Magnetic metal-organic framework MIL-100 (Fe)/polyethyleneimine composite as an adsorbent for the magnetic solid-phase extraction of fungicides and their determination using HPLC-UV.

Fe3O4@MIL-100 (Fe)/PEI are used for the first time as an adsorbent material for the extraction of pesticide residues (epoxiconazole, flusilazole, tebuconazole, and triadimefon) from food matrices. The adsorbent proposed (Fe3O4@MIL-100(Fe)/PEI) was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), thermogravimetric (TG) analysis, and vibrating sample magnetometer (VSM) techniques to evaluate the properties of the sorbent. Then, the Fe3O4@MIL-100 (Fe)/PEI was employed for the quantification of the four triazole fungicides in fruits and vegetables (apple, orange, tomato, cabbage, and cucumber) using HPLC-UV for separation and detection. During the extraction process, the main parameters such as amount of adsorbent, extraction time, pH value, ionic strength, eluting solvent, and eluting volume were optimized. Under the optimum conditions, good linearity of this method was observed for all analytes, with correlation coefficients (R2) ≥ 0.9908. The limits of detection (LODs) ranged from 0.021-3.04 µg kg-1. The extraction recoveries of the four triazole fungicides varied from 73.9 to 109.4% with relative standard deviations (RSD) in the range 0.5 to 6.2%. Compared with other MOFs, the modification of Fe3O4@MIL-100 (Fe) with PEI shows high efficient adsorption due to the combined benefits of MIL-100 (Fe) and PEI. The material is easily synthesized, has good stability, and is of low cost.  Graphical abstract.

Corydalis saxicolaBunting total alkaloid eliminates Porphyromonas gingivalis strain 33277 internalized into macrophages by inhibition of TLR2.

OBJECTIVE: This study aimed to investigate the impact of Corydalis Saxicola Bunting Total Alkaloid (CSBTA) on Porphyromonas gingivalis internalization within macrophages and explore the potential role of Toll-Like Receptor 2 (TLR2) in this process. METHODS: We established a P. gingivalis internalization model in macrophages by treating P. gingivalis-infected macrophages (MOI=100:1) with 200 µg/mL metronidazole and 300 µg/mL gentamicin for 1 h. Subsequently, the model was exposed to CSBTA at concentrations of 0.02 g/L or 1 µg/mL Pam3CSK4. After a 6 h treatment, cell lysis was performed with sterile water to quantify bacterial colonies. The mRNA expressions of TLR2 and interleukin-8 (IL-8) in macrophages were analyzed using RT-qPCR, while their protein levels were assessed via Western blot and ELISA respectively. RESULTS: P. gingivalis could internalize into macrophages and enhance the expression of TLR2 and IL-8. Activation of TLR2 by Pam3CSK4 contributed to P. gingivalis survival within macrophages and increased TLR2 and IL-8 expression. Conversely, 0.02 g/L CSBTA effectively cleared intracellular P. gingivalis, achieving a 90 % clearance rate after 6 h. Moreover, it downregulated the expression of TLR2 and IL-8 induced by P. gingivalis. However, the inhibitory effect of CSBTA on the internalized P. gingivalis model was attenuated by Pam3CSK4. CONCLUSION: CSBTA exhibited the ability to reduce the presence of live intracellular P. gingivalis and lower IL-8 expression in macrophages, possibly by modulating TLR2 activity.

Optimization of agarose-alginate hydrogel bead components for encapsulation and transportation of stem cells.

Hydrogels have potential uses in various biological applications because of their unique characteristics. Fine-tuning of agarose-alginate (Ag-Al) hydrogel components improves the mechanical characteristics of the final construct for cell encapsulation and transportation. Formulation of suitable dissolving agents may enable the release of encapsulated cells for further applications in laboratory or clinical settings. Objectives: This study aimed at optimizing the composition of Ag-Al hydrogel beads and their dissolving agents for potential use in the transportation of stem cells. Methods: Various agarose, alginate, and CaCl2 concentrations were tested to construct hydrogel beads. The degradation rate and swelling ratio of each hydrogel sample were recorded. The optimized Ag-Al hydrogels were used for encapsulation of stem cells from human exfoliated deciduous teeth (SHED). Optimization of dissolving agents was performed and tested with the hydrogel-encapsulated cells. Data were statistically analyzed in SPSS. Results: The selected concentration of Ag-Al hydrogels components was successfully demonstrated to encapsulate SHED, which remained viable until day 10. An average of 2 min was required for degradation of the hydrogel with encapsulated SHED by a dissolving agent consisting of 100 mM sodium citrate and 100 mM EDTA. The cell viability of SHED released after day 10 of encapsulation was 29.1%. Conclusion: Alteration of Ag-Al components has considerable influence on the mechanical properties of the constructed hydrogel. The feasibility of performing the optimized cell encapsulation protocol, as well as the dissolving step, may provide a useful guide for the transportation of viable cells between countries, for medical research.

