Cerebral cavernous malformations are a rare and congenital vascular malformation that can present as a challenge in neurosurgical management. The term “giant cerebral cavernous malformations” still does not have a c...Cerebral cavernous malformations are a rare and congenital vascular malformation that can present as a challenge in neurosurgical management. The term “giant cerebral cavernous malformations” still does not have a clear definition in the literature, with a wide variety of results. It is known, however, that there is an association between the size of the cavernoma and postoperative sequelae, especially in those with a size greater than 3 cm in its largest diameter. We present a case report of resection of a giant brain cavernoma measuring approximately 8 cm in its largest diameter, emphasizing on clinical presentation, diagnoses and postoperative evolution. Additionally, we performed a comprehensive review of the existing literature on the subject, addressing the epidemiology, pathophysiology, diagnostic methods, treatment options, and prognosis associated with this condition.展开更多
The publisher regrets that the article type for this publication was incorrectly labeled as a Research Article.The correct designation should be Review Article.
The big underground powerhouse cavern of the China Baihetan hydropower plant is 438m long,34m wide,and 88.7m high.It is cut by a weak interlayer shear zone and its high sidewall poses a huge stability problem.This pap...The big underground powerhouse cavern of the China Baihetan hydropower plant is 438m long,34m wide,and 88.7m high.It is cut by a weak interlayer shear zone and its high sidewall poses a huge stability problem.This paper reports our successful solution of this problem through numerical simulations and a replacement-tunnel scheme in the detailed design stage and close site monitoring in the excavation stage.Particularly,in the detail design stage,mechanical parameters of the shear zone were carefully determined through laboratory experiments and site tests.Then,deformation of the surrounding rocks and the shear zone under high in situ stress conditions was predicted using 3 Dimensional Distinct Element Code(3DEC).Subsequently,a replacement-tunnel scheme was proposed for the treatment on the shear zone to prevent severe unloading relaxation of surrounding rocks.In the construction period,excavation responses were closely monitored on deformations of surrounding rocks and the shear zone.The effect of local cracking in the replacement tunnels on sidewall stability was evaluated using the strength reduction method.These monitoring results were compared with the predicted numerical simulation in the detailed design stage.It is found that the shear zone greatly modified the deformation mode of the cavern surrounding rocks.Without any treatment,rock mass deformation on the downstream sidewall was larger than 125mm and the shearing deformation of the shear zone was 60–70 mm.These preset replacement tunnels can reduce not only the unloading and relaxation of rock masses but also the maximum shearing deformation of the shear zone by 10–20 mm.The predictions by numerical simulation were in good agreement with the monitoring results.The proposed tunnel-replacement scheme can not only restrain the shear zone deformation but also enhance the safety of surrounding rocks and concrete tunnels.This design procedure offers a good reference for interaction between a big underground cavern and a weak layer zone in the future.展开更多
BACKGROUND Hepatic hemangioma represents the most common benign primary hepatic neo-plasm.Although most such tumors are small and asymptomatic,giant cavernous hemangioma(GCH)is frequently symptomatic,and needs interve...BACKGROUND Hepatic hemangioma represents the most common benign primary hepatic neo-plasm.Although most such tumors are small and asymptomatic,giant cavernous hemangioma(GCH)is frequently symptomatic,and needs intervention.More-over,diffuse hepatic hemangiomatosis(DHH)is not rare in the liver parenchyma adjacent to a GCH.The management strategy for hepatic hemangiomas can differ depending on the presence of associated hemangiomatosis and the amount and distribution of the residual hepatic parenchyma.CASE SUMMARY Herein,we report two patients with GCH coexistent with DHH successfully treated by laparoscopic microwave ablation.The two GCHs were ablated com-pletely and the ablated zone atrophied obviously in imaging follow-ups after ablation.Surprisingly,there was a trend toward gradual reduction and dimini-shment of DHH.CONCLUSION Thermal ablation treatment might be an effective and less invasive treatment for GCH coexistent with DHH around the hemangioma.展开更多
The rapid development of energy storage technology has provided tremendous support for the energy transition in countries worldwide.Salt cavern energy storage,as a form of energy storage technology,has gained widespre...The rapid development of energy storage technology has provided tremendous support for the energy transition in countries worldwide.Salt cavern energy storage,as a form of energy storage technology,has gained widespread attention due to its large storage capacity and broad distribution.Therefore,this paper primarily discusses the current research status of salt cavern energy storage technology,with a focus on analyzing its classifications,advantages,disadvantages,and the challenges and countermeasures associated with its development.This study aims to promote further advancement in salt cavern energy storage technology.展开更多
Stem cell treatment may enhance erectile dysfunction(ED)in individuals with cavernous nerve injury(CNI).Nevertheless,no investigations have directly ascertained the implications of varying amounts of human umbilical c...Stem cell treatment may enhance erectile dysfunction(ED)in individuals with cavernous nerve injury(CNI).Nevertheless,no investigations have directly ascertained the implications of varying amounts of human umbilical cord-derived mesenchymal stem cells(HUC-MSCs)on ED.We compare the efficacy of three various doses of HUC-MSCs as a therapeutic strategy for ED.Sprague–Dawley rats(total=175)were randomly allocated into five groups.A total of 35 rats underwent sham surgery and 140 rats endured bilateral CNI and were treated with vehicles or doses of HUC-MSCs(1×106 cells,5×106 cells,and 1×107 cells in 0.1 ml,respectively).Penile tissues were harvested for histological analysis on 1 day,3 days,7 days,14 days,28 days,60 days,and 90 days postsurgery.It was found that varying dosages of HUC-MSCs enhanced the erectile function of rats with bilateral CNI and ED.Moreover,there was no significant disparity in the effectiveness of various dosages of HUC-MSCs.However,the expression of endothelial markers(rat endothelial cell antigen-1[RECA-1]and endothelial nitric oxide synthase[eNOS]),smooth muscle markers(alpha smooth muscle actin[α-SMA]and desmin),and neural markers(neurofilament[RECA-1]and neurogenic nitric oxide synthase[nNOS])increased significantly with prolonged treatment time.Masson’s staining demonstrated an increased in the smooth muscle cell(SMC)/collagen ratio.Significant changes were detected in the microstructures of various types of cells.In vivo imaging system(IVIS)analysis showed that at the 1st day,the HUC-MSCs implanted moved to the site of damage.Additionally,the oxidative stress levels were dramatically reduced in the penises of rats administered with HUC-MSCs.展开更多
