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1.
J Theor Biol ; 484: 110027, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31568791

RESUMO

Repeated outbreaks of Hand, foot and mouth disease (HFMD) infections have been observed in recent decades and dominated by various enteroviral serotypes. In particular, enterovirus 71 (EV-A71), coxsackievirus A16 (CV-A16) and coxsackievirus A6 (CV-A6) dominated the prevalence of HFMD infections alternatively in recent years with various outbreak sizes in Baoji, a city of Shaanxi Province in Northwest China. Estimating the reproduction number for various enteroviruses serotypes in northwest China (north temperate zone) and identification of cyclicity of HFMD infections are therefore an issue of great importance for future epidemics prediction and control. The basic/effective reproduction numbers for EV-A71, CV-A16 and CV-A6 were estimated based on daily new cases in 2010, 2011 and 2018, respectively, in which the corresponding pathogen dominated the epidemic. Two different methods based on serial interval were adopted and the basic reproduction number were estimated to be in the range of (1.33, 1.46) for CV-A16, (1.20, 1.29) for EV-A71, and (1.38, 1.59) for CV-A6, respectively. The estimated daily effective reproduction numbers significantly fluctuated before June or after July but varied mildly in (0.5,2) in around June to July for three serotypes. The weekly effective reproduction number for HFMD was estimated based on weekly new cases from year 2010 to 2018, and in most years it peaked in the range of (1.6,2.0) in February to March as well as in the range of (1.0,1.2) in September to October. The wavelet analysis based on the time series of HFMD cases from 2008 to 2018 showed obvious annual and semi-annual cyclicity, while the inter-annual cycles are infeasible. In this study we found that CV-A6 shows the greatest transmission ability among these three pathogens while EV-A71 exhibits the weakest ability of transmission, and moreover, the estimated values of basic reproduction number in northwest China are lower than those in Singapore, Hongkong and Guangdong, which may be due to different climatic circumstances.

2.
Mater Sci Eng C Mater Biol Appl ; 106: 110249, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753409

RESUMO

Biofilm-associated infections are in a high rate of recurrence and biofilms show formidable resistance to current antibiotics, making them a growing challenge in biomedical field. In this study, a biocompatible composite was developed by incorporating tannic acid (TA) and MgCl2 to bacterial cellulose (BC) for antimicrobial and anti-biofilm purposes. The morphology was investigated by scanning electron microscopy (SEM), and chemical structure were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectra (XPS). In vitro release profiles of tannic acid revealed that the Mg2+ cross-links help impede the release of TA from BC matrix, while composite BC-TA lacked Mg2+ ionic cross-links, thus more TA was released from the hydrogel. The BC-TA-Mg composites also displayed strong antibacterial activity against S. aureus, E. coli and P. aeruginosa. Moreover, the composites significantly reduced biofilm formation of S. aureus and P. aeruginosa after 24 h incubation by ∼80% and ∼87%, respectively. As a consequence, the BC-TA-Mg composites are a very promising material for combating biofilm-associated infections in biomedical and public health fields.

3.
Talanta ; 206: 120214, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514851

RESUMO

In this paper, a tetrahydro[5]helicene-based imide dye with thienyl group (THID) was studied on its solvatochromism and aggregation-induced emission (AIE) properties by dissolved in various organic solvents. The linear relationship between Stokes shift and aprotic solvent polarity parameter was well fitted with Lippert-Mataga model. Furthermore, Stokes shift also were positively correlated with the normalized molar electronic transition energy, suggested that THID exceptionally depends on solvent polarity for twisted intramolecular charge transfer. In addition, THID demonstrated typical AIE features when adding large amounts of water into good solvent. Meanwhile, it can function as intensity and wavelength-based fluorescence sensor for detecting low-level water content in water soluble solvents, even the low of detection was 0.014 vol% in ACN. Therefore, a simple and highly selective fluorescence analysis for glyceryl monostearate has been established on basis of its AIE property.

