Disposal and resource utilization of waste masks: a review.

Waste masks pose a serious threat to the environment, including marine plastic pollution and soil pollution risks caused by landfills since the outbreak of COVID-19. Currently, numerous effective methods regarding disposal and resource utilization of waste masks have been reported, containing physical, thermochemical, and solvent-based technologies. As for physical technologies, the mechanical properties of the mask-based materials could be enhanced and the conductivity or antibacterial activity was endowed by adding natural fibers or inorganic nanoparticles. Regarding thermochemical technologies, catalytic pyrolysis could yield considerable hydrogen, which is an eco-friendly resource, and would mitigate the energy crisis. Noticeably, the solvent-based technology, as a more convenient and efficient method, was also considered in this paper. In this way, soaking the mask directly in a specific chemical reagent changes the original structure of polypropylene and obtains multi-functional materials. The solvent-based technology is promising in the future with the researches of sustainable and universally applicable reagents. This review could provide guidance for utilizing resources of waste masks and address the issues of plastic pollution.

Correlation Between Chemical Constituents and Ecological Factors of Tibetan Medicine Swertia mussotii / 中国实验方剂学杂志

Objective:The HPLC fingerprinting of Swertia mussotii was established to study the correlation between chemical components and ecological factors in different areas. Method:The fingerprint of S. mussotii was established by high performance liquid chromatography (HPLC),and the evaluation and analysis were made based on the " Chinese Medicine Chromatographic Fingerprint Similarity Evaluation System 2004A Edition" promulgated by the National Pharmacopoeia Commission. The analysis was carried out on a Wondasil C18 column(4.6 mm×250 mm,5 μm), with methanol-0.2%phosphoric acid as the mobile phase for gradient elution,and the column temperature was set at 30℃. The flow rate was 1.0 mL·min-1, and the detection wavelength was set at 245 nm. And data on ecological factors in each sample habitat, such as climate and soil, were collected. The gray correlation and bivariate analysis were carried out on the chemical constituents and ecological factors of medicinal materials in different areas using DPS data processing system and SPSS 21.0 statistical software. Result:The HPLC fingerprint of S. mussotii was established,a total of 12 common fingerprint peaks were marked, and the chemical constituent of the seven peaks were determined. The chemical constituents, such as swertiamain and mangiferin of S. mussotii, were significantly correlated with ecological factors. Moreover,the chemical constituents were obviously affected by the monthly average temperature range,annual precipitation,precipitation seasonality in the climatic factors,the soil organic carbon ratio and soil pH in the soil factors. Conclusion:The chemical constituents of S. mussotii have a correlation with the external ecological factors,the findings could provide a basis for the artificial planting of the medicinal material and the scientific connotation of the " environment-based" theory for Tibetan medicines.

Study on quality standard of Berberidis Cortex / 中国中药杂志

In order to establish the quality standard of Berberidis Cortex and improve its quality control level, water, total ash, acid-insoluble ash and alcohol-soluble extract were determined according to procedures recorded in the Chinese Pharmacopoeia (2010 edition). The qualitative and quantitative analyses were performed by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) methods. The results showed that TLC identification had a good resolution with clear spots. The water content was 8.39%-12.23%; total ash was 4.50%-9.96%; acid-insoluble ash was 0.10%-0.69%, and the alcohol-soluble extraction was 20.62%-37.13%. The average contents of magnoflorine, jatrorrhizine, palmatine, and berberine in Berberidis Cortex were 5.98%, 0.63%, 0.30%, 2.50%, respectively. It was concluded that the developed method was accurate and good in specificity, which can be used for quality control of Berberidis Cortex in the future.

