[Pathogenesis of Psoriatic Pruritus].

Pruritus is a common symptom of most primary skin diseases and some systemic diseases. Despite the high incidence of pruritus in patients with psoriasis,the specific pathogenesis is complex and unclear. The occurrence and development of skin pruritus in psoriasis patients involve the joint participation of nervous,immune,endocrine,and vascular systems.This article reviews the mediators related to the pathogenesis of pruritus in psoriasis,aiming to improve the understanding of itching symptoms and the treatment of pruritus.

[Effects of Temperature on Outpatient Visits for Urticaria among Lanzhou Residents Based on Distributed Lag Non-linear Model].

Objective To evaluate the influence of temperature on the outpatient visits for urticaria in Lanzhou City and its hysteresis and to find out the sensitive populations by sex and age stratification.Methods We collected the urticaria outpatient data in three grade A class three hospitals as well as the meteorological data and air pollutant data in Lanzhou from January 2011 to December 2017.The distributed lag non-linear model(DLNM)was employed to analyze the influence of daily mean temperature on the outpatient visits for urticaria.Stratification analysis was performed for different age groups(0-14,15-59,≥60 years)and different sex populations.Results Temperature had a non-linear relationship with the outpatient visits for urticaria,and there existed hysteresis.During the research period,the average daily outpatient visits for urticaria at the three hospitals in Lanzhou was 25,ranging from 1 to 76.With the rise in the daily mean temperature within 0-10 ℃,the risk of outpatient visits for urticaria first increased and then decreased.When the daily mean temperature was 2 ℃,hysteresis occurred on the 18th day,and the relative risk(RR)reached the maximum(1.12,95% CI:1.04-1.20)at the lag of 21 days.The risk of urticaria increased with the rise in temperature at high temperature.In addition,the effect of high temperature on the outpatient visits for urticaria in Lanzhou presented hysteresis,and the hysteresis was more obvious at higher temperatures.At the lag of 21 days,when the temperatures were 19.9 ℃ and 25.5 ℃,the RR values were 1.20(95% CI:1.12-1.27)and 1.39(95% CI:1.31-1.48),respectively.The results of stratified analysis showed that the effect of high temperature was more sensitive for those of 0-14 years and 15-59 years as well as the female population,and the RR values at a lag of 21 days were 1.60(95% CI:1.45-1.71),1.34(95% CI:1.25-1.43),and 1.43(95% CI:1.33-1.53)for the population of 0-14 years,the population of 15-59 years,and female population,respectively.Low temperature mainly affected the people aged ≥60 years,with a maximum RR of 1.38(95% CI:1.03-1.85)when the daily mean temperature was -4.8 ℃ at a lag of 12 days.It did not affect other populations.Conclusions The daily mean temperature in Lanzhou share a close relationship with the outpatient visits for urticaria.High temperature will increase the risk of urticaria for people at the age of 0-14 years and 15-59 years,while low temperature will increase the risk of urticaria for people above 60 years.

[Effects of Air Pollutants on Outpatient Visits for Atopic Dermatitis in Lanzhou].

Objective To quantitatively evaluate the associations of PM2.5,PM10,NO2,and SO2 concentrations with the outpatient visits for atopic dermatitis in Lanzhou. Methods The data of outpatient visits,together with meteorological data and air pollutant data,from January 2013 to December 2017 were collected.The generalized additive model based on Poisson distribution was employed to study the lag effects of PM2.5,PM10,NO2,and SO2 concentrations on the visits of outpatients,with the seasonal and long-term trends and day-of-the-week effect controlled. Results The results of the single pollutant model showed that PM2.5 and PM10 had the most obvious while still insignificant impact on the outpatient visits for atopic dermatitis on the current day(lag0).NO2 also had the most obvious impact in the case of lag0 and showed a lag effect.For each 10 µg/m3 increase in NO2 concentration,the excess risk(ER)of outpatient visits for atopic dermatitis was 1.95%(95% CI=1.09%-2.82%,P=0.01).SO2 had the most significant effect on lag6,and the outpatient visits increased by 1.55%(95% CI=0.48%-2.54%)for every 10 µg/m3 rise in SO2 concentration(P=0.02).Females were more sensitive to PM10 and SO2 than males.For every 10 µg/m3 increase in PM10 and SO2,the female outpatient visits increased by 0.02% and 2.47%,respectively.Males were sensitive to PM2.5 and NO2,and the every 10 µg/m3 rise in PM2.5 and NO2 increased male outpatient visits by 0.47% and 1.78%,respectively.Gaseous pollutants(NO2 and SO2)had more significant effect on people ≤2 years old than on those of other ages.Every 10 µg/m3 rise in NO2 and SO2 would increase the ≤2-year-old outpatient visits by 2.35% and 1.57%,respectively(P=0.02).People of 13-59 years old were sensitive to NO2 concentration,and every 10 µg/m3 rise in NO2 concentration increased their visits by 1.39%.NO2 affected the outpatient visits during the cold and warm seasons,with the ER values of 2.35% and 1.89%,respectively(P=0.01).Particulate matter(PM2.5 and PM10)had the most obvious yet insignificant association with the outpatient visits in winter.The interactions between PM2.5 and NO2,between PM10 and NO2,and between SO2 and NO2 affected the total outpatient visits for atopic dermatitis.The results of double pollutant model showed that in the presence of PM2.5,PM10,or SO2,the effect of NO2 on the outpatient visits for atopic dermatitis enhanced compared with that predicted by single pollutant model(P=0.01). Conclusion The air pollutants(PM2.5,PM10,NO2,and SO2)in Lanzhou were closely related to the outpatient visits for atopic dermatitis,and the increased concentrations of NO2 and SO2 was more likely to increase the risk of atopic dermatitis.