This study investigates the mechanical response of an underground cavern subjected to cyclic high gas pressure,aiming to establish a theoretical foundation for the design of lined rock caverns(LRCs)for energy storage ...This study investigates the mechanical response of an underground cavern subjected to cyclic high gas pressure,aiming to establish a theoretical foundation for the design of lined rock caverns(LRCs)for energy storage with high internal pressure,e.g.compressed air energy storage(CAES)underground caverns or hydrogen storage caverns.Initially,the stress paths of the surrounding rock during the excavation,pressurization,and depressurization processes are delineated.Analytical expressions for the stress and deformation of the surrounding rock are derived based on the MohreCoulomb criterion.These expressions are then employed to evaluate the displacement of cavern walls under varying qualities of surrounding rock,the contact pressure between the steel lining and the surrounding rock subject to different gas storage pressures,the load-bearing ratio of the surrounding rock,and the impact of lining thickness on the critical gas pressure.Furthermore,the deformation paths of the surrounding rock are evaluated,along with the effects of tunnel depth and diameter on residual deformation of the surrounding rock,and the critical minimum gas pressure at which the surrounding rock and the lining do not detach.The results indicate that residual deformation of the surrounding rock occurs after depressurization under higher internal pressure for higher-quality rock masses,leading to detachment between the surrounding rock and the steel lining.The findings indicate that thicker linings correspond to higher critical minimum gas pressures.However,for lower-quality surrounding rock,thicker linings correspond to lower critical minimum gas pressures.These findings will provide invaluable insights for the design of LRCs for underground energy storage caverns.展开更多
Seismicity resulting from the near-or in-field fault activation significantly affects the stability of large-scale underground caverns that are operating under high-stress conditions.A comprehensive scientific assessm...Seismicity resulting from the near-or in-field fault activation significantly affects the stability of large-scale underground caverns that are operating under high-stress conditions.A comprehensive scientific assessment of the operational safety of such caverns requires an in-depth understanding of the response characteristics of the rock mass subjected to dynamic disturbances.To address this issue,we conducted true triaxial modeling tests and dynamic numerical simulations on large underground caverns to investigate the impact of static stress levels,dynamic load parameters,and input directions on the response characteristics of the surrounding rock mass.The findings reveal that:(1)When subjected to identical incident stress waves and static loads,the surrounding rock mass exhibits the greatest stress response during horizontal incidence.When the incident direction is fixed,the mechanical response is more pronounced at the cavern wall parallel to the direction of dynamic loading.(2)A high initial static stress level specifically enhances the impact of dynamic loading.(3)The response of the surrounding rock mass is directly linked to the amplitude of the incident stress wave.High amplitude results in tensile damage in regions experiencing tensile stress concentration under static loading and shear damage in regions experiencing compressive stress concentration.These results have significant implications for the evaluation and prevention of dynamic disasters in the surrounding rock of underground caverns experiencing dynamic disturbances.展开更多
Rock masses are often exposed to dynamic loads such as earthquakes and mechanical disturbances in practical engineering scenarios.The existence of underground caverns and weak geological structures like columnar joint...Rock masses are often exposed to dynamic loads such as earthquakes and mechanical disturbances in practical engineering scenarios.The existence of underground caverns and weak geological structures like columnar jointed rock masses(CJRMs)and interlayer shear weakness zones(ISWZs)with inferior mechanical properties,significantly undermines the overall structural stability.To tackle the dynamic loading issues in the process of constructing subterranean caverns,a programmable modeling approach was utilized to reconstruct a large-scale underground cavern model incorporating ISWZs and columnar joints(CJs).By conducting dynamic simulations with varying load orientations,the analyses focused on the failure patterns,deformation characteristics,and acoustic emission activity within the caverns.Results revealed that the failure modes of the underground caverns under dynamic loading were predominantly tensile failures.Under X-direction loading,the failed elements were mainly distributed parallel to the CJs,while under Y-direction loading,they were distributed parallel to the transverse weak structural planes.Furthermore,the dynamic stability of the overall structure varied with the number of caverns.The dual-cavern model demonstrated the highest stability under X-direction loading,while the single-cavern model was the least stable.Under Y-direction loading,the cavern stability increased with the number of caverns.Importantly,different weak structures affected the dynamic response of caverns in different ways;the CJRMs were the primary contributors to structural failure,while ISWZs could mitigate the rock mass failure induced by CJs.The findings could offer valuable insights for the dynamic stability analysis of caverns containing CJRMs and ISWZs.展开更多
The surrounding rock is prone to large-scale loosening and failure after the excavation of shallow large-span caverns because of the thin overlying strata and large cross-section span.The rational design of bolt suppo...The surrounding rock is prone to large-scale loosening and failure after the excavation of shallow large-span caverns because of the thin overlying strata and large cross-section span.The rational design of bolt support is very important to the safety control of surrounding rock as a common support means.The control mechanism and design method of bolt support for shallow-buried large-span caverns is carried out.The calculation method of bolt prestress and length based on arched failure and collapsed failure mode is established.The influence mechanism of different influencing factors on the bolt prestress and length is clarified.At the same time,the constant resistance energy-absorbing bolt with high strength and high toughness is developed,and the comparative test of mechanical properties is carried out.On this basis,the design method of high prestressed bolt support for shallow-buried large-span caverns is put forward,and the field test is carried out in Qingdao metro station in China.The monitoring results show that the maximum roof settlement is 6.8 mm after the new design method is adopted,and the effective control of the shallow-buried large-span caverns is realized.The research results can provide theoretical and technical support for the safety control of shallow-buried large-span caverns.展开更多
BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)is contraindicated for patients with cavernous transformation of the portal vein(CTPV)due to high surgery-related mortality risk.However,surgically assiste...BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)is contraindicated for patients with cavernous transformation of the portal vein(CTPV)due to high surgery-related mortality risk.However,surgically assisted TIPS(SATIPS)can significantly reduce the risk.AIM To evaluate the clinical efficacy of SATIPS,this study was conducted.METHODS One hundred and seven patients with CTPV and esophagogastric variceal bleeding were recruited from January 2023 to December 2024.The patients were recruited from three different hospitals.Overall,54 patients received SATIPS treatment(SATIPS group),while 53 patients did not receive SATIPS and underwent prophylactic endoscopic sclerosing ligation(control group).Subsequently,survival rates,incidence rates of gastrointestinal bleeding,incidence of hepatic encephalopathy rate,and the incidence of liver failure after treatment in both groups at 3 and 6 months were observed.RESULTS The survival rates for the SATIPS and control groups were 94.4%and 92.5%at 3 months(P value=0.72)and 94.4%and 73.6%at 6 months(P value=0.0051)respectively.The incidence of liver failure was 3.7%and 9.4%at 3 months(P value=0.26)and 3.7%and18.9%at 6 months(P value=0.016);the incidence of gastrointestinal bleeding was 5.6%and 37.7%at 3 months(P value<0.001)and 9.3%and 47.2%(P value<0.001)at 6 months;and the incidence of hepatic encephalopathy was 3.7%and 17.0%at 3 months(P value=0.026)and 7.4%and 26.4%at 6 months(P value=0.026)respectively.CONCLUSION For patients with CTPV,there were no optimal treatment.Regarding long-term efficacy,SATIPS can significantly reduce the rate of rebleeding,hepatic encephalopathy and liver failure,and is associated with better survival.展开更多
