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1.
J Mater Chem B ; 8(9): 1801-1822, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32048689

RESUMO

Cardiovascular diseases, especially ones involving narrowed or blocked blood vessels with diameters smaller than 6 millimeters, are the leading cause of death globally. Vascular grafts have been used in bypass surgery to replace damaged native blood vessels for treating severe cardio- and peripheral vascular diseases. However, autologous replacement grafts are not often available due to prior harvesting or the patient's health. Furthermore, autologous harvesting causes secondary injury to the patient at the harvest site. Therefore, artificial blood vessels have been widely investigated in the last several decades. In this review, the progress and potential outlook of small-diameter blood vessels (SDBVs) engineered in vitro are highlighted and summarized, including material selection and development, fabrication techniques, surface modification, mechanical properties, and bioactive functionalities. Several kinds of natural and synthetic polymers for artificial SDBVs are presented here. Commonly used fabrication techniques, such as extrusion and expansion, electrospinning, thermally induced phase separation (TIPS), braiding, 3D printing, hydrogel tubing, gas foaming, and a combination of these methods, are analyzed and compared. Different surface modification methods, such as physical immobilization, surface adsorption, plasma treatment, and chemical immobilization, are investigated and are compared here as well. Mechanical requirements of SDBVs are also reviewed for long-term service. In vitro biological functions of artificial blood vessels, including oxygen consumption, nitric oxide (NO) production, shear stress response, leukocyte adhesion, and anticoagulation, are also discussed. Finally, we draw conclusions regarding current challenges and attempts to identify future directions for the optimal combination of materials, fabrication methods, surface modifications, and biofunctionalities. We hope that this review can assist with the design, fabrication, and application of SDBVs engineered in vitro and promote future advancements in this emerging research field.

2.
Chemosphere ; 247: 125909, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31972492

RESUMO

The adsorptive removal possibility of persistent pharmaceuticals with different charges by activated carbon fiber (ACF) was examined. The pharmaceuticals tested included carbamazepine (CBZ), propranolol (PRO), and diclofenac (DCF), in neutral, cationic, and anionic forms, respectively, which were frequently detected in sewage. The adsorption characteristics of ACF were identified according to the kinetics, isotherm, pH, and ionic strength experiments. The results revealed that ACF can effectively remove these pharmaceuticals, and the adsorption capacities of CBZ, PRO, and DCF by ACF were 1.27 ± 0.06, 1.07 ± 0.08, and 0.95 ± 0.08 mmol g-1, respectively. Moreover, the adsorption of ACF for CBZ was independent of pH and ionic strength, whereas that of anionic diclofenac decreased at alkaline pHs and high concentrations of NaCl. Using a syringe system packed with ACF mat, the scavenging ability of intermittently generated secondary sewage was evaluated. As a result, the residual concentration of PRO and CBZ could not be even detected after consecutive 10 runs in secondary sewage mixture solution. This indicates ACF has the powerful potential for removing pharmaceutical micropollutants in the actual aqueous solutions. FTIR and XPS analyses showed that hydrophobic and π-π interactions and hydrogen bonding contributed to the adsorption process.

3.
Blood ; 135(3): 167-180, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31805184

RESUMO

NF-κB is a key regulator of inflammation and cancer progression, with an important role in leukemogenesis. Despite its therapeutic potential, targeting NF-κB using pharmacologic inhibitors has proven challenging. Here, we describe a myeloid cell-selective NF-κB inhibitor using an miR-146a mimic oligonucleotide conjugated to a scavenger receptor/Toll-like receptor 9 agonist (C-miR146a). Unlike an unconjugated miR146a, C-miR146a was rapidly internalized and delivered to the cytoplasm of target myeloid cells and leukemic cells. C-miR146a reduced expression of classic miR-146a targets (IRAK1 and TRAF6), thereby blocking activation of NF-κB in target cells. IV injections of C-miR146a mimic to miR-146a-deficient mice prevented excessive NF-κB activation in myeloid cells, and thus alleviated myeloproliferation and mice hypersensitivity to bacterial challenge. Importantly, C-miR146a showed efficacy in dampening severe inflammation in clinically relevant models of chimeric antigen receptor (CAR) T-cell-induced cytokine release syndrome. Systemic administration of C-miR146a oligonucleotide alleviated human monocyte-dependent release of IL-1 and IL-6 in a xenotransplanted B-cell lymphoma model without affecting CD19-specific CAR T-cell antitumor activity. Beyond anti-inflammatory functions, miR-146a is a known tumor suppressor commonly deleted or expressed at reduced levels in human myeloid leukemia. Using The Cancer Genome Atlas acute myeloid leukemia data set, we found an inverse correlation of miR-146a levels with NF-κB-related genes and with patient survival. Correspondingly, C-miR146a induced cytotoxic effects in human MDSL, HL-60, and MV4-11 leukemia cells in vitro. The repeated IV administration of C-miR146a inhibited expression of NF-κB target genes and thereby thwarted progression of disseminated HL-60 leukemia. Our results show the potential of using myeloid cell-targeted miR-146a mimics for the treatment of inflammatory and myeloproliferative disorders.