[Confocal Raman microspectroscopy study on the distribution of cellulose and lignin in Daphne odora Thunb].

Confocal Raman microspectroscopy is well suited to investigating cellulose and lignin distribution in-situ in the native cell walls of woody tissue. In this study, transmission electron microscopy (TEM) was used to determine the ultrastructure of Daphne odora Thunb. In the TEM images, cell wall of Daphne odora Thunb. is typically divided into three layers: middle lamellar (ML), primary wall (P) and secondary wall (S1, S2 and S3). More detailed information about cellulose and lignin distribution in different cell wall layers was analyzed in situ by confocal Raman microspectroscopy. Raman spectra and images reveal that the distribution of cellulose and lignin in the cell wall layers is not uniform. Lignin concentration in different morphological areas follows the decreasing order: the cell corner (CC) > the middle lamellar (CML) > the secondary wall (S2). In contrast, cellulose distribution shows the opposite pattern-low concentration in CC and CML and high in S2 regions.

Adsorption behavior of azole fungicides on polystyrene and polyethylene microplastics.

Agricultural plastic films and triazole fungicides are widely used in agricultural production process. Exposure to natural environment, agricultural plastic films will degrade into micron plastic particles, which will adsorb pesticide molecules and may affect their toxicity, biological activity and persistence. The long-term coexistence of microplastics (MPs) and triazole fungicides will bring potential harms to the agricultural ecological environment. Therefore, two kinds of triazole fungicides flusilazole (FLU) and epoxiconazole (EPO) were selected as cases and the adsorption behaviors of them on polystyrene and polyethylene were investigated. A series of factors which could affect the adsorption behavior were evaluated. Specifically, the particle size of MPs could affect its adsorption capacity, and the smaller the particle size, the stronger the adsorption capacity. Moreover, with the increase of pH value from 6.0 to 9.0, the adsorption capacity of MPs to target compounds gradually increased. The effect of ionic strength was evaluated by NaCl, and 0.05% of NaCl was beneficial to the adsorption process, while the continuous increase of NaCl concentration inhibited the adsorption. Oxalic acid and humic acid decreased the adsorption capacity of flusilazole on PE by 15.99-32.00% and PS by 35.02-48.67%, respectively. In addition, compared with the single pesticide system, the adsorption capacity of MPs for flusilazole and epoxiconazole in the binary pesticides system decreased by 36.13-37.93% and 44.36-51.35%, respectively, indicating that competitive adsorption occurred between the two pesticides. Meanwhile, the adsorption process was evaluated by adsorption kinetics and adsorption isotherms and were consistent with pseudo-second-order kinetic model and Freundlich isotherm model, respectively. Finally, several characterization analyses were conducted to investigated the adsorption mechanism, and hydrogen, halogen bonding and hydrophobic interaction proved to play an important role. The study on the adsorption behavior and mechanism of pesticide on MPs was the basis of assessing the risk of joint exposure.

Poly(caffeic acid)-coated molecularly imprinted magnetic nanoparticles for specific and ultrasensitive detection of glycoprotein.