BACKGROUND Direct carotid cavernous fistulas(CCFs)are typically the result of a severe traumatic brain injury.High-flow arteriovenous shunts secondary to rupture of an intracavernous aneurysm,resulting in direct CCFs,...BACKGROUND Direct carotid cavernous fistulas(CCFs)are typically the result of a severe traumatic brain injury.High-flow arteriovenous shunts secondary to rupture of an intracavernous aneurysm,resulting in direct CCFs,are rare.The use of a pipeline embolization device in conjunction with coils and Onyx glue for treatment of direct high-flow CCF resulting from ruptured cavernous carotid artery aneurysm in a clinical setting is not well documented.CASE SUMMARY A 58-year-old woman presented to our department with symptoms of blepharoptosis and intracranial bruits for 1 wk.During physical examination,there was right eye exophthalmos and ocular motor palsy.The rest of the neurological examination was clear.Notably,the patient had no history of head injury.The patient was treated with a pipeline embolization device in the ipsilateral internal carotid artery across the fistula.Coils and Onyx were placed through the femoral venous route,followed by placement of the pipeline embolization device with assistance from a balloon-coiling technique.No intraoperative or perioperative complications occurred.Preoperative symptoms of bulbar hyperemia and bruits subsided immediately after the operation.CONCLUSION Pipeline embolization device in conjunction with coiling and Onyx may be a safe and effective approach for direct CCFs.展开更多
Background: Cavernous transformation of the portal vein(CTPV) due to portal vein obstruction is a rare vascular anomaly defined as the formation of multiple collateral vessels in the hepatic hilum. This study aimed to...Background: Cavernous transformation of the portal vein(CTPV) due to portal vein obstruction is a rare vascular anomaly defined as the formation of multiple collateral vessels in the hepatic hilum. This study aimed to investigate the imaging features of intrahepatic portal vein in adult patients with CTPV and establish the relationship between the manifestations of intrahepatic portal vein and the progression of CTPV. Methods: We retrospectively analyzed 14 CTPV patients in Beijing Tsinghua Changgung Hospital. All patients underwent both direct portal venography(DPV) and computed tomography angiography(CTA) to reveal the manifestations of the portal venous system. The vessels measured included the left portal vein(LPV), right portal vein(RPV), main portal vein(MPV) and the portal vein bifurcation(PVB). Results: Nine males and 5 females, with a median age of 40.5 years, were included in the study. No significant difference was found in the diameters of the LPV or RPV measured by DPV and CTA. The visualization in terms of LPV, RPV and PVB measured by DPV was higher than that by CTA. There was a significant association between LPV/RPV and PVB/MPV in term of visibility revealed with DPV( P = 0.01), while this association was not observed with CTA. According to the imaging features of the portal vein measured by DPV, CTPV was classified into three categories to facilitate the diagnosis and treatment. Conclusions: DPV was more accurate than CTA for revealing the course of the intrahepatic portal vein in patients with CTPV. The classification of CTPV, that originated from the imaging features of the portal vein revealed by DPV, may provide a new perspective for the diagnosis and treatment of CTPV.展开更多
Underground hydrogen storage(UHS)and compressed air energy storage(CAES)are two viable largescale energy storage technologies for mitigating the intermittency of wind and solar power.Therefore,it is meaningful to comp...Underground hydrogen storage(UHS)and compressed air energy storage(CAES)are two viable largescale energy storage technologies for mitigating the intermittency of wind and solar power.Therefore,it is meaningful to compare the properties of hydrogen and air with typical thermodynamic storage processes.This study employs a multi-physical coupling model to compare the operations of CAES and UHS,integrating gas thermodynamics within caverns,thermal conduction,and mechanical deformation around rock caverns.Gas thermodynamic responses are validated using additional simulations and the field test data.Temperature and pressure variations of air and hydrogen within rock caverns exhibit similarities under both adiabatic and diabatic simulation modes.Hydrogen reaches higher temperature and pressure following gas charging stage compared to air,and the ideal gas assumption may lead to overestimation of gas temperature and pressure.Unlike steel lining of CAES,the sealing layer(fibre-reinforced plastic FRP)in UHS is prone to deformation but can effectively mitigates stress in the sealing layer.In CAES,the first principal stress on the surface of the sealing layer and concrete lining is tensile stress,whereas UHS exhibits compressive stress in the same areas.Our present research can provide references for the selection of energy storage methods.展开更多
Underground salt cavern CO_(2) storage(SCCS)offers the dual benefits of enabling extensive CO_(2) storage and facilitating the utilization of CO_(2) resources while contributing the regulation of the carbon market.Its...Underground salt cavern CO_(2) storage(SCCS)offers the dual benefits of enabling extensive CO_(2) storage and facilitating the utilization of CO_(2) resources while contributing the regulation of the carbon market.Its economic and operational advantages over traditional carbon capture,utilization,and storage(CCUS)projects make SCCS a more cost-effective and flexible option.Despite the widespread use of salt caverns for storing various substances,differences exist between SCCS and traditional salt cavern energy storage in terms of gas-tightness,carbon injection,brine extraction control,long-term carbon storage stability,and site selection criteria.These distinctions stem from the unique phase change characteristics of CO_(2) and the application scenarios of SCCS.Therefore,targeted and forward-looking scientific research on SCCS is imperative.This paper introduces the implementation principles and application scenarios of SCCS,emphasizing its connections with carbon emissions,carbon utilization,and renewable energy peak shaving.It delves into the operational characteristics and economic advantages of SCCS compared with other CCUS methods,and addresses associated scientific challenges.In this paper,we establish a pressure equation for carbon injection and brine extraction,that considers the phase change characteristics of CO_(2),and we analyze the pressure during carbon injection.By comparing the viscosities of CO_(2) and other gases,SCCS’s excellent sealing performance is demonstrated.Building on this,we develop a long-term stability evaluation model and associated indices,which analyze the impact of the injection speed and minimum operating pressure on stability.Field countermeasures to ensure stability are proposed.Site selection criteria for SCCS are established,preliminary salt mine sites suitable for SCCS are identified in China,and an initial estimate of achievable carbon storage scale in China is made at over 51.8-77.7 million tons,utilizing only 20%-30%volume of abandoned salt caverns.This paper addresses key scientific and engineering challenges facing SCCS and determines crucial technical parameters,such as the operating pressure,burial depth,and storage scale,and it offers essential guidance for implementing SCCS projects in China.展开更多
