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1.
Carbohydr Polym ; 252: 117137, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33183596

RESUMO

Bacterial cellulose (BC) and polyhydroxybutyrate (PHB) are microbial polymers considered to be promising biodegradable alternatives to fossil fuel derivatives. BC and PHB can be combined into a composite with enhanced mechanical properties. The synthesis processes of BC/PHB composites described until now are complicated with multiple steps. Here, BC/PHB composites were synthesized by a facile Gluconacetobacter xylinus and Ralstonia eutropha co-culture method generating BC and PHB simultaneously in situ. This co-culture approach ensured a certain level of control over the synthesis process. By simply varying the R. eutropha inoculum, the weight ratio of PHB into BC/PHB was adjusted from 15.62 to 42.88 %. The fabricated composites were networks of BC fibers connecting PHB particles. BC/PHBs were characterized by thermal and mechanical analyses and exhibited a 2.6 times higher capacity for toxic copper adsorption than pure BC. The co-culture technique described here is a simple synthesis method to obtain BC/PHB with adjustable characteristics.

2.
Sci Total Environ ; 753: 141990, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32889321

RESUMO

The "emerging contaminants" (ECs) are predominantly unregulated anthropogenic chemicals that occur in air, soil, water, food, and human/animal tissues in trace concentrations. The ECs are persistent in the environment, capable of perturbing the physiology of target receptors and, therefore, are regarded as contaminants of emerging environmental concerns in recent years. The prominent classes of ECs include pharmaceuticals and personal care products (PCPs), surfactants, plasticizers, pesticides, fire retardants, and nanomaterials. Some of the ECs with harmful effects on endocrine systems have been recognized as endocrine disrupting chemicals (EDCs). Since the 1990s intensive research has been done covering environmental occurrence, fate, ecological effects, and treatment technologies of ECs. However, a comprehensive summary of the EC removal techniques, particularly in wastewater treatment plants (WWTPs) are limited. Though the WWTPs are inefficient when it comes to ECs removal, they act as primary barriers against the spread of ECs. Therefore, this paper reviews the treatment technologies currently engaged for ECs removal in WWTPs for further possible upgrades of the existing designs. Results of this review indicate that the fate and distribution of ECs can be approximately estimated based on physicochemical properties like octanol-water partitioning coefficient (e.g., log KOW > 4, maximum sorption potential) and solid-water distribution coefficient [e.g., Kd < 300-500 L/kg MLSS (mixed liquor suspended solids), insignificant sorption into sludge]. Biodegradation potential of ECs can be predicted from biodegradation constant values (e.g., Kbio < 0.01 = low biodegradation and >10 = high biodegradation). In WWTPs, the EC removal efficiency varies in the range of 20-50%, 30-70%, and >90% during the primary, secondary, and tertiary treatment steps, respectively. Tertiary treatment technologies are considered as the most suitable alternatives for ECs treatment, but complete ECs removal is yet to be achieved. Further advancements in the treatment technologies will unquestionably be necessary in the future.

3.
Bioresour Technol ; 319: 124056, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33038655

RESUMO

The related microbial metabolomics on biological recovery of manganese (Mn) from Electrolytic Manganese Slag (EMS) has not been studied. This study aimed at open the door to the metabolic characteristics of microorganisms in leaching Mn from EMS by using waste molasses (WM) as carbon source. Results show Microbacterium trichothecenolyticum Y1 (Y1) could effectively leach Mn from EMS in combination with using waste molasses as carbon and energy sources. For the first time, Y1 was identified to be capable of generating and then metabolizing several organic acids or other organic matter (e.g., fumaric acid, succinic acid, malic acid, glyoxylic acid, 3-hydroxybutyric acid, glutaric acid, L(+)-tartaric acid, citric acid, tetrahydrofolic acid, and L-methionine). The production of organic acids by Y1 bacteria was promoted by EMS with the carbon source. This study demonstrated for the first time that metabolic characteristics and carbon source metabolic pathways of Y1 in bioleaching of Mn from EMS.

