An investigation on anti-impact and penetration performance of basalt fiber composites with different weave and lay-up modes

The woven basalt fiber composites(WBFC) and the unidirectional [0°/90°/45°/-45°]s basalt fiber composites(UBFC) were prepared by hot-pressing.Three-point bending test,low velocity impact test,and ballistic test were performed to the prepared composites.After the tests,the specimens were recovered and analyzed for micromorphology.Three-point bending tests show that both the bending strength and stiffness of the WBFC surpass those of the UBFC.Low velocity impact test results show that the low velocity impact resistance to hemispherical impactor of the UBFC is higher than that of the WBFC,but the low velocity impact resistance to sharp impactor of the UBFC is lower than that of the WBFC.For the ballistic test,it can be found that the ballistic property of the UBFC is higher than that of the WBFC. After the tests,microscopic analysis of the specimens was applied,and their failure mechanism was discussed.The main failure modes of the UBFC are delamination and fibers breakage under the above loading conditions while the main failure mode of the WBFC is fibers breakage.Although delamination damage can be found in the WBFC under the above loading conditions,the degree of delamination is far less than that of the UBFC.

Evaluation of a new frequency-volume chart for children with primary monosymptomatic nocturnal enuresis:a prospective,comparative study

Introduction To improve compliance with voiding diaries in children with primary monosymptomatic nocturnal enuresis(PMNE),a new modified 3-day weekend frequency-volume chart(FVC)was designed,and the compliance and validity of this modified FVC was evaluated by comparing with the International Children's Continence Society(ICCS)recommended voiding diary.Methods A total of 1200 patients with PMNE were enrolled in the study from 13 centers in China and were randomly assigned to record this modified FVC or the ICCS-recommended voiding diary.The primary outcome measure was the compliance,assessed by comparing the completing index and the quality score of diaries between two groups.The secondary outcome measure was the validity,evaluated by comparing the constituent of subtypes,micturition parameters and response rate to desmopressin.Results Among the 1200 participants enrolled in the study,447 patients completed the ICCS-recommended voiding diary and 469 completed the modified diary.The diurnal completing index and the quality score of the modified FVC group were better than those of the ICCS group.In addition,there was no significant difference between these two groups in the subtype classification,or in the response rate to desmopressin.Conclusions The modified FVC could be applied to obtain the voiding characteristics of children with PMNE as the ICCS-recommended voiding diary does and offers a reasonable and better choice for children with PMNE from the unselected population in the future.

Coronavirus disease 2019 vaccine for children in China:when to start?Mandatory or voluntary?

To the Editor:As the coronavirus disease 2019(COVID-19)pandemic continues to expand in many countries,and the more transmissible variants emerged,the second wave could be more severe and result in a greater peak of infection and mortality.There is an urgent need to develop effective vaccines,which remains a critical tool to control the pandemic.Vaccination is equally important in areas where outbreaks persist and in well-controlled countries.

Recurrent rhabdomyolysis and glutaric aciduria type I: a case report and literature review

Background:Glutaric acidemia type I(GA-I)is a rare metabolic disorder caused by mutation of the glutaryl-CoA dehydrogenase(GCDH)gene.The occurrence of rhabdomyolysis with GA-I is extremely rare.Methods:We reported a child with recurrent rhabdomyolysis and undiagnosed glutaric acidemia type I(GA-I).And a literature review was performed.Results:A 4.5-year-old girl was admitted to our hospital due to recurrent rhabdomyolysis for 3 times within three years.At the third admission,she was diagnosed with GA-I by biochemical testing and mutation analysis.The girl was found to have a serine to leucine replacement mutation of the GCDH gene in exon 8 at position 764.Other three patients with rhabdomyolysis and GA-I were discovered by literature searching.Conclusion:This report highlights that patients with GA-I may have an increased risk of rhabdomyolysis.