In this work, different mass percentage of activated carbon (YBC) doped carbon paste electrodes (YBCPE) were firstly prepared, then electrodeposition of Pt nanoparticles was performed at a constant ...potential -0.1 V vs. Ag|AgCl|KCl (3 M) to prepare working electrodes Pt/YBCPE. It was shown that Pt/YBCPE(16%) exhibits the highest mass activity for formaldehyde oxidation compared to platinum deposited on pure carbon paste electrode (CPE) and other YBCPE(X%) electrodes. Afterwards, poly-o-anisidine (POA) film was prepared by electro-polymerization onto the CPE and YBCPE(16%) in o-anisidine monomer solution at 0.7 V and then Pt nanoparticles were electro-deposited at the POA film surface for fabrication of the Pt/POA/CPE and Pt/POA/YBCPE composite electrodes. The morphology of the composite electrodes was characterized by SEM, TEM, XRD and XPS which revealed that the presence of YBC and POA in the composite electrodes significantly improves the dispersion of Pt nanoparticles on the electrodes. Electrochemical impedance spectroscopy (EIS), chronoamperometry and cyclic voltammetry were used to verify the conductivity and durability of the composite electrode and its electro-catalytic activity. The obtained results indicated that the Pt/POA(16mC)/YBCPE(16%) exhibits excellent electro-catalytic activity towards the formaldehyde oxidation owing to the synergistic effect of the support-catalyst. Some comparisons for the electrooxidation of formaldehyde and the electrooxidation of methanol and formic acid on the composite electrodes also were conducted.
Bone marrow mesenchymal stem cells (BMMSCs) are characterized by their pluripotent differentiation and self-renewal capability and have been widely applied in regenerative medicine, gene therapy, and ...tissue repair. However, inflammatory response after BMMSCs transplantation was found to impair the osteogenic differentiation of BMMSCs. Thus, understanding the mechanisms underlying inflammation response will benefit the clinical use of BMMSCs. In this study, using a cell model of TNF-α-induced inflammatory response, we found that TNF-α treatment greatly elevated intracellular oxidative stress and induced endoplasmic reticulum (ER) stress by elevating the expression levels of ER sensors, such as PERK, ATF6 and IRE1A. Oxidative stress and ER stress formed a feedback loop to mediate TNF-α-induced inflammation response in BMMSCs. Moreover, c-Jun N-terminal kinase (JNK) signal pathway that coupled to the ER stress was significantly activated by increasing its phosphorylation upon TNF-α treatment. Importantly, pharmacological inhibition of ER stress effectively eliminated the phosphorylation of JNK and attenuated the TNF-α-induced inflammation response. In conclusion, our results indicated that TNF-α induced oxidative and ER stress, thereby leading to JNK activation, and generating inflammation response in BMMSCs. This pathway underlying TNF-α-induced inflammation response may provide new strategies to improve BMMSCs osteogenesis and other inflammation-associated bone diseases.
•TNF-α induced inflammatory response in BMMSCs in vitro.•TNF-α greatly elevated intracellular oxidative stress and induced ER stress in BMMSCs.•Inhibition of ER stress or JNK activation attenuated the TNF-α-induced inflammation response in BMMSCs.
Insulin-like growth factor 1 (IGF-1), a multifunctional peptide that involves in cell proliferation and differentiation, can induce strong osteogenic differentiation in bone marrow mesenchymal stem ...cells (BMMSCs). However, it remains unknown whether intracellular Ca2+ signal contributes to the IGF-1-induced osteogenic differentiation of BMMSCs. In this study, we attempted to investigate the effect of IGF-1 on the gene expression of intracellular Ca2+-handling proteins and figure out whether the intracellular Ca2+ signal affects IGF-1-induced osteogenic differentiation. We found that IGF-1 treatment significantly increased cell proliferation and induced cell morphological changes with an increase of cell surface area. Quantitative PCR and Western blot analysis showed that osteoblast marker proteins, including alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) were significantly upregulated by IGF-1 treatment, indicating IGF-1 induced osteogenic differentiation in BMMSCs. Interestingly, the expression levels of the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) 3 and inositol-1,4,5-triphosphate receptor (IP3R) 2 were dramatically elevated during the IGF-1-induced osteogenic differentiation. Consistently, IGF-1-treated cells exhibited greater Ca2+ response to ATP. Importantly, blocking SERCA by thapsigargin markedly impaired IGF-1-induced osteogenic differentiation, indicating that intracellular Ca2+ mediated IGF-1-induced osteogenic differentiation in BMMSCs, probably via Akt signal pathway, which may provide new insight for the treatment of osteoporosis.