Molecularly imprinted polymers (MIPs) are artificial chemical receptors, and can recognize template molecules with a high selectivity and affinity. As "antibody mimics", MIPs have been widely studied in various fields. However, the general applicability of MIPs is limited by the type of functional monomers. Herein, we developed caffeic acid (CA, a natural polyphenol) as novel a functional monomer. An innovative poly(caffeic acid)-coated molecularly imprinted magnetic nanoparticles (PCA-MIMN) with transferrin (TRF) as a model glycoprotein template was fabricated by autoxidation of CA with hexamethylenediamine (HMDA) in an aerobic environment as imprinted layer. The successful fabrication of PCA-MIMN was proved in detail by diversified characterization. The PCA-MIMN exhibited not only outstanding binding affinity and specificity for target glycoprotein, but also excellent hydrophilicity due to the externally generous hydrophilic groups. To evaluate the preeminent performance, the PCA-MIMN was linked with pH-triggered allochroic-graphene oxide (AGO), which was used for determination of TRF in real samples. The proposed PCA-MIMN linked AGO strategy exhibited ultrahigh sensitivity with limit of detection of 0.38 pg mL-1 for TRF. Finally, the proposed strategy was successfully applied in determination of TRF in spiked human serum sample with recovery and relative standard deviation in the range of 97.2%-103.9% and 4.6%-5.8%, respectively. This work demonstrates that the "autoxidation of CA with HMDA" may be a universal tool for synthesis of highly specific MIPs, and the type of functional monomers will increase exponentially due to the presence of numerous polyphenols in nature.

Surface-modified polylactic acid nanospheres with chitosan for antibacterial activity of 1, 2-benzisothiazolin-3-one.

The primary purpose of this study was to develop an innovative chitosan (CS) modified polylactic acid (PLA) nanospheres for enhancing the bioavailability of 1, 2-benzisothiazolin-3-one (BIT). The cellular uptake efficiency was corresponded positively to the quantity of CS coated on BIT-PLA nanospheres against E. coli and S. aureus. The membrane potentials of E.coli and S. aureus treated with BIT-PLA, BIT-PLA-0.1%CS and BIT-PLA-0.5%CS were reduced with the extension of incubation time and the ratio of coated CS. The enhancement of CS modified on BIT-PLA nanospheres was reduced antioxidase activities and generated excessive reactive oxygen species. The lowest EC50 value of the modified BIT-PLA-0.5%CS suggested that its toxicity index was around 2.95-fold and 2.11-fold that of non-modified BIT-PLA against E. coli and S. aureus, respectively. These results revealed that the CS modified BIT-PLA nanospheres had a bright prospect in antibacterial formulation delivery system and improving the bioavailability.

[Effects of plastic film mulching on soil quality, growth of Angelica sinensis, and weed occurrence in cold and humid areas]. / è¦†è†œå¯¹é«˜å¯’é˜´æ¹¿åŒºå½“å½’åœŸå£¤è´¨é‡ã€æ¤æ ªç”Ÿé•¿å’Œæ‚è‰å‘ç”Ÿçš„å½±å“.

We analyzed the growth dynamic and bolting rate of Angelica sinensis, soil quality and enzyme activities and weed density and control effect in a field experiment under different mulching patterns, to provide theoretical basis for the application of plastic film in genuine producing area of A. sinensis. The planting patterns were conducted as hole seeding under ridging with plastic-film mulching (LS), trenching and slant planting under film-side cultivation (MC) and trenching and slant planting in open field (LD). Our results showed that, 1) compared with LD, soil organic matter content in top layer under the treatments of LS and MC was increased by 4.4% and 14.3%, respectively, with that under MC being statistically significant. Soil bulk density was significantly decreased by 11.6% and 8.5%, while pH was significantly decreased by 4.6% and 1.7%. The activities of soil sucrase, phosphatase and urease were significantly increased by the two mulching methods, but that of catalase was inhibited to a certain extent. 2) Mulching film improved the speed of returning green after transplanting, the early bolting rate, and the individual medicinal quality of A. sinensis. MC showed the fastest, the most uniform, and the highest greening rate. LS bolting rate was the highest, and the fresh mass of MC and LS was significantly increased by 20.4% and 58.4%, respectively. 3) Weed density under the treatment of MC and LS was significantly reduced by 34.0% and 25.8%. Compared with LS, MC significantly increased the control effect of plant and fresh mass by 21.7% and 63.4%, respectively. In conclusion, film cultivation methods could improve the environment for root growth, reduce weed density, improve weed control effect, and promote growth process and substance accumulation, but could promote the bolting of A. sinensis in early phase.

[Chemical Characteristics and Causes of Groups Water in Niangziguan Spring].