4.
Sci Total Environ ; 698: 134106, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505350

RESUMO

Chronic exposure to cadmium (Cd) can cause renal dysfunction. Studies of animals, cell cultures, and plants have found that selenium (Se) can effectively alleviate the hazard generated by Cd, but there has been little study of this in general human populations. This study recruited 313 subjects from China's Hubei Province, including 160 living in areas with high soil Cd and Se (exposure group) and 153 living in clean areas (control group). The levels of the following were detected: Cd and Se in blood (B-Cd and B-Se), urine (U-Cd and U-Se), and hair (H-Cd and H-Se); N-acetyl-ß-D-glucosaminidase (U-NAG), ß2-microglobulin (U-ß2-MG), and albumin (U-ALB) in urine; and malondialdehyde (S-MDA), superoxide dismutase (S-SOD), and glutathione peroxidase (S-GSH-Px) in serum. In addition, the interactions between Cd and Se were assessed. The median levels of B-Cd, B-Se, U-Cd, U-Se, H-Cd, H-Se, S-MDA, and S-GSH-Px of exposure group (2.60 ng/mL, 238.90 ng/mL, 3.13 µg/g Cr, 45.43 µg/g Cr, 0.06 µg/g, 0.70 µg/g, 5.22 nmol/mL, and 308.89 U, respectively) were significantly higher than of controls (0.95 ng/mL, 130.50 ng/mL, 1.08 µg/g Cr, 30.51 µg/g Cr, 0.04 µg/g, 0.49 µg/g, 4.71 nmol/mL, and 267.54 U, respectively), but there were no significant differences in U-NAG, U-ß2-MG, U-ALB, or S-SOD between the two groups. U-NAG levels were significantly negatively associated with the interaction between Cd and Se (B: -0.511, 95% CI: -0.886, -0.136). Additionally, changes in the direction of the estimated regression coefficient in the low and high H-Se groups were observed for U-Cd and S-MDA (from 0.018 to -0.090), U-Cd and S-GSH-Px (from -0.039 to 0.101). This study found that populations living in areas with high levels of soil Cd and Se did not show greater Cd-induced renal tubular and glomerular injuries than the control population, which could attribute to the protective effects of Se. The protective effects may be related to the peculiar function of Se that Se can combine with free Cd to activate the antioxidant enzyme system.

5.
Exp Cell Res ; : 111714, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31711919

RESUMO

FAM122A protein is a highly conserved in mammals, however its function is still largely unknown so far. In this study, we investigated the potential role of FAM122A in hepatocellular carcinoma (HCC). By analyzing HCC patient cohorts from RNA sequencing datasets, we found the expression level of FAM122A mRNA is significantly upregulated in HCC patients. Moreover, this abnormally higher expression pattern of FAM122A protein was also found in partial HCC tumor tissues, compared with the normal parts. Further, we demonstrated that CRISPR/Cas9-mediated FAM122A knockout significantly inhibits the growth, clonogenic potential and xenografts of HCC cells, induces cell cycle arrest and reduces the expression of proliferation-related genes. Interestingly, FAM122A deletion significantly enhances the cytotoxicity effect of Doxorubicin (Dox), a drug used in standard chemotherapy in HCC patients. In contrary, overexpression of FAM122A not only promotes HCC cell growth, but also inhibits Dox-induced DNA damage and cell death. Considering that FAM122A is previously identified as an endogenous inhibitor of PP2A, we asked whether FAM122A regulating HCC cell growth is associated with PP2A. The results showed FAM122A can also modulate PP2A activity in HCC cells although the modulated effect is relatively slight, however, treatment with a PP2A inhibitor okadaic acid did not rescue the inhibitory effects of cell growth and proliferation in FAM122A deletion cells, indicating that FAM122A may support HCC cell growth independent of its ability to modulate PP2A. Collectively, these results suggest that FAM122A is required for maintaining HCC cell growth, and its elimination combined with chemotherapy may represent a potential novel therapeutic strategy for HCC patients.

