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1.
Food Chem ; 303: 125399, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31470274

RESUMO

It is still a challenge to solve the matrix interferences in veterinary drug residue analysis. In this study, we reported a thin layer chromatography (TLC)-high-performance liquid chromatography (HPLC) method for determining total florfenicol (FF) residues, expressed as florfenicol amine (FFA), in porcine edible tissues. The tissue homogenate were acid-hydrolyzed to liberate the bound residues and convert them into FFA. The hydrolysates were washed with ethyl acetate and subsequently extracted with ethyl acetate under alkaline conditions. The supernatants were concentrated through evaporation, defatted with hexane, purified by TLC and analyzed by HPLC at 225 nm. The optimal developing solvent for TLC purification was ethyl acetate-acetone-ammonium hydroxide mixtures (2:8:0.5, v/v/v). The method was fully validated according to decision 2002/657/EC, and could be used for the routine monitoring of FF residues in pig. TLC showed excellent purification efficiency, and was expected to solve the matrix interferences in veterinary drug residue analysis.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia em Camada Delgada/métodos , Resíduos de Drogas/análise , Tianfenicol/análogos & derivados , Drogas Veterinárias/análise , Estruturas Animais/química , Animais , Cromatografia Líquida/métodos , Carne/análise , Suínos , Tianfenicol/análise
2.
Food Chem ; 306: 125611, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31606631

RESUMO

Aromatic secondary metabolites are closely related to quality attributes of postharvest fruit. In the present study, 20% CO2 was applied to strawberry fruit to investigate the regulation of elevated CO2 on aromatic secondary metabolites. The results showed that elevated CO2 delayed accumulations of anthocyanins, eugenol and lignin. Phenylalanine and tyrosine, the precursors of the above secondary metabolites, were 18.90% and 35.61%, respectively, lower in CO2-treated fruit compared with the control on day 6. Furthermore, enzyme activities and transcriptional profiles analysis showed pentose phosphate pathway and glycolysis were activated by elevated CO2 whereas the aromatic amino acids (AAAs) pathway was inhibited. These results indicated that elevated CO2 restricted carbon flux into aromatic secondary metabolism by inhibiting the AAAs pathway, leading to the decrease of phenylalanine and tyrosine, and thus, delayed the accumulation of aromatic secondary metabolites. In addition, the effect of elevated CO2 was eliminated after transferred CO2-treated fruit to air.

3.
Food Chem ; 307: 125550, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31639575

RESUMO

Modified atmosphere has widely been evident to contribute to fruit quality maintenance, however the correlation among these quality traits was less known. To explore main factors of elevated atmosphere and reduce the detection indexes, we exposed strawberry to either high O2 (80% O2 + 20% N2) or CO2 (20% CO2 + 20% O2 + 60% N2) atmosphere and compared quality characteristics. It was demonstrated that both atmospheres well maintained the fruit firmness, alleviated weight loss and decay rate. Elevated O2 maintained the polyphenolic contents and cell integrity by significantly decreasing superoxide and hydrogen peroxide levels. PCA analysis implied that HO treatment mainly affected oxygen metabolism while HCO affected carbon metabolism more. Significantly positive correlation was observed between weight loss, anthocyanin content and decay rate in elevated O2 and control groups. This study provided new insights into correlation and difference between impact of elevated O2 and CO2 to postharvest preservation.

4.
Sci Total Environ ; 698: 134289, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514034

RESUMO

Microeukaryotes are the key ecosystem drivers mediating marine productivity, the food web and biogeochemical cycles. The northwestern Pacific Ocean (NWPO), as one of the world's largest oligotrophic regions, remains largely unexplored regarding diversity and biogeography of microeukaryotes. Here, we investigated the community composition and geographical distribution of microeukaryotes collected from the euphotic zone of three different regions in the NWPO using high-throughput sequencing of the 18S rRNA gene and quantified the contributions of environmental factors on the distributions of microeukaryotes. The relative abundance of different group taxa, except for Ciliophora, presented distinct patterns in each region, and Metazoa and Dinoflagellata dominated the community, contributing approximately half of reads abundance. Spatial and environmental factors explained 66.01% of community variation in the NWPO. Temperature was the most important environmental factor significantly correlated with community structure. Bacterial biomass was also significantly correlated with microeukaryotic distribution, especially for Dinoflagellata and Diatomea. Network analysis showed strong correlations between microeukaryotic groups and free-living bacteria and different bacterial taxa were correlated with specific microeukaryotic groups, indicating that their interactions enabled microeukaryotic groups to adapt to diverse environments. This study provides a first glance at the diversity and geographical distribution of microeukaryotes in the NWPO and sheds light on the biotic and abiotic factors in shaping the microeukaryotic community in the ocean.

