Correction to:Nuclear Science and Techniques(2024)35:145 https://doi.org/10.1007/s41365-024-01517-y In this article the author’s name Wan-Bing He was incorrectly written as Wan-Bin He.The original article has been co...Correction to:Nuclear Science and Techniques(2024)35:145 https://doi.org/10.1007/s41365-024-01517-y In this article the author’s name Wan-Bing He was incorrectly written as Wan-Bin He.The original article has been corrected.展开更多
BACKGROUND Anterior cutaneous nerve entrapment syndrome(ACNES)is a condition mani-festing with pain caused by strangulation of the anterior cutaneous branch of the lower intercostal nerves.This case report aims to pro...BACKGROUND Anterior cutaneous nerve entrapment syndrome(ACNES)is a condition mani-festing with pain caused by strangulation of the anterior cutaneous branch of the lower intercostal nerves.This case report aims to provide new insight into the selection of peripheral nerve blocks for the ACNES treatment.CASE SUMMARY A 66-year-old woman manifested ACNES after a robot-assisted distal gastrec-tomy.An ultrasound-guided rectal sheath block was effective for pain triggered by the port scar.However,the sudden severe pain,which radiated laterally from the previous site,remained.A transversus abdominis plane block was performed for the remaining pain and effectively relieved it.CONCLUSION In this case,the trocar port was inserted between the rectus and transverse abdominis muscles.The intercostal nerves might have been entrapped on both sides of the rectus and transversus abdominis muscles.Hence,rectus sheath and transverse abdominis plane blocks were required to achieve complete pain relief.To the best of our knowledge,this is the first report on use of a combination of rectus sheath and transverse abdominis plane blocks for pain relief in ACNES.展开更多
In blockchain-based unmanned aerial vehicle(UAV)communication systems,the length of a block affects the performance of the blockchain.The transmission performance of blocks in the form of finite character segments is ...In blockchain-based unmanned aerial vehicle(UAV)communication systems,the length of a block affects the performance of the blockchain.The transmission performance of blocks in the form of finite character segments is also affected by the block length.Therefore,it is crucial to balance the transmission performance and blockchain performance of blockchain communication systems,especially in wireless environments involving UAVs.This paper investigates a secure transmission scheme for blocks in blockchain-based UAV communication systems to prevent the information contained in blocks from being completely eavesdropped during transmission.In our scheme,using a friendly jamming UAV to emit jamming signals diminishes the quality of the eavesdropping channel,thus enhancing the communication security performance of the source UAV.Under the constraints of maneuverability and transmission power of the UAV,the joint design of UAV trajectories,transmission power,and block length are proposed to maximize the average minimum secrecy rate(AMSR).Since the optimization problem is non-convex and difficult to solve directly,we first decompose the optimization problem into subproblems of trajectory optimization,transmission power optimization,and block length optimization.Then,based on firstorder approximation techniques,these subproblems are reformulated as convex optimization problems.Finally,we utilize an alternating iteration algorithm based on the successive convex approximation(SCA)technique to solve these subproblems iteratively.The simulation results demonstrate that our proposed scheme can achieve secure transmission for blocks while maintaining the performance of the blockchain.展开更多
Discovery of materials using“bottom-up”or“top-down”approach is of great interest in materials science.Layered materials consisting of two-dimensional(2D)building blocks provide a good platform to explore new mater...Discovery of materials using“bottom-up”or“top-down”approach is of great interest in materials science.Layered materials consisting of two-dimensional(2D)building blocks provide a good platform to explore new materials in this respect.In van der Waals(vdW)layered materials,these building blocks are charge neutral and can be isolated from their bulk phase(top-down),but usually grow on substrate.In ionic layered materials,they are charged and usually cannot exist independently but can serve as motifs to construct new materials(bottom-up).In this paper,we introduce our recently constructed databases for 2D material-substrate interface(2DMSI),and 2D charged building blocks.For 2DMSI database,we systematically build a workflow to predict appropriate substrates and their geometries at substrates,and construct the 2DMSI database.For the 2D charged building block database,1208 entries from bulk material database are identified.Information of crystal structure,valence state,source,dimension and so on is provided for each entry with a json format.We also show its application in designing and searching for new functional layered materials.The 2DMSI database,building block database,and designed layered materials are available in Science Data Bank at https://doi.org/10.57760/sciencedb.j00113.00188.展开更多
BACKGROUND Osteonecrosis or avascular necrosis(AVN)of the hip was one of the dreaded complications of coronavirus disease 2019(COVID-19),which emerged in patients who received steroid therapy.Corticosteroids have been...BACKGROUND Osteonecrosis or avascular necrosis(AVN)of the hip was one of the dreaded complications of coronavirus disease 2019(COVID-19),which emerged in patients who received steroid therapy.Corticosteroids have been a mainstay in the treatment protocol of COVID-19 patients.Popular corticosteroid drugs used in patients suffering from COVID-19 were intravenous(IV)or oral dexamethasone,methylprednisolone or hydrocortisone.The use of such high doses of corticost-eroids has shown very positive results and has been lifesaving in many cases.Still,long-term consequences were drug-induced diabetes,osteoporosis,Cushing syndrome,muscle wasting,peripheral fat mobilization,AVN,hirsutism,sleep disturbances and poor wound healing.A significant number of young patients were admitted for bilateral total hip replacements(THR)secondary to AVN following steroid use for COVID-19 treatment.AIM To assess the efficacy of bilateral pericapsular end