6.
Nanomedicine (Lond) ; 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31696756

RESUMO

Aim: A redox-triggered camptothecin (CPT) liposomal system was developed for an improved clinical potential in tumor therapy. Materials & methods: CPT-phosphorylcholine conjugates (CPT-SS-GPCs: CPT-SS-3-GPC and CPT-SS-11-GPC) were synthesized by conjugating CPT to glycerylphosphorylcholine via disulfide bond linker. CPT-SS-GPCs could be assembled into liposomes. Different in vitro and in vivo analyses were used to evaluate the anticancer activities of CPT-SS-GPCs. Results: CPT-SS-GPCs liposomes exhibited extremely high drug loading and uniform size of 150-200 nm. Moreover, the rapid release of parent CPT in reductive condition and high cellular uptake of CPT-SS-GPCs liposomes were observed. At last, in vitro and in vivo anticancer assay showed the enhanced efficacy of CPT-SS-GPCs liposomes. Conclusion: Redox-triggered CPT-SS-GPC liposomes have great potential in tumor therapy.

7.
J Gene Med ; : e3139, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31697008

RESUMO

BACKGROUND: The aim of this study was to investigate the association of several single nucleotide polymorphisms (SNPs) within Toll-like receptors 4 (TLR4) gene and additional gene- environment interaction with primary open angle glaucoma (POAG) risk. METHODS: Testing for Hardy-Weinberg equilibrium in controls and haplotype analysis are performed using SNPstats. Generalized multifactor dimensionality reduction (GMDR) was performed to test the interaction effects among 4 SNPs within TLR4 gene and environmental factors. Logistic regression was performed to calculate the ORs (95%CI) for association between 4 SNPs within TLR4 gene and POAG risk. RESULTS: The POAG risk was significantly higher in carriers with the T allele of rs4986791, the T allele of rs2149356 within TLR4 gene than those with wild genotype, adjusted ORs (95%CI) were 1.65 (1.23-2.12) and 1.70 (1.16-2.31). GMDR model suggested a significant two-locus model (p=0.0010) involving rs2149356 and alcohol drinking. Alcohol drinkers with rs2149356- GT+ TT genotype within TLR4 gene have the highest POAG risk, compared to never alcohol drinkers with rs2149356- GG genotype, OR (95%CI) = 2.62 (1.48-3.78), after covariates adjustment. But the study did not find a significant any-locus model involving SNP and smoking. In all samples, the haplotype rs2149356 - G- rs7873784- C was observed most frequently in two groups, with 47.47% and 48.21% for the POAG patients and controls, respectively. The results also indicated no significant haplotype associated with POAG risk. CONCLUSIONS: The minor alleles of rs4986791 and rs2149356 within TLR4 gene, interaction between rs2149356 and alcohol drinking were all associated with increased POAG risk.

8.
Aging (Albany NY) ; 11(21): 9442-9460, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31694982

RESUMO

Transforming growth factor-ß1 (TGFß1)-induced differentiation into and the activation of myofibroblasts have been regarded as critical events in benign prostatic hyperplasia (BPH); however, the underlying mechanisms of BPH pathogenesis remain unclear. Microarray profiling, STRING analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation, and Gene Ontology (GO) enrichment analysis were performed to confirm the candidate genes and long non-coding RNA (lncRNAs) related to BPH. Collagen Type III (COL3A1) was significantly upregulated by TGFß1 in prostate stromal cells (PrSCs) and might be involved in DNM3OS function in myofibroblasts upon TGFß1 stimulation. Upon TGFß1 stimulation, COL3A1 protein was decreased by DNM3OS silencing. miR-29a and miR-29b could directly bind to the DNM3OS and COL3A1 3' untranslated region (UTR)s to negatively regulate their expression, and by serving as a competing endogenous RNAs (ceRNA), DNM3OS competed with COL3A1 for miR-29a/29b binding, therefore counteracting miR-29a/29b-mediated COL3A1 suppression. The effect of DNM3OS silencing on ECM components and TGFß1 downstream signaling was similar to that of the TGFß1 inhibitor SB431542. miR-361 could target DNM3OS and TGFß1; DNM3OS competed for miR-361 binding to counteract miR-361-mediated TGFß1 suppression. In conclusion, we identified DNM3OS as a specifically-upregulated lncRNA upon TGFß1 stimulation in PrSCs; by serving as a ceRNA for the miR-29a/29b cluster and miR-361, DNM3OS eliminated miRNA-mediated suppression of COL3A1 and TGFß1, thereby promoting TGFß1-induced PrSC transformation into myofibroblasts.