4.
Chemosphere ; 238: 124634, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31473525

RESUMO

A cavity attenuated phase shift single scattering albedo monitor was set up on a tethered airship platform to study the vertical profiles of particle light extinction coefficient (bext) in the lower troposphere (<1000 m) in Shanghai during 12-29 December 2015. Clear transition heights (THs) for vertical profiles of bext during the polluted days (PM2.5 > 75 µg m-3) were observed below 1000 m. The vertical differences of bext were highly dynamic as the vertical variation in bext was significant by as much as 605 Mm-1. The TH was observed mostly at about 100-200 m, and 450-650 m during night and daytime, respectively, and was in a wide range of ∼50-900 m during 15:00-22:00 due to the low boundary layer and/or the transport of pollutants. In particular, the TH was consistently below 500 m throughout the day during highly polluted haze episodes, highlighting the important role of a stagnant atmosphere situation for high concentrations of PM2.5. The vertical distribution of bext did not have a constant rule with respect to relative humidity and wind. Sometimes, peak values of bext at ∼350 m and 500 m during daytime were caused by enhanced regional transport. During stagnant and highly polluted situations or well-mixed clean days, bext was usually uniformly distributed below and above the TH, respectively, although bext was much smaller above the TH. For other situations, local emissions, pollutant transport, and the physical and chemical characteristics of aerosols resulted in highly dynamic vertical profiles of bext.


Assuntos
Poluentes Atmosféricos/análise , Atmosfera/química , Monitoramento Ambiental/métodos , Material Particulado/análise , Aerossóis/análise , China , Estações do Ano , Vento
5.
J Affect Disord ; 262: 337-343, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31735407

RESUMO

BACKGROUND: Recent works suggest recent changes in anhedonia may be specifically predictive of key elements of psychopathology. The present study aimed to identify the trajectories of state anhedonia and recent changes in anhedonia, and to investigate their associations with other psychiatric syndromes over time. METHODS: A total of 859 college students were assessed at three time points. State anhedonia was assessed using the Snaith Hamilton Pleasure Scale and recent changes in anhedonia were assessed with a subscale extracted from the Symptom Check-List-90. The Latent Growth Curve Modelling analysis was used to analyze trajectories. Associations with anhedonia were investigated with logistic regression models. RESULTS: Three state anhedonia trajectories and two recent changes in anhedonia trajectories were identified. The decreasing trajectory was the most prevalent class in both two types of anhedonia. Depression and suicidal ideation predicted recent changes in anhedonia whereas other psychiatric syndromes predicted state anhedonia. CONCLUSIONS: The current study highlighted the development trajectories of different measures of anhedonia. The results showed that the relationships between anhedonia and psychiatric syndromes were different according to the kind of anhedonia.

6.
Mater Sci Eng C Mater Biol Appl ; 107: 110212, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761208

RESUMO

A critical challenge to the development of tissue engineering small-diameter vascular grafts is to achieve rapid endothelialization and long-term anticoagulation. It is necessary to graft both adhesion and antithrombus factors onto the surface of polycaprolactone without burst release to promote endothelial cell affinity and antithrombogenicity. A bionic structure with a nanocoating that allows a biologically responsive, long-term release was employed in this work to enable the grafting of various bioactive molecules such as gelatin, polylysine, and heparin. This approach involved orienting the biomimetic vascular structures; the self-assembly grafting of gelatin, polylysine, and heparin nanoparticles; and genipin crosslinking to form a multiphase crosslinked nanocoating. In this biologically inspired design, vascular endothelialization and long-term anticoagulation were successfully induced through a matrix metallopeptidase 2 regulative mechanism by delivering both adhesion and antithrombus factors with a responsive, long-term release without burst release. The method provided a simple and effective approach for delivering dual factors for tissue engineering small-diameter vascular grafts.

