Theory,technology and application of grouted bolting in soft rock roadways of deep coal mines

The grouted bolt,combining rock bolting with grouting techniques,provides an effective solution for controlling the surrounding rock in deep soft rock and fractured roadways.It has been extensively applied in numerous deep mining areas characterized by soft rock roadways,where it has demonstrated remarkable control results.This article systematically explores the evolution of grouted bolting,covering its theoretical foundations,design methods,materials,construction processes,monitoring measures,and methods for assessing its effectiveness.The overview encompassed several key elements,delving into anchoring theory and grouting reinforcement theory.The new principle of high pretensioned high-pressure splitting grouted bolting collaborative active control is introduced.A fresh method for dynamic information design is also highlighted.The discussion touches on both conventional grouting rock bolts and cable bolts,as well as innovative grouted rock bolts and cables characterized by their high pretension,strength,and sealing hole pressure.An examination of the merits and demerits of standard inorganic and organic grouting materials versus the new inorganic–organic composite materials,including their specific application conditions,was conducted.Additionally,the article presents various methods and instruments to assess the support effect of grouting rock bolts,cable bolts,and grouting reinforcement.Furthermore,it provides a foundation for understanding the factors influencing decisions on grouted bolting timing,the sequence of grouting,the pressure applied,the volume of grout used,and the strategic arrangement of grouted rock bolts and cable bolts.The application of the high pretensioned high-pressure splitting grouted bolting collaborative control technology in a typical kilometer-deep soft rock mine in China—the soft coal seam and soft rock roadway in the Kouzidong coal mine,Huainan coal mining area,was introduced.Finally,the existing problems in grouted bolting control technology for deep soft rock roadways are analyzed,and the future development trend of grouted bolting control technology is anticipated.

Effects of adding sodium dichloroacetate to low-protein diets on nitrogen balance and amino acid metabolism in the portaldrained viscera and liver of pigs

Background:Identifying regulatory measures to promote glucose oxidative metabolism while simultaneously reducing amino acid oxidative metabolism is one of the foremost challenges in formulating low-protein(LP)diets designed to reduce the excretion of nitrogen-containing substances known to be potential pollutants.In this study,we investigated the effects of adding sodium dichloroacetate(DCA)to a LP diet on nitrogen balance and amino acid metabolism in the portal-drained viscera(PDV)and liver of pigs.To measure nitrogen balance,18 barrows(40±1.0 kg)were fed one of three diets(n=6 per group):18%crude protein(CP,control),13.5%CP(LP),and 13.5%CP+100 mg DCA/kg dry matter(LP-DCA).To measure amino acid metabolism in the PDV and liver,15 barrows(40±1.0 kg)were randomly assigned to one of the three diets(n=5 per group).Four essential amino acids(Lys,Met,Thr,and Trp)were added to the LP diets such that these had amino acid levels comparable to those of the control diet.Results:The LP-DCA diet reduced nitrogen excretion in pigs relative to that of pigs fed the control diet(P<0.05),without any negative effects on nitrogen retention(P>0.05).There were no differences between the control and LP-DCA groups with respect to amino acid supply to the liver and extra-hepatic tissues in pigs(P>0.05).The net release of ammonia into the portal vein and production rate of urea in the liver of pigs fed the LP-DCA diet was reduced relative to that of pigs fed the control and LP diets(P<0.05).Conclusion:The results indicated that addition of DCA to a LP diet can efficiently reduce nitrogen excretion in pigs and maximize the supply of amino acids to the liver and extra-hepatic tissues.

Radiotherapy delays malignant transformation and prolongs survival in patients with IDH-mutant gliomas

Objective:IDH-mutant lower-grade gliomas(LGGs,grade 2 or 3)eventually transform into secondary grade 4 astrocytomas(sAIDHmut/G4).Here,we sought to describe the transformation time,risk factors,and outcomes in malignant transformation of IDHmutant LGGs.Methods:We screened data for 108 patients with sAIDHmut/G4 in the Chinese Glioma Genome Atlas who had initial IDH-mutant LGGs and underwent reoperation during 2005–2021.We evaluated the transformation time from IDH-mutant LGGs to sAIDHmut/G4,and associated risk factors and outcomes.Malignant transformation was defined as pathological confirmation of grade 4 astrocytoma.Results:The median age of the 108 patients with IDH-mutant LGGs was 35 years(range,19–54);the median age at transformation was 40 years(range,25–62);and the median follow-up time for all patients was 146 months(range,121–171).The average transformation time was 58.8 months for all patients with LGGs(range,5.9–208.1);63.5 and 51.9 months for grade 2 and 3 gliomas,respectively;and 58.4 and 78.1 months for IDH-mutant/1p/19q-non-codeleted astrocytomas and IDH-mutant/1p/19q-codeleted oligodendrogliomas,respectively.Univariate and multivariate analysis indicated that radiotherapy[hazard ratio(HR),0.29;95%confidence interval(CI),0.137–0.595;P=0.001]and non-A blood type(HR,0.37;95%CI,0.203–0.680;P=0.001)were protective factors against delayed malignant transformation.Radiotherapy was associated with improved survival after transformation(HR,0.44;95%CI,0.241–0.803;P=0.008),overall survival(HR,0.50;95%CI,0.265–0.972;P=0.041),and progression-free survival(HR,0.25;95%CI,0.133–0.479;P<0.0001)in patients with IDH-mutant gliomas.Conclusions:Radiotherapy is associated with delayed malignant transformation and improved survival in patients with IDHmutant gliomas.

Mutual interaction between gut microbiota and protein/amino acid metabolism for host mucosal immunity and health

In recent years,many studies have shown that the intestinal microflora has various effects that are linked to the critical physiological functions and pathological systems of the host.The intestinal microbial community is widely involved in the metabolism of food components such as protein,which is one of the essential nutrients in diets.Additionally,dietary protein/amino acids have been shown to have had a profound impact on profile and operation of gut microbiota.This review summarizes the current liter-ature on the mutual interaction between intestinal microbiota and protein/amino acid metabolism for host mucosal immunity and health.