In this work a system which consists of chitosan (CS) microcores entrapped within enteric polymer is presented. Vitamin D2, used as a model drug, was efficiently entrapped within CS microcores using spray-drying and then microencapsulated into ethylic cellulose(EC). The morphology and release properties of microcapsules were tested. The influential factors of preparation conditions included molecular weight of chitosan, concentration of chitosan solution, concentration of acetic acid, loading of vitamin D2 were discussed. The results of in vitro release studies showed that the microcapsules prepared in this article could realize sustained release in intestine.
Capsules ; Cellulose ; analogs & derivatives ; pharmacology ; Chitin ; analogs & derivatives ; pharmacology ; Chitosan ; Delayed-Action Preparations ; Drug Compounding ; Drug Delivery Systems ; Ergocalciferols ; pharmacology ; In Vitro Techniques

The aryl hydrocarbon receptor(AhR),also known as dioxin receptor,is a ligand-dependent transcription factor.Because of its important role in occurrence and development of cancer,it has been widely studied.AhR is now considered to be an important regulator of host-environment interactions in immune and inflammatory responses and is involved in pathogenesis of many skin diseases.Because AhR is highly expressed in all types of skin cells and regulates many genes that are critical to skin function,it has the potential to be a new target for the treatment of inflammatory skin diseases.This paper presents and analyzes research findings on the relationship between AhR and inflammatory skin diseases to help accelerate the development of new drugs.

Objective To detecting the expression of nicastrin,N1ICD and hes1 proteins in normal liver tissues and liver cancer tissues of C57BL/6 mice.Methods Twelve 6-week-old male C57BL/6 mice were ran-domly equally divided into the control group and model group.In the model group,the in situ liver cancer model was established with injection of Hepa1-6 cells into the liver,and the control group was treated with injection of the same amount of normal saline.Liver cancer was verified by HE staining.The expression of nicastrin,N1ICD and hes1 proteins in the normal and cancerous liver tissues was detected by IHC and Western blot.Results IHC results showed that nicastrin,N1ICD and hes1 proteins were localized in the hepatic sinusoidal endothelial cells in the normal hepatocytes,but not expressed in the hepatocytes.The model group showed higher expression of nicas-trin protein but lower expression of N1ICD and hes1 protein in the cancer cells compared with the control group.Conclusion NCSTN gene may play a carcinogenic role in mouse hepatocellular carcinoma,while notch1 and hes1 may play a carcinostasis role in the carcinoma.

Background The converter stations of high-voltage direct current (HVDC) transmission lines generate special total electric fields. At present, few investigations have been conducted on total electric fields in the workplace of converter stations from an perspective of occupational health. Objective To understand the current situation of total electric field strength in the workplace of converter stations. Methods Using purposive sampling, a calibrated HDEM-1 direct current (DC) total electric field strength measurement system was used to measure the total electric fields of 12 converter stations serving 6 DC lines in Southeast and Southwest China according to the Measurement method for total electric field strength and ion current density of the converter stations and DC transmission lines (DL/T 1089—2008). The results were evaluated according to occupational exposure limits recommended by The limits of electromagnetic environment at ±800 kV UHV DC converter station (DL/T 275—2012), the American Conference of Governmental Industrial Hygienists (ACGIH), and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Results A total of 615 check points were planned, the total electric field strength was 0.05-37.05 kV·m⁻¹, and the median was 10.45 kV·m⁻¹. The total electric field strength of 39 check points (6.3%) exceeded 25 kV·m⁻¹ (the limits of ACGIH and ICNIRP), and the total electric field strength of 12 check points (2.0%) exceeded 30 kV·m⁻¹ (the limit of DL/T 275—2012). There were statistically significant differences in the total electric field strength values and the proportions of exceeding 25 kV·m⁻¹ between the neutral regions and the positive regions and between the neutral regions and the negative regions (P < 0.01). The proportion of total electric field strength exceeding 30 kV·m⁻¹ in the negative regions was higher than that in the positive regions (P < 0.01). There were no significant differences in the total electric field strength of converter stations at different voltage levels and different altitudes (P > 0.05). There were no significant differences in the proportions of total electric field exceeding 25 kV·m⁻¹ and exceeding 30 kV·m⁻¹ in converter stations at different voltage levels and different altitudes (P > 0.05). Conclusion The total electric field in some workplace of converter stations exceeds selected limits. Converter station operators may be exposed to high-strength total electric field for a short time.