Large‐scale underground hydrogen storage(UHS)provides a promising method for increasing the role of hydrogen in the process of carbon neutrality and energy transition.Of all the existing storage deposits,salt caverns...Large‐scale underground hydrogen storage(UHS)provides a promising method for increasing the role of hydrogen in the process of carbon neutrality and energy transition.Of all the existing storage deposits,salt caverns are recognized as ideal sites for pure hydrogen storage.Evaluation and optimization of site selection for hydrogen storage facilities in salt caverns have become significant issues.In this article,the software CiteSpace is used to analyze and filter hot topics in published research.Based on a detailed classification and analysis,a“four‐factor”model for the site selection of salt cavern hydrogen storage is proposed,encompassing the dynamic demands of hydrogen energy,geological,hydrological,and ground factors of salt mines.Subsequently,20 basic indicators for comprehensive suitability grading of the target site were screened using the analytic hierarchy process and expert survey methods were adopted,which provided a preliminary site selection system for salt cavern hydrogen storage.Ultimately,the developed system was applied for the evaluation of salt cavern hydrogen storage sites in the salt mines of Pingdingshan City,Henan Province,thereby confirming its rationality and effectiveness.This research provides a feasible method and theoretical basis for the site selection of UHS in salt caverns in China.展开更多
The demand for underground space and sustainable energy has driven the need for underground structures.Large underground caverns,being an underground structure carrier,offers a feasible solution.However,the stability ...The demand for underground space and sustainable energy has driven the need for underground structures.Large underground caverns,being an underground structure carrier,offers a feasible solution.However,the stability analysis and optimization design of large underground caverns is always a great challenge due to the high geostress,complicated rock condition,and high sidewalls and large spans in size.By collecting and reviewing a large amount of relevant research literature from 1970 to 2023,the efforts on the advances in stability analysis methods and optimization design of large underground caverns are described,then the research trends in this field through keywords were found and typical deformation and break modes of large underground caverns with high geostress are summarized.The review reveals that stability analysis and optimization are the recent active research topics.There are seven typical deformation and break modes of large underground caverns under high geostress,four stability analysis methods and four theories of optimization design of large under-ground caverns.With the progress of science and technology and society,intelligent design,mechanized con-struction and greening construction are the development trend in this field.The research results can provide a constructive reference for the stability analysis and optimization design of large underground caverns under high geostress.展开更多
Salt caverns are extensively utilized for storing various substances such as fossil energy,hydrogen,compressed air,nuclear waste,and industrial solid waste.In China,when the salt cavern is leached through single-well ...Salt caverns are extensively utilized for storing various substances such as fossil energy,hydrogen,compressed air,nuclear waste,and industrial solid waste.In China,when the salt cavern is leached through single-well water solution mining with oil as a cushion,engineering challenges arise with the leaching tubing,leading to issues like damage and instability.These problems significantly hinder the progress of cavern construction and the control of cavern shape.The primary cause of this is the flowinduced vibration instability of leaching tubing within a confined space,which results in severe bending or damage to the tubing.This study presents a model experimental investigation on the dynamic characteristics of leaching tubing using a self-developed liquid-solid coupling physical model experiment apparatus.The experiment utilizes a silicone-rubber pipe(SRP)and a polycarbonate pipe(PCP)to examine the effects of various factors on the dynamic stability of cantilevered pipes conveying fluid.These factors include external space constraint,flexural rigidity,medium outside the pipe,overhanging length,and end conditions.The experiments reveal four dynamic response phenomena:water hammer,static buckling,chaotic motion,and flutter instability.The study further demonstrates that the length of the external space constraint has a direct impact on the flutter critical flow velocity of the cantilevered pipe conveying fluid.Additionally,the flutter critical flow velocity is influenced by the end conditions and different external media.展开更多
Underground energy and resource development,deep underground energy storage and other projects involve the global stability of multiple interconnected cavern groups under internal and external dynamic disturbances.An ...Underground energy and resource development,deep underground energy storage and other projects involve the global stability of multiple interconnected cavern groups under internal and external dynamic disturbances.An evaluation method of the global stability coefficient of underground caverns based on static overload and dynamic overload was proposed.Firstly,the global failure criterion for caverns was defined based on its band connection of plastic-strain between multi-caverns.Then,overloading calculation of the boundary geostress and seismic intensity on the caverns model was carried out,and the critical unstable state of multi-caverns can be identified,if the plastic-strain band appeared between caverns during these overloading processes.Thus,the global stability coefficient for the multi-caverns under static loading and earthquake was obtained based on the corresponding overloading coefficient.Practical analysis for the Yingliangbao(YLB)hydraulic caverns indicated that this method can not only effectively obtain the global stability coefficient of caverns under static and dynamic earthquake conditions,but also identify the caverns’high-risk zone of local instability through localized plastic strain of surrounding rock.This study can provide some reference for the layout design and seismic optimization of underground cavern group.展开更多
BACKGROUND Colorectal cavernous hemangioma is a rare vascular malformation resulting in recurrent lower gastrointestinal hemorrhage,and can be misinterpreted as colitis.Surgical resection is currently the mainstay of ...BACKGROUND Colorectal cavernous hemangioma is a rare vascular malformation resulting in recurrent lower gastrointestinal hemorrhage,and can be misinterpreted as colitis.Surgical resection is currently the mainstay of treatment,with an emphasis on sphincter preservation.CASE SUMMARY We present details of two young patients with a history of persistent hematochezia diagnosed with colorectal cavernous hemangioma by endoscopic ultrasound(EUS).Cavernous hemangioma was relieved by several EUS-guided lauromacrogol injections and the patients achieved favorable clinical prognosis.CONCLUSION Multiple sequential EUS-guided injections of lauromacrogol is a safe,effective,cost-efficient,and minimally invasive alternative for colorectal cavernous hemangioma.展开更多
文摘Cerebral cavernous malformations are a rare and congenital vascular malformation that can present as a challenge in neurosurgical management. The term “giant cerebral cavernous malformations” still does not have a clear definition in the literature, with a wide variety of results. It is known, however, that there is an association between the size of the cavernoma and postoperative sequelae, especially in those with a size greater than 3 cm in its largest diameter. We present a case report of resection of a giant brain cavernoma measuring approximately 8 cm in its largest diameter, emphasizing on clinical presentation, diagnoses and postoperative evolution. Additionally, we performed a comprehensive review of the existing literature on the subject, addressing the epidemiology, pathophysiology, diagnostic methods, treatment options, and prognosis associated with this condition.