9.
Nanomedicine ; : 102105, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31740406

RESUMO

PEG coating was regarded as one effective method to improve the tumor-targeting efficiency of hyaluronic acid-based nanoparticles (HBN). However, the research of interaction between PEG coating and different receptors such as stabilin-2 and CD44 was limited. Herein, we synthesized a series of PEGylated hyaluronic acid with Curcumin (PHCs) to evaluate the role of PEG coating density in the interaction between HA and its receptors, which influenced tissues targeting, pharmacokinetic profiles and therapeutic efficacy of HBN. Compared with other counterparts, PHC HBN with about 5% PEG coating density preferably accumulated in the tumor mass, rather than in the liver, and hold desirable anti-cancer effect. These results indicated that to obtain optimized anticancer effect of HBN, the cellular uptake efficiency between different types of the cells should be carefully balanced by different PEG densities.

10.
Langmuir ; 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31756107

RESUMO

Site-specific immobilization of proteins on a surface has been a long-lasting challenge in the fields of biosensing and biotechnology, because of the need for improving the biological activity of immobilized protein via the maximal exposure of its bioactive domain. Herein, we reported a new site-specific immobilization method for his-tagged proteins onto vinyl sulfone (VS)-bearing surface in a covalent manner. X-ray photoelectron spectroscopy (XPS) characterization indicated the specificity of the addition reaction of the imidazole group in histidine on the VS-bearing surface at pH 7.0. Solution-based experiments were carried out to verify the reaction priority of imidazole residue of histidine with the VS group at neutral conditions. The real-time immobilization process of two his-tagged proteins (HaloTag-6His and anti-HER2 Fab-6His) on surfaces presenting VS, pre-activated carboxyl, and NTA groups were studied by quartz crystal microbalance (QCM). Compared to the existing methods utilizing covalent (NHS/EDC activated carboxyl) and coordinate (Ni2+-NTA) linking, our method offers the two significant advantages for protein immobilization: high density and high specificity. The orientation of the two his-tagged proteins on the VS-bearing surface was confirmed by an enzyme-linked assay and a HER2+ liposome binding experiment, respectively. Our method of the site-specific immobilization of his-tagged proteins is efficient and straightforward, which would be helpful to expand the applications of recombinant proteins in enzyme immobilization, biosensor and array fabrication and drug delivery system.

11.
Int Immunopharmacol ; : 105954, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31757676

RESUMO

Osteoarthritis (OA) is a chronic inflammatory disease that is the basis of cartilage extracellular matrix degeneration and joint inflammation. Scutellarin is an herbal flavonoid glucuronide, isolated from the Chinese traditional herb Erigeron breviscapus, has been reported to have anti-inflammatory effect. Here, we showed that Scutellarin could inhibit inflammation and protects cartilage from degeneration in vitro and in vivo. Scutellarin downregulate the mRNA and protein expression of MMP1, MMP13, and ADAMTS-5, Wnt3a, Frizzled7 and promote the expression of Collagen II and Aggrecan. Moreover, scutellarin inhibit the migration of ß-catenin and phosphorylation of p38 into the nucleus, which may relate to the mediation of the Wnt/ß-catenin and MAPK signaling pathway. Furthermore, scutellarin significantly inhibit the cartilage degradation of DMM-induced OA mice by safranin-O and fast green staining. In conclusion, our study indicates that scutellarin may be a potential drug for the treatment of OA.

