Molecular and functional analysis of chitin synthase genes in Chilo suppressalis(Lepidoptera:Crambidae)

The rice stem borer,Chilo suppressalis,has developed a high level of resistance to many of the compounds currently used for control.There is therefore an urgent need to develop novel control methods for C.suppressalis.Insect chitin synthases(CHS)have attracted interest as a potential target for insect pest management.However,to date,CHS have not been characterized in C.suppressalis.Two CHS genes(CsCHSI and CsCHS2)were identified and cloned from C.suppressalis.Two transcript variants were identified for CsCHS1,CsCHSla and CsCHS1b.Spatiotemporal expression profiling showed that both transcripts of CsCHS1 are most highly expressed on the last day of each larval instar stage and show the highest expression levels in the integument.In contrast,CsCHS2 is predominantly expressed during the larval feeding stages and shows the highest expression levels in the midgut.Knockdown of CsCHSI by RNA interference significantly inhibited the molting and pupation of C.suppressalis,and knockdown of CsCHS2 significantly affected growth during the larval stage,but had no significant effect on the pupation.Moreover,knockout of CsCHS1 by CRISPR/Cas9 genome editing severely lowered the hatching rate,larval survivorship,pupation rate,and eclosion rate,but only larval survivorship at the GO generation was lowered after the knockout of CsCHS2.These results demonstrate that CsCHS1 and CsCHS2 play vital roles in the growth and development of C.suppressalis,and so have potential as insecticidal targets for the control of this highly damaging pest.

Optimization of preparation process of high-strength pellets from Panzhihua ilmenite concentrate

The preparation of high-strength pellets from Panzhihua ilmenite concentrate is important for the hydrogen-rich smelting of titania slag and was investigated.The effects of the magnetite concentrate and heating procedure including the pre-heating temperature and period as well as roasting temperature and period on the compressive strength of the roasted pellets were investigated.High-strength ilmenite concentrate pellets(>2000 N)were prepared by optimizing the roasting process.The addition of magnetite concentrate is beneficial for increasing the compressive strength of the Panzhihua ilmenite concentrate pellet by oxidizing hematite which filled the pseudobrookite particles,functioned as a bridge bond,and improved the interconnection between the grains.The compressive strength can reach up to 2900 N when the ilmenite concentrate pellet with 15%magnetite concentrate is pre-heated above 800℃ for 20 min and then roasted at 1250℃ for 20 min.In addition,there is an overall upward trend in the compressive strength with an increase in the pre-heating temperature and period as well as the roasting temperature and period.The micromorphology and strengthening consolidation mechanism of Panzhihua ilmenite concentrate pellets were also discussed.

Association between glioblastoma cell-derived vessels and poor prognosis of the patients

Background:Vessels with different microcirculation patterns are required for glioblastoma(GBM)growth.However,details of the microcirculation patterns in GBM remain unclear.Here,we examined the microcirculation patterns of GBM and analyzed their roles in patient prognosis together with two well-known GMB prognosis factors(O^(6)-methylguanine DNA methyltransferase[MGMT]promoter methylation status and isocitrate dehydrogenase[IDH]mutations).Methods:Eighty GBM clinical specimens were collected from patients diagnosed between January 2000 and December 2012.The microcirculation patterns,including endothelium-dependent vessels(EDVs),extracellular matrix-dependent vessels(ECMDVs),GBM cell-derived vessels(GDVs),and mosaic vessels(MVs),were evaluated by immunohistochemistry(IHC)and immunofluorescence(IF)staining in both GBM clinical specimens and xenograft tissues.Vascular density assessments and three-dimensional reconstruction were performed.MGMT promoter methylation status was determined by methylation-specific PCR,and IDH1/2 mutations were detected by Sanger sequencing.The relationship between the microcirculation patterns and patient prognosis was analyzed by Kaplan-Meier method.Results:All 4 microcirculation patterns were observed in both GBM clinical specimens and xenograft tissues.EDVs were detected in all tissue samples,while the other three patterns were observed in a small number of tissue samples(ECMDVs in 27.5%,GDVs in 43.8%,and MVs in 52.5%tissue samples).GDV-positive patients had a median survival of 9.56 months versus 13.60 months for GDV-negative patients(P=0.015).In MGMT promoter-methylated cohort,GDV-positive patients had a median survival of 6.76 months versus 14.23 months for GDV-negative patients(P=0.022).Conclusion:GDVs might be a negative predictor for the survival of GBM patients,even in those with MGMT promoter methylation.