4.
Sci Total Environ ; 753: 142050, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32898811

RESUMO

Particulate photocatalysts developed for the solar energy-driven reduction of the greenhouse gas CO2 have a small product range and low specificity. Hybrid photosynthesis expands the number of products with photocatalysts harvesting sunlight and transferring charges to microbes harboring versatile metabolisms for bioproduction. Besides CO2, abiotic photocatalysts have been employed to increase microbial production yields of reduced compounds from organic carbon substrates. Most single-reactor hybrid photosynthesis systems comprise CdS assembled in situ by microbial activity. This approach limits optimization of the morphology, crystal structure, and crystallinity of CdS for higher performance, which is usually done via synthesis methods incompatible with life. Here, shape and activity optimized CdS nanorods were hydrothermally produced and subsequently applied to Cupriavidus necator for the heterotrophic and autotrophic production of the bioplastic polyhydroxybutyrate (PHB). C. necator with CdS NR under light produced 1.5 times more PHB when compared to the same bacterium with suboptimal commercially-available CdS. Illuminated C. necator with CdS NR synthesized 1.41 g PHB from fructose over 120 h and 28 mg PHB from CO2 over 48 h. Interestingly, the beneficial effect of CdS NR was specific to C. necator as the metabolism of other microbes often employed for bioproduction including yeast and bacteria was negatively impacted. These results demonstrate that hybrid photosynthesis is more productive when the photocatalyst characteristics are optimized via a separated synthesis process prior to being coupled with microbes. Furthermore, bioproduction improvement by CdS-based photocatalyst requires specific microbial species highlighting the importance of screening efforts for the development of performant hybrid photosynthesis.


Assuntos
Cupriavidus necator , Nanotubos , Dióxido de Carbono , Frutose , Hidroxibutiratos
5.
Mol Divers ; 2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33200293

RESUMO

Here, two series of novel ursolic acid-based 1,2,4-triazolo[1,5-a]pyrimidines derivatives were synthesized and screened for their anti-inflammatory activity by evaluating their inhibition effect of using LPS-induced inflammatory response in RAW 264.7 macrophages in vitro; the effects of different concentrations of the compounds on the secretion of nitric oxide (NO) and inflammatory cytokines including TNF-α and IL-6 were evaluated. Their toxicity was also assessed in vitro. Results showed that the most prominent compound 3 could significantly decrease production of the above inflammatory factors. Docking study was performed for the representative compounds 3, UA, and Celecoxib to explain their interaction with cyclooxygenase-2 (COX-2) receptor active site. In vitro enzyme study implied that compound 3 exerted its anti-inflammatory activity through COX-2 inhibition.

6.
J Hazard Mater ; : 124373, 2020 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-33153788

RESUMO

In recent years, ultraviolet (UV) irradiation coupled with chlor(am)ination process is ubiquitous in secondary water supply systems in many cities of China. However, the disinfection by-products (DBPs) formation in a UV-activated mixed chlorine/chloramine system (MCCS) still remains unclear. In this study, the DBPs formation in a UV-activated MCCS was systematically investigated, considering influencing factors including the mass ratios of free chlorine to NH2Cl, UV irradiation, pH values, NOM types, Br- concentration and toxicity of the DBPs. Results indicated that DBPs formation decreased remarkably as mass ratio of free chlorine to NH2Cl changed from 5:0 to 0:5. The DBPs formation in humic acid (HA)-containing water was the highest, followed by those in fulvic acid (FA) and algal organic matter (AOM). Besides, better control of the DBP-related calculated toxicity can be achieved in acidic conditions regardless of the UV irradiation. Furthermore, in the presence of Br-, a significant reduction of DBPs formation could be achieved in a UV-activated MCCS. The findings also demonstrated that DBPs formation in real water can be effectively reduced at high UV fluence in a MCCS.