7.
J Affect Disord ; 262: 23-30, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31706156

RESUMO

BACKGROUND: Recent work suggests that the social component of anhedonia is more associated with suicide ideation than the other component of pleasure. The present study investigated the differential effects of state and trait social anhedonia on suicidal ideation across two undergraduate samples based on the Interpersonal Theory and Three-Step Theory of Suicide. METHODS: State social anhedonia was assessed with a single item (Loss of Interest in People) extracted from the Beck Depression Inventory, while trait social anhedonia was assessed using the Anticipatory and Consummatory Interpersonal Pleasure Scale. Suicidal ideation was re-administered at a 3-month follow-up. RESULTS: In Study 1, higher state social anhedonia was associated with greater levels of suicidal ideation, while trait social anhedonia moderated the relationship between thwarted belongingness, perceived burdensomeness and suicidal ideation. In Study 2, state social anhedonia was margin significant predictor of suicidal ideation, while trait social anhedonia moderated the relationship between psychological pain and suicidal ideation. CONCLUSIONS: These findings confirmed the presence of two different effects on suicidal ideation in state and trait social anhedonia: state social anhedonia directly was associated with suicidal ideation, while trait social anhedonia was indirectly related through their effects on other risk factors of suicidality.

8.
Artigo em Inglês | MEDLINE | ID: mdl-31820053

RESUMO

Isosteviol has been reported to reverse hypertrophy and related inflammatory responses in in vitro models representative of cardiac muscle cells. The disposition of isosteviol is, however, characterized by secondary peaks and long plasma residence time despite reports of a relatively short half-life in liver fractions. The present study describes a compartmental approach to modelling the secondary peaks characteristic of isosteviol's concentration-time data in Sprague-Dawley rats. Oral (4 mg/kg) and intravenous (4 mg/kg) doses of isosteviol were administered to male and female Sprague-Dawley rats. Plasma samples collected between 0 and 72 h, and total bile secreted in 24 h, were analysed for isosteviol content with LC-MS/MS techniques. The disposition of isosteviol was, thereafter, described with a structural model that accounted for the sampling, liver and biliary secretion compartments, with a gap-time characterizing the accumulation and subsequent emptying of isosteviol for re-absorption. The half-life of isosteviol following oral dosing was about 103% greater in female rats than in the male, and the model-derived area under the concentration-time curve (AUC) in 72 h was about 756% greater in female animals than in males. Following the administration of intravenous doses of isosteviol, half-life and AUC in 24 h were about 332% and 595%, respectively, higher in female rats than in males. Isosteviol equivalent secreted into bile over 24 h accounted for about 94% of orally administered dose in male rats, and about 59% of oral dose in females. These findings show a differential systemic removal of isosteviol in Sprague-Dawley rats, likely explainable by gender-related differences in the glucuronidation-capacity of isosteviol.

9.
Artigo em Inglês | MEDLINE | ID: mdl-31833831

RESUMO

A novel short-rod-shaped bacterial strain with poly-ß-hydroxybutyric acid granules inside, designated as Z7-4T, was isolated from a culture of a marine dinoflagellate with palytoxin-producing capacity, Ostreopsis lenticularis OS06, collected from the East China Sea. Cells of Z7-4T were Gram-stain-negative, non-motile, strictly aerobic, 0.9-1.2 µm wide and 2.0-3.9 µm long. Growth occurred in 1-4 % (w/v) NaCl, at 15-37 °C and at pH 5.0-10.0, with optimum growth in 3.5 % (w/v) NaCl, at 30 °C and at pH 7.0. Analysis of 16S rRNA gene sequence revealed that Z7-4T shared the highest 16S rRNA gene sequence similarities with Nioella aestuarii JCM 30752T (98.8 %), followed by Nioella sediminis KCTC 42144T (98.6 %) and Nioella nitratireducens KCTC 32417T (96.9 %). Phylogenetic analysis based on nearly complete 16S rRNA gene sequences revealed that Z7-4T clearly represented a member of the genus Nioella within the family Rhodobacteraceae. The respiratory quinone of Z7-4T was identified as Q-10. Polar lipids of Z7-4T were phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, three unidentified aminophospholipids and one unidentified phospholipid. The major fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The DNA G+C content of Z7-4T was 63.0 mol%. DNA-DNA hybridization values of the isolate against the closely related type strains were far below the 70 % limit for species delineation. The average nucleotide identity and in silico DNA-DNA genome hybridization relatedness between Z7-4T and the closely related members of the genus Nioella, N. sediminis KCTC 42144T and N. nitratireducens KCTC 32417T, were 91.1 and 46.3 %, and 79.3 and 19.4 %, respectively. On the basis of the results of polyphasic analysis, Z7-4T is proposed to represent a novel species of the genus Nioella, for which the name Nioella ostreopsis sp. nov. is proposed. The type strain of Nioella ostreopsis is Z7-4T (=KCTC 62459T=CCTCC AB 2017231T).