12.
J Environ Manage ; 254: 109767, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31704643

RESUMO

This paper presents exergo-economic and enviro-economic assessment of a novel building integrated photovoltaic thermal-compound sensible rotary heat exchanger (BIPVT-SRHX) system. The innovative BIPVT-SRHX system preheats/precools the outdoor air in winter/summer and generates electric power. The performance of the system are analyzed from the energy/exergy viewpoints for Kermanshah, Iran climatic conditions. Then, the multi-objective genetic algorithm (MOGA) optimization is used to optimize to determine the optimum values of geometric and operating parameters in order to maximize the annual average exergo-economic and enviro-economic aspects of the system. The considered geometric and operating parameters include the length, width and depth of the air channel located underneath the PV modules, the air mass flow rate, and the diameter, rotational velocity and length of the SRHX. Moreover, the annual performance of the optimized and non-optimized BIPVT-SRHX systems are compared. The results showed that the annual average exergo-economic and enviro-economic aspects of the optimized BIPVT-SRHX system are 0.0076 $/annum and 246.9 kWh/$, respectively. Furthermore, it was found that the annual average enviro-economic aspect, annual average exergo-economic aspect, and yearly sum of CO2 mitigation of the optimized BIPVT-SRHX system are respectively 36.8%, 23.1% and 37.7% higher than the non-optimized system.

13.
J Neuroinflammation ; 16(1): 217, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31722730

RESUMO

BACKGROUND: Microglial activation contributes to the development of chronic migraine (CM). The P2Y12 receptor (P2Y12R), a metabolic purinoceptor that is expressed on microglia in the central nervous system (CNS), has been indicated to play a critical role in the pathogenesis of chronic pain. However, whether it contributes to the mechanism of CM remains unknown. Thus, the present study investigated the precise details of microglial P2Y12R involvement in CM. METHODS: Mice subjected to recurrent nitroglycerin (NTG) treatment were used as the CM model. Hyperalgesia were assessed by mechanical withdrawal threshold to electronic von Frey and thermal withdrawal latency to radiant heat. Western blot and immunohistochemical analyses were employed to detect the expression of P2Y12R, Iba-1, RhoA, and ROCK2 in the trigeminal nucleus caudalis (TNC). To confirm the role of P2Y12R and RhoA/ROCK in CM, we systemically administered P2Y12R antagonists (MRS2395 and clopidogrel) and a ROCK2 inhibitor (fasudil) and investigated their effects on microglial activation, c-fos, and calcitonin gene-related peptide (CGRP) expression in the TNC. To further confirm the effect of P2Y12R on microglial activation, we preincubated lipopolysaccharide (LPS)-treated BV-2 microglia with MRS2395 and clopidogrel. ELISA was used to evaluate the levels of inflammatory cytokines. RESULTS: The protein levels of P2Y12R, GTP-RhoA, ROCK2, CGRP, c-fos, and inducible nitric oxide synthase (iNOS) in the TNC were increased after recurrent NTG injection. A double labeling study showed that P2Y12R was restricted to microglia in the TNC. MRS2395 and clopidogrel attenuated the development of tactile allodynia and suppressed the expression of CGRP, c-fos, and GTP-RhoA/ROCK2 in the TNC. Furthermore, fasudil also prevented hyperalgesia and suppressed the expression of CGRP in the TNC. In addition, inhibiting P2Y12R and ROCK2 activities suppressed NTG-induced microglial morphological changes (process retraction) and iNOS production in the TNC. In vitro, a double labeling study showed that P2Y12R was colocalized with BV-2 cells, and the levels of iNOS, IL-1ß, and TNF-α in LPS-stimulated BV-2 microglia were reduced by P2Y12R inhibitors. CONCLUSIONS: These data demonstrate that microglial P2Y12R in the TNC plays a critical role in the pathogenesis of CM by regulating microglial activation in the TNC via RhoA/ROCK pathway.