5.
Bioresour Technol ; : 122460, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31784250

RESUMO

To investigate the effects of viscosity on the mesophilic digestion of Maotai-flavored distiller's grains, a continuous experiment was conducted in a 70 L reactor at organic loading rates of 3, 4, 5, and 6 g VS/(L·d) with and without effluent recirculation. High organic loading rates and continuous effluent recirculation increased the digestate viscosity, and high viscosity caused severe foaming, which blocked the biogas outlet pipe. Moreover, a viscosity above 782 mPa·s was proposed as an early warning indicator for foaming. A maximum volumetric biogas production rate of 1.72 L/(L·d) was accomplished by diluting the feed without effluent recirculation at a recommended organic loading rate of 5 g VS/(L·d). Proteiniphilum, Ruminococcus_2, norank_f_Synergistaceae, norank_o__DTU014, Syntrophomonas, Methanosarcina, Methanobacterium, and Methanosaeta were the dominant acidogens, syntrophic bacteria, and methanogens existed in both low and high viscosity groups. Candidatus_Methanofastidiosum capable of employing the methylated thiol reduction pathway was found only in the high viscosity system.

6.
Biomaterials ; : 119636, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31785776

RESUMO

Sonodynamic therapy (SDT) has rapidly developed as a powerful alternative to traditional photodynamic therapy due to its intrinsically deeper tissue-penetration. However, single SDT dose is incapable of radical cure because the long-term hypoxia of tumor limits its therapeutic effect. Herein, we developed a biomimetic nanoplatform with dual pH/ultrasound response, homologous targeting and low phototoxicity for combined nitric oxide (NO) gas therapy with SDT to solve the problem. This nanoplatform is composed of zeolite imidazole framework-8 material embedded with nitrosoglutathione (GSNO) and chlorin e6 (Ce6) by one-step encapsulation, and then wrapped by homologous tumor cell membrane. In vitro and in vivo experiments indicate that the biomimetic nanoplatform has excellent biocompatibility and shows higher retention in tumor by homologous targeting. Importantly, it can sustainably release the encapsulated drug in acidic tumor microenvironment and accelerate degradation by ultrasound (US). Furthermore, NO released from GSNO and reactive oxygen species generated by Ce6, which are both triggered by US, react with each other to produce highly reactive peroxynitrite to inhibit the growth of tumor. Moreover, by repeated US irradiation, the tumor hypoxia can be relieved for a much-longer term, resulting in an effective gas-sonodynamic combined treatment. This study fully utilizes the advantages of US, providing a new strategy for high-performance cancer therapy.

7.
Psych J ; 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31788984

RESUMO

Impairment in semantic association has been reported in bipolar disorder (BD) and schizophrenia (SZ) patients and could underlie abnormal speech patterns in both disorders. In this study, we compared the electrophysiological semantic processing features in patients with these two disorders. Participants (n = 61; BD = 19; SZ = 19; healthy controls [HCs] = 23) were administered a semantic judgment task and event-related potentials (ERPs) were recorded. Responses of the two patient groups were significantly slower than HCs, but comparable behavioral semantic priming effects were observed in both patient groups. The N400 priming effect was observed in all groups, with a delayed peak in the two patient groups. The N400 effect was enhanced for both BD and SZ patients over the left frontal and frontal pole region, but SZ patients showed additional reduction of N400 over the right posterior and occipital regions. The N400 mean amplitudes for related targets correlated with less severe negative symptoms in patients with SZ. Discriminant functional analysis using reaction time and N400 measures successfully classified 82% of the participants into their respective clinical groups. These results suggest that patients with BD and SZ have both overlapping and distinctive semantic processing dysfunction. These findings are consistent with the continuum conceptualization of these disorders, but also offer some support for the traditional Kraepelinian dichotomy.

8.
J Org Chem ; 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31797673

RESUMO

The synthesis and properties of a series of U-shaped helical azaarenes are reported. Crystal structures of these helical azaarenes were obtained, and the solid-state structures unequivocally exhibited their helicity.