10.
Artigo em Inglês | MEDLINE | ID: mdl-31861162

RESUMO

In order to evaluate the environmental risk caused by land application of sewage sludge, leaching characteristics of heavy metals and plant nutrients in the sewage sludge immobilized by composite phosphorus-bearing materials were investigated. Their cumulative release characteristics were confirmed. Furthermore, the first-order kinetics equation, modified Elovich equation, double-constant equation, and parabolic equation were used to explore dynamic models of release. Results showed that sewage sludge addition significantly increased electricity conductivity (EC) in leachates, and the concentrations of heavy metals (Cu, Cr, Zn) and plant nutrients (N, P, K) were also obviously increased. The highest concentrations of Cu, Cr, and Zn in the leachates were all below the limit values of the fourth level in the Chinese national standard for groundwater quality (GB/T14848-2017). The immobilization of composite phosphorus-bearing materials reduced the release of Cu and Cr, while increased that of Zn. The fitting results of modified Elovich model and double-constant model were in good agreement with the leaching process of heavy metals and plant nutrients, indicating their release process in soil under simulated leaching conditions was not a simple first-order reaction, but a complex heterogeneous diffusion process controlled by multifactor.


Assuntos
Metais Pesados/análise , Nutrientes/metabolismo , Fósforo/análise , Plantas/metabolismo , Esgotos , Poluentes do Solo/análise
11.
Artigo em Inglês | MEDLINE | ID: mdl-31671052

RESUMO

A Gram-stain-negative, strictly aerobic, non-motile and non-pigmented spirillum, designated strain LZ-5T, was isolated from cultures of the paralytic shellfish poisoning (PSP) toxin-producing marine dinoflagellate Alexandrium catenella LZT09 collected from the Zhoushan sea area in the East China Sea during an algal bloom. The isolate grew at 4-40 °C (optimum, 25-33 °C) and pH 5.0-9.0 (optimum, 7.5) in the presence of 0.5-10 % (w/v) NaCl (optimum, 4.0 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain LZ-5T clearly belonged to the genus Saccharospirillum of the family Saccharospirillaceae. Strain LZ-5T shared highest 16S rRNA gene sequence similarity with Saccharospirillum impatiens EL-105T (98.9 %), Saccharospirillum mangrovi HK-33T (97.2 %), Saccharospirillum correiae CPA1T (96.8 %), Saccharospirillum salsuginis YIM-Y25T (96.8 %) and Saccharospirillum aestuarii IMCC 4453T (95.1 %). The average nucleotide identity and in silico DNA-DNA hybridization between strain LZ-5T and the two most closely related Saccharospirillum strains, S. impatiens EL-105T and S. mangrovi HK-33T, were 82.2 and 19.3 %, and 72.2 and 13.2 %, respectively. The predominant respiratory quinone of strain LZ-5T was Q-8, and the major fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The polar lipids of strain LZ-5T were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylcholine (PC), glycolipid (GL), two unidentified glycophospholipids (GPLs), three unidentified aminophospholipids (APLs) and two unidentified lipids. The genomic DNA G+C content was 57.2 mol%. On the basis of this polyphasic characterization, strain LZ-5T represents a novel species of the genus Saccharospirillum, for which the name Saccharospirillum alexandrii sp. nov. is proposed. The type strain is LZ-5T (=KCTC 62460T=CCTCC AB2017232T).