nerve group(PENG)blocks in patients posted for bilateral THR post-steroid therapy after COVID-19 infection and assess the time taken to first ambulate after surgery.METHODS This prospective observational study was conducted between January 2023 and August 2023 at Care Hospitals,Hyderabad,India.Twenty young patients 30-35 years of age who underwent bilateral THR were studied after due consent over 8 months.All the patients received spinal anaesthesia for surgery and bilateral PENG blocks for postoperative analgesia.RESULTS The duration of surgery was 2.5 h on average.Seventeen out of twenty patients(85%)had a Visual Analog Score(VAS)of less than 2 and did not require any supplementation.One patient was removed from the study,as he required re-exploration.The remaining two patients had a VAS of more than 8 and received IV morphine post-operatively as a rescue analgesic drug.Fifteen out of seventeen patients(88.2%)could be mobilized 12 h after the procedure.CONCLUSION Osteonecrosis or AVN of the hip was one of the dreaded complications of COVID-19,which surfaced in patients who received steroid therapy requiring surgical intervention.Bilateral PENG block is an effective technique to provide post-operative analgesia resulting in early mobilization and enhanced recovery after surgery.展开更多
Local geometric information and discontinuity features are key aspects of the analysis of the evolution and failure mechanisms of unstable rock blocks in rock tunnels.This study demonstrates the integration of terrest...Local geometric information and discontinuity features are key aspects of the analysis of the evolution and failure mechanisms of unstable rock blocks in rock tunnels.This study demonstrates the integration of terrestrial laser scanning(TLS)with distinct element method for rock mass characterization and stability analysis in tunnels.TLS records detailed geometric information of the surrounding rock mass by scanning and collecting the positions of millions of rock surface points without contact.By conducting a fuzzy K-means method,a discontinuity automatic identification algorithm was developed,and a method for obtaining the geometric parameters of discontinuities was proposed.This method permits the user to visually identify each discontinuity and acquire its spatial distribution features(e.g.occurrences,spac-ings,trace lengths)in great detail.Compared with hand mapping in conventional geotechnical surveys,the geometric information of discontinuities obtained by this approach is more accurate and the iden-tification is more efficient.Then,a discrete fracture network with the same statistical characteristics as the actual discontinuities was generated with the distinct element method,and a representative nu-merical model of the jointed surrounding rock mass was established.By means of numerical simulation,potential unstable rock blocks were assessed,and failure mechanisms were analyzed.This method was applied to detection and assessment of unstable rock blocks in the spillway and sand flushing tunnel of the Hongshiyan hydropower project after a collapse.The results show that the noncontact detection of blocks was more labor-saving with lower safety risks compared with manual surveys,and the stability assessment was more reliable since the numerical model built by this method was more consistent with the distribution characteristics of actual joints.This study can provide a reference for geological survey and unstable rock block hazard mitigation in tunnels subjected to complex geology and active rockfalls.展开更多
BACKGROUND The background of this study was analgesia in natural delivery.The combined spinal-epidural anesthesia has obvious analgesic effect on the parturients in natural labor,and combined spinal-epidural anesthesi...BACKGROUND The background of this study was analgesia in natural delivery.The combined spinal-epidural anesthesia has obvious analgesic effect on the parturients in natural labor,and combined spinal-epidural anesthesia has been widely used in anesthesia for various diseases.AIM To study the effects of combined spinal-epidural anesthesia on anxiety,labor analgesia,and motor blocks in parturients during natural delivery.METHODS A total of 120 women who gave birth at Changning District Maternal and Child Health Hospital between December 2021 to December 2022 were included;a random number table approach was employed to divide the women into a control group and a joint group,with each group consisting of 60 women.The control group was given epidural anesthesia,while the joint group was given combined spinal-epidural anesthesia.The visual analog scale(VAS)was used to evaluate the degree of maternal pain.Comparisons were made between the two groups’conditions of childbirth and the duration of labor.Apgar scores were used to evaluate the status of the newborns at birth;Self-rating Anxiety Scale(SAS)and General Self-Efficacy Scale(GSES)scores,umbilical artery blood gas analysis indices and stress indices were compared between the two groups;and the frequencies of motor block and postpartum complications were analyzed.RESULTS In comparison to the control group,in the joint group,the VAS scores for the first,second,and third stages of labor were lower(P<0.05).The rates of conversion to cesarean section and postpartum blood loss in the joint group were lower than those in the control group(P<0.05).No significant differences were observed in the Apgar score,the duration of the first stage of labor,or the total duration of labor between the two groups(P>0.05).The second and third stages of labor in the joint group were shorter than those in the control group(P<0.05).When compared to the control group,the postpartum SAS score of the joint group was lower,while the GSES score was greater(P<0.05).Between the control group and the joint group,the differences observed in pH,arterial carbon dioxide partial pressure,arterial oxygen partial pressure,or arterial hydrogen ion concentration were not significant(P>0.05).Nitric oxide,cortisol,and adrenaline levels were lower in the joint group than in the control group(P<0.05).There were no substantial differences in Bromage grade or rate of complications between the two groups(P>0.05).CONCLUSION For parturients during natural delivery,combined spinal-epidural anesthesia can reduce anxiety,provide labor analgesia,shorten labor time,and reduce postoperative stress levels but did not result in a motor block.展开更多