9.
Artigo em Inglês | MEDLINE | ID: mdl-31801015

RESUMO

Aerogels based on rod-like cellulose nanocrystals (CNCs) have been used in anisotropic materials, adsorbents and sensors, whereas they also suffer a low elasticity, leading to hard handling/processing in practical applications. Inspired by sea cucumber, which transits from rigid to flexible when its crosslink network of collagen fibers is weakened by stiparin inhibitor, we cross-linked the CNCs with flexible poly ethylene glycol (PEG) to prepare an aerogel owning variable mechanical properties in different environments. This aerogel not only had a chemical-bond crosslink network, but also an H-bond one, which could be easily weakened by water. The results showed that the obtained CNC/PEG aerogel owned a high modulus of 0.80 MPa in a dry state and transited to an elastic state (modulus is 0.87 kPa) in a wet state. In the dry state, the shape change of the CNC/PEG aerogel could not recover when the strain was over 10%, when in the wet state the shape change could be reversible. Interestingly, the irreversible strain in the dry state could further transit to reversible in the wet state, and the wet aerogel could then transit back to rigid after freeze drying. The mechanism study proved that this recovery came from the solvation-controlled weakening of the H-bond network between PEG and CNC. This work offered a simple but useful design of stimulation-response aerogels that can conduce an elastification and shape recovery.

10.
Medicine (Baltimore) ; 98(49): e18267, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31804363

RESUMO

RATIONALE: Rhizobium radiobacter is a Gram-negative pathogen present in soil and plants. Cases of R radiobacter infection in immunocompromised hosts have been sporadically reported. However, septic shock caused by R radiobacter is rarely seen. PATIENT CONCERNS: Here, we describe an elderly patient with a rapid progression of watery diarrhea, anorexia, fever, weakness, oliguria, and shock. Blood results showed increased total white blood cell count and C-reactive protein. Arterial blood gas results showed hypoxia and elevated lactate level. The Sequential Organ Failure Assessment score was 11. Blood culture at admission showed Gram-negative bacteria, which were later confirmed as R radiobacter. DIAGNOSIS: Septic shock caused by R Radiobacter. INTERVENTIONS: The patient was treated with intravenous cefoperazone/sulbactam and sequential oral levofloxacin. OUTCOMES: The patient recovered completely. CONCLUSION: R radiobacter may be considered as a potential opportunistic pathogen that may cause severe sepsis in elderly patients, especially those with multiple underlying diseases.

11.
Sci Rep ; 9(1): 18408, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31804618

RESUMO

Microorganisms play important roles in soil improvement. Therefore, clarifying the contribution of environmental factors in shaping the microbial community structure is beneficial to improve soil fertility in karst rocky desertification areas. Here, the bacterial community structures of eight rhizospheric soil samples collected from perennial fruit plantations were analysed using an Illumina HiSeq2500 platform. The diversity and abundance of bacteria in rocky desertification areas were significantly lower than those in non-rocky desertification areas, while the bacterial community structure was not significantly different between root surface and non-root surface soils in the same rhizospheric soil samples. Proteobacteria predominated in rocky desertification areas, while Actinobacteria predominated in non-rocky desertification areas. Correlation analysis revealed that water-soluble phosphorus content (r2 = 0.8258), latitude (r2 = 0.7556), altitude (r2 = 0.7501), and the age of fruit trees (r2 = 0.7321) were positively correlated with the bacterial community structure, while longitude, pH, and total phosphorus content did not significantly influence the soil bacterial community structure. As water-soluble phosphorus content is derived from insoluble phosphorus minerals, supplementing phosphorus-solubilising bacteria to soils in rocky desertification areas is a feasible strategy for accelerating the dissolution of insoluble phosphorus minerals and improving agricultural production and environment ecology.

