Surface molecularly imprinted polymers based on magnetic multi-walled carbon nanotubes for the highly selective purification of resveratrol from crude extracts of Vitis vinifera, Arachis hypogaea, and Polygonum cuspidatum.

In this work, surface molecularly imprinted polymers based on magnetic multi-walled carbon nanotubes were prepared for the specific recognition and adsorption of resveratrol. The functionalization of magnetic multi-walled carbon nanotubes and the synthesis process of surface molecularly imprinted polymers were optimized. Characterizations were performed to demonstrate the successful synthesis of the imprinted materials. The imprinted materials showed satisfactory adsorption capacity of resveratrol (45.73 ± 1.72 mg/g) and excellent selectivity (imprinting factor 2.89 ± 0.15). In addition, the imprinted materials were used as adsorbents in molecularly imprinted solid-phase extraction for the purification of resveratrol from crude extracts of some food and medicinal resources, achieving recoveries of 93.69%-95.53% with high purities of 88.37%-92.33%. Moreover, the purified products exhibited extremely strong free radical scavenging activity compared with crude extracts. Overall, this work provided a promising approach for the highly selective purification of resveratrol from natural resources, which would contribute to the application of this valuable compound in the food/nutraceutical fields.

A novel ternary deep eutectic solvent pretreatment for the efficient separation and conversion of high-quality gutta-percha, value-added lignin and monosaccharide from Eucommia ulmoides seed shells.

A novel ternary deep eutectic solvent (DES), consisted of choline chloride, oxalic acid and ethylene glycol, was developed as a green, low-cost and recyclable pretreatment system for multi-stage utilization of Eucommia ulmoides seed shells. Under optimum conditions, 79.7 % hemicellulose and 65.6 % lignin were quickly removed while 84.0 % cellulose was retained. After DES pretreatment, the yield and purity of gutta-percha achieved 85.1 mg/g and 96.2 %, which increased 1.4 and 1.8 folds higher than that of un-treatment ones. Meanwhile, 69.1 % enzymatic digestibility of cellulose was obtained, that was 2.3 folds higher than that of raw substrates. Moreover, 53.6 % low-condensation lignin with aromatic structures and valuable aryl-ether linkages was well collected. Importantly, the DES that has been recycled five runs can still remove 73.9 % hemicellulose and 58.0 % lignin. Overall, the DES was determined to efficiently promote the separation and conversion of high-quality gutta-percha, value-added lignin and high-yield glucose from Eucommia ulmoides seed shells.

An all-cellulose sponge with a nanofiller-assisted hierarchical cellular structure for fruit maintaining freshness.

Cellulose sponges with compressibility and resilience are an ideal packaging material for fruits with fragile skin. Here, a soft and elastic all-cellulose sponge (CS) with a hierarchical cellular structure was fabricated, where the long molecular chain cellulose constructed major pores, the cellulose at nanoscale acted as an elastic nanofiller to fill the gaps of long molecular chain cellulose fibers and constructed minor pores. With these two kinds of pores, this structure can absorb strain hierarchically. The sponge can protect fruits from mechanical damage when dropped or repeated vibration. Furthermore, the CS modified with chlorogenic acid (C-CGAS) had excellent antibacterial and antifungal abilities. Therefore, C-CGAS could extend the storage time of strawberries to 18 days without any microbial invasion, which is the longest storage time reported thus far. This study provides a new idea for the preparation of polymer sponges and a new design for the development of antimicrobial packaging materials.

[Segmentation and accuracy validation of mandibular molar and pulp cavity on cone-beam CT images by U-net neural network].

PURPOSE: To realize the automatic segmentation of mandibular molar and pulp cavity on cone-beam CT (CBCT) images by U-net convolutional neural network, and to use the 3D models reconstructed by Micro-CT data as the ground truth to validate its accuracy. METHODS： Twenty groups of small field of view(FOV) CBCT data containing complete mandibular molars were collected from the Department of Radiology, Affiliated Stomatology Hospital of Tongji University. After preprocessing, an endodontic specialist labeled teeth and pulp cavities by MITK Workbench software. These data were used as the training set for training U-net neural network. In addition, five mandibular molars and corresponding small FOV CBCT data were collected. These five CBCT were processed in the same way and used as the testing set. Then, teeth and pulp cavities on CBCT images of the testing set were segmented and reconstructed by U-net neural network and the same specialist. The isolated teeth were scanned by a Micro-CT machine after preprocessing and the results were reconstructed to 3D models, which were used as the ground truth. Then the 3D models reconstructed by the specialist's labeling, U-net network segmentation results, and the ground truth in the testing set were compared. Dice similarity coefficient(DSC), average symmetric surface distance (ASSD), Hausdorff distance (HD), and morphological analysis were used to evaluate the results. SPSS 20.0 software package was used for statistical analysis. RESULTS: Compared with the ground truth, the segmentation accuracy of the U-net neural network measured by DSC, ASSD, and AHD was (95.30±1.01)%, (0.11±0.02) mm, and (1.05±0.31) mm in teeth and (81.21±2.27)%, (0.15±0.05) mm, and (3.29±1.85) mm in the pulp cavity, respectively. Morphological analysis results showed that the U-net network segmentation results were similar to the ground truth in tooth and pulp chamber. As for the segmentation results of root canals, only thick root canals could be segmented rather than the thin root canals, such as the canals in the apical third and lateral root canals. CONCLUSIONS: Under the experimental conditions, the U-net neural network trained by the specialist's labeling realized the automatic and accurate segmentation of mandibular molar and their pulp chamber on CBCT images. For the segmentation of root canals, the results need to be further improved.

