Analysis of the Effect of Anesthetics Comprising of Remifentanil Combined with Propofol During Thyroidectomy

Objective:To analyze the anesthetic effect of remifentanil combined with propofol during thyroidectomy.Methods:A total of 70 patients who underwent thyroidectomy during November 2018 to November 2019 in Chongqing Eleventh People’s Hospital were selected and recruited.These patients were divided into control group and observation group by random number table method.Each group consisted of 35 patients.The patients in the control group was given intravenous anesthesia comprising of propofol combined with intermittent fentanyl anesthesia,whereas the patients in the observation group was given intravenous anesthesia comprising of remifentanil combined with propofol.Results:The heart rate and mean arterial pressure of the observation group after anesthesia for 30 minutes were lower than those of the control group,and the differences were statistically significant(P<0.05).The total incidence of adverse reactions in the observation group was lower than that of the control group,and the differences were statistically significant(P<0.05).Conclusion:Remifentanil combined with propofol is effective in thyroidectomy.This combination can reduce the risk of adverse reactions and maintain stable hemodynamic parameters.

Different Volumes of Local Anesthetics in Ultrasound-Guided Combined Interscalene-Supraclavicular Block for Traumatic Humeral Fracture

Background: Procedures that require anesthesia of entire length of the arm should have combined Interscalene block (ISB) and Supraclavicular block (SCB) to ensure adequate block. However, dual block requires high dose of local anesthetic (LA). We examined if Ultrasound (U/S) guided block helps to decrease the required volume of LA by visualizing trunks, so we only need injection of LA toward cervical nerve roots C5 and C6 aiming to block branches escaped from supraclavicular block. Patients and methods: Ninety-three patients were randomly allocated into one of three equal groups, each included 31 patients. All patients received SCB 20 ml (10 ml Bupivacaine 0.5% plus 10 ml lidocaine 2%) and ISB with different volumes of LA according to the group as follow: group A: 20 ml, group B: 15 ml, and group C: 10 ml. Result: No significant difference in onset of block (sensory and motor) and duration of block (motor only) between the three groups (P value > 0.05). The duration of sensory block was significantly longer in group A (760.65 ± 30.87 minutes) than in either group B (740.48 ± 21.15 minutes, P value P value P value P value P value P value < 0.001). Conclusion: A reduced volume of LA can be used in ultra sound guided ISB in combined with SCB to give satisfactory level of anesthesia to entire length of the arm, but the sensory block duration and duration of post-operative analgesia will be decreased significantly with decreasing the volume.

Anesthesia,Anesthetics,and Postoperative Cognitive Dysfunction in Elderly Patients

Postoperative cognitive dysfunction(POCD)remains a major issue that worsens the prognosis of elderly surgery patients.This article reviews the current research on the effect of different anesthesia methods and commonly utilized anesthetics on the incidence of POCD in elderly patients,aiming to provide an understanding of the underlying mechanisms contributing to this condition and facilitate the development of more reasonable anesthesia protocols,ultimately reducing the incidence of POCD in elderly surgery patients.

Inhaled volatile anesthetics in the intensive care unit

The discovery and utilization of volatile anesthetics has significantly transformed surgical practices since their inception in the mid-19th century.Recently,a paradigm shift is observed as volatile anesthetics extend beyond traditional confines of the operating theatres,finding diverse applications in intensive care settings.In the dynamic landscape of intensive care,volatile anesthetics emerge as a promising avenue for addressing complex sedation requirements,managing refractory lung pathologies including acute respiratory distress syndrome and status asthmaticus,conditions of high sedative requirements including burns,high opioid or alcohol use and neurological conditions such as status epilepticus.Volatile anesthetics can be administered through either inhaled route via anesthetic machines/devices or through extracorporeal membrane oxygenation circuitry,providing intensivists with multiple options to tailor therapy.Furthermore,their unique pharmacokinetic profiles render them titratable and empower clinicians to individualize management with heightened accuracy,mitigating risks associated with conventional sedation modalities.Despite the amounting enthusiasm for the use of these therapies,barriers to widespread utilization include expanding equipment availability,staff familiarity and training of safe use.This article delves into the realm of applying inhaled volatile anesthetics in the intensive care unit through discussing their pharmacology,administration considerations in intensive care settings,complication considerations,and listing indications and evidence of the use of volatile anesthetics in the critically ill patient population.