7.
Artigo em Inglês | MEDLINE | ID: mdl-33155889

RESUMO

BACKGROUND: In Traditional Chinese Medicine (TCM), the heads and tails of Angelica sinensis (Oliv.) Diels (AS) is used in treating different diseases due to their different pharmaceutical efficacies. The underline mechanisms, however, have not been fully explored. OBJECTIVE: Novel mechanisms responsible for the discrepant activities between AS heads and tails were explored by a combined strategy of transcriptomes and metabolomics. METHOD: Six pairs of the heads and tails of AS roots were collected in Min County, China. Total RNA and metabolites, which were used for RNA-seq and untargeted metabolomics analysis, were respectively isolated from each AS sample (0.1 g) by Trizol and methanol reagent. Subsequently, differentially expressed genes (DEGs) and discrepant pharmaceutical metabolites were identified for comparing AS heads and tails. Key DEGs and metabolites were quantified by qRT-PCR and targeted metabolomics experiment. RESULTS: Comprehensive analysis of transcriptomes and metabolomics results suggested that five KEGG pathways with significant differences included 57 DEGs. Especially, fourteen DEGs and six key metabolites were relation to the metabolic regulation of Phenylpropanoid biosynthesis (PB) pathway. Results of qRT-PCR and targeted metabolomics indicated that higher levels of expression of crucial genes in PB pathway, such as PAL, CAD, COMT and peroxidase in the tail of AS were positively correlated with levels of ferulic acid-related metabolites. The average content of ferulic acid in tails (569.58162.39 nmol/g) was higher than those in the heads (168.73  67.30 nmol/g) (P˂0.01); Caffeic acid in tails (3.82  0.88 nmol/g) vs heads (1.37  0.41 nmol/g) (P˂0.01), and Cinnamic acid in tails (0.24  0.09 nmol/g) vs heads (0.14  0.02 nmol/g) (P˂0.05). CONCLUSION: Our work demonstrated that overexpressed genes and accumulated metabolites derived from PB pathway might be responsible for the discrepant pharmaceutical efficacies between AS heads and tails.

8.
Int J Soc Psychiatry ; : 20764020975792, 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33231134

RESUMO

BACKGROUND: Although knowledge is a crucial component in contact theory delineating how prejudice changes toward out-groups with stigmatized conditions, little is known about the mediating role of knowledge on contact, stigmatizing attitudes, and behaviors toward mental illness. AIM: This study aimed to examine the mechanism underlie contact and stigma change by knowledge. METHODS: A total of 366 participants including family members (FM), mental health providers (MHP), and community residents (CR) recruited across communities in Hong Kong and completed measures of contact level, contact quantity, contact quality, mental health related knowledge, prejudice, and discriminatory behaviors. Structural equation modeling was adopted to test the association among the key variables. RESULTS: Higher level of contact was significantly correlated with better knowledge, less prejudice, and less discriminatory behaviors. Knowledge was directly and negatively correlated with prejudicial attitudes but was not significantly related to discriminatory behaviors. Furthermore, lower levels of prejudice were associated with less discriminatory behaviors. CONCLUSION: Enhancement of contact may increase understanding toward people with mental illness (PMI) and diminish stigmatizing attitudes and behaviors. Although prejudicial attitudes may be reduced by broadening mental health knowledge, increasing knowledge only might not ameliorate discriminatory behaviors. Future research should test mediators on contact and stigma by using longitudinal data.