12.
Mol Immunol ; 116: 160-166, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31675523

RESUMO

Duck viral enteritis (DEV) is a DNA virus that leads to heavy economic losses in the commercial duck industry. As a key cytoplasmic sensor, melanoma differentiation-associated gene 5 (MDA5) can recognize viral RNA and enhance the antiviral immune response. Retinoic acid-inducible gene-I (RIG-I) and MDA5 both belong to the RIG-I-like receptors family, and RIG-I is known to be involved in the anti-DEV signaling pathway. However, the role of MDA5 in DEV infection remains unclear. In this study, we used overexpression and knockdown methods to determine if MDA5 affected DEV infection in ducks. We confirmed that DEV infection was significantly suppressed in MDA5-overexpressing DEF cells, while knockdown of MDA5 by siRNA markedly enhanced DEV growth. We demonstrated that overexpression of duck MDA5 significantly upregulated expression of interferon (IFN)-stimulated genes, including myxovirus resistance protein (Mx), IFN-induced oligodenylate synthetase-like (OASL), IFN-induced transmembrane protein 1 (IFITM1) and IFN-ß. In addition, the transcriptional level of MDA5 was upregulated both in vivo and in vitro upon DEV infection. We also showed that there was an association between MDA5 and laboratory of genetics and physiology 2 (LGP2) in antiviral signaling. LGP2 functioned as a concentration-dependent switch between MDA5-specific enhancement and interference. Overall, these findings indicated that MDA5 restricted DEV replication and LGP2 plays a critical role in MDA5-mediated antiviral activity against DEV.


Assuntos
Antivirais/farmacologia , Coronavirus/efeitos dos fármacos , Helicase IFIH1 Induzida por Interferon/genética , RNA Helicases/genética , 2',5'-Oligoadenilato Sintetase/genética , Animais , Antígenos de Diferenciação/genética , Patos , Enterite/tratamento farmacológico , Enterite/genética , Enterite/virologia , Interferon beta/genética , Interferons/genética , Proteínas de Resistência a Myxovirus/genética , RNA Interferente Pequeno/genética , RNA Viral/genética , Transdução de Sinais/efeitos dos fármacos , Transcrição Genética/genética , Regulação para Cima/genética
13.
BMC Med Genomics ; 12(1): 164, 2019 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-31722693

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is the major type of primary liver cancer. Intrahepatic metastasis, such as portal vein tumor thrombosis (PVTT), strongly indicates poor prognosis of HCC. But now, there are limited understandings of the molecular features and mechanisms of those metastatic HCCs. METHODS: To characterize the molecular alterations of the metastatic HCCs, we implemented an integrative analysis of the copy number variations (CNVs), DNA methylations and transcriptomes of matched adjacent normal, primary tumor and PVTT samples from 19 HCC patients. RESULTS: CNV analysis identified a frequently amplified focal region chr11q13.3 and a novel deletion peak chr19q13.41 containing three miRNAs. The integrative analysis with RNA-seq data suggests that CNVs and differential promoter methylations regulate distinct oncogenic processes. Then, we used individualized differential analysis to identify the differentially expressed genes between matched primary tumor and PVTT of each patient. Results show that 5 out of 19 studied patients acquire evidential progressive alterations of gene expressions (more than 1000 differentially expressed genes were identified in each patient). While, another subset of eight patients have nearly identical gene expressions between the corresponding matched primary tumor and PVTT. Twenty genes were found to be recurrently and progressively differentially expressed in multiple patients. These genes are mainly associated with focal adhesion, xenobiotics metabolism by cytochrome P450 and amino acid metabolism. For several differentially expressed genes in metabolic pathways, their expressions are significantly associated with overall survivals and vascular invasions of HCC patients. The following transwell assay experiments validate that they can regulate invasive phenotypes of HCC cells. CONCLUSIONS: The metastatic HCCs with PVTTs have significant molecular alterations comparing with adjacent normal tissues. The recurrent alteration patterns are similar to several previously published general HCC cohorts, but usually with higher severity. By an individualized differential analysis strategy, the progressively differentially expressed genes between the primary tumor and PVTT were identified for each patient. A few patients aquire evidential progressive alterations of gene expressions. And, experiments show that several recurrently differentially expressed genes can strongly regulate HCC cell invasions.

