The mechanism of microwave rock breaking and its potential application to rock-breaking technology in drilling

The exploration and development of oil and gas resources have shifted from shallow to deep and ultradeep.The difficulty of rock breaking has also increased,introducing new challenges to traditional rock-breaking technology.Hence,there is an urgent need to develop new rock-breaking technologies to improve the development efficiency of deep oil and gas resources.Therefore,this study focused on the new microwave rock-breaking technology and conducted experimental and numerical simulation research on typical deep,hard rock granite.The research results showed that granite in the microwave field exhibited high-temperature melting and fracture,and the highest temperature could reach 550°C.Under the irradiation of circulating microwaves,a minimum irradiation time threshold of 3 min was needed to cause irreversible damage to the rock.The numerical simulation results showed that the interaction of thermal stress and in situ stress would cause the inside of the rock stratum to separate into a disturbed deterioration area,disturbed unloading area and initial stress area.These results are expected to provide the necessary technical guidance and theoretical support for the research and development of high-efficiency rock-breaking drilling for deep hard rock.

A Potential Anti-cancer Compound Separated from the Chloroform Extract of the Chinese Medicine Formula Shenqi San

This study examined anti-cancer compounds present in the chloroform extract of the Chinese medicine formula Shenqi San(CE-SS).Silica gel column chromatography,Sephadex LH-20,octadecylsilyl(ODS)column chromatography,and high performance liquid chromatography(HPLC)were used to separate the compounds from CE-SS.The structural formulas of the separated compounds were determined using ID1H and 13C experiments as well as high resolution electrospray ionization mass spectroscopy(HRESIMS).The corresponding results were compared with the reported literature data.A total of six compounds were separated and their structures were identified on the basis of corresponding spectroscopic and physico-chemical properties.They were Saikogenin F(Ⅰ),Prosaikogenin D(Ⅱ),Prosaikogenin F(Ⅲ),p-sitosterol(Ⅳ),3β,16β,23-trihydroxy-13,28-epoxyurs-11-ene-3-O-β-D-glucopyranoside(V),and methyl ursolic acid(VI).The separated compounds were evaluated in vitro for their inhibitory ability against the proliferation of A549 cells via MTT assay.Apoptosis was investigated using Annexin V-FITC/propidium iodide(PI)by flow cytometry.Apoptosis-associated proteins were examined by Western blotting.All the compounds were observed to have inhibitory activities against the proliferation of A549 cells to different degrees.Flow cytometry showed that compound V increased the proportion of apoptotic A549 cells in a dose-dependent manner.Western blotting showed that compound V increased the expression of Bax,cleaved-caspase-3,cleaved-caspase-9 and cleaved-poly ADP-ribose polymerase(PARP),and decreased the expression of Bcl-2.These results indicated that compound V featured a significant inhibitory effect on A549 cells when compared with other compounds,and it may be considered a potential drug against cancers.