[Effect of Gaseous Pollutant Concentration on the Number of Daily Outpatient Visits for Acne in Lanzhou].

Objective To determine the relationship between air pollutants [SO2,NO2,8 hours average concentration of ozone(O38h)] and outpatient visits for acne in Lanzhou,China. Methods Data of daily outpatient visits for acne and concentrations of air pollutants(SO2,NO2,and O38h)from January 2013 to December 2017 were collected.With the control of long-term trend and day-of-week effect,a distributed lag nonlinear model was used to analyze the lag and cumulative effects of air pollutants on the outpatient visits.The model was established based on the different groups of gender and age. Results During the study period,the average daily outpatient visits were 34.94±15.27,and the average concentrations of SO2,NO2,and O38h were 24.09,43.77,and 82.94 µg/m3,respectively.The Spearman's correlation analysis showed that the daily outpatient visits for acne were positively correlated with NO2 concentration while negatively correlated with O38h concentration;SO2 concentration was negatively correlated with O38h concentration;NO2 concentration was positively correlated with SO2 and O38h concentrations.A 10 µg/m3 increase in daily concentrations of NO2 and SO2 was respectively associated with 2.61%(95% CI=0.98%-4.27%)and 1.71%(95% CI=0.54%-2.89%)increase in the outpatient visits for acne.A 10 µg/m3 increase in O38h concentration was associated with -0.62%(95% CI=-1.12%--0.11%)increase in the outpatient visits.Multipollutant models indicated that air pollutant concentrations were significantly associated with the daily outpatient visits for acne. Conclusions SO2 and NO2 are positively associated with daily dermatological department visits for acne in Lanzhou,while O38h concentration has a negative correlation with the visits.The sensitivity of acne daily outpatient visits to changes in SO2,NO2,and O38h varies among patients of different genders and at different ages.

[Insulin Resistance and Skin Diseases].

Insulin resistance refers to a pathological condition in which cells fail to respond sufficiently to insulin,leading to impaired glucose uptake and utilization. In recent years,some skin diseases have been found to be associated with metabolic syndrome,and insulin resistance is considered to be the most important pathophysiological feature of the metabolic syndrome. Recent literatures have described the role of insulin resistance in the pathogenesis of these skin diseases. This article elucidates the mechanisms of insulin resistance involved in skin diseases.

A high-efficiency L-band coaxial three-period relativistic Cherenkov oscillator.

Miniaturization is one of the important research directions of low frequency high power microwave sources. This paper presents a three-period coaxial slow-wave structure L-band high-power microwave source. Because the coaxial Quasi-TEM mode has no cut-off frequency, the radial size of the device can be reduced. At the same time, in order to reduce the transverse dimension, the coaxial extractor structure is introduced to realize the longitudinal mode selection and improve the conversion efficiency of the device. In simulation, the device obtains the microwave output with the central frequency of 1.53 GHz, the average power of 3.3 GW and the efficiency of 40%. By optimizing the scheme of electron beam collection, the phenomenon of pulse shortening is effectively suppressed. In the experiment, the device obtains the microwave output with the central frequency of 1.52 GHz, the average power of 3 GW, the efficiency of 33% and the pulse width of 40 ns.

Isolation and genotyping of vaginal non-albicans Candida spp. in women from two different ethnic groups in Lanzhou, China.

OBJECTIVE: To investigate whether the vaginal flora of women from 2 different ethnic groups living in the same region of China harbored the same species of Candida in the same proportions. METHODS: The ethnicity of the women was determined by conventional cultural identification, and the Candida spp. harbored by the women were determined by conventional methods and DNA genotyping. RESULTS: Candida albicans accounted for 77.1% and 89.6%, respectively, of the Candida spp. isolated from the normal vaginal flora of Han Chinese and Tibetan women. This difference was statistically significant and may explain the differences in the rates of opportunistic infections in these 2 groups. Among the non-albicans Candida spp. isolated were C. glabrata and C. tropicalis. CONCLUSION: Different species of Candida were differently distributed in the normal vaginal flora of ethnic Han Chinese and Tibetan women living in the same geographic region.