12.
Math Biosci Eng ; 16(6): 7405-7420, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31698619

RESUMO

Primary angle-closure glaucoma (PACG) is a major cause of blindness worldwide, with a particularly high prevalence in Asian populations. Laser iridotomy (LI) has been the standard therapeutic modality for treating PACG to avoid blindness. However, the complex structure of the eyeball, the aqueous fluidity, and the limitation of detecting equipment will cause difficulty in surgery and the probability of complications. Numerical simulation was conducted to investigate aqueous humor (AH) flow under different physiological structures before and after laser surgery. When the anterior chamber depth decreases from 2.8 mm to 2.0 mm (caused by angle-closure glaucoma), the maximum velocity of natural convection is doubled, and the pressure difference between the posterior and anterior chambers increases by 20%. Therefore, a shallow anterior chamber depth is crucial for the accurate investigation of glaucoma. Pupil block sharply increases the intraocular pressure (IOP). When the gap between the lens and iris decreases from 10 µm to 0.5 µm, P between the posterior and anterior chambers is approximately 37 times higher than before, thereby damaging intraocular tissues. LI can effectively reduce the IOP caused by pupil block, but the velocity of AH after operation is 40 times the normal condition, and the increased corneal shear stress could lead to corneal damage, which can be solved by adjusting the incident angle of laser beam On the basis of the allowable angle range of surgical equipment and the effect of different incident angles on the cornea and iris, the optimum angle of laser drilling is 45°.

13.
Math Biosci Eng ; 16(6): 7546-7561, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31698628

RESUMO

Medical ultrasound images are corrupted by speckle noise, and despeckling methods are required to effectively and efficiently reduce speckle noise while simultaneously preserving details of tissues. This paper proposes a despeckling approach named the Gabor-based anisotropic diffusion coupled with the lattice Boltzmann method (GAD-LBM), which uses the lattice Boltzmann method (LBM) to fast solve the partial differential equation of an anisotropic diffusion model embedded with the Gabor edge detector. We evaluated the GAD-LBM on both synthetic and clinical ultrasound images, and the experimental results suggested that the GAD-LBM was superior to other nine methods in speckle suppression and detail preservation. For synthetic and clinical images, the computation time of the GAD-LBM was about 1/90 to 1/20 of the GAD solved with the finite difference, indicating the advantage of the GAD-LBM in efficiency. The GAD-LBM not only has excellent ability of noise reduction and detail preservation for ultrasound images, but also has advantages in computational efficiency.

14.
Math Biosci Eng ; 16(6): 8179-8194, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31698662

RESUMO

In this paper, we study a single-species population model with pulse toxicant input in a small polluted environment. The intrinsic rate of population change is affected by the environmental toxin load and toxin in the organisms which is influenced by toxin in the environment and the food chain. A new mathematical model is established. By the Pulse Compare Theorem, we find the surviving threshold of the population and obtain the sufficient conditions of persistence and extinction of the population.

15.
Sensors (Basel) ; 19(22)2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31698779

RESUMO

In maneuvering target tracking applications, the performance of the traditional interacting multiple model (IMM) filter deteriorates seriously under heavy-tailed measurement noises which are induced by outliers. A robust IMM filter utilizing Student's t-distribution is proposed to handle the heavy-tailed measurement noises in this paper. The measurement noises are treated as Student's t-distribution, whose degrees of freedom (dof) and scale matrix are assumed to be governed by gamma and inverse Wishart distributions, respectively. The mixing distributions of the target state, dof, and scale matrix are achieved through the interacting strategy of IMM filter. These mixing distributions are used for the initialization of time prediction. The posterior distributions of the target state, dof, and scale matrix conditioned on each mode are obtained by employing variational Bayesian approach. Then, the target state, dof, and scale matrix parameters are jointly estimated. A variational method is also given to estimate the mode probability. The unscented transform is utilized to solve the nonlinear estimation problem. Simulation results show that the proposed filter improves the estimation accuracy of target state and mode probability over existing filters under heavy-tailed measurement noises.

16.
Artigo em Inglês | MEDLINE | ID: mdl-31699591

RESUMO

In this work, a primary method was constructed for detecting hydrazine in plant, thus accomplished the closed-loop monitoring of hydrazine circulation within manufacture, environment, plants, animals and human. From a series of sensors, QYL-1 was selected to present the hydrazine sensing properties. As a preliminary tool, QYL-1 suggested the ultra-wide linear range (0-20.0 equivalent) and high selectivity, which were extremely essential for linking the monitoring in various scale and field. For the first time, concentration-dependent tracking of hydrazine was successfully performed in Arabidopsis Thaliana root tips. Afterwards applications in water samples and living MCF-7 cells then fulfilled the demonstration of closing the loop by linking both the upstream and downstream nodes. More than raising a practical method, this work offered initial information for the closed-loop monitoring of hydrazine circulation, which might be significant for the ideal systematic managing in future.