Historical and cultural blocks are witnesses of history and inheritors of culture. As one of the main spaces for outdoor interaction in historical and cultural blocks, the improvement of its vitality is of great signi...Historical and cultural blocks are witnesses of history and inheritors of culture. As one of the main spaces for outdoor interaction in historical and cultural blocks, the improvement of its vitality is of great significance for the improvement of residential environment and the better inheritance of history and culture. Taking Daopashi Street in Anqing City as an example, an evaluation model of landscape spatial vitality of historical and cultural blocks was constructed from three aspects of viewing function, store status and service facilities, and analytic hierarchy process was used to determine the index weight and vaguely evaluate the landscape spatial vitality of historical and cultural blocks. The results show that through the comparison of weight, architectural style(0.317), the practicability of service facilities(0.168) and plant landscape(0.165) had a significant impact on the landscape spatial vitality of historical and cultural blocks,and the landscape spatial vitality of historical and cultural blocks in Daopashi Street in Anqing City was at a good level.展开更多
Primary toppling usually occurs in layered rock slopes with large anti-dip angles.In this paper,the block toppling evolution was explored using a large-scale centrifuge system.Each block column in the layered model sl...Primary toppling usually occurs in layered rock slopes with large anti-dip angles.In this paper,the block toppling evolution was explored using a large-scale centrifuge system.Each block column in the layered model slope was made of cement mortar.Some artificial cracks perpendicular to the block column were prefabricated.Strain gages,displacement gages,and high-speed camera measurements were employed to monitor the deformation and failure processes of the model slope.The centrifuge test results show that the block toppling evolution can be divided into seven stages,i.e.layer compression,formation of major tensile crack,reverse bending of the block column,closure of major tensile crack,strong bending of the block column,formation of failure zone,and complete failure.Block toppling is characterized by sudden large deformation and occurs in stages.The wedge-shaped cracks in the model incline towards the slope.Experimental observations show that block toppling is mainly caused by bending failure rather than by shear failure.The tensile strength also plays a key factor in the evolution of block toppling.The simulation results from discrete element method(DEM)is in line with the testing results.Tensile stress exists at the backside of rock column during toppling deformation.Stress concentration results in the fragmented rock column and its degree is the most significant at the slope toe.展开更多
The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification proc...The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient protection.In the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly technique.The outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)film.The FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier capability.The Ce film connects the outer layer with the substrate,showing the transition effect.The corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling behavior.The synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.展开更多
Gentle slopes with large amounts of granite blocks are widespread in granitic areas with warm and humid climate.These blocks pose a potential risk to the existing and planned infrastructure.The instability type and ge...Gentle slopes with large amounts of granite blocks are widespread in granitic areas with warm and humid climate.These blocks pose a potential risk to the existing and planned infrastructure.The instability type and geometry of these blocks will influence their motility and destructive power to some extent.This study aims at creating a classification system that can indicate both the shape and the instability type of these blocks and then developing a block removal scheme.The classification system was constructed based on the mechanical stability analysis of blocks on an inclined surface.This analysis identified key factors affecting stability,including block shape,block weathering roundness,the existing state of a block on a slope,and the friction between the block and the slope.The achieved work allowed the establishment of a direct correlation between block geometry and their instability types.The availability of this classification system was validated by field data and experimental data in the literature.The proposal to remove blocks identified as the toppling types,such as cylindrical-toppling types,cuboid-toppling types,cube-toppling types,was put forward to avoid the uneconomical problem of a complete clearance.Meanwhile,this classification provides a foundation for further research on the instability probability of each type of block and the development of a more refined blocks’removal scheme.The classification approach adopted in this paper can provide a reference for the classification of other lithological blocks under similar engineering geological conditions.展开更多
BACKGROUND Regional anesthesia is a promising method in patients with post coronavirus disease 2019(COVID-19)pulmonary sequelae for preserving pulmonary function and preventing postoperative pulmonary complications,co...BACKGROUND Regional anesthesia is a promising method in patients with post coronavirus disease 2019(COVID-19)pulmonary sequelae for preserving pulmonary function and preventing postoperative pulmonary complications,compared with general anesthesia.CASE SUMMARY We provided surgical anesthesia and analgesia suitable for breast surgery by performing pectoral nerve block type II(PECS-II),parasternal,and intercostobrachial nerve blocks with intravenous dexmedetomidine administration in a 61-year-old female patient with severe pulmonary sequelae after COVID-19infection.CONCLUSION Sufficient analgesia for 7 h was provided via PECS-II,parasternal,and intercostobrachial blocks perioperatively.展开更多