14.
Neurosci Lett ; : 134634, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31751668

RESUMO

BACKGROUND & AIMS: Studies have shown that moderate to severe stenosis of the carotid was associated with abnormal neural activity and functional connectivity (FC). However, whether there is a change of neuronal activity in individuals with asymptomatic vulnerable carotid plaque but mild stenosis (VCP) remains unknown. METHODS: From December 2015 to December 2017, a total of 31 patients with VCP and 31 no carotid plaque (NCP) controls were performed multi-modal state functional magnetic resonance imaging and investigated the regional brain activity and FC. Two basic algorithms of rs-fMRI, arterial spin labeling, and inflammatory biomarkers were comprehensively evaluated. The time series of aberrant ReHo and FC were also extracted and correlated with other clinical imaging features. RESULTS: As compared with NCP group, decreased regional brain activity was found mainly in left middle occipital gyrus (MOG) in the VCP group, but there was no significant difference in cerebral blood flow between the two groups. With the left MOG as seed, decreased FC was found between left MOG and right MOG and frontoparietal network in VCP group. Carotid intima-media thickness but not inflammatory biomarkers including high sensitivity c-reactive protein and interleukin-6 was significantly correlated with aberrant ReHo and FC in left MOG and right MOG. CONCLUSIONS: regional brain activity and FC may serve as early imaging markers for vascular-related brain dysfunctions and clinical indicators for early intervention of both atherosclerotic cerebral infarction and vascular cognitive impairments.

15.
Artigo em Inglês | MEDLINE | ID: mdl-31767151

RESUMO

Trichomes are specialized epidermal cells that play crucial roles in resisting environmental stress and enhancing plant development. In Arabidopsis thaliana, the main genes controlling trichome formation have been consecutively identified. However, few genes like this were reported in rice. In this study, we identified the hairy phenotype of indica variety 75-1-127. This was used to construct a segregation population with a cross of hairless variety Minghui63 (MH63) to fine map the trichome formation genes. Genetic analysis indicated that hairy phenotype was controlled by a pair of dominant genes on chromosome 6, which was designated as GLABRA6 (OsGL6). OsGL6 was an allele of HL6 gene whose sequences containing rich variations in genomes. Compared to wild type, the overexpressing transgenic lines revealed that OsGL6 promoted trichome initiation. We found that OsGL6 interacted with serine/threonine protein kinase OSK3 (OSK3) or COP9 signalosome complex subunit 5a (CSN5) in yeast. These results provide potential information for understanding the molecular mechanism of trichome formation in rice.

16.
Ecotoxicol Environ Saf ; : 109984, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31767461

RESUMO

In this study, we analyzed the effects of sludge aging pre-treatment on the stabilization mechanisms of heavy metals during sludge pyrolysis. First, the form of copper (Cu) and chromium (Cr) was conducted using the sequential extraction procedure proposed by the European Community Bureau of Reference (BCR). The stabilization mechanisms for the sludge pyrolysis of Cu and Cr were then analyzed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Results indicate the following: 1) with aging pre-treatment, the improvement in adsorption performance and the formation of newly crystallized materials, like polyhydroxy copper phosphate and chromium phosphate minerals, occur concurrently with the stabilization of heavy metals during pyrolysis; 2) after four weeks of aging, active functional groups like amino and carboxyl groups were significantly sharpened, and caused sustained complexation of the heavy metals. Results suggested that the aging pre-treatment aided the stabilization of heavy metals during sludge pyrolysis. Notably, the aging effect can decrease the potential ecological risk of heavy metals.

17.
Arch Insect Biochem Physiol ; : e21643, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31667894

RESUMO

Mass spectrometry imaging (MSI) can visualize the composition, abundance, and spatial distribution of molecules in tissues or cells, which has been widely used in the research of life science. Insects, especially the agricultural pests, have received a great deal of interests from the scientists in biodiversity and food security. This review introduces the major characteristics of MSI, summarizes its application to the investigation of insect endogenous metabolites, exogenous metabolites, and the spatiotemporal changes of metabolites between insects and plants, and discusses its shortfalls and perspectives. The significance of these concerns is beneficial for future insect research such as physiology and metabolism.

18.
Int J Biol Macromol ; 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31712154

RESUMO

Mesenchymal stem cell (MSC) delivery has been broadly investigated as a cell-based therapy strategy towards various diseases and tissue injury. In these applications, the cell-delivery vehicle plays a crucial role in determining the therapeutic performance of MSCs and their fate post-implantation. We report here the development of a microcarrier system combining platelet-derived growth factor-BB (PDGF-BB) and a PDGF-BB-binding polysaccharide - Eucommia ulmoides (EUP3) - for MSC cultivation. First, we investigated the optimal conditions to prepare the EUP3-PDGF-BB complex, by comparing its i) diameter, ii) morphology, and iii) bioactivity to promote MSC proliferation and fibroblast migration in vitro, under different PDGF-BB/EUP3 ratios. Then, we fabricated microspheres using gelatin and EUP3 as the matrix while stabilizing PDGF-BB at the optimal ratio for MSC adhesion and growth. Live staining and SEM observation indicated that the prepared microspheric carrier supported MSC growth and maintained cell stemness. We suggest that the EUP3/PDGF-gelatin microcarriers can potentially serve as a cell-delivery vehicle for tissue engineering.