Discharge in Niangziguan Spring is 7.19 m3·s-1, which is the main water supply source for Yangquan City and Pingding County. Every year, Yangquan municipal government take water from the mouth of Niangziguan Spring to supply drinking water to urban residents at a rate of approximately 1.7 m3·s-1. It is of great significance to determine the characteristics and causes of variations in spring water flow conditions for the appropriate utilization of water resources and pollution prevention. Here, sample collection and hydrochemical isotope analyses were undertaken for the Niangziguan Spring area to chemically characterize the water environment and genesis. The pH of the karst spring is 7.2-7.5 with an average of 7.36; the calcium content of the water is 112.1-135.2 mg·L-1 with a mean value of 131.4 mg·L-1; the concentration of magnesium ions is 34.8-42.3 mg·L-1 with an average of 40.8 mg·L-1; the concentration of K++Na- ions is 41.6-46.7 mg·L-1 with an average of 45.2 mg·L-1; and the sulfate ion concentration is 185.6-271.8 mg·L-1 with a mean value of 255.4 mg·L-1. The hydrochemical type of the aquifer is classified as HCO3·SO4-Ca·Mg. The spring water is characterized by high Ca2+, Mg2+, and SO42- concentrations, and low Na+, K+, and Cl- concentrations. The supply path of Chengxi Spring is shortest followed by Wulong Spring. The supply paths of the remaining five spring are much longer. The Niangziguan Spring water environment is characterized by increasing pollution from coal mine acid drainage alongside decreasing inputs from domestic sewage. Environmental isotope tracing shows that sulfate in Chengxi Spring mainly derives from precipitation and gypsum dissolution, and the concentrations of sulfate in Wulong Spring are increasing. These changes are mainly driven by the amount of coal mine acid water pollution in the area.

The effect of implant neck microthread design on stress distribution of peri-implant bone with different level: A finite element analysis.

BACKGROUND/PURPOSE: Significant research has proposed that the implant with microthread in the neck can significantly reduce marginal bone loss, but whether it is consistent in the condition of marginal bone loss is still unknown. The objective of this study is to investigate the effect of microthread on stress distribution in peri-implant bone with different bone level using finite element analysis. MATERIALS AND METHODS: A series of computational models of mandible segments with different bone resorption and implant models with or without microthread in the neck was installed by computer-aided design software. The simulated occlusal force of 150N was applied buccolingually on the top center point of implant. The FEA was performed, and the von Mises stress, principal stress and shear stress in peri-implant bone were recorded and analyzed. RESULTS: In all models, the T-neck group exhibits higher von Mises stress and principal stress, as well as lower shear stress than S-neck group. Three types of stresses increase with the depth of bone resorption developed, but the differences of shear stress between two groups of implants were gradually decreased. CONCLUSION: The micro-thread design in implant neck can reduce marginal bone loss by decreasing shear stress in peri-implant bone, but this effect is gradually weakened with the decline of the marginal bone level.

Application of polydopamine functionalized magnetic graphene in triazole fungicides residue analysis.

In this work, a new analytical method based on polydopamine functionalized magnetic graphene (PDA@MG) adsorbent material has been developed to determine three triazole fungicides in water samples. As previous step, a novel polydopamine functionalized PDA@MG adsorbent material has been successfully prepared, which was characterized by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscope (TEM), and vibrating sample magnetometer (VSM). Based on this novel material, a new magnetic solid phase extraction (MSPE) method coupled with high performance liquid chromatography (HPLC) has been established for the determination of triazole fungicides in water samples. The main factors which could affect the experimental results were optimized. Under the optimal conditions, good linarites has been achieved in the range of 0.2-50 µg L-1, with the correlation coefficients (R2) were between 0.9962 and 0.9996. The limits of detections (LODs) were 0.0048-0.0084 µg L-1, and the relative standard deviations (RSDs) were between 1.7% and 4.8%. In addition, enrichment factors (EFs) were 572-916 times, which showed triazole fungicides residues could be accurately extracted and analyzed in this way. In the final experiment, the established method was applied to the detection of target analyzes in water samples. Satisfied results could be obtained for tebuconazole, propiconazole, and flusilazole. The recoveries of five water samples were between 69.4% and 106.4%, and the RSD were between 1.0% and 6.5%. The development method is more easy, effective, green and environmental-friendly, and has potential for application.

False esophageal hiatus hernia caused by a foreign body: a fatal event.