BACKGROUND Coronavirus disease 2019(COVID-19)caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has resulted in a worldwide health crisis since it first appeared.Numerous studies demonstrated the...BACKGROUND Coronavirus disease 2019(COVID-19)caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has resulted in a worldwide health crisis since it first appeared.Numerous studies demonstrated the virus’s predilection to cardiomyocytes;however,the effects that COVID-19 has on the cardiac conduc-tion system still need to be fully understood.AIM To analyze the impact that COVID-19 has on the odds of major cardiovascular complications in patients with new onset heart blocks or bundle branch blocks(BBB).METHODS The 2020 National Inpatient Sample(NIS)database was used to identify patients admitted for COVID-19 pneumonia with and without high-degree atrioven-tricular blocks(HDAVB)and right or left BBB utilizing ICD-10 codes.The patients with pre-existing pacemakers,suggestive of a prior diagnosis of HDAVB or BBB,were excluded from the study.The primary outcome was inpatient mortality.Secondary outcomes included total hospital charges(THC),the length of hospital stay(LOS),and other major cardiac outcomes detailed in the Results section.Univariate and multivariate regression analyses were used to adjust for confounders with Stata version 17.RESULTS A total of 1058815 COVID-19 hospitalizations were identified within the 2020 NIS database,of which 3210(0.4%)and 17365(1.6%)patients were newly diagnosed with HDAVB and BBB,respectively.We observed a significantly higher odds of in-hospital mortality,cardiac arrest,cardiogenic shock,sepsis,arrythmias,and acute kidney injury in the COVID-19 and HDAVB group.There was no statistically significant difference in the odds of cerebral infarction or pulmonary embolism.Encounters with COVID-19 pneumonia and newly diagnosed BBB had a higher odds of arrythmias,acute kidney injury,sepsis,need for mechanical ventilation,and cardiogenic shock than those without BBB.However,unlike HDAVB,COVID-19 pneumonia and BBB had no significant impact on mortality compared to patients without BBB.CONCLUSION In conclusion,there is a significantly higher odds of inpatient mortality,cardiac arrest,cardiogenic shock,sepsis,acute kidney injury,supraventricular tachycardia,ventricular tachycardia,THC,and LOS in patients with COVID-19 pneumonia and HDAVB as compared to patients without HDAVB.Likewise,patients with COVID-19 pneumonia in the BBB group similarly have a higher odds of supraventricular tachycardia,atrial fibrillation,atrial flutter,ventricular tachycardia,acute kidney injury,sepsis,need for mechanical ventilation,and cardiogenic shock as compared to those without BBB.Therefore,it is essential for healthcare providers to be aware of the possible worse predicted outcomes that patients with new-onset HDAVB or BBB may experience following SARS-CoV-2 infection.展开更多
The purpose of this paper is to investigate the simulation of mixed convection in a lid-driven wavy enclosure with blocks positioned at various positions. This study also examined the impact of the longitudinal positi...The purpose of this paper is to investigate the simulation of mixed convection in a lid-driven wavy enclosure with blocks positioned at various positions. This study also examined the impact of the longitudinal position of the heated block on heat transfer enhancement. The Galerkin weighted residual finite element method is employed to computationally solve the governing equations of Navier-Stokes, thermal energy, and mass conservation. The enclosure consists of two square heated blocks strategically placed at different heights—firstly, one set is closer to the bottom surface;secondly, one set is nearer to the middle area and finally, one set is closer to the upper undulating surface of the enclosure. The wavy top wall’s thermal insulation, along with active heating of the bottom wall and blocks, generates a dynamic convective atmosphere. In addition, the left wall ascends as the right wall falls, causing the flow formed by the lid. The study investigates the impact of the Richardson number on many factors, such as streamlines, isotherms, dimensionless temperature, velocity profiles, and average Nusselt numbers. These impacts are depicted through graphical illustrations. In all instances, two counter-rotating eddies were generated within the cage. Higher rotating speed consistently leads to improved performance, irrespective of other characteristics. Furthermore, an ideal amalgamation of the regulating factors would lead to increased heat transmission.展开更多
BACKGROUND Ultrasound guide technology,which can provide real-time visualization of the needle tip and tissues and avoid many adverse events,is widely used in mini-mally invasive therapy.However,the studies on ultraso...BACKGROUND Ultrasound guide technology,which can provide real-time visualization of the needle tip and tissues and avoid many adverse events,is widely used in mini-mally invasive therapy.However,the studies on ultrasound-guided Lateral recess block(LRB)are limited,this is probably because there is no recognized standard method for ultrasound scanning.This study aimed to evaluate the effect of ultrasound-guided LRB in patients with lateral recess stenosis(LRS).CASE SUMMARY A 65-year-old patient complained of low back pain accompanied occasionally by pain and numbness in the left lower limb.Physical examination showed ten-derness on the spinous process and paraspinal muscles from L1 to S1,extensor hallucis longus and tibialis anterior weakness(muscle strength:4-),and a positive straight leg raising test in the left lower limb(60°).Magnetic resonance imaging showed L4–L5 disc degeneration with left LRS and nerve root entrapment.Subsequently,the patient was diagnosed with LRS.This patient was treated with a novel ultrasound-guided LRB approach.The patient’s symptoms significantly improved without any complications at 1 wk postoperatively and at the 3-month follow-up.CONCLUSION This is the first report on the LRS treatment with ultrasound-guided LRB from the contralateral spinous process along the inner side of the articular process by out-plane technique.Further studies are expected to investigate the efficacy and safety of ultrasound-guided LRB for patients with LRS.展开更多
文摘Correction to:Nuclear Science and Techniques(2024)35:145 https://doi.org/10.1007/s41365-024-01517-y In this article the author’s name Wan-Bing He was incorrectly written as Wan-Bin He.The original article has been corrected.