Influence of static cartoons combined with dynamic virtual environments on preoperative anxiety of preschool-aged children undergoing surgery

BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons combined with dynamic virtual environments on preoperative anxiety and anesthesia induction compliance in preschool-aged children undergoing surgery.METHODS One hundred and sixteen preschool-aged children were selected and assigned to the drug(n=37),intervention(n=40),and control(n=39)groups.All the children received routine preoperative checkups and nursing before being transferred to the preoperative preparation room on the day of the operation.The drug group received 0.5 mg/kg midazolam and the intervention group treatment consisting of static cartoons combined with dynamic virtual environments.The control group received no intervention.The modified Yale Preoperative Anxiety Scale was used to evaluate the children’s anxiety level on the day before surgery(T0),before leaving the preoperative preparation room(T1),when entering the operating room(T2),and at anesthesia induction(T3).Compliance during anesthesia induction(T3)was evaluated using the Induction Compliance Checklist(ICC).Changes in mean arterial pressure(MAP),heart rate(HR),and respiratory rate(RR)were also recorded at each time point.RESULTS The anxiety scores of the three groups increased variously at T1 and T2.At T3,both the drug and intervention groups had similar anxiety scores,both of which were lower than those in the control group.At T1 and T2,MAP,HR,and RR of the three groups increased.The drug and control groups had significantly higher MAP and RR than the intervention group at T2.At T3,the MAP,HR,and RR of the drug group decreased and were significantly lower than those in the control group but were comparable to those in the intervention group.Both the drug and intervention groups had similar ICC scores and duration of anesthesia induction(T3),both of which were higher than those of the control group.CONCLUSION Combining static cartoons with dynamic virtual environments as effective as medication,specifically midazolam,in reducing preoperative anxiety and fear in preschool-aged children.This approach also improve their compliance during anesthesia induction and helped maintain their stable vital signs.

Performance of Gas-Steam Combined Cycle Cogeneration Units Influenced by Heating Network Terminal Steam Parameters

The determination of source-side extracted heating parameters is of great significance to the economic operation of cogeneration systems.This paper investigated the coupling performance of a cogeneration heating and power system multidimensionally based on the operating characteristics of the cogeneration units,the hydraulic and thermodynamic characteristics of the heating network,and the energy loads.Taking a steam network supported by a gas-steam combined cycle cogeneration system as the research case,the interaction effect among the source-side prime movers,the heating networks,and the terminal demand thermal parameters were investigated based on the designed values,the plant testing data,and the validated simulation.The operating maps of the gas-steam combined cycle cogeneration units were obtained using THERMOFLEX,and the minimum source-side steam parameters of the steam network were solved using an inverse solution procedure based on the hydro-thermodynamic coupling model.The cogeneration operating maps indicate that the available operating domain considerably narrows with the rise of the extraction steam pressure and flow rate.The heating network inverse solution demonstrates that the source-side steam pressure and temperature can be optimized from the originally designed 1.11 MPa and 238.8°C to 1.074 MPa and 191.15°C,respectively.Under the operating strategy with the minimum source-side heating parameters,the power peak regulation depth remarkably increases to 18.30%whereas the comprehensive thermal efficiency decreases.The operation under the minimum source-side heating steam parameters can be superior to the originally designed one in the economy at a higher price of the heating steam.At a fuel price of$0.38/kg and the power to fuel price of 0.18 kg/(kW·h),the critical price ratio of heating steam to fuel is 119.1 kg/t.The influence of the power-fuel price ratio on the economic deviation appears relatively weak.

Left atrial appendage occluder detachment treated with transthoracic ultrasound combined with digital subtraction angiography guided catcher:A case report

BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after detachment.This case innovatively used ultrasound guidance combined with digital subtraction angiography(DSA)to completely remove the occluder,accumulating some experience.CASE SUMMARY The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial fibrillation.After the surgery,the occluder fell off and became free in the left ventricle,which is very dangerous.We innovatively used ultrasound guidance,combined with DSA,and interventional surgery to successfully capture the free occluder using a catcher,completely remove it,and then re implant a new left atrial appendage occluder.After the surgery,the patient recovered very well.CONCLUSION The size selection of the occluder is slightly conservative,and the shape of the left atrial appendage opening is irregular.