•IGF-1 greatly upregulated SERCA3 and IP3R2 expression, and elevated intracellular Ca2+ response to ATP during osteogenic differentiation.•Inhibition of SERCA by thapsigargin markedly impaired IGF-1-induced osteogenic differentiation.•Intracellular Ca2+ signal mediated IGF-1-induced osteogenic differentiation of BMMSCs via Akt pathway.
Tumor Necrosis Factor α (TNF-α), a multifunctional pro-inflammatory cytokine, is produced by macrophages/monocytes during acute inflammation, and plays a critical role in orchestrating the cytokine ...cascade in various inflammatory diseases. Previous studies demonstrated that TNF-α induces inflammatory responses in bone marrow mesenchymal stem cells (BMSCs) transplantation, leading to unsatisfactory effects and limit the clinical use of BMSCs. MicroRNAs are reported to involve in inflammation by regulating the expression of their targets in inflammatory response pathway. However, whether microRNAs mediate TNF-α-induced inflammatory responses in BMSCs remains elusive. Here, we found that TNF-α treatment induced an inflammatory response by increasing the levels of key inflammatory mediators, including IL-6, IL-1β, matrix metalloproteinase 9 (MMP9) and monocyte chemotactic protein-1 (MCP-1) in BMSCs. Moreover, real-time PCR result showed dramatically up-regulation of miR-128-3p after exposure to TNF-α. Interestingly, miR-128-3p over-expression exacerbated the TNF-α-induced inflammatory response, while suppression of miR-128-3p effectively eliminated the inflammatory response in BMSCs. Bioinformatic analysis identified sirtuin 1 is a direct target of miR-128-3p. Up-regulation of sirtuin 1 induced by resveratrol also diminished the TNF-α-induced inflammatory response in BMSCs. Altogether, our results indicated that miR-128-3p targets sirtuin 1 to mediate the TNF-α-induced inflammatory response in BMSCs, which may provide new strategies to protect against inflammatory-dependent impairments in BMSCs.
•The expression of MiR-128-3p strongly correlated with the TNF-α-induced inflammatory responses in BMSCs.•Sirtuin 1 was identified to be a direct target of miR-128-3p that mediated TNF-α-induced inflammatory responses in BMSCs.•MiR-128-3p over-expression exacerbated the TNF-α-induced inflammatory response, while suppression of miR-128-3p effectively eliminated the inflammatory response in BMSCs.
•Giving an analytical model of pullout behavior of the root system (ARSM).•Giving a detailed analysis of root architecture.•Considering the root angle.•Allowing the force deviation from the axis of ...the root.•Regardless of the friction between roots and soil.
The pullout resistance is significant to protect slopes from tensive rainfall and strong wind. Explaining the pullout behavior of a root system is challenging because the root mechanical and architectural characteristics are difficult to characterize. This study proposes a new simplified analytical model of the pullout behavior with displacement. The root system is divided into several topological levels along depth, and then the parameter of the root diameter and root number distribution at each topological level is summarized respectively according to the test result. Mechanical characteristics are expressed as functions of the root diameter. The pullout force of the whole system is the sum of the force of every root segment. Then, the expression is verified by the result of field test, and its parameters are summarized. The influence of these parameters on pullout behavior is discussed. The model is also compared with other models: (1) a detailed analysis of the root architecture; (2) considering the root angle; (3) allowing the pullout force to deviate from roots. However, (1) the model needs more parameters; (2) the model can be improved by more consideration of the interaction between roots and soil. The model can be used in stability analysis, which should be researched.