文摘BACKGROUND Anterior cutaneous nerve entrapment syndrome(ACNES)is a condition mani-festing with pain caused by strangulation of the anterior cutaneous branch of the lower intercostal nerves.This case report aims to provide new insight into the selection of peripheral nerve blocks for the ACNES treatment.CASE SUMMARY A 66-year-old woman manifested ACNES after a robot-assisted distal gastrec-tomy.An ultrasound-guided rectal sheath block was effective for pain triggered by the port scar.However,the sudden severe pain,which radiated laterally from the previous site,remained.A transversus abdominis plane block was performed for the remaining pain and effectively relieved it.CONCLUSION In this case,the trocar port was inserted between the rectus and transverse abdominis muscles.The intercostal nerves might have been entrapped on both sides of the rectus and transversus abdominis muscles.Hence,rectus sheath and transverse abdominis plane blocks were required to achieve complete pain relief.To the best of our knowledge,this is the first report on use of a combination of rectus sheath and transverse abdominis plane blocks for pain relief in ACNES.
基金supported in part by the National Key R&D Program of China under Grant 2022YFB3104503in part by the China Postdoctoral Science Foundation under Grant 2024M750199+1 种基金in part by the National Natural Science Foundation of China under Grants 62202054,62002022 and 62472251in part by the Fundamental Research Funds for the Central Universities under Grant BLX202360.
文摘In blockchain-based unmanned aerial vehicle(UAV)communication systems,the length of a block affects the performance of the blockchain.The transmission performance of blocks in the form of finite character segments is also affected by the block length.Therefore,it is crucial to balance the transmission performance and blockchain performance of blockchain communication systems,especially in wireless environments involving UAVs.This paper investigates a secure transmission scheme for blocks in blockchain-based UAV communication systems to prevent the information contained in blocks from being completely eavesdropped during transmission.In our scheme,using a friendly jamming UAV to emit jamming signals diminishes the quality of the eavesdropping channel,thus enhancing the communication security performance of the source UAV.Under the constraints of maneuverability and transmission power of the UAV,the joint design of UAV trajectories,transmission power,and block length are proposed to maximize the average minimum secrecy rate(AMSR).Since the optimization problem is non-convex and difficult to solve directly,we first decompose the optimization problem into subproblems of trajectory optimization,transmission power optimization,and block length optimization.Then,based on firstorder approximation techniques,these subproblems are reformulated as convex optimization problems.Finally,we utilize an alternating iteration algorithm based on the successive convex approximation(SCA)technique to solve these subproblems iteratively.The simulation results demonstrate that our proposed scheme can achieve secure transmission for blocks while maintaining the performance of the blockchain.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61888102,52272172,and 52102193)the Major Program of the National Natural Science Foundation of China(Grant No.92163206)+2 种基金the National Key Research and Development Program of China(Grant Nos.2021YFA1201501 and 2022YFA1204100)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB30000000)the Fundamental Research Funds for the Central Universities.
文摘Discovery of materials using“bottom-up”or“top-down”approach is of great interest in materials science.Layered materials consisting of two-dimensional(2D)building blocks provide a good platform to explore new materials in this respect.In van der Waals(vdW)layered materials,these building blocks are charge neutral and can be isolated from their bulk phase(top-down),but usually grow on substrate.In ionic layered materials,they are charged and usually cannot exist independently but can serve as motifs to construct new materials(bottom-up).In this paper,we introduce our recently constructed databases for 2D material-substrate interface(2DMSI),and 2D charged building blocks.For 2DMSI database,we systematically build a workflow to predict appropriate substrates and their geometries at substrates,and construct the 2DMSI database.For the 2D charged building block database,1208 entries from bulk material database are identified.Information of crystal structure,valence state,source,dimension and so on is provided for each entry with a json format.We also show its application in designing and searching for new functional layered materials.The 2DMSI database,building block database,and designed layered materials are available in Science Data Bank at https://doi.org/10.57760/sciencedb.j00113.00188.