Winter Wheat Yield Estimation Based on Sparrow Search Algorithm Combined with Random Forest:A Case Study in Henan Province,China

Precise and timely prediction of crop yields is crucial for food security and the development of agricultural policies.However,crop yield is influenced by multiple factors within complex growth environments.Previous research has paid relatively little attention to the interference of environmental factors and drought on the growth of winter wheat.Therefore,there is an urgent need for more effective methods to explore the inherent relationship between these factors and crop yield,making precise yield prediction increasingly important.This study was based on four type of indicators including meteorological,crop growth status,environmental,and drought index,from October 2003 to June 2019 in Henan Province as the basic data for predicting winter wheat yield.Using the sparrow search al-gorithm combined with random forest(SSA-RF)under different input indicators,accuracy of winter wheat yield estimation was calcu-lated.The estimation accuracy of SSA-RF was compared with partial least squares regression(PLSR),extreme gradient boosting(XG-Boost),and random forest(RF)models.Finally,the determined optimal yield estimation method was used to predict winter wheat yield in three typical years.Following are the findings:1)the SSA-RF demonstrates superior performance in estimating winter wheat yield compared to other algorithms.The best yield estimation method is achieved by four types indicators’composition with SSA-RF)(R^(2)=0.805,RRMSE=9.9%.2)Crops growth status and environmental indicators play significant roles in wheat yield estimation,accounting for 46%and 22%of the yield importance among all indicators,respectively.3)Selecting indicators from October to April of the follow-ing year yielded the highest accuracy in winter wheat yield estimation,with an R^(2)of 0.826 and an RMSE of 9.0%.Yield estimates can be completed two months before the winter wheat harvest in June.4)The predicted performance will be slightly affected by severe drought.Compared with severe drought year(2011)(R^(2)=0.680)and normal year(2017)(R^(2)=0.790),the SSA-RF model has higher prediction accuracy for wet year(2018)(R^(2)=0.820).This study could provide an innovative approach for remote sensing estimation of winter wheat yield.yield.

Dynamic simulation analysis of molten salt reactor-coupled air-steam combined cycle power generation system

A nonlinear dynamic simulation model based on coordinated control of speed and flow rate for the molten salt reactor and combined cycle systems is proposed here to ensure the coordination and stability between the molten salt reactor and power system.This model considers the impact of thermal properties of fluid variation on accuracy and has been validated with Simulink.This study reveals the capability of the control system to compensate for anomalous situations and maintain shaft stability in the event of perturbations occurring in high-temperature molten salt tank outlet parameters.Meanwhile,the control system’s impact on the system’s dynamic characteristics under molten salt disturbance is also analyzed.The results reveal that after the disturbance occurs,the controlled system benefits from the action of the control,and the overshoot and disturbance amplitude are positively correlated,while the system power and frequency eventually return to the initial values.This simulation model provides a basis for utilizing molten salt reactors for power generation and maintaining grid stability.

Grain Yield,Biomass Accumulation,and Leaf Photosynthetic Characteristics of Rice under Combined Salinity-Drought Stress

Simultaneous stresses of salinity and drought often coincide during rice-growing seasons in saline lands,primarily due to insufficient water resources and inadequate irrigation facilities.Consequently,combined salinity-drought stress poses a major threat to rice production.In this study,two salinity levels(NS,non-salinity;HS,high salinity)along with three drought treatments(CC,control condition;DJ,drought stress imposed at jointing;DH,drought stress imposed at heading)were performed to investigate their combined influences on leaf photosynthetic characteristics,biomass accumulation,and rice yield formation.Salinity,drought,and their combination led to a shortened growth period from heading to maturity,resulting in a reduced overall growth duration.Grain yield was reduced under both salinity and drought stress,with a more substantial reduction under the combined salinity-drought stress.The combined stress imposed at heading caused greater yield losses in rice compared with the stress imposed at jointing.Additionally,the combined salinity-drought stress induced greater decreases in shoot biomass accumulation from heading to maturity,as well as in shoot biomass and nonstructural carbohydrate(NSC)content in the stem at heading and maturity.However,it increased the harvest index and NSC remobilization reserve.Salinity and drought reduced the leaf area index and SPAD value of flag leaves and weakened the leaf photosynthetic characteristics as indicated by lower photosynthetic rates,transpiration rates,and stomatal conductance.These reductions were more pronounced under the combined stress.Salinity,drought,and especially their combination,decreased the activities of ascorbate peroxidase,catalase,and superoxide dismutase,while increasing the contents of malondialdehyde,hydrogen peroxide,and superoxide radical.Our results indicated a more significant yield loss in rice when subjected to combined salinity-drought stress.The individual and combined stresses of salinity and drought diminished antioxidant enzyme activities,inhibited leaf photosynthetic functions,accelerated leaf senescence,and subsequently lowered assimilate accumulation and grain yield.