14.
Artigo em Inglês | MEDLINE | ID: mdl-31750566

RESUMO

BACKGROUND: Recent works suggested taking into account the severity and the type of anhedonia when examining suicidal ideation. The present study investigated a moderated mediation model addressing the psychosocial mechanisms that account for the association between state or trait anhedonia and suicidal ideation. METHODS: State anhedonia was assessed using the Snaith-Hamilton Pleasure Scale, while trait anhedonia was assessed using the Temporal Experience of Pleasure Scale. A total number of 1,361 of undergraduates completed questionnaires at three different times, with one-year intervals. RESULTS: The direct effect of stress on suicidal ideation was significantly greater for those students who had lower trait anticipatory and consummatory anhedonia, whereas the indirect effect from stress on suicidal ideation through depression was significantly greater for those who had higher state anhedonia. Moreover, trait consummatory anhedonia moderated the relationship between stress and suicidal ideation after one year, and trait anticipatory anhedonia moderated the relationship between stress and suicidal ideation after two years. CONCLUSIONS: Low levels of trait anhedonia were associated with elevated suicidal ideation, while high levels of state anhedonia were associated with elevated suicidal ideation. Trait consummatory anhedonia was associated with short-term suicidal ideation, while trait anticipatory anhedonia was associated with long-term suicidal ideation.

15.
Sci Total Environ ; 688: 1124-1136, 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31726543

RESUMO

Diesel fuel (DF)-contamination remediation has aroused increasing concern in environmental field. In our work, nano sponge was modified by silylation of amino silicon oil (ASO) and aminopropyltriethoxysilane (APTES) to obtain hydrophobic nano sponge (SPAA). SPAA possessed a micro/nano network structure and could efficiently adsorb DF through hydrophobic polysiloxane group. The results revealed that SPAA could effectively remove DF and control its migration in water and soil under various conditions. Importantly, SPAA could inhibit the harmful effect of DF on the growth of plants, earthworms, and fish. Therefore, this work provides a promising and low-cost approach for removal of DF from water and soil, which might have a potential application value.

16.
ACS Nano ; 13(11): 12787-12797, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31633902

RESUMO

Triboelectric nanogenerators (TENGs) are a potential solution to the depleted state of fossil fuels, on the condition that the energy conversion efficiency can be further improved. Tribomaterials are important not only for improving the output performance of TENGs but also for extending their applications. In this work, a poly-ε-caprolactone (PCL) electrospun membrane is proposed as a highly effective positive tribomaterial, paired with an expanded polytetrafluoroethylene (ePTFE) membrane, to fabricate TENGs (PCL/ePTFE TENGs). Compared with a widely used polyamide-6 (PA6)/ePTFE TENG, the output performance of the PCL/ePTFE TENG is enhanced by about 28%, indicating that PCL possesses a stronger electron-donating ability owing to the existence of oxygen-containing functional groups as electron donors. Furthermore, the PCL membrane is modified using poly(ethylene glycol) methyl ether (mPEG), which possesses more O atoms, by electrospinning (ES) and dip coating (DC). The results reveal that mPEG is very effective at improving the positive electron polarity of PCL. With the increase of mPEG content, the output performance increases by more than 40%, yielding a maximum power density of 115.83 W·m-2. More polymers have been compared to confirm that many oxygen-rich polymers show excellent electron-donating abilities and act as highly efficient positive tribomaterials. This work also provides additional options for more effective positive tribomaterials.

17.
ACS Appl Mater Interfaces ; 11(35): 32533-32542, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31393107

RESUMO

Viable tissue-engineering small-diameter vascular grafts should support rapid growth of an endothelial cell layer and exhibit long-term antithrombogenic property. In this study, multiple layers of various bioactive molecules, such as vascular endothelial growth factor (VEGF) and heparin, on an electrospun polycaprolactone scaffold have been developed through repeated electrostatic adsorption self-assembly (up to 20 layers), followed by genipin cross-linking. Programmed and sustained release of biomolecules embedded within the multilayered structure can be triggered by matrix metallopeptidase 2 enzyme in vitro. The result is an early and full release of VEGF to promote rapid endothelialization on the intended vascular grafts, followed by a gradual but sustained release of heparin for long-term anticoagulation and antithrombogenicity. This method of forming a biologically responsive, multimodal delivery of VEGF and heparin is highly suitable for all hydrophobic surfaces and provides a promising way to meet the critical requirements of engineered small-diameter vascular grafts.