文摘BACKGROUND Osteonecrosis or avascular necrosis(AVN)of the hip was one of the dreaded complications of coronavirus disease 2019(COVID-19),which emerged in patients who received steroid therapy.Corticosteroids have been a mainstay in the treatment protocol of COVID-19 patients.Popular corticosteroid drugs used in patients suffering from COVID-19 were intravenous(IV)or oral dexamethasone,methylprednisolone or hydrocortisone.The use of such high doses of corticost-eroids has shown very positive results and has been lifesaving in many cases.Still,long-term consequences were drug-induced diabetes,osteoporosis,Cushing syndrome,muscle wasting,peripheral fat mobilization,AVN,hirsutism,sleep disturbances and poor wound healing.A significant number of young patients were admitted for bilateral total hip replacements(THR)secondary to AVN following steroid use for COVID-19 treatment.AIM To assess the efficacy of bilateral pericapsular end nerve group(PENG)blocks in patients posted for bilateral THR post-steroid therapy after COVID-19 infection and assess the time taken to first ambulate after surgery.METHODS This prospective observational study was conducted between January 2023 and August 2023 at Care Hospitals,Hyderabad,India.Twenty young patients 30-35 years of age who underwent bilateral THR were studied after due consent over 8 months.All the patients received spinal anaesthesia for surgery and bilateral PENG blocks for postoperative analgesia.RESULTS The duration of surgery was 2.5 h on average.Seventeen out of twenty patients(85%)had a Visual Analog Score(VAS)of less than 2 and did not require any supplementation.One patient was removed from the study,as he required re-exploration.The remaining two patients had a VAS of more than 8 and received IV morphine post-operatively as a rescue analgesic drug.Fifteen out of seventeen patients(88.2%)could be mobilized 12 h after the procedure.CONCLUSION Osteonecrosis or AVN of the hip was one of the dreaded complications of COVID-19,which surfaced in patients who received steroid therapy requiring surgical intervention.Bilateral PENG block is an effective technique to provide post-operative analgesia resulting in early mobilization and enhanced recovery after surgery.
基金support of the National Natural Science Foundation of China(Grant No.42102316)the Open Project of the Technology Innovation Center for Geological Environment Monitoring of Ministry of Natural Resources of China(Grant No.2022KFK1212005).
文摘Local geometric information and discontinuity features are key aspects of the analysis of the evolution and failure mechanisms of unstable rock blocks in rock tunnels.This study demonstrates the integration of terrestrial laser scanning(TLS)with distinct element method for rock mass characterization and stability analysis in tunnels.TLS records detailed geometric information of the surrounding rock mass by scanning and collecting the positions of millions of rock surface points without contact.By conducting a fuzzy K-means method,a discontinuity automatic identification algorithm was developed,and a method for obtaining the geometric parameters of discontinuities was proposed.This method permits the user to visually identify each discontinuity and acquire its spatial distribution features(e.g.occurrences,spac-ings,trace lengths)in great detail.Compared with hand mapping in conventional geotechnical surveys,the geometric information of discontinuities obtained by this approach is more accurate and the iden-tification is more efficient.Then,a discrete fracture network with the same statistical characteristics as the actual discontinuities was generated with the distinct element method,and a representative nu-merical model of the jointed surrounding rock mass was established.By means of numerical simulation,potential unstable rock blocks were assessed,and failure mechanisms were analyzed.This method was applied to detection and assessment of unstable rock blocks in the spillway and sand flushing tunnel of the Hongshiyan hydropower project after a collapse.The results show that the noncontact detection of blocks was more labor-saving with lower safety risks compared with manual surveys,and the stability assessment was more reliable since the numerical model built by this method was more consistent with the distribution characteristics of actual joints.This study can provide a reference for geological survey and unstable rock block hazard mitigation in tunnels subjected to complex geology and active rockfalls.
基金Changning District Health Commission Medical Key(Characteristic)Specialized Program,No.20192003.
文摘BACKGROUND The background of this study was analgesia in natural delivery.The combined spinal-epidural anesthesia has obvious analgesic effect on the parturients in natural labor,and combined spinal-epidural anesthesia has been widely used in anesthesia for various diseases.AIM To study the effects of combined spinal-epidural anesthesia on anxiety,labor analgesia,and motor blocks in parturients during natural delivery.METHODS A total of 120 women who gave birth at Changning District Maternal and Child Health Hospital between December 2021 to December 2022 were included;a random number table approach was employed to divide the women into a control group and a joint group,with each group consisting of 60 women.The control group was given epidural anesthesia,while the joint group was given combined spinal-epidural anesthesia.The visual analog scale(VAS)was used to evaluate the degree of maternal pain.Comparisons were made between the two groups’conditions of childbirth and the duration of labor.Apgar scores were used to evaluate the status of the newborns at birth;Self-rating Anxiety Scale(SAS)and General Self-Efficacy Scale(GSES)scores,umbilical artery blood gas analysis indices and stress indices were compared between the two groups;and the frequencies of motor block and postpartum complications were analyzed.RESULTS In comparison to the control group,in the joint group,the VAS scores for the first,second,and third stages of labor were lower(P<0.05).The rates of conversion to cesarean section and postpartum blood loss in the joint group were lower than those in the control group(P<0.05).No significant differences were observed in the Apgar score,the duration of the first stage of labor,or the total duration of labor between the two groups(P>0.05).The second and third stages of labor in the joint group were shorter than those in the control group(P<0.05).When compared to the control group,the postpartum SAS score of the joint group was lower,while the GSES score was greater(P<0.05).Between the control group and the joint group,the differences observed in pH,arterial carbon dioxide partial pressure,arterial oxygen partial pressure,or arterial hydrogen ion concentration were not significant(P>0.05).Nitric oxide,cortisol,and adrenaline levels were lower in the joint group than in the control group(P<0.05).There were no substantial differences in Bromage grade or rate of complications between the two groups(P>0.05).CONCLUSION For parturients during natural delivery,combined spinal-epidural anesthesia can reduce anxiety,provide labor analgesia,shorten labor time,and reduce postoperative stress levels but did not result in a motor block.