文摘The publisher regrets that the article type for this publication was incorrectly labeled as a Research Article.The correct designation should be Review Article.
基金Program of China Three Gorges Corporation,Grant/Award Number:BHT 0679-1。
文摘The big underground powerhouse cavern of the China Baihetan hydropower plant is 438m long,34m wide,and 88.7m high.It is cut by a weak interlayer shear zone and its high sidewall poses a huge stability problem.This paper reports our successful solution of this problem through numerical simulations and a replacement-tunnel scheme in the detailed design stage and close site monitoring in the excavation stage.Particularly,in the detail design stage,mechanical parameters of the shear zone were carefully determined through laboratory experiments and site tests.Then,deformation of the surrounding rocks and the shear zone under high in situ stress conditions was predicted using 3 Dimensional Distinct Element Code(3DEC).Subsequently,a replacement-tunnel scheme was proposed for the treatment on the shear zone to prevent severe unloading relaxation of surrounding rocks.In the construction period,excavation responses were closely monitored on deformations of surrounding rocks and the shear zone.The effect of local cracking in the replacement tunnels on sidewall stability was evaluated using the strength reduction method.These monitoring results were compared with the predicted numerical simulation in the detailed design stage.It is found that the shear zone greatly modified the deformation mode of the cavern surrounding rocks.Without any treatment,rock mass deformation on the downstream sidewall was larger than 125mm and the shearing deformation of the shear zone was 60–70 mm.These preset replacement tunnels can reduce not only the unloading and relaxation of rock masses but also the maximum shearing deformation of the shear zone by 10–20 mm.The predictions by numerical simulation were in good agreement with the monitoring results.The proposed tunnel-replacement scheme can not only restrain the shear zone deformation but also enhance the safety of surrounding rocks and concrete tunnels.This design procedure offers a good reference for interaction between a big underground cavern and a weak layer zone in the future.
文摘BACKGROUND Hepatic hemangioma represents the most common benign primary hepatic neo-plasm.Although most such tumors are small and asymptomatic,giant cavernous hemangioma(GCH)is frequently symptomatic,and needs intervention.More-over,diffuse hepatic hemangiomatosis(DHH)is not rare in the liver parenchyma adjacent to a GCH.The management strategy for hepatic hemangiomas can differ depending on the presence of associated hemangiomatosis and the amount and distribution of the residual hepatic parenchyma.CASE SUMMARY Herein,we report two patients with GCH coexistent with DHH successfully treated by laparoscopic microwave ablation.The two GCHs were ablated com-pletely and the ablated zone atrophied obviously in imaging follow-ups after ablation.Surprisingly,there was a trend toward gradual reduction and dimini-shment of DHH.CONCLUSION Thermal ablation treatment might be an effective and less invasive treatment for GCH coexistent with DHH around the hemangioma.
基金supported by the National Natural Science Foundation of China(Grant No.U20A20266)Scientific and technological research projects in Sichuan province(Grant No.2024NSFSC0973)Sichuan Science and Technology Program(2024YFHZ0286)。
文摘The rapid development of energy storage technology has provided tremendous support for the energy transition in countries worldwide.Salt cavern energy storage,as a form of energy storage technology,has gained widespread attention due to its large storage capacity and broad distribution.Therefore,this paper primarily discusses the current research status of salt cavern energy storage technology,with a focus on analyzing its classifications,advantages,disadvantages,and the challenges and countermeasures associated with its development.This study aims to promote further advancement in salt cavern energy storage technology.
基金supported by the Xuzhou City 2022 Special Program for Promoting Science and Technology Innovation(grant No.KC22096)Shandong Provincial Hospital Research Incubation Fund(No.2022FY063).
文摘Stem cell treatment may enhance erectile dysfunction(ED)in individuals with cavernous nerve injury(CNI).Nevertheless,no investigations have directly ascertained the implications of varying amounts of human umbilical cord-derived mesenchymal stem cells(HUC-MSCs)on ED.We compare the efficacy of three various doses of HUC-MSCs as a therapeutic strategy for ED.Sprague–Dawley rats(total=175)were randomly allocated into five groups.A total of 35 rats underwent sham surgery and 140 rats endured bilateral CNI and were treated with vehicles or doses of HUC-MSCs(1×106 cells,5×106 cells,and 1×107 cells in 0.1 ml,respectively).Penile tissues were harvested for histological analysis on 1 day,3 days,7 days,14 days,28 days,60 days,and 90 days postsurgery.It was found that varying dosages of HUC-MSCs enhanced the erectile function of rats with bilateral CNI and ED.Moreover,there was no significant disparity in the effectiveness of various dosages of HUC-MSCs.However,the expression of endothelial markers(rat endothelial cell antigen-1[RECA-1]and endothelial nitric oxide synthase[eNOS]),smooth muscle markers(alpha smooth muscle actin[α-SMA]and desmin),and neural markers(neurofilament[RECA-1]and neurogenic nitric oxide synthase[nNOS])increased significantly with prolonged treatment time.Masson’s staining demonstrated an increased in the smooth muscle cell(SMC)/collagen ratio.Significant changes were detected in the microstructures of various types of cells.In vivo imaging system(IVIS)analysis showed that at the 1st day,the HUC-MSCs implanted moved to the site of damage.Additionally,the oxidative stress levels were dramatically reduced in the penises of rats administered with HUC-MSCs.
基金supported by the State Key Laboratory of Disaster Reduction in Civil Engineering(Grant No.SLDRCE23-02)Ningbo PublicWelfare Fund Project(Grant No.2023S100)the National Key Research and Development Program of China(Grant No.2024YFE0105800).