Fungi are the causal agents of many of the world's most serious plant diseases causing disastrous consequences for large-scale agricultural production. Pathogenicity genomic basis is complex in fungi ...as multicellular eukaryotic pathogens. The fungus Cercospora sojina is a plant pathogen that threatens global soybean supplies. Here, we report the genome sequence of C. sojina strain S9 and detect genome features and predicted genomic elements. The genome sequence of C. sojina is a valuable resource with potential in studying the fungal pathogenicity and soybean host resistance to frogeye leaf spot (FLS), which is caused by C. sojina. The C. sojina genome sequence has been deposited and available at DDBJ/EMBL/GenBank under the project accession number AHPQ00000000.
The prepared carbon-coated silicon (Si@C) material was blended with graphite powder together to form the specific carbon paste electrode with different mass percent X% of Si@C (CPE-Si@C(X%)). The ...electrochemical impedance spectroscopy (EIS) was performed on the prepared CPE-Si@C and the pure carbon paste electrode (CPE), and the results show that the CPE-Si@C (X%) electrode has a smaller charge transfer resistance. Pt/CPE and Pt/CPE-Si@C(X%) electrodes were prepared by electrodepositing Pt particles on CPE-Si@C and CPE, and the obtained electrodes were used for electrocatalytic oxidation of methanol in acid media. The results show that the activity of Pt/CPE-Si@C(X%) electrode for electrocatalytic oxidation of methanol was higher than that of Pt/CPE electrode, and the mass peak current density of Pt/CPE-Si@C(10%) electrode for electrocatalytic oxidation of methanol reached 321 mA mg−1, which was 1.8 times higher than that of Pt/CPE electrode. The Pt/CPE-Si@C (10%) electrode and the Pt/CPE electrode were characterized by chronoamperometry. The results show that Pt/CPE-Si@C (10%) has a better stability of activity and stronger tolerance against CO poisoning.
•Carbon-coated silicon can enhance the conductivity of carbon paste electrode.•More Pt particles with longer and denser burr are on CPE-Si@C(10%).•Pt/CPE-Si@C has an excellent activity for electrooxidation of methanol.•Activity of Pt/CPE-Si@C is better than other electrodes in the literatures.
In order to elucidate the relationship between sulfate reduction and mineralization of organic matter in coastal sediments, the content of sulfate in sediment samples should be measured. Chloride, ...sulfate, bromide, nitrate, and phosphate are the standard anions in coastal sediment samples. Ion chromatography (IC) is one of the popularly used techniques for determinations of these anions. However, the peaks of the five anions in the IC system coincide with each other under high chloride conditions when using the normal method. In this article, an improved, highly sensitive method for simultaneous separation and determination of sulfate, bromide, nitrate, and phosphate in the samples with high chloride concentration is established and evaluated by IC. In high concentrations of chloride samples, the effects of eluent concentration on the retention time and separation of other anions are studied. The peaks of these anions can be well separated on an AS11 ion-exchange column by a low concentration of NaOH eluent (10 mM). in one injection. Gradient elution is helpful to shorten retention time, especially for phosphate. The method detection limit of sulfate is 0.091 mg · L
−1
. The recovery of sulfate ranged from 100.5% to 106.8%, when the concentrations of standard solution are close to those of the samples. This technique was validated by determining the content of sulfate and chloride in coastal salt marsh sediment samples.
Cytocompatibility of high nitrogen nickel-free stainless steel （HNS） with different nitrogen content was evalu- ated and compared with a conventional austenitic stainless steel 317L. The MTT assay ...（3-（4,5-dimethylthiazol- 2-yl）-2,5-diphenyltetrazolium bromide） was performed on MG63 osteoblasts to assess the cytotoxicity. The expression of selected marker typical of differentiated osteoblasts, such as alkaline phosphatase activity （AKP）, was also monitored in MG63 cells cultured on the tested materials. As a result, HNS had higher cell growth than 317L; meanwhile the cytocompatibility was increased with increasing nitrogen content. Furthermore, HNS enhanced osteoblasts differentiation, as confirmed by AKP activity. Overall these facts indicated that HNS had higher cytocompatibility than 317L and the nitrogen content contributed to the higher cytocompatibility of HNS. The influence of nitrogen on surface energy further explained the cytocompatibility of HNS.
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