Soft and elastic silver nanoparticle-cellulose sponge as fresh-keeping packaging to protect strawberries from physical damage and microbial invasion.

Strawberry is a nutritious food that is susceptible to mechanical injury and microbiological infection. Traditional coatings for strawberry packaging provide resistance against microbial infection but not against mechanical damage. In this study, a soft and elastic cellulose sponge modified with silver nanoparticles (AgNPs@CS-1:1) was prepared as strawberry packaging material, and it provided effective protection against mechanical damage. In addition, after 1000 cyclic compression, AgNPs@CS-1:1 presented only 16.80% unrecoverable deformation and still had elasticity, suggesting its fatigue resistance and durable protection for strawberry against damage caused by repeated vibrations during transportation. In addition, AgNPs@CS-1:1 had good antibacterial (E. coli and S. aureus) and antifungal (Rhizopus stolonifer) abilities. The storage time of strawberries packaged by AgNPs@CS-1:1 was extended to 12 days without microbial invasion. Thus, AgNPs@CS-1:1 provided dual protection at the physical and microbial levels. This study proposes a new method for the preservation of strawberries based on the utilization of cellulose.

Diverse microbiota in palatal radicular groove analyzed by Illumina sequencing: Four case reports.

BACKGROUND: A palatal radicular groove is an unusual developmental deformity of the tooth, which may serve as a channel linking the periodontal and periapical inflammation, and yet no literature could be obtained analyzing microbiota within the palatal radicular grooves. CASE SUMMARY: Four patients diagnosed with palatal radicular groove and concomitant periodontal-endodontic deformity in permanent maxillary lateral incisors were enrolled in this work. Twelve bacterial samples from 4 patients were collected from different parts of the palatal radicular groove during intentional replantation surgery. Illumina sequencing was performed to analyze the taxonomical composition and microbiome structure inside the palatal grooves, and 1162 operational taxonomic units were obtained. The phyla of Firmicutes and Proteobacteria predominated in most of the samples. An unknown genus from the Bacillaceae family, Lactococcus, and Porphyromonas were the most abundant genera identified. There was no difference in the microbiota richness and diversity in three sections of the groove. CONCLUSION: The unique ecological niches inside the palatal grooves harbored bacterial communities that shared some component features of both the endodontic and periodontal infections. The existence of palatal groove may play an interaction bridge between the root apex and tooth cervix and thus impair the outcome of traditional therapeutic methods such as root canal treatment and periodontal management.

Magnetism and NIR dual-response polypyrrole-coated Fe3O4 nanoparticles for bacteria removal and inactivation.

Microbial contamination of water represents a great threat to the public health that has attracted worldwide attention. In this work, polypyrrole magnetic nanoparticles (Fe3O4@PPy NPs) with sterilization properties were fabricated. More specifically, the Fe3O4@PPy NPs obtained via aqueous dispersion polymerization and an in situ chemical oxidative polymerization exhibited a cationic surface and high photothermal conversion efficiency. More than 50% of bacteria adsorption can be achieved at a dosage of 100 µg/mL Fe3O4@PPy NPs under magnetic field, and high photothermal sterilization efficacy (~100%) can be obtained upon NIR exposure at the same dosage for 10 min. Noteworthy, the Fe3O4@PPy NPs can be recycled by magnetism and reused without affecting their photothermal sterilization capability. This study clearly provides experimental evidence of the great potential of Fe3O4@PPy NPs as stable and reusable nanocomposite materials for bacteria adsorption and photothermal sterilization performance. The application of Fe3O4@PPy NPs can realize enviromental-friendly bacterial contaminated water treatment as well as provide stratgies for synergistical antibacterial materials design.

Preparative enrichment and separation of astragalosides from Radix Astragali extracts using macroporous resins.