17.
Hemoglobin ; : 1-3, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31690135

RESUMO

A female of Chinese origin carried the codon 43 (G>T) (HBB: c.130G > T) and codons 71/72 (+A) (HBB: c.216_217insA) mutations of the ß-globin gene in cis, identified during prenatal thalassemia screening. The double in cis mutations were inherited from her mother. Both of the two carriers behave as a traditional heterozygote for ß-thalassemia (ß-thal) with microcytosis and a high Hb A2 level. This case report indicates that the possibility of multiple mutations in cis in a fetus with thalassemia trait has to be considered in a prenatal screening program.

18.
Oncol Rep ; 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31746439

RESUMO

The present study aimed to explore specific molecular targets for the diagnosis and treatment of non­small cell lung cancer (NSCLC). The expression profiles of microRNAs (miRNAs) and mRNAs were downloaded from the GEO (GSE102286 and GSE101929) and TCGA databases. After data preprocessing, differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) in cancer and normal tissues were selected and used to construct a DEM­DEG regulatory network and a protein­protein interaction (PPI) network. The genes and miRNAs in these networks were subjected to functional enrichment and survival analyses. Several key DEMs and DEGs were verified using RT­qPCR, and the results were statistically interpreted using a multivariate logistic regression analysis. In this study, 25 DEMs and 789 DEGs common to all datasets were identified, which were then used for the construction of a DEM­DEG regulatory network and a PPI network module. Survival analyses of 19 DEMs in the DEM­DEG regulatory network and 36 DEGs in the PPI network module revealed that 34 DEGs (including TOP2A, CCNB1, BIRC5, and TTK) and two miRNAs (miR­21­5p and miR­31­5p) were significantly associated with NSCLC prognosis. Moreover, RT­qPCR analysis identified three DEGs and five DEMs that had changes in expression consistent with those observed in the bioinformatic analysis. Finally, a multivariate logistic regression analysis of the data showed that TOP2A, CCNB1, BIRC5, miR­21­5p, miR­193b­3p, miR­210­3p and miR­31­5p could be combined for the diagnosis of NSCLC. In conclusion, TOP2A, CCNB1, BIRC5, miR­21­5p, miR­193b­3p, miR­210­3p and miR­31­5p may therefore serve as important biomarkers and diagnostic targets for NSCLC.

19.
Small ; : e1904099, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31738003

RESUMO

Ever-growing tissue regeneration and other stem cell therapies cause pressing need for large population of self-renewable stem cells. However, stem cells gradually lose their stemness after long-term in vitro cultivation. In this study, a ZnO nanorod (ZnO NR) array is used to maintain the stemness of human adipose-derived stem cells (hADSCs). The results prove that after culturing hADSCs on ZnO NRs for 3 weeks, the stemness genes and protein expression level are higher than that on culture plates and ZnO film. ZnO NRs can maintain stemness of hADSCs without inhibiting the cell proliferation and oriented differentiation capabilities. KLF4 (Kruppel-like factor 4) is a Zn2+ -binding gene that plays a vital role in cell proliferation and differentiation. Sustained Zn2+ release and the increased expression of KLF4 can be detected, suggesting that ZnO NRs have efficiently released Zn2+ for stemness maintenance. Taken together, the nanotopography of ZnO NRs and the Zn2+ release synergistically facilitate stemness maintenance. This study has provided a powerful tool for directing cell fate, maintaining stemness, and realizing the expansion of stem cells in vitro, which will open a new route for the manufacture of large populations of stem cells and fulfilling the growing demand for the cell therapy market.

20.
Bioorg Med Chem Lett ; : 126791, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31740251

RESUMO

Neddylation modification is often over-expressed in a variety of human tumor cells. Therefore, targeting neddylation pathway may represent a potential approach to the treatment of human tumors. Herein, we describe the discovery of a hit scaffold from our in-house library and further structure-based optimizations. In this work, compound V11 could block the neddylation and inhibit the activity of NAE (with an EC50 value of 3.56 µM), and a dose-dependent reduction of the Ubc12-NEDD8 conjugations was also observed. Molecular docking results suggest compound V11 could bind tightly to NAE via hydrogen bonds and hydrophobic interactions. Compound V11 showed the best antiproliferative ability with an IC50 value of 8.22 µM against gastric cancer MGC-803 cells. Further anticancer activity studies suggested that compound V11 inhibited MGC-803 cell growth, caused a cell cycle arrestment at G2/M phase and induced apoptosis via extrinsic and intrinsic apoptosis pathways. All the findings suggest that 1,2,4-triazine scaffold might provide a novel scaffold for the further development of neddylation inhibitors and compound V11 might be a potential neddylation inhibitor with anticancer activity.

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