9.
Environ Sci Technol ; 54(22): 14482-14493, 2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33138382

RESUMO

Coal combustion emits a large amount of PM2.5 (particulate matters with aerodynamic diameters less than 2.5 µm) and causes adverse damages to the cardiovascular system. In this study, emissions from anthracite and bitumite were examined. Red mud (RM) acts as an additive and is mixed in coal briquettes with a content of 0-10% as a single variable to demonstrate the reduction in the PM2.5 emissions. Burnt in a regulated combustion chamber, the 10% RM-containing bitumite and anthracite briquettes showed 52.3 and 18.6% reduction in PM2.5, respectively, compared with their chunk coals. Lower cytotoxicity (in terms of oxidative stresses and inflammation factors) was observed for PM2.5 emitted from the RM-containing briquettes than those from non-RM briquettes, especially for the bitumite groups. Besides, the results of western blotting illustrated that the inhibition of NF-κB and MAPK was the potential pathway for the reduction of cytokine levels by the RM addition. The regression analyses further demonstrated that the reduction was attributed to the lower emissions of transition metals (i.e., Mn) and PAHs (i.e., acenaphthene). This pilot study provides solid evidence for the cytotoxicity to vascular smooth muscle cells induced by PM2.5 from coal combustion and potential solutions for reducing the emission of toxic pollutants from human health perspectives.

10.
Bioorg Chem ; 105: 104451, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33197851

RESUMO

Twelve new sesquiterpene lactone dimers, lavandiolides A-L (1-12), were isolated from the whole plants of Artemisia lavandulifolia. Among them, compounds 1-6 are 1,3-linked Diels-Alder adducts between two guaianolide monomers, and 7-12 are 2,4-linked sesquiterpene lactone dimers. Their structures were elucidated by comprehensive analysis of HRESIMS, 1D and 2D NMR spectra. Their absolute configurations were determined by ECD spectra and single-crystal X-ray diffraction analyses with Cu Kα radiation. The nitric oxide (NO) inhibitory effect of all the isolates was assessed on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Compounds 1, 3, 7 and 9 showed potent inhibitory effects on NO production, with IC50 values of 0.61 ± 0.15, 1.64 ± 0.04, 1.89 ± 0.16, and 1.40 ± 0.23 µM, respectively. Furthermore, compound 1 inhibited NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome-mediated interleukin-1ß (IL-1ß) production through activating autophagy.

11.
Cell Stem Cell ; 27(5): 693-695, 2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33157042

RESUMO

Most patients with AML succumb to chemoresistant leukemia stem cells (LSCs), which persist and reinitiate disease years after clinical remission. In this issue of Cell Stem Cell, Jones et al. (2020) identify a therapeutically targetable mechanism of resistance to venetoclax in relapsed and refractory AML LSCs mediated by nicotinamide metabolism.

12.
J Radiat Res ; 2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33140083

RESUMO

Radiation-induced enteritis is a major side effect in cancer patients undergoing abdominopelvic radiotherapy. The Nrf2/HO-1 pathway is a critical endogenous antioxidant stress pathway, but its precise role in radiation-induced enteritis remains to be clarified. Polysaccharides extracted from Rheum tanguticum (RTP) can protect the intestinal cells from radiation-induced damage, but the underlying mechanism is unknown. SD rats and IEC-6 cells were exposed to 12 or 10 Gy X-ray radiation. Rat survival, and histopathological and immunohistochemical profiles were analyzed at different time points. Indicators of oxidative stress and inflammatory response were also assessed. Cell viability, apoptosis and Nrf2/HO-1 expression were evaluated at multiple time points. Significant changes were observed in the physiological and biochemical indexes of rats after radiation, accompanied by significant oxidative stress response. The mRNA and protein expression of Nrf2 peaked at 12 h after irradiation, and HO-1 expression peaked at 48 h after irradiation. RTP administration reduced radiation-induced intestinal damage, upregulated Nrf2/HO-1, improved physiological indexes, significantly decreased apoptosis and inflammatory factors, and upregulated HO-1, particularly at 48 h after irradiation. In conclusion, Nrf2 is activated in the early stage of radiation-induced intestinal injury and plays a protective role. RTP significantly ameliorates radiation-induced intestinal injury via the regulation of Nrf2 and its downstream protein HO-1.