Effect of laminarin polysaccharide on activity of matrix metalloproteinase in photoaging skin / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of laminarin polysaccharide (LP) on the activity of matrix metalloproteinase of photoaging skins.</p><p><b>METHOD</b>Kunming SPF mice were prepared with back hair shaved, and randomly divided into the control group, the model group, the LP low does group (LP-L, 1 mg x kg(-1)), the LP high dose group (LP-H, 5 mg x kg(-1)) and the Vit E (100 mg x kg(-1)) group. They were abdominally injected with drugs twice on a daily basis. Except for the control group, all groups were exposed to ultraviolet rays for 1 hour every day, five times on a weekly basis, with accumulated exposure dose of UVB being 21.60 J x cm(-2) and accumulated exposure dose of UVA being 84.02 J x cm(-2). Eight weeks later, exposed back skins were collected to detect thickness of dermis by HE stain, content of hydroxyproline (Hyp) by chemical colorimetry, and serum MMP-1 and TIMP-1 content by ELISA. In addition, matrix metalloproteinase-1 (MMP-1) mRNA and relative content of tissue inhibitor of metalloproteinase-1 (TIMP1) mRNA was analyzed with Real-time PCR.</p><p><b>RESULT</b>Compared with the model group, the LP-H group could significantly increase the thickness of dermis, skin Hyp content and serum TIMP-1 level, and decrease relative content of MMP-1 mRNA in skin and MMP-1 content in serum.</p><p><b>CONCLUSION</b>LP can regulate the metabolism of collagen photoaging skins by adjusting the activity of matrix metalloproteinase.</p>

Nanoparticle-based bio-barcode assay for the detection of bluetongue virus.

The ultrasensitive bio-barcode amplification assay (BCA) technique was developed for the specific detection of the outer-core protein VP7 of bluetongue virus (BTV). The target antigen VP7 was first captured by gold nanoparticles (GNPs) coated with polyclonal antibodies. Magnetic microparticles (MMP) coated with VP7 monoclonal antibody were then added to form a sandwich immuno-complex. After the immuno-complex was formed, signal DNA annealed to DNA strands covalently bound to the GNPs were released by heating and characterized by PCR and real-time fluorescence PCR. A detection limit of 0.1fg/ml was measured for purified VP7, seven orders of magnitude more sensitive than that of conventional antigen capture ELISA. The BCA demonstrated the same enhanced sensitivity for detecting BTV in serum samples from sheep. In the following work it is demonstrated that this assay is a highly sensitive method for the detection of BTV proteins that could be adapted to measure other proteins.

Comparative study of laparoscopic and open D_2 radical gastrectomy for gastric cancer / 中华消化外科杂志

Objective To evaluate the efficacy of laparuseopic and open D_2 radical gastrectomy for gastric cancer. Methods From January 2008 to February 2009, 64 gastric cancer patients received laparoscopic radical gastrectomy (LAP group) and 60 gastric cancer patients received open gastrectomy (open group) at Changzhou No. 2 People's Hospital. Clinical parameters including operation time, blood loss, resection margin of gastric cancer, number of lymph nodes dissected, time for passage of flatus, time for out-of-bed activity, hospital stay and postoperative complications in the 2 groups were analyzed via t test and chi-square test. Results Gastrectomy was successfully performed on all patients. Mean operation time in LAP group was significantly longer than open group (t=5.56, P<0.05). There was no significant difference in the length of resection margin and number of lymph nodes dissected between the 2 groups (t=0.67, 0.86, 1.09, P>0.05). The mean blood loss, time for passage of flatus, time for out-of-bed activity and hospital stay in LAP group were significantly lesser than in open group (t=4.59, 5.56, 16.39, 4.79, P<0.05). Six patients in LAP group and 5 patients in open group had compli-cations postoperatively. All patients were followed up for 1-13 months, and no recurrence or death occurred. Conclusion Laparoscopic D_2 radical gastrectomy is safe and effective for gastric cancer.

Natural macrocyclic molecules have a possible limited structural diversity.

This paper examines ring size patterns of natural product macrocycles. Evidence is presented that natural macrocycles containing 14-, 16-, and 18-membered rings are of frequent occurrence based on a data mining study. The results raise a question about the limited diversity of macrocycle ring sizes and the nature of the constraints that may cause them. The data suggest that the preference bears no relationship to the odd-even frequency in natural fatty acids. The trends reported here, along with those reported previously (Wessjohann et al. (2005) Mol Divers 9:171), may be generalized to better understand the possible structure preferences of natural macrocycles.