Foreign body ingestion is a common complaint in gastrointestinal clinics. It is usually not difficult to diagnose because most of the patients report a definitive history of accidental foreign body ingestion. However, in rare cases, patients do not have a clear history. Thus, the actual condition of the patient is difficult to diagnosis or is misdiagnosed; consequently, treatment is delayed or the wrong treatment is administered, respectively. This report describes a fatal case of esophageal perforation caused by an unknowingly ingested fishbone, which resulted in lower esophageal necrosis, chest cavity infection, posterior mediastinum fester, and significant upper gastrointestinal accumulation of blood. However, his clinical symptoms and imaging data are very similar with esophageal hiatal hernia. Unfortunately, because the patient was too late in consulting a physician, he finally died of chest infection and hemorrhage caused by thoracic aortic rupture. First, this case report underlines the importance of immediate consultation with a physician as soon as symptoms are experienced so as not to delay diagnosis and treatment, and thus avoid a fatal outcome. Second, diagnostic imaging should be performed in the early stage, without interference by clinical judgment. Third, when computed tomography reveals esophageal hiatus hernia with stomach incarceration, posterior mediastinal hematoma, and pneumatosis caused by esophageal, a foreign body should be suspected. Finally, medical professionals are responsible for making people aware of the danger of foreign body ingestion, especially among children, those who abuse alcohol, and those who wear dentures, particularly among the elderly, whose discriminability of foreign bodies is decreased, to avoid dire consequences.

[Experimental study of tissue-engineered bone constructed with simvastatin carried by PLGA/CPC and bone marrow stromal cells].

PURPOSE: To study the feasibility of tissue engineered bone constructed with simvastatin carried by PLGA/CPC and bone marrow stromal cells (BMSCs) and screen the effective drug loading of simvastatin. METHODS: Solvent casting-particle leaching technology combined with the phase separation process was used to prepare the different concentrations (simvastatin mass: 0.1, 0.5, 1 mg) of simvastatin carried by PLGA/CPC composite scaffold materials. Scanning electron microscopy was used to observe the porosity and drug release curve was drawn; Alizarin red staining and type I collagen staining were applied to observe the effect of osteogenic medium and simvastatin on the role of BMSCs to the osteogenetic differentiation. The induced passage 3 cells after dil staining were mixed with the composite scaffold material to a complex. Scanning electron microscopy and laser confocal microscope were used to observe the adhesion on the complex. CCK-8 and alkaline phosphatase (ALP) were applied to observe the proliferation and differentiation. SPSS 18.0 software package was used for statistical analysis. RESULTS: The scaffold porosity was more than 90% with an average aperture of 200-300 µm. The drug released slowly. There was no obvious interpretation. Type I collagen showed positive expression. Alizarin red staining proofed the formation of mineralization nodules in group which was induced with the conditional medium and simvastatin. 0.5 mg group showed cells adhered to the inner surface of the scaffold material and could significantly promote the proliferation and differentiation of cells. CONCLUSIONS: Combination of simvastatin and osteogenic medium can effectively promote the differentiation of BMSCs. Simvastatin carried by PLGA/CPC scaffold materials is an ideal tissue engineering scaffold material. PLGA/CPC scaffold containing 0.5 mg simvastatin can effectively promote the proliferation and differentiation of BMSCs. Supported by Natural Science Foundation of Jilin Province (201215052).

Use of the composite membrane of poly(ether-block-amide) and carbon nanotubes (CNTs) in a pervaporation system incorporated with fermentation for butanol production by Clostridium acetobutylicum.

Fermentation incorporated with pervaporation was regarded as an efficient way to relieve the feedback inhibition of butanol in acetone-butanol-ethanol (ABE) fermentation. The addition of CNTs (carbon nanotubes) to PEBA (poly(ether-block-amide)) could greatly enhance the removal flux of solvents (acetone, butanol and ethanol) in a model solution test. The butanol removing rate results in a 61% increase in the batch with PEBA+CNTs (5%) membrane compared with that of the batch with PEBA alone. Besides the increase of removal flux, the addition of CNTs enforces the mechanical strength of the pervaporation membrane, which leads to more resistance for a longer operational time. The combination of a 5-L fermenter with the pervaporation membrane of PEBA+CNTs (10%) indicates a 20% increase both in productivity and yield compared to using PEBA. In conclusion, the addition of CNTs to a PEBA pervaporation membrane has great potential when applied in the ABE fermentation industry.