文摘This study investigates the mechanical response of an underground cavern subjected to cyclic high gas pressure,aiming to establish a theoretical foundation for the design of lined rock caverns(LRCs)for energy storage with high internal pressure,e.g.compressed air energy storage(CAES)underground caverns or hydrogen storage caverns.Initially,the stress paths of the surrounding rock during the excavation,pressurization,and depressurization processes are delineated.Analytical expressions for the stress and deformation of the surrounding rock are derived based on the MohreCoulomb criterion.These expressions are then employed to evaluate the displacement of cavern walls under varying qualities of surrounding rock,the contact pressure between the steel lining and the surrounding rock subject to different gas storage pressures,the load-bearing ratio of the surrounding rock,and the impact of lining thickness on the critical gas pressure.Furthermore,the deformation paths of the surrounding rock are evaluated,along with the effects of tunnel depth and diameter on residual deformation of the surrounding rock,and the critical minimum gas pressure at which the surrounding rock and the lining do not detach.The results indicate that residual deformation of the surrounding rock occurs after depressurization under higher internal pressure for higher-quality rock masses,leading to detachment between the surrounding rock and the steel lining.The findings indicate that thicker linings correspond to higher critical minimum gas pressures.However,for lower-quality surrounding rock,thicker linings correspond to lower critical minimum gas pressures.These findings will provide invaluable insights for the design of LRCs for underground energy storage caverns.
基金supported by the National Natural Science Foundation of China (Grant No.52279116)the Key Projects of the Yalong River Joint Fund of the National Natural Science Foundation of China (Grant No.U1865203).
文摘Seismicity resulting from the near-or in-field fault activation significantly affects the stability of large-scale underground caverns that are operating under high-stress conditions.A comprehensive scientific assessment of the operational safety of such caverns requires an in-depth understanding of the response characteristics of the rock mass subjected to dynamic disturbances.To address this issue,we conducted true triaxial modeling tests and dynamic numerical simulations on large underground caverns to investigate the impact of static stress levels,dynamic load parameters,and input directions on the response characteristics of the surrounding rock mass.The findings reveal that:(1)When subjected to identical incident stress waves and static loads,the surrounding rock mass exhibits the greatest stress response during horizontal incidence.When the incident direction is fixed,the mechanical response is more pronounced at the cavern wall parallel to the direction of dynamic loading.(2)A high initial static stress level specifically enhances the impact of dynamic loading.(3)The response of the surrounding rock mass is directly linked to the amplitude of the incident stress wave.High amplitude results in tensile damage in regions experiencing tensile stress concentration under static loading and shear damage in regions experiencing compressive stress concentration.These results have significant implications for the evaluation and prevention of dynamic disasters in the surrounding rock of underground caverns experiencing dynamic disturbances.
基金funded by the National Natural Science Foundation of China(Grant Nos.42077251,41807269,and U1865203).
文摘Rock masses are often exposed to dynamic loads such as earthquakes and mechanical disturbances in practical engineering scenarios.The existence of underground caverns and weak geological structures like columnar jointed rock masses(CJRMs)and interlayer shear weakness zones(ISWZs)with inferior mechanical properties,significantly undermines the overall structural stability.To tackle the dynamic loading issues in the process of constructing subterranean caverns,a programmable modeling approach was utilized to reconstruct a large-scale underground cavern model incorporating ISWZs and columnar joints(CJs).By conducting dynamic simulations with varying load orientations,the analyses focused on the failure patterns,deformation characteristics,and acoustic emission activity within the caverns.Results revealed that the failure modes of the underground caverns under dynamic loading were predominantly tensile failures.Under X-direction loading,the failed elements were mainly distributed parallel to the CJs,while under Y-direction loading,they were distributed parallel to the transverse weak structural planes.Furthermore,the dynamic stability of the overall structure varied with the number of caverns.The dual-cavern model demonstrated the highest stability under X-direction loading,while the single-cavern model was the least stable.Under Y-direction loading,the cavern stability increased with the number of caverns.Importantly,different weak structures affected the dynamic response of caverns in different ways;the CJRMs were the primary contributors to structural failure,while ISWZs could mitigate the rock mass failure induced by CJs.The findings could offer valuable insights for the dynamic stability analysis of caverns containing CJRMs and ISWZs.
基金Project(2023YFC3805700) supported by the National Key Research and Development Program of ChinaProjects(42477166,42277174) supported by the National Natural Science Foundation of China+2 种基金Project(2024JCCXSB01) supported by the Fundamental Research Funds for the Central Universities,ChinaProject(KFJJ24-01M) supported by the State Key Laboratory of Explosion Science and Safety Protection,Beijing Institute of Technology,ChinaProject(HLCX-2024-04) supported by the Open Foundation of Collaborative Innovation Center of Green Development and Ecological Restoration of Mineral Resources,China。
文摘The surrounding rock is prone to large-scale loosening and failure after the excavation of shallow large-span caverns because of the thin overlying strata and large cross-section span.The rational design of bolt support is very important to the safety control of surrounding rock as a common support means.The control mechanism and design method of bolt support for shallow-buried large-span caverns is carried out.The calculation method of bolt prestress and length based on arched failure and collapsed failure mode is established.The influence mechanism of different influencing factors on the bolt prestress and length is clarified.At the same time,the constant resistance energy-absorbing bolt with high strength and high toughness is developed,and the comparative test of mechanical properties is carried out.On this basis,the design method of high prestressed bolt support for shallow-buried large-span caverns is put forward,and the field test is carried out in Qingdao metro station in China.The monitoring results show that the maximum roof settlement is 6.8 mm after the new design method is adopted,and the effective control of the shallow-buried large-span caverns is realized.The research results can provide theoretical and technical support for the safety control of shallow-buried large-span caverns.
文摘BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)is contraindicated for patients with cavernous transformation of the portal vein(CTPV)due to high surgery-related mortality risk.However,surgically assisted TIPS(SATIPS)can significantly reduce the risk.AIM To evaluate the clinical efficacy of SATIPS,this study was conducted.METHODS One hundred and seven patients with CTPV and esophagogastric variceal bleeding were recruited from January 2023 to December 2024.The patients were recruited from three different hospitals.Overall,54 patients received SATIPS treatment(SATIPS group),while 53 patients did not receive SATIPS and underwent prophylactic endoscopic sclerosing ligation(control group).Subsequently,survival rates,incidence rates of gastrointestinal bleeding,incidence of hepatic encephalopathy rate,and the incidence of liver failure after treatment in both groups at 3 and 6 months were observed.RESULTS The survival rates for the SATIPS and control groups were 94.4%and 92.5%at 3 months(P value=0.72)and 94.4%and 73.6%at 6 months(P value=0.0051)respectively.The incidence of liver failure was 3.7%and 9.4%at 3 months(P value=0.26)and 3.7%and18.9%at 6 months(P value=0.016);the incidence of gastrointestinal bleeding was 5.6%and 37.7%at 3 months(P value<0.001)and 9.3%and 47.2%(P value<0.001)at 6 months;and the incidence of hepatic encephalopathy was 3.7%and 17.0%at 3 months(P value=0.026)and 7.4%and 26.4%at 6 months(P value=0.026)respectively.CONCLUSION For patients with CTPV,there were no optimal treatment.Regarding long-term efficacy,SATIPS can significantly reduce the rate of rebleeding,hepatic encephalopathy and liver failure,and is associated with better survival.