Pressure stimulated current in progressive failure process of combined coal-rock under uniaxial compression:Response and mechanism

Effective monitoring of the structural health of combined coal-rock under complex geological conditions by pressure stimulated currents(PSCs)has great potential for the understanding of dynamic disasters in underground engineering.To reveal the effect of this way,the uniaxial compression experiments with PSC monitoring were conducted on three types of coal-rock combination samples with different strength combinations.The mechanism explanation of PSCs are investigated by resistivity test,atomic force microscopy(AFM)and computed tomography(CT)methods,and a PSC flow model based on progressive failure process is proposed.The influence of strength combinations on PSCs in the progressive failure process are emphasized.The results show the PSC responses between rock part,coal part and the two components are different,which are affected by multi-scale fracture characteristics and electrical properties.As the rock strength decreases,the progressive failure process changes obviously with the influence range of interface constraint effect decreasing,resulting in the different responses of PSC strength and direction in different parts to fracture behaviors.The PSC flow model is initially validated by the relationship between the accumulated charges of different parts.The results are expected to provide a new reference and method for mining design and roadway quality assessment.

Numerical Investigation of Combined Production of Natural Gas Hydrate and Conventional Gas

Natural gas hydrate(NGH)is generally produced and accumulated together with the underlying conventional gas.Therefore,optimizing the production technology of these two gases should be seen as a relevant way to effectively reduce the exploitation cost of the gas hydrate.In this study,three types of models accounting for the coexistence of these gases are considered.Type A considers the upper hydrate-bearing layer(HBL)adjacent to the lower conventional gas layer(CGL);with the Type B a permeable interlayer exists between the upper HBL and the lower CGL;with the type C there is an impermeable interlayer between the upper HBL and the lower CGL.The production performances associated with the above three models are calculated under different conditions,including only a depressurized HBL(only HBL DP);only a depressurized CGL(only CGL DP);and both the HBL and the CGL being depressurized(HBL+CGL DP).The results show that for Type A and Type B coexistence accumulation models,when only HBL or CGL is depressurized,the gas from the other layer will flow into the production layer due to the pressure difference between the two layers.In the coexistence accumulation model of type C,the cumulative gas production is much lower than that of Type A and Type B,regardless of whether only HBL DP,only CGL DP,or HBL+CGL DP are considered.This indicates that the impermeable interlayer restricts the cross-flow of gas between HBL and CGL.For three different coexistence accumulation models,CGL DP has the largest gas-to-water ratio.

Lenvatinib combined with sintilimab plus transarterial chemoembolization as first-line treatment for advanced hepatocellular carcinoma

BACKGROUND Recently,combination therapy has shown a better trend towards improved tumour response and survival outcomes than monotherapy in patients with hepatocellular carcinoma(HCC).However,research on triple therapy[lenvatinib+sintilimab+transarterial chemoembolization(TACE)]as a first-line treatment for advanced HCC is limited.AIM To evaluate the safety and efficacy of triple therapy as a first-line treatment for advanced HCC.METHODS HCC patients with Barcelona Clinic Liver Cancer stage C treated with triple therapy were enrolled.All patients were treated with lenvatinib every day and sintilimab once every 3 wk.Moreover,TACE was performed every 4-6 wk if necessary.The primary outcome of the study was overall survival(OS).The secondary outcomes were the objective response rate(ORR),disease control rate(DCR),and incidence of adverse events.RESULTS Forty HCC patients who underwent triple therapy were retrospectively analysed from January 2019 to January 2022.With a median follow-up of 8.5 months,the 3-,6-,and 12-mo OS rates were 100%,88.5%,and 22.5%,respectively.The ORR and DCR were 45%and 90%,respectively.The median progressive free survival and median OS were not reached.Common complications were observed in 76%of the patients(grade 3,15%;grade 4,2.5%).CONCLUSION Combination therapy comprising lenvatinib,sintilimab and TACE achieved promising outcomes in advanced HCC patients and had manageable effects.

