUND: Vaccine hesitancy has been little studied in low- and middle-income countries but is a potential concern because vaccine refusal may increase the burden of infectious diseases and impede control efforts. The aim of this study was to compare vaccine hesitancy between locals, long-time city residents, and non-locals, who have more recently moved to the city from either other urban or rural areas, in Shanghai, China. METHODS: Parents of infants ≤3 months of age were surveyed at immunization clinics in Shanghai, China. Participants completed a paper questionnaire utilizing the 10-item Vaccine Hesitancy Scale, which was developed by the World Health Organization Strategic Advisory Group of Experts on Immunization. Items were grouped based on internal consistency, and regressed onto demographic variables using a negative binomial model. RESULTS: In total, 1,188 (92.5%) individuals participated. For most items on the scale, parents expressed positive beliefs about vaccines. However, about half of parents somewhat or strongly agreed that new vaccines carried more risks than older vaccines, and 71.6% somewhat or strongly agreed that they were concerned about serious adverse effects. Seven items from the Vaccine Hesitancy Scale were highly correlated and mapped onto "lack of confidence"; the other three items were analysed separately. Compared to mothers, fathers had less lack of confidence (ß: -0.06, 95% CI: -0.12, -0.01), and individuals living in the outer suburbs (ß: 0.13, 95% CI: 0.01, 0.25) and rural non-locals (ß: 0.10, 95% CI: 0.02, 0.18) had greater lack of confidence in vaccines compared to their urban or local counterparts, respectively. DISCUSSION: Shanghai parents professed confidence in certain vaccine benefits, but vaccine messaging could focus on addressing misconceptions about vaccines for diseases no longer common, newer vaccines, and adverse effects associated with vaccination. These messages may need to be separately tailored to locals and non-locals, who have differing concerns.
Assuntos
Cidades/estatística & dados numéricos , Demografia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Vacinas , Adulto , China , Feminino , Humanos , Recém-Nascido , Masculino , Aceitação pelo Paciente de Cuidados de Saúde/psicologiaRESUMO
The biodegradable poly(butylene adipate-co-terephthalate)(PBAT)/thermoplastic starch (TPS) composite has received considerable attention because of the environmental concerns raised by solid waste disposal. However, the application of PBAT/TPS blends was limited due to the poor mechanical properties originating from the incompatibility between PBAT and TPS. In this work, two approaches were developed to improve the mechanical properties of PBAT/TPS blends. One approach is to use compatibilizers, including the synthesized reactive compatibilizer - a styrene-maleic anhydride-glycidyl methacrylate (SMG) terpolymer, and the commercial compatibilizer (Joncryl-ADR-4368). The chemical structures of SMG were analyzed with (1)H NMR and FT-IR. The other approach is to use the modified PBAT (M-PBAT) to replace part of PBAT in the PBAT/TPS blends. M-PBATs with higher molecular weight were obtained via reactive extrusion of PBAT in the presence of a chain extender. The better dispersion of TPS in PBAT was observed in SEM images when using M-PBAT, leading to the higher tensile strength and elongation at break of PBAT/TPS blends. However, the elongation at break decreased in the presence of compatibilizer (SMG or 4368), though the tensile strength remained in a similar level or slightly higher. Overall, the tensile strength and the elongation at break of the resulting biodegradable PBAT/M-PBAT/TPS blends (TPS=40wt%) were above 27.0MPa and 500%, respectively, which is promising for various applications, including packaging and agricultural mulching films.