基金the Research on the Application of the Perception Teaching of“Graphics”in Architectural Design Course(JZ213702)Landscape Architecture Stracture(JZ213704)+1 种基金Research on the Teaching of Architectural Design Course for Urban and Rural Planning Major with the concept of“Local Design”(JZ223706)Anhui Provincial Key Laboratory of Huizhou Architecture Open Subjects Funding Project(HPJZ-2020-03).
文摘Historical and cultural blocks are witnesses of history and inheritors of culture. As one of the main spaces for outdoor interaction in historical and cultural blocks, the improvement of its vitality is of great significance for the improvement of residential environment and the better inheritance of history and culture. Taking Daopashi Street in Anqing City as an example, an evaluation model of landscape spatial vitality of historical and cultural blocks was constructed from three aspects of viewing function, store status and service facilities, and analytic hierarchy process was used to determine the index weight and vaguely evaluate the landscape spatial vitality of historical and cultural blocks. The results show that through the comparison of weight, architectural style(0.317), the practicability of service facilities(0.168) and plant landscape(0.165) had a significant impact on the landscape spatial vitality of historical and cultural blocks,and the landscape spatial vitality of historical and cultural blocks in Daopashi Street in Anqing City was at a good level.
基金The authors wish to thank National Key R&D Program of China(Grant No.2022YFC308100)the National Nature Science Foundation of China(Grant Nos.42107172 and 42072303)for financial support.
文摘Primary toppling usually occurs in layered rock slopes with large anti-dip angles.In this paper,the block toppling evolution was explored using a large-scale centrifuge system.Each block column in the layered model slope was made of cement mortar.Some artificial cracks perpendicular to the block column were prefabricated.Strain gages,displacement gages,and high-speed camera measurements were employed to monitor the deformation and failure processes of the model slope.The centrifuge test results show that the block toppling evolution can be divided into seven stages,i.e.layer compression,formation of major tensile crack,reverse bending of the block column,closure of major tensile crack,strong bending of the block column,formation of failure zone,and complete failure.Block toppling is characterized by sudden large deformation and occurs in stages.The wedge-shaped cracks in the model incline towards the slope.Experimental observations show that block toppling is mainly caused by bending failure rather than by shear failure.The tensile strength also plays a key factor in the evolution of block toppling.The simulation results from discrete element method(DEM)is in line with the testing results.Tensile stress exists at the backside of rock column during toppling deformation.Stress concentration results in the fragmented rock column and its degree is the most significant at the slope toe.
基金the National Natural Science Foundation of China(Grant number 51771178)Shaanxi Outstanding Youth Fund project(Grant number 2021JC-45)+2 种基金Key international cooperation projects in Shaanxi Province(Grant number 2020KWZ-007)the Major Program of Science and Technology in Shaanxi Province(Grant number20191102006)Open Fund of State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body(Grant number 32115019)。
文摘The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient protection.In the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly technique.The outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)film.The FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier capability.The Ce film connects the outer layer with the substrate,showing the transition effect.The corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling behavior.The synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.
基金supported by the National Natural Science Foundation of China(Grants No.41672295 and No.42107155)the Research Project of the Department of Natural Resources of Sichuan Province(No.Kj-2022-29).
文摘Gentle slopes with large amounts of granite blocks are widespread in granitic areas with warm and humid climate.These blocks pose a potential risk to the existing and planned infrastructure.The instability type and geometry of these blocks will influence their motility and destructive power to some extent.This study aims at creating a classification system that can indicate both the shape and the instability type of these blocks and then developing a block removal scheme.The classification system was constructed based on the mechanical stability analysis of blocks on an inclined surface.This analysis identified key factors affecting stability,including block shape,block weathering roundness,the existing state of a block on a slope,and the friction between the block and the slope.The achieved work allowed the establishment of a direct correlation between block geometry and their instability types.The availability of this classification system was validated by field data and experimental data in the literature.The proposal to remove blocks identified as the toppling types,such as cylindrical-toppling types,cuboid-toppling types,cube-toppling types,was put forward to avoid the uneconomical problem of a complete clearance.Meanwhile,this classification provides a foundation for further research on the instability probability of each type of block and the development of a more refined blocks’removal scheme.The classification approach adopted in this paper can provide a reference for the classification of other lithological blocks under similar engineering geological conditions.
文摘BACKGROUND Regional anesthesia is a promising method in patients with post coronavirus disease 2019(COVID-19)pulmonary sequelae for preserving pulmonary function and preventing postoperative pulmonary complications,compared with general anesthesia.CASE SUMMARY We provided surgical anesthesia and analgesia suitable for breast surgery by performing pectoral nerve block type II(PECS-II),parasternal,and intercostobrachial nerve blocks with intravenous dexmedetomidine administration in a 61-year-old female patient with severe pulmonary sequelae after COVID-19infection.CONCLUSION Sufficient analgesia for 7 h was provided via PECS-II,parasternal,and intercostobrachial blocks perioperatively.