13.
Stem Cell Res Ther ; 11(1): 460, 2020 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-33129347

RESUMO

BACKGROUND: Adipose-derived stem cells (ADSCs) promote tissue regeneration and repair. Cryoprotective agents (CPAs) protect cells from cryodamage during cryopreservation. Safe and efficient cryopreservation of ADSCs is critical for cell-based therapy in clinical applications. However, most CPAs are used at toxic concentrations, limiting their clinical application. OBJECTIVE: The aim of this study is to develop a non-toxic xeno-free novel CPA aiming at achieving high-efficiency and low-risk ADSC cryopreservation. METHODS: We explored different concentrations of trehalose (0.3 M, 0.6 M, 1.0 M, and 1.25 M) and glycerol (10%, 20%, and 30% v/v) for optimization and evaluated and compared the outcomes of ADSCs cryopreservation between a combination of trehalose and glycerol and the commonly used CPA DMSO (10%) + FBS (90%). All samples were slowly frozen and stored in liquid nitrogen for 30 days. The effectiveness was evaluated by the viability, proliferation, migration, and multi-potential differentiation of the ADSCs after thawing. RESULTS: Compared with the groups treated with individual reagents, the 1.0 M trehalose (Tre) + 20% glycerol (Gly) group showed significantly higher efficiency in preserving ADSC activities after thawing, with better outcomes in both cell viability and proliferation capacity. Compared with the 10% DMSO + 90% FBS treatment, the ADSCs preserved in 1.0 M Tre + 20% Gly showed similar cell viability, surface markers, and multi-potential differentiation but a significantly higher migration capability. The results indicated that cell function preservation can be improved by 1.0 M Tre + 20% Gly. CONCLUSIONS: The 1.0 M Tre + 20% Gly treatment preserved ADSCs with a higher migration capability than 10% DMSO + 90% FBS and with viability higher than that with trehalose or glycerol alone but similar to that with 10% DMSO + 90% FBS and fresh cells. Moreover, the new CPA achieves stemness and multi-potential differentiation similar to those in fresh cells. Our results demonstrate that 1.0 M Tre + 20% Gly can more efficiently cryopreserve ADSCs and is a non-toxic CPA that may be suitable for clinical applications.

14.
J Immunol Res ; 2020: 8528976, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33145364

RESUMO

Objective: Recent studies have focused on the special roles of NADPH-oxidase in multiple autoimmune diseases. Nevertheless, the association of genetic variation in NADPH-oxidase genes with rheumatoid arthritis (RA) was not extensively studied in a Chinese population. We performed this study to examine the association of NCF2, NCF4, and CYBA gene polymorphisms with RA susceptibility in a Chinese population. Methods: Six single nucleotide polymorphisms (SNPs) (NCF2 rs10911363, NCF4 rs1883112, rs4821544, rs729749, CYBA rs3794624, and rs4673) were genotyped in a cohort composed of 593 RA patients and 596 normal controls. Improved multiple ligase detection reaction (iMLDR) was used for genotyping. Results: We observed that NCF4 rs4821544 CT genotype and C allele frequencies in RA patients were significantly decreased when compared to controls (CT vs. TT: P = 0.043; C vs. T: P = 0.031), and rs4821544 polymorphism was significantly associated with an increased RA risk under the dominant model (TT vs. CT+CC: P = 0.031). Our results also indicated that rs729749 CT genotype frequency was significantly lower in RA patients than that in controls (CT vs. CC: P = 0.033). Moreover, the rs729749 CT genotype frequency was also significantly decreased in RA patients in males (CT vs. CC: P = 0.024). No significant association between NCF2 and CYBA gene polymorphisms and RA susceptibility was observed. There were significant associations between rs4821544 TT genotype and T allele frequencies and anti-CCP in male RA patients. Conclusions: In summary, NCF4 rs4821544 and rs729749 polymorphisms might contribute to RA susceptibility, while NCF2 and CYBA gene polymorphisms were not associated with RA susceptibility.