19.
Artigo em Inglês | MEDLINE | ID: mdl-31729614

RESUMO

Over-track buildings have been increasingly favored in the construction of metro depots and freight depots in China in the last decade due to advantages of intensive utilization of land resources and high-profits. However, due to the relatively heavy transportation mass and high-operating frequency of bridge cranes, over-track buildings are often complained by occupants for annoying noise and vibrations. So far this issue is rarely concerned and the characteristics of noise and vibrations under bridge crane loading remain unclear. In this study, field measurements of two full-scale over-track buildings, including a seven-story building over a metro depot and a three-story building over a freight depot, were conducted. Vibration characteristics of both the structure and the bridge crane were obtained. The transmission of vibrations from bridge crane system to the over-track building was obtained by transfer function (TF) of vibration from the column bracket towards the outdoor platform or building floors. The structure-borne noise inside the building was also captured and evaluated. The effect of bridge crane operational parameters (loading capacity and running velocity) and structural dynamic properties (non-structural components) on system responses was further discussed. Results show that the bridge crane-induced vibrations are comparable to the levels of train-induced vibrations. Besides, both buildings tested in this study suffer from unacceptable structure-borne noise, although the building vibration is acceptable. We recommend to carefully examining design of new over-track buildings to avoid annoying indoor noise and improve the living or working environment of occupants. It is demonstrated that vibrations of over-track buildings are more sensitive to running velocity than load capacity of bridge crane. It could be expected that the future increase of velocity will worsen the noise and vibration environment of over-track buildings. Furthermore, it is seen that non-structural components would remarkably affect dynamic responses of the building.

20.
Environ Int ; 133(Pt B): 105275, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31675563

RESUMO

After reviewing the species- and community-level ecological risk assessments (ERAs) of chemicals in the aquatic environment, the present study attempted to propose a third stage of ERA, i.e., the ecosystem-level ERA. Based on the species sensitivity distribution model (SSD) and thermodynamic theory, the exergy and biomass indicators of communities from various trophic levels (TLs) were introduced to improve ecological connotation of SSDs. The species were classified into three TLs based on algae (TL1), invertebrates (TL2), and vertebrates (TL3), and the weight of each TL was determined based on relative biomass and ß value, which indicated a holistic contribution of each species or community to the ecosystem. Then, a system-level ERA protocol was successfully established, and the community- and system-level ecological risks of 10 typical toxic micro-organic pollutants in the western area of Lake Chaohu and its inflowing rivers were evaluated. System-level ERA curves (ExSSD) were mainly affected by the community-level SSD at TL2 for most chemicals in the present study. The uncertain boundary of ExSSD was mostly related to TLs with a wider uncertain boundary, but had little relation to the weight of each TL. The results of system-level ERAs revealed that dibutyl phthalate had the highest eco-risk, whereas γ-hexachlorocyclohexane presented the lowest eco-risk. Results of the system-level ERA were not fully consistent with the those of community-level ERA owing to the lack of a sufficient dataset, SSD model type, and ecosystem structure, as indicated by the weight of each TL. The successful application of ExSSD in Lake Chaohu signifies the start of the third stage of ERA at the system-level, and it also provides a scientific basis for ecosystem-level ERA, aquatic ecosystem protection, and future water safety management. However, there were some limitations, including sufficient data dependence, neglect of ecological interactions, and neglect of environmental parameters such as natural organic matter. We propose to employ toxicogenomics to enrich the toxicity database, to simulate the interaction using the ecological dynamic model, and to introduce the chemical fate model into the system-level ERA.

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