Mitigation effects on the reflected overpressure of blast shock with water surrounding an explosive in a confined space

The mitigation of blast shock with water has broad application prospects. Understanding the mitigation effects on the reflected overpressure of the explosion shock with water surrounding an explosive in a confined space is of great significance for military explosives safety applications. To estimate the effects of the parameters on the reflected overpressure of blasted shock wave, a series of experiments were carried out in confined containers with spherical explosives immersed in a certain thickness of water,and numerical simulations were conducted to explore the corresponding mechanisms. The results reveal that the reflected overpressure is abnormally aggravated at a small scaled distance. This aggravation is due to the high impulse of the bulk accelerated water shell converted from the explosion. With increasing scaled distance, the energy will be gradually dissipated. The mitigation effects will appear with the dispersed water phase front impacting at a larger scaled distance, except in the case of a dense water phase state. A critical scaled distance range of 0.7-0.8 m/kg^(1/3) for effective mitigation was found. It is suggested that the scaled distance of space walls should be larger than the critical value for a certain water-to-explosive weight ratio range(5-20).

Effect of stearic acid on the morphological and structural evolution of mechanically milled Nb-based powder

Nb-based powder was fabricated via mechanical grinding. The influence of stearic acid on the grinding process was studied. The slructural evolution and morphological evolution of the milled powder were characterized by X-ray diffraction （XRD）, scanning electron mi- croscopy （SEM）, and energy dispersive spectroscopy （EDS） analysis. It is indicated that an appropriate amount of stearic acid accelerates the particle refinement process and favors the production of superfine Nb-based particles with good dispersivity and high activity. However, an inappropriate amount of stearic acid has an adverse effect on the refinement process.

Effectiveness and safety of different doses of pioglitazone in psoriasis:a meta-analysis of randomized controlled trials

Background:Pioglitazone may be beneficial in the treatment of psoriasis.However,based on the effectiveness and safety considerations,it has not been widely used.To fully evaluate the strength of evidence supporting psoriasis treatment with pioglitazone,we conducted a meta-analysis of existing published studies.Methods:PubMed,Ovid,Cochrane Library,Google Scholar,and Web of Science databases were systematically searched before February 2019.Randomized controlled trials(RCTs)of pioglitazone administration compared with placebo,administered to patients with psoriasis for at least 10 weeks,and published in English were included.Quality of the included RCTs was identified by the modified Jadad scale.The quality of evidence for each outcome was evaluated using the GRADEpro Guideline Development Tool online software.Primary outcomes were proportion of patients showing psoriasis area and severity index(PASI)score improvement(<75%)and the mean percent change in PASI score from baseline to the end of treatment.Dichotomous data were analyzed using odds ratios(ORs)corresponding to the 95%confidence interval(CI),whereas continuous variables,expressed as mean and standard deviation,were analyzed using the mean differences(MD)with the 95%CI.Results:Six RCTs were analyzed.Meta-analysis showed that pioglitazone reduced the PASI scores in patients with psoriasis compared with the control group when administered at 30 mg per day(P<0.001,MD=-3.82,95%CI=-5.70,-1.93)and at 15 mg per day(P=0.04,MD=-3.53,95%CI=-6.86,-0.20).The PASI-75 of the pioglitazone group was significantly higher than that of the control group at 30 mg per day(P<0.001,OR=8.30,95%CI=3.99,17.27)and at 15 mg per day(P=0.03,OR=2.96,95%CI=1.08,8.06).No statistically significant differences in total adverse events were observed between the groups.There were no significant differences in common adverse reactions such as weight gain and elevated liver enzymes between the two pioglitazone groups.Conclusions:Use of pioglitazone in the current treatment of psoriasis is beneficial.The therapeutic effect of the daily 30 mg dose may be greater than that of the 15 mg dose per day with no significant change in the frequency of adverse reactions.

Clinical and Epidemiological Characteristics of Vitiligo at Different Ages: An Analysis of 571 Patients in Northwest China

Objective:This study was performed to elucidate the clinical end epidemiological characteristics of vitiligo patients of different ages in Northwest China.Methods:We retrospectively reviewed the case records and questionnaires of all patients diagnosed with vitiligo,who visited People's Hospital of Xinjieng Uygur Autonomous Region from May 2016 to December 2017.The clinical end epidemiological characteristics of these patients were enalyzed by Pearson's x2 test end Fishar's exact test.Results:In total,we collected data of 571 Vitiligo patients with age of 32.9 ± 16.4 years.The prevalence of segmental Vitiligo in children end adolescents < 19 years old (24/175[13.7%]) was higher than that in adults aged from 20-59 years (23/370[6.2%]) and advanced patients aged >60 years (1/26[3.8%]) (P=0.020).The prevalence of progressive vitiligo was higher in children end adolescents < 19 years (72/175[41.1%]) and adults from 20-59 years (141/370[38.1%) than in patients ≥60 years (5/26[19.2 %]) (P =0.063).Children and adolescents < 19 years with Vitiligo had a higher rate of a family history of vitiligo (20/175[11.4%]) then adults (20/370[5.4%]) and advanced age (1/26[3.8%]) (P=0.031).Conclusions:This study provides clinical evidence that vitiligo at different ages has different characteristics,mainly regarding en increased incidence of segmental vitiligo,a higher prevalence of atopic dermatitis end halo nevus,and a more common positive family history among children and adolescent patients.

Childhood bullous pemphigoid with progressive muscular dystrophy: a case report

Introduction Bullous pemphigoid (BP) is an acquired autoimmune disorder,which is clinically characterised by subepidermal blistering,eosinophilia,and severe itch,and it can be complicated by a variety of senile diseases,including neurological diseases.BP mostly attacks older people and is considered rare in children.BP patients were often comorbid with neurological diseases,including dementia,stroke,epilepsy,Parkinson's disease,and multiple sclerosis has been demonstrated.