A Subdivision-Based Combined Shape and Topology Optimization in Acoustics

We propose a combined shape and topology optimization approach in this research for 3D acoustics by using the isogeometric boundary element method with subdivision surfaces.The existing structural optimization methods mainly contain shape and topology schemes,with the former changing the surface geometric profile of the structure and the latter changing thematerial distribution topology or hole topology of the structure.In the present acoustic performance optimization,the coordinates of the control points in the subdivision surfaces fine mesh are selected as the shape design parameters of the structure,the artificial density of the sound absorbing material covered on the structure surface is set as the topology design parameter,and the combined topology and shape optimization approach is established through the sound field analysis of the subdivision surfaces boundary element method as a bridge.The topology and shape sensitivities of the approach are calculated using the adjoint variable method,which ensures the efficiency of the optimization.The geometric jaggedness and material distribution discontinuities that appear in the optimization process are overcome to a certain degree by the multiresolution method and solid isotropic material with penalization.Numerical examples are given to validate the effectiveness of the presented optimization approach.

Early Application Study of Intravenous Pain Pump Combined with Parecoxib Injection in Relieving Pain in Patients after Thoracoscopy

Objective: To explore the clinical effectiveness of combined use of intravenous pain pump with Parecoxib injection in alleviating pain in patients during the early postoperative period after thoracoscopic surgery. Methods: Eighty patients who underwent thoracoscopic surgery in a tertiary hospital were selected as the study subjects and randomly divided into two groups, with 40 patients in each group. The control group received routine postoperative treatment with intravenous pain pump, while the experimental group received Parecoxib in addition to the standard postoperative pain pump treatment. Visual Analog Scale (VAS) pain scores were used to evaluate postoperative pain relief in both groups, along with adverse reactions, postoperative complications, and patient satisfaction with pain relief. Results: Patients who received Parecoxib injection in addition to the routine use of intravenous pain pump had VAS pain scores lower than 3 points at 6 h, 12 h, 24 h, and 36 h postoperatively compared to those in the control group. The incidence of postoperative lung collapse, pleural effusion, and pulmonary infections was also significantly lower in the experimental group. The differences between the two groups were statistically significant (P Conclusion: Early combined use of Parecoxib injection in the early postoperative period after thoracoscopic surgery has shown good clinical efficacy. It can reduce the level of pain in patients, promote effective coughing and expectoration, facilitate early mobilization of patients, improve patient compliance, reduce complications, shorten hospital stay, and expedite patient recovery. Therefore, it is worth promoting the widespread clinical application of Parecoxib injection in this setting.

Anti-OX40 Antibody Combined with HBc VLPs Delays Tumor Growth in a Mouse Colon Cancer Model

Objective Combination immunotherapy strategies targeting OX40,a co-stimulatory molecule that can enhance antitumor immunity by modulating the proliferation,differentiation,and effector function of tumor-infiltrating T cells,have attracted much attention for their excellent therapeutic effects.In this study,we aimed to evaluate the antitumor efficacy of combined anti-OX40 and hepatitis B core viruslike particles(HBc VLPs)therapy using a mouse colon cancer model.Methods Humanized B-h OX40 mice were injected subcutaneously with MC38 colon tumor cells and treated with HBc VLPs+anti-h OX40 antibody.Tumor growth was monitored.Flow cytometric analysis was performed to evaluate the populations of T cell subsets in the tumors.Results The combination of anti-OX40 with HBc VLPs resulted in a significant delay in tumor growth,suggesting that a potent antitumor immunity was induced by the combination therapy.Further studies revealed that HBc VLPs+anti-OX40 treatment induced a significant increase in effector T cells(Teffs)and a significant decrease in regulatory T cells(Tregs)in the tumor microenvironment(TME),which accounted for the synergistic antitumor effect of anti-OX40 in combination with HBc VLPs.Conclusion Combination therapy of anti-h OX40 and HBc VLPs provides synergistic antitumor activity in colon cancer-bearing mice,which may represent a potential design strategy for cancer immunotherapy.

Multidisciplinary treatment of molten aluminum combined burn:An unusual case report

Molten aluminum is among the most common causes of burns in the metal industry.However,only few reports are available on molten aluminum injuries.Herein,we report an unusual case of molten aluminum burn.The patient had burns not only on the body surface but also in the respiratory tract and esophagus,adding to the difficulty of treatment.Multidisciplinary consultation and cooperation led to the development of a treatment plan for the patient,which included tracheotomy,respiratory management,endoscopic therapy,infection control,and psychological support.To our knowledge,this is the first report of molten aluminum-induced burns involving the face,neck,respiratory tract,esophagus,and eyes.We also describe our experience with multidisciplinary treatment for the management of molten aluminum burns.

