Evolution of particle size distribution in air in the rainfall process via the moment method

Population balance equation is converted to three moment equations to describe the dynamical behavior of particle size distribution in air in the rainfall. The scavenging coefficient is expressed as a polynomial function of the particle diameter, the raindrop diameter and the raindrop velocity. The evolutions of particle size distribution are simulated numerically and the effects of the raindrop size distribution on particle size distribution are studied. The results show that the raindrops with smaller geometric mean diameter and geometric standard deviation of size remove particles much more efficiently. The particles which fall in the “greenfield gap” are the most difficult to be scavenged from the air

Rotective effect of Fengliao-Changweikang extracts, a traditional Chinese herbal medicine formula,on mucosa in rat with chronic gastritis

Background: Fengliao-Changwei-Kang(FCK), the Chinese patent drug, is a famous traditional Chinese herbal medicine formula. It has a significant effect on the clinic treatment of gastrointestinal diseases  including gastritis, enteritis and diarrhea for many years. However, there is few research on the  protective effects of FCK on the gastric mucosa of chronic gastritis (CG) model rat. Objective: The present study aimed to explore the effects of FCK extract on mucosa in rats with Chronic Gastritis.Materials and Methods: 50 SD mice were randomly divided into 5 groups with 10 in each group（five per sex). The groups are respectively control group, model group, low, middle and high FCK extracts (FCK I, II and III) group. The CG rat model was induced by synthetic methods. FCK I, II and III group were  administrated with FCK extracts at 2.16g• kg, 4.32g• kg, 8.94g• kg once per day for 21 consecutive  days, and the control group and model group were administrated the same volume of distilled water at 10mL/kg once per day. 16 hours after the last administration, the rats were anesthetized and their blood and stomach were drawn from vena cava and abdominal cavity. The serum levels of EGF was measured by enzyme linked immunosorbent assay(ELISA) method, the expression of growth factor receptor (EGFR) in gastric mucosa was detected by immunohistochemical method, and the mRNA expressions of NF-κB p65 was detected in-situ hybridization.Results: The inflammation grades and the expressions of NF-κB p65 mRNA in gastric mucosa of the model group were markedly higher than those of the control group (P<0.05). The inflammation grades of gastric mucosa and the expressions of NF-κB p65 mRNA in gastric mucosa the FCK extract group are significantly lower than those of the model group, and the FCK extract group at 8.64g/kg could greatly increase the serum levels of EGF and the expressions of EGFR in gastric mucosa. High EGF level was found in FCK extract group at 4.32g/kg, but low in FCK extract groups at 2.16g/kg. There were no marked differences among the rats from control group, model group and FCK extract group on ratio of Ll/L2 (P>0.05).Conclusions: FCK extract could alleviate mucosal inflammation by down regulating the expressions of NF-κB p65 mRNA and promote tissue repair by up regulating EGFR expression in gastric mucosa cell.Keywords: chronic gastritis; fengliao-changwei-kang extract; epidermal growth factor receptor; nuclear factor kappa B