Assuntos
Prótese Vascular , Materiais Revestidos Biocompatíveis/química , Heparina/química , Células Endoteliais da Veia Umbilical Humana/metabolismo , Poliésteres/química , Fator A de Crescimento do Endotélio Vascular , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Fator A de Crescimento do Endotélio Vascular/química , Fator A de Crescimento do Endotélio Vascular/farmacologia
18.
Environ Pollut ; 254(Pt A): 112864, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31369912

RESUMO

To better understand the mechanism of PM2.5 explosive growth (EG), we conducted concurrent measurements of gaseous pollutants, PM2.5 and its chemical composition (inorganic ions, organic carbon, and element carbon) with a time resolution of 1 h in Shanghai in late autumn and winter from 2014 to 2017. In this study, the EG events, which are defined as the net increase in the mass concentration of PM2.5 by more than 100 µg m-3 within hours, are separately discussed for 3, 6, or 9 h. The number of EG events decreased from 19 cases in 2014 to 6 cases in 2017 and the corresponding PM2.5 concentration on average decreased from 183.6 µg m-3 to 128.8 µg m-3. Both regional transport and stagnant weather (windspeed < 2.0 m s-1) could lead to EG events. The potential source contribution function (PSCF) shows that the major high-pollution region is in East China (including Zhejiang, Jiangsu, Shandong, and Anhui Province) and the North China Plain. The contribution of stagnant conditions to EG episode hours of 55% (198 h, 156.9 µg m-3) is higher than that of regional transport (45%, 230 h, 163.0 µg m-3). To study the impact of local emission, chemical characteristics and driving factors of EG were discussed under stagnant conditions. The major components contributing to PM2.5 are NO3- (17.9%), organics (14.1%), SO42- (13.1%), and NH4+ (13.1%). The driving factors of EG events are the secondary aerosol formation of sulfate and nitrate and primary emissions (vehicle emissions, fireworks, and biomass burning), but the secondary transformation contributes more to EG events. The formation of sulfate and nitrate is dominated by gas-phase oxidation and heterogeneous reactions, which are enhanced by a high relative humidity. The current study helps to understand the chemical mechanism of haze and provides a scientific basis for air pollution control in Shanghai.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , Aerossóis/análise , Carbono/análise , China , Poluentes Ambientais , Poluição Ambiental , Gases , Nitratos/análise , Óxidos de Nitrogênio , Estações do Ano , Sulfatos/análise , Emissões de Veículos/análise , Tempo (Meteorologia)
19.
BMC Psychiatry ; 19(1): 260, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31455294

RESUMO

BACKGROUND: Functional somatic symptoms in depression disorder may cause inappropriate illness behavior hindering the treatment process. Health anxiety may play a role in this relationship, but few studies have examined it. The current study aimed to investigate the role of health anxiety in the relationship between functional somatic symptoms and illness behavior in patients with depression. METHODS: The present study recruited 323 hospitalized patients with depression to complete the Patient Health Questionnaire-15, Whiteley-Index-7, and Scale for the Assessment of Illness Behavior, then constructed a structural equation model to examine whether health anxiety mediated the relationship between functional somatic symptoms and illness behavior. RESULTS: The results showed significant correlations between any two of the three variables of interest. More importantly, health anxiety played a partially mediating role (42.86%) in the relationship between functional somatic symptoms and illness behavior. Further analysis suggested that elderly patients reached higher health anxiety than younger patients when their functional somatic symptoms were mild. CONCLUSIONS: These results highlight that health anxiety may mediate the influence of functional somatic symptoms on illness behavior. The implications of assessing and intervening in health anxiety in patients with depression were discussed.

20.
Nat Plants ; 5(7): 676-680, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31285560

RESUMO

The molecular mechanisms underlying mycorrhizal symbioses, the most ubiquitous and impactful mutualistic plant-microbial interaction in nature, are largely unknown. Through genetic mapping, resequencing and molecular validation, we demonstrate that a G-type lectin receptor-like kinase (lecRLK) mediates the symbiotic interaction between Populus and the ectomycorrhizal fungus Laccaria bicolor. This finding uncovers an important molecular step in the establishment of symbiotic plant-fungal associations and provides a molecular target for engineering beneficial mycorrhizal relationships.

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