文摘BACKGROUND Direct carotid cavernous fistulas(CCFs)are typically the result of a severe traumatic brain injury.High-flow arteriovenous shunts secondary to rupture of an intracavernous aneurysm,resulting in direct CCFs,are rare.The use of a pipeline embolization device in conjunction with coils and Onyx glue for treatment of direct high-flow CCF resulting from ruptured cavernous carotid artery aneurysm in a clinical setting is not well documented.CASE SUMMARY A 58-year-old woman presented to our department with symptoms of blepharoptosis and intracranial bruits for 1 wk.During physical examination,there was right eye exophthalmos and ocular motor palsy.The rest of the neurological examination was clear.Notably,the patient had no history of head injury.The patient was treated with a pipeline embolization device in the ipsilateral internal carotid artery across the fistula.Coils and Onyx were placed through the femoral venous route,followed by placement of the pipeline embolization device with assistance from a balloon-coiling technique.No intraoperative or perioperative complications occurred.Preoperative symptoms of bulbar hyperemia and bruits subsided immediately after the operation.CONCLUSION Pipeline embolization device in conjunction with coiling and Onyx may be a safe and effective approach for direct CCFs.
文摘Background: Cavernous transformation of the portal vein(CTPV) due to portal vein obstruction is a rare vascular anomaly defined as the formation of multiple collateral vessels in the hepatic hilum. This study aimed to investigate the imaging features of intrahepatic portal vein in adult patients with CTPV and establish the relationship between the manifestations of intrahepatic portal vein and the progression of CTPV. Methods: We retrospectively analyzed 14 CTPV patients in Beijing Tsinghua Changgung Hospital. All patients underwent both direct portal venography(DPV) and computed tomography angiography(CTA) to reveal the manifestations of the portal venous system. The vessels measured included the left portal vein(LPV), right portal vein(RPV), main portal vein(MPV) and the portal vein bifurcation(PVB). Results: Nine males and 5 females, with a median age of 40.5 years, were included in the study. No significant difference was found in the diameters of the LPV or RPV measured by DPV and CTA. The visualization in terms of LPV, RPV and PVB measured by DPV was higher than that by CTA. There was a significant association between LPV/RPV and PVB/MPV in term of visibility revealed with DPV( P = 0.01), while this association was not observed with CTA. According to the imaging features of the portal vein measured by DPV, CTPV was classified into three categories to facilitate the diagnosis and treatment. Conclusions: DPV was more accurate than CTA for revealing the course of the intrahepatic portal vein in patients with CTPV. The classification of CTPV, that originated from the imaging features of the portal vein revealed by DPV, may provide a new perspective for the diagnosis and treatment of CTPV.
基金the financial support from the Natural Science Foundation of China (Nos.52179118,52209151 and 42307238)the Science and Technology Project of Jiangsu Provincial Department of Science and Technology-Carbon Emissions Peak and Carbon Neutrality Science and Technology Innovation Specia Fund Project (No.BK20220025)+3 种基金the Excellent Postdoctoral Program of Jiangsu Province (No.2023ZB602)the China Postdoctora Science Foundation (Nos.2023M733773 and 2023M733772)Xuzhou City Science and Technology Innovation Special Basic Research Plan (KC23045)State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering,China University of Mining&Technology (No SKLGDUEK1916)。
文摘Underground hydrogen storage(UHS)and compressed air energy storage(CAES)are two viable largescale energy storage technologies for mitigating the intermittency of wind and solar power.Therefore,it is meaningful to compare the properties of hydrogen and air with typical thermodynamic storage processes.This study employs a multi-physical coupling model to compare the operations of CAES and UHS,integrating gas thermodynamics within caverns,thermal conduction,and mechanical deformation around rock caverns.Gas thermodynamic responses are validated using additional simulations and the field test data.Temperature and pressure variations of air and hydrogen within rock caverns exhibit similarities under both adiabatic and diabatic simulation modes.Hydrogen reaches higher temperature and pressure following gas charging stage compared to air,and the ideal gas assumption may lead to overestimation of gas temperature and pressure.Unlike steel lining of CAES,the sealing layer(fibre-reinforced plastic FRP)in UHS is prone to deformation but can effectively mitigates stress in the sealing layer.In CAES,the first principal stress on the surface of the sealing layer and concrete lining is tensile stress,whereas UHS exhibits compressive stress in the same areas.Our present research can provide references for the selection of energy storage methods.
基金supported by the National Natural Science Foundation of China(52074046,52122403,51834003,and 52274073)the Graduate Research and Innovation Foundation of Chongqing(CYB22023)+2 种基金the Chongqing Talents Plan for Young Talents(cstc2022ycjh-bgzxm0035)Hunan Institute of Engineering(21RC025 and XJ2005)Hunan Province Education Department(21B0664).
文摘Underground salt cavern CO_(2) storage(SCCS)offers the dual benefits of enabling extensive CO_(2) storage and facilitating the utilization of CO_(2) resources while contributing the regulation of the carbon market.Its economic and operational advantages over traditional carbon capture,utilization,and storage(CCUS)projects make SCCS a more cost-effective and flexible option.Despite the widespread use of salt caverns for storing various substances,differences exist between SCCS and traditional salt cavern energy storage in terms of gas-tightness,carbon injection,brine extraction control,long-term carbon storage stability,and site selection criteria.These distinctions stem from the unique phase change characteristics of CO_(2) and the application scenarios of SCCS.Therefore,targeted and forward-looking scientific research on SCCS is imperative.This paper introduces the implementation principles and application scenarios of SCCS,emphasizing its connections with carbon emissions,carbon utilization,and renewable energy peak shaving.It delves into the operational characteristics and economic advantages of SCCS compared with other CCUS methods,and addresses associated scientific challenges.In this paper,we establish a pressure equation for carbon injection and brine extraction,that considers the phase change characteristics of CO_(2),and we analyze the pressure during carbon injection.By comparing the viscosities of CO_(2) and other gases,SCCS’s excellent sealing performance is demonstrated.Building on this,we develop a long-term stability evaluation model and associated indices,which analyze the impact of the injection speed and minimum operating pressure on stability.Field countermeasures to ensure stability are proposed.Site selection criteria for SCCS are established,preliminary salt mine sites suitable for SCCS are identified in China,and an initial estimate of achievable carbon storage scale in China is made at over 51.8-77.7 million tons,utilizing only 20%-30%volume of abandoned salt caverns.This paper addresses key scientific and engineering challenges facing SCCS and determines crucial technical parameters,such as the operating pressure,burial depth,and storage scale,and it offers essential guidance for implementing SCCS projects in China.