The enrichment and separation of astragalosides I-IV (AGs I-IV) were studied on eight macroporous resins in the present study. SA-3 resin offered the best adsorption and desorption capacities for AGs I-IV than other resins. The models of adsorption kinetics were investigated in order to elucidate the mechanism of adsorption. The pseudo-second-order model was the better choice than the pseudo-first-order model to describe the adsorption behavior of AGs I-IV onto SA-3 resin. The equilibrium experimental data were well fitted to Langmuir and Freundlich isotherms. SA-3 resin adsorption chromatography tests were carried out to optimize the separation process of AGs I-IV from Radix Astragali extracts. With the optimum parameters for adsorption and desorption, the contents of AGs I-IV were 8.78-, 11.60-, 10.52- and 11.28-fold increased with the recovery yields being 65.88, 90.92, 84.25 and 94.17%, respectively. The preparative enrichment and separation of AGs I-IV from Radix Astragali extracts can be easily and effectively achieved by SA-3 resin adsorption chromatography. The developed methodology can also be referenced for the separation of other active constituents from herbal materials and manufacture of Radix Astragali products.

Microwave-assisted synthesis of PdNPs by cellulose solution to prepare 3D porous microspheres applied on dyes discoloration.

In this study, a simple and environmentally friendly method was developed for synthesizing 3D porous cellulose supported palladium nanoparticles (PdNPs) catalysts. PdNPs (3.1 ± 1.4 nm) can be synthesized directly by cellulose solution through microwave heating (60 °C, 4 h) and prepared into microspheres by freeze-drying to degrade methylene blue (MB) and Congo red (CR) rapidly. In addition, the reduction ability of cellulose hydroxyl group was proved by XPS and FTIR results. And the contact angle of 38.20° proves its hydrophilic ability. Cellulose-PdNPs microspheres showed high catalytic efficiency achieved 99 % and after multiple cycles it was still higher than 90 %. Therefore, the method proposed in this paper provides some new applications for cellulose, and the cellulose-Pd catalysts prepared by the research also have potential application value in the field of environment.

Degradation of lignin in birch sawdust treated by a novel Myrothecium verrucaria coupled with ultrasound assistance.

Combined treatment of a novel fungal endophyte Myrothecium verrucaria coupled with ultrasound assistance was conducted to enhance lignin degradation in birch sawdust. The optimum treatment conditions were confirmed as the materials to liquid ratio 1:20, temperature 30°C, time 4days and pH 7, respectively. The results showed that the combined treatment led to the lignin degradation reaching 67.95±2.14%, while the lignin degradation were 45.50±2.12% and 13.75±0.66% with separate fungal treatment and ultrasound treatment, respectively. Moreover, SEM and FTIR analysis indicated that combined treatment significantly altered surface morphology and chemical structure of birch sawdust. The combined treatment greatly increased lignin removal during short time in mild environment. Therefore, these results demonstrated that the combined treatment of fungal endophyte coupled with ultrasound assistance has the high potential for the removal lignin in lignocellulose.

Preparative separation of dryofragin and aspidin BB from Dryopteris fragrans extracts by macroporous resin column chromatography.

A simple, efficient and environment-friendly chromatographic separation method was developed for preparative separation and enrichment of dryofragin and aspidin BB from Dryopteris fragrans. The adsorption properties of twelve macroporous adsorption resins were evaluated. The three selected resins were further screened depending on the separation performance of their packed columns, in which AB-8 resin showed better separation efficiency for dryofragin and aspidin BB. In order to maximize column efficiency, the operating parameters (flow rate, ethanol concentration and volume) of the resin column chromatography were optimized and compared with the conventional resin column adsorption. After preparative separation and enrichment on resin column chromatography, the contents of dryofragin and aspidin BB in the product were 8.39- and 5.99-fold increased with recovery yields of 91.22% and 75.64%, respectively. Moreover, the regenerated adsorbent exhibited excellent reusability within at least five cycles of adsorption/desorption. It suggested that multi-targets would be enriched effectively by resin column chromatography.

Preliminary enrichment and separation of genistein and apigenin from extracts of pigeon pea roots by macroporous resins.

Enrichment and separation of genistein and apigenin from extracts of pigeon pea roots were studied using eleven macroporous resins with different physical and chemical properties. ADS-5 resin showed the maximum effectiveness among the tested resins. The solute affinity towards ADS-5 resin at different temperatures was described in terms of Langmuir and Freundlich isotherms, and the equilibrium experimental data were well-fitted to the two isotherms. In order to optimize the operating parameters for separating genistein and apigenin, dynamic adsorption and desorption tests were carried out. After one run treatment with ADS-5 resin, the contents of genistein and apigenin in the product were 9.36-fold and 11.09-fold increased with recovery yields of 89.78% and 93.41%, respectively. The process achieved easy and effective enrichment and separation of genistein and apigenin by using ADS-5 resin, and it is a promising basis for large-scale preparation of genistein and apigenin from pigeon pea or other plants extracts.