文摘BACKGROUND Coronavirus disease 2019(COVID-19)caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has resulted in a worldwide health crisis since it first appeared.Numerous studies demonstrated the virus’s predilection to cardiomyocytes;however,the effects that COVID-19 has on the cardiac conduc-tion system still need to be fully understood.AIM To analyze the impact that COVID-19 has on the odds of major cardiovascular complications in patients with new onset heart blocks or bundle branch blocks(BBB).METHODS The 2020 National Inpatient Sample(NIS)database was used to identify patients admitted for COVID-19 pneumonia with and without high-degree atrioven-tricular blocks(HDAVB)and right or left BBB utilizing ICD-10 codes.The patients with pre-existing pacemakers,suggestive of a prior diagnosis of HDAVB or BBB,were excluded from the study.The primary outcome was inpatient mortality.Secondary outcomes included total hospital charges(THC),the length of hospital stay(LOS),and other major cardiac outcomes detailed in the Results section.Univariate and multivariate regression analyses were used to adjust for confounders with Stata version 17.RESULTS A total of 1058815 COVID-19 hospitalizations were identified within the 2020 NIS database,of which 3210(0.4%)and 17365(1.6%)patients were newly diagnosed with HDAVB and BBB,respectively.We observed a significantly higher odds of in-hospital mortality,cardiac arrest,cardiogenic shock,sepsis,arrythmias,and acute kidney injury in the COVID-19 and HDAVB group.There was no statistically significant difference in the odds of cerebral infarction or pulmonary embolism.Encounters with COVID-19 pneumonia and newly diagnosed BBB had a higher odds of arrythmias,acute kidney injury,sepsis,need for mechanical ventilation,and cardiogenic shock than those without BBB.However,unlike HDAVB,COVID-19 pneumonia and BBB had no significant impact on mortality compared to patients without BBB.CONCLUSION In conclusion,there is a significantly higher odds of inpatient mortality,cardiac arrest,cardiogenic shock,sepsis,acute kidney injury,supraventricular tachycardia,ventricular tachycardia,THC,and LOS in patients with COVID-19 pneumonia and HDAVB as compared to patients without HDAVB.Likewise,patients with COVID-19 pneumonia in the BBB group similarly have a higher odds of supraventricular tachycardia,atrial fibrillation,atrial flutter,ventricular tachycardia,acute kidney injury,sepsis,need for mechanical ventilation,and cardiogenic shock as compared to those without BBB.Therefore,it is essential for healthcare providers to be aware of the possible worse predicted outcomes that patients with new-onset HDAVB or BBB may experience following SARS-CoV-2 infection.
文摘The purpose of this paper is to investigate the simulation of mixed convection in a lid-driven wavy enclosure with blocks positioned at various positions. This study also examined the impact of the longitudinal position of the heated block on heat transfer enhancement. The Galerkin weighted residual finite element method is employed to computationally solve the governing equations of Navier-Stokes, thermal energy, and mass conservation. The enclosure consists of two square heated blocks strategically placed at different heights—firstly, one set is closer to the bottom surface;secondly, one set is nearer to the middle area and finally, one set is closer to the upper undulating surface of the enclosure. The wavy top wall’s thermal insulation, along with active heating of the bottom wall and blocks, generates a dynamic convective atmosphere. In addition, the left wall ascends as the right wall falls, causing the flow formed by the lid. The study investigates the impact of the Richardson number on many factors, such as streamlines, isotherms, dimensionless temperature, velocity profiles, and average Nusselt numbers. These impacts are depicted through graphical illustrations. In all instances, two counter-rotating eddies were generated within the cage. Higher rotating speed consistently leads to improved performance, irrespective of other characteristics. Furthermore, an ideal amalgamation of the regulating factors would lead to increased heat transmission.
基金Supported by the National Natural Science Foundation of China,No.82305380The Postdoctoral Research Program,West China Hospital,Sichuan University,No.2020HXBH018.
文摘BACKGROUND Ultrasound guide technology,which can provide real-time visualization of the needle tip and tissues and avoid many adverse events,is widely used in mini-mally invasive therapy.However,the studies on ultrasound-guided Lateral recess block(LRB)are limited,this is probably because there is no recognized standard method for ultrasound scanning.This study aimed to evaluate the effect of ultrasound-guided LRB in patients with lateral recess stenosis(LRS).CASE SUMMARY A 65-year-old patient complained of low back pain accompanied occasionally by pain and numbness in the left lower limb.Physical examination showed ten-derness on the spinous process and paraspinal muscles from L1 to S1,extensor hallucis longus and tibialis anterior weakness(muscle strength:4-),and a positive straight leg raising test in the left lower limb(60°).Magnetic resonance imaging showed L4–L5 disc degeneration with left LRS and nerve root entrapment.Subsequently,the patient was diagnosed with LRS.This patient was treated with a novel ultrasound-guided LRB approach.The patient’s symptoms significantly improved without any complications at 1 wk postoperatively and at the 3-month follow-up.CONCLUSION This is the first report on the LRS treatment with ultrasound-guided LRB from the contralateral spinous process along the inner side of the articular process by out-plane technique.Further studies are expected to investigate the efficacy and safety of ultrasound-guided LRB for patients with LRS.