15.
Math Biosci Eng ; 17(5): 5672-5685, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-33120572

RESUMO

To address the problem of steel strip surface defect detection, a feature fusion-based preprocessing strategy is proposed based on machine vision technology. This strategy can increase the feature dimension of the image, highlight the pixel features of the image, and improve the recognition accuracy of the convolutional neural network. This method is based on commonly used image feature extraction operators (e.g., Sobel, Laplace, Prewitt, Robert, and local binary pattern) to process the defect image data, extract the edges and texture features of the defect image, and fuse the grayscale image processed by the feature operator with the original grayscale image by using three channels. To consider also computational efficiency and reduce the number of calculation parameters, the three channels are converted into a single channel according to a certain weight ratio. With this strategy, the steel plate surface defect database of NEU is processed, and fusion schemes with different operator combinations and different weight ratios for conversion to the single channel are explored. The test results show that, under the same network framework and with the same computational cost, the fusion scheme of Sobel:image:Laplace and the single-channel conversion weight ratio of 0.2:0.6:0.2 can improve the recognition rate of a previously unprocessed image by 3% and can achieve a final accuracy rate of 99.77%, thereby demonstrating the effectiveness of the proposed strategy.

16.
Mol Cell ; 2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33128871

RESUMO

Cancer-associated mutations that stabilize NRF2, an oxidant defense transcription factor, are predicted to promote tumor development. Here, utilizing 3D cancer spheroid models coupled with CRISPR-Cas9 screens, we investigate the molecular pathogenesis mediated by NRF2 hyperactivation. NRF2 hyperactivation was necessary for proliferation and survival in lung tumor spheroids. Antioxidant treatment rescued survival but not proliferation, suggesting the presence of distinct mechanisms. CRISPR screens revealed that spheroids are differentially dependent on the mammalian target of rapamycin (mTOR) for proliferation and the lipid peroxidase GPX4 for protection from ferroptosis of inner, matrix-deprived cells. Ferroptosis inhibitors blocked death from NRF2 downregulation, demonstrating a critical role of NRF2 in protecting matrix-deprived cells from ferroptosis. Interestingly, proteomics analyses show global enrichment of selenoproteins, including GPX4, by NRF2 downregulation, and targeting NRF2 and GPX4 killed spheroids overall. These results illustrate the value of spheroid culture in revealing environmental or spatial differential dependencies on NRF2 and reveal exploitable vulnerabilities of NRF2-hyperactivated tumors.

17.
Pediatr Surg Int ; 36(12): 1481-1487, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33098448

RESUMO

PURPOSE: Vitamins and trace elements are essential nutrients for growth and intestinal adaptation in children with short bowel syndrome (SBS). This study aimed to assess micronutrients' status during and after weaning off PN in pediatric SBS. METHODS: This retrospective study evaluated the follow-up of 31 children with SBS between Jan 2010 and Sep 2019. Clinical data were reviewed from the patients' electric medical record. Serum electrolytes, trace elements, vitamin B12, vitamin D, and folate concentrations were collected before and after enteral autonomy. RESULTS: Thirty-one SBS cases were reviewed (median onset age 11 days after birth, 51.6% boys, mean PN duration 4 months, and mean residual small intestine length 58.2 cm). Median duration of follow-up was 10 months (interquartile range [IQR]: 4, 19). The common micronutrient deficiencies were zinc (51.6%), copper (38.7%), vitamin D (32.3%), and phosphorus (25.8%) after the transition to EN. The proportion of patients deficient in vitamin D decreased dramatically from 93.5% to 32.3% (P < 0.001), and serum concentrations of vitamin D increased significantly (27.4 ± 12.3 vs. 60.3 ± 32.9 nmol/l, P = 0.03) after achieving full enteral feeding more than 1 month. Additionally, serum magnesium levels significantly increased (0.76 ± 0.17 vs. 0.88 ± 0.14 mmol/l, P = 0.03). Hemoglobin levels elevated significantly after weaning off PN (104.3 ± 10.7 vs. 117.8 ± 13.7 g/l, P = 0.03). CONCLUSIONS: Micronutrient deficiencies remain a common problem in pediatric SBS through intestinal rehabilitation. Therefore, we strongly recommend supplementation of more vitamin D and trace elements (zinc, copper, and phosphorus) under regular monitoring during long-term intestinal rehabilitation.