基金supported by the Henan Institute for Chinese Development Strategy of Engineering&Technology(Grant No.2022HENZDA02)the Since&Technology Department of Sichuan Province Project(Grant No.2021YFH0010)the High‐End Foreign Experts Program of the Yunnan Revitalization Talents Support Plan of Yunnan Province.
文摘Large‐scale underground hydrogen storage(UHS)provides a promising method for increasing the role of hydrogen in the process of carbon neutrality and energy transition.Of all the existing storage deposits,salt caverns are recognized as ideal sites for pure hydrogen storage.Evaluation and optimization of site selection for hydrogen storage facilities in salt caverns have become significant issues.In this article,the software CiteSpace is used to analyze and filter hot topics in published research.Based on a detailed classification and analysis,a“four‐factor”model for the site selection of salt cavern hydrogen storage is proposed,encompassing the dynamic demands of hydrogen energy,geological,hydrological,and ground factors of salt mines.Subsequently,20 basic indicators for comprehensive suitability grading of the target site were screened using the analytic hierarchy process and expert survey methods were adopted,which provided a preliminary site selection system for salt cavern hydrogen storage.Ultimately,the developed system was applied for the evaluation of salt cavern hydrogen storage sites in the salt mines of Pingdingshan City,Henan Province,thereby confirming its rationality and effectiveness.This research provides a feasible method and theoretical basis for the site selection of UHS in salt caverns in China.
基金the financial support from the National Natural Science Foundation of China(No.52325905)Key Technology Research Projects of Power China(No.DJ-HXGG-2023-04 and No.DJ-HXGG-2023-16).
文摘The demand for underground space and sustainable energy has driven the need for underground structures.Large underground caverns,being an underground structure carrier,offers a feasible solution.However,the stability analysis and optimization design of large underground caverns is always a great challenge due to the high geostress,complicated rock condition,and high sidewalls and large spans in size.By collecting and reviewing a large amount of relevant research literature from 1970 to 2023,the efforts on the advances in stability analysis methods and optimization design of large underground caverns are described,then the research trends in this field through keywords were found and typical deformation and break modes of large underground caverns with high geostress are summarized.The review reveals that stability analysis and optimization are the recent active research topics.There are seven typical deformation and break modes of large underground caverns under high geostress,four stability analysis methods and four theories of optimization design of large under-ground caverns.With the progress of science and technology and society,intelligent design,mechanized con-struction and greening construction are the development trend in this field.The research results can provide a constructive reference for the stability analysis and optimization design of large underground caverns under high geostress.
基金financial support received from the Open Research Fund of the State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences (Grant No.Z019011)the Shandong Provincial Natural Science Foundation (Grant No.ZR2020QE112)+1 种基金the National Natural Science Foundation of China (No.51874273)the Excellent Young Scientists Fund Program of National Natural Science Foundation of China (No.52122403)。
文摘Salt caverns are extensively utilized for storing various substances such as fossil energy,hydrogen,compressed air,nuclear waste,and industrial solid waste.In China,when the salt cavern is leached through single-well water solution mining with oil as a cushion,engineering challenges arise with the leaching tubing,leading to issues like damage and instability.These problems significantly hinder the progress of cavern construction and the control of cavern shape.The primary cause of this is the flowinduced vibration instability of leaching tubing within a confined space,which results in severe bending or damage to the tubing.This study presents a model experimental investigation on the dynamic characteristics of leaching tubing using a self-developed liquid-solid coupling physical model experiment apparatus.The experiment utilizes a silicone-rubber pipe(SRP)and a polycarbonate pipe(PCP)to examine the effects of various factors on the dynamic stability of cantilevered pipes conveying fluid.These factors include external space constraint,flexural rigidity,medium outside the pipe,overhanging length,and end conditions.The experiments reveal four dynamic response phenomena:water hammer,static buckling,chaotic motion,and flutter instability.The study further demonstrates that the length of the external space constraint has a direct impact on the flutter critical flow velocity of the cantilevered pipe conveying fluid.Additionally,the flutter critical flow velocity is influenced by the end conditions and different external media.
基金Project(2023YFC2907204)supported by the National Key Research and Development Program of ChinaProject(52325905)supported by the National Natural Science Foundation of ChinaProject(DJ-HXGG-2023-16)supported by the Key Technology Research Projects of Power China。
文摘Underground energy and resource development,deep underground energy storage and other projects involve the global stability of multiple interconnected cavern groups under internal and external dynamic disturbances.An evaluation method of the global stability coefficient of underground caverns based on static overload and dynamic overload was proposed.Firstly,the global failure criterion for caverns was defined based on its band connection of plastic-strain between multi-caverns.Then,overloading calculation of the boundary geostress and seismic intensity on the caverns model was carried out,and the critical unstable state of multi-caverns can be identified,if the plastic-strain band appeared between caverns during these overloading processes.Thus,the global stability coefficient for the multi-caverns under static loading and earthquake was obtained based on the corresponding overloading coefficient.Practical analysis for the Yingliangbao(YLB)hydraulic caverns indicated that this method can not only effectively obtain the global stability coefficient of caverns under static and dynamic earthquake conditions,but also identify the caverns’high-risk zone of local instability through localized plastic strain of surrounding rock.This study can provide some reference for the layout design and seismic optimization of underground cavern group.
基金Supported by Natural Science Foundation of Zhejiang Province,No.LY20H030010Medical Health Science and Technology Project of Zhejiang Provincial Health Commission,No.2019-KY1-001-181.
文摘BACKGROUND Colorectal cavernous hemangioma is a rare vascular malformation resulting in recurrent lower gastrointestinal hemorrhage,and can be misinterpreted as colitis.Surgical resection is currently the mainstay of treatment,with an emphasis on sphincter preservation.CASE SUMMARY We present details of two young patients with a history of persistent hematochezia diagnosed with colorectal cavernous hemangioma by endoscopic ultrasound(EUS).Cavernous hemangioma was relieved by several EUS-guided lauromacrogol injections and the patients achieved favorable clinical prognosis.CONCLUSION Multiple sequential EUS-guided injections of lauromacrogol is a safe,effective,cost-efficient,and minimally invasive alternative for colorectal cavernous hemangioma.