18.
Molecules ; 25(20)2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33066297

RESUMO

Metal-Organic Framework (MOF) materials are often modified or functionalized, and then the crystal size and morphology of MOF materials are changed. In the process of preparing UiO-66 confined phosphomolybdic acid (PMA) composites (PU), the TiF4-modified PU (PMA + UiO-66) composite catalyst (TiF4-PU) was successfully synthesized by adding titanium tetrafluoride, and the catalytic desulfurization activity was excellent. Similarly, the reaction mechanism was investigated by means of infrared spectroscopy, Raman spectroscopy, XPS, and UV/Vis spectroscopy. The results show that the addition of TiF4 not only changes the appearance and color of the catalyst, but also changes the valence distribution of the elements in the catalyst. The number of oxygen vacancies in the MOF increases due to the addition of TiF4, and more electrons are transferred from the Zr-MOF to PMA to form more Mo5+, which improved the performance of oxidative desulfurization in comparison. Thus, a stronger strong metal-support interaction (SMSI) effect is observed for TiF4-modified PU catalysts. In addition, the quenching experiment of free radicals shows that ·OH radical is the main active substance in the oxidative desulfurization reaction over TiF4-PU catalyst.

19.
Molecules ; 25(20)2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33066298

RESUMO

Protein-tyrosine phosphatase 1B (PTP1B) has been considered as a promising target for treating insulin resistance. In searching for naturally occurring PTB1B antagonists, two new pimarane diterpenoids, named 2α-hydroxy-7-oxo-pimara-8(9),15-diene (1) and 19-hydroxy-2α-acetoxy-7-oxo-pimara-8(9),15-diene (2), were isolated from the seeds of Caesalpinia minax. Their structures were determined by extensive analysis of NMR and HR-ESIMS data, and their absolute configurations were determined by electronic circular dichroism (ECD) spectra. Compound 1 was disclosed as a competitive inhibitor of PTP1B with an IC50 (the half-maximal inhibitory concentration) value of 19.44 ± 2.39 µM and a Ki (inhibition constant) value of 13.69 ± 2.72 µM. Moreover, compound 1 dose-dependently promoted insulin-stimulated glucose uptake in C2C12 myotubes through activating insulin signaling pathway. Compound 1 might be further developed as an insulin sensitizer.

20.
Apoptosis ; 25(11-12): 853-863, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33068199

RESUMO

Blockade of hypoxia-caused nonmyocytes apoptosis helps improve survival and mitigate ventricular remodeling and dysfunction during the chronic stage of myocardial infarction. But tools affecting nonmyocyte apoptosis are very rare. Sphingosylphosphorylcholine (SPC), a naturally occurring bioactive sphingolipid in plasma, was proved to protect cardiomyocyte against apoptosis in an ischemic model in our previous study. Here, we showed that SPC also inhibited hypoxia-induced apoptosis in myofibroblasts, an important type of nonmyocytes in the heart. Calmodulin (CaM) is an identified receptor of SPC. We clarified that SPC inhibited myofibroblast apoptosis through CaM as evidenced by decreased cleaved caspase 3, PARP1 and condensed nucleus. Furthermore, the employment of inhibitor and agonist of p38 and STAT3 suggests that SPC inhibits myofibroblast apoptosis by regulating the phosphorylation of p38 and STAT3, and they act as downstream of CaM. The present work may provide new evidence on the regulation of myofibroblasts apoptosis by SPC and a novel target for heart remodeling after hypoxia.

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