Targeted anti-tumor synergistic effects of Myc decoy oligodeoxynucleotides-loaded selenium nanostructure combined with chemoradiotherapy on LNCaP prostate cancer cells

In the present study,we investigated the synergistic effects of targeted methotrexate-selenium nanostructure containing Myc decoy oligodeoxynucleotides along with X-irradiation exposure as a combination therapy on LNCaP prostate cancer cells.Myc decoy ODNs were designed based on the promoter of Bcl-2 gene and analyzed by molecular docking and molecular dynamics assays.ODNs were loaded on the synthesized Se@BSA@Chi-MTX nanostructure.The physicochemical characteristics of nanostructures were determined by FTIR,DLS,UV-vis,TEM,EDX,in vitro release,and hemolysis tests.Subsequently,the cytotoxicity properties of them with and without X-irradiation were investigated by uptake,MTT,cell cycle,apoptosis,and scratch assays on the LNCaP cell line.The results of DLS and TEM showed negative charge(−9 mV)and nanometer size(40 nm)for Se@BSA@Chi-DEC-MTX NPs,respectively.The results of FTIR,UV-vis,and EDX showed the proper interaction of different parts and the correct synthesis of nanoparticles.The results of hemolysis showed the hemocompatibility of this nanoparticle in concentrations less than 6 mg/mL.The ODNs release from the nanostructures showed a pH-dependent manner,and the release rate was 15%higher in acidic pH.The targeted Se@BSA@Chi-labeled ODN-MTX NPs were efficiently taken up by LNCaP cells by targeting the prostate-specific membrane antigen(PSMA).The significant synergistic effects of nanostructure(containing MTX drug)treatment along with X-irradiation showed cell growth inhibition,apoptosis induction(~57%),cell cycle arrest(G2/M phase),and migration inhibition(up to 90%)compared to the control.The results suggested that the Se@BSA@Chi-DEC-MTX NPs can potentially suppress the cell growth of LNCaP cells.This nanostructure system can be a promising approach for targeted drug delivery and chemoradiotherapy in prostate cancer treatment.

Control effect and optimization scheme of combined rockboltecable support for a tunnel in horizontally layered limestone:A case study

This study focused on the mechanical behavior of a deep-buried tunnel constructed in horizontally layered limestone,and investigated the effect of a new combined rockboltecable support system on the tunnel response.The Yujingshan Tunnel,excavated through a giant karst cave,was used as a case study.Firstly,a multi-objective optimization model for the rockboltecable support was proposed by using fuzzy mathematics and multi-objective comprehensive decision-making principles.Subsequently,the parameters of the surrounding rock were calibrated by comparing the simulation results obtained by the discrete element method(DEM)with the field monitoring data to obtain an optimized support scheme based on the optimization model.Finally,the optimization scheme was applied to the karst cave section,which was divided into the B-and C-shaped sections.The distribution range of the rockboltecable support in the C-shaped section was larger than that in the B-shaped section.The field monitoring results,including tunnel crown settlement,horizontal convergence,and axial force of the rockboltecable system,were analyzed to assess the effectiveness of the optimization scheme.The maximum crown settlement and horizontal convergence were measured to be 25.9 mm and 35 mm,accounting for 0.1%and 0.2%of the tunnel height and span,respectively.Although the C-shaped section had poorer rock properties than the B-shaped section,the crown settlement and horizontal convergence in the C-shaped section ranged from 46%to 97%of those observed in the B-shaped section.The cable axial force in the Bshaped section was approximately 60%of that in the C-shaped section.The axial force in the crown rockbolt was much smaller than that in the sidewall rockbolt.Field monitoring results demonstrated that the optimized scheme effectively controlled the deformation of the layered surrounding rock,ensuring that it remained within a safe range.These results provide valuable references for the design of support systems in deep-buried tunnels situated in layered rock masses.

A technique for enhancing tight oil recovery by multi-field reconstruction and combined displacement and imbibition

A seepage-geomechanical coupled embedded fracture flow model has been established for multi-field coupled simulation in tight oil reservoirs,revealing the patterns of change in pressure field,seepage field,and stress field after long-term water injection in tight oil reservoirs.Based on this,a technique for enhanced oil recovery(EOR)combining multi-field reconstruction and combination of displacement and imbibition in tight oil reservoirs has been proposed.The study shows that after long-term water flooding for tight oil development,the pressure diffusion range is limited,making it difficult to establish an effective displacement system.The variation in geostress exhibits diversity,with the change in horizontal minimum principal stress being greater than that in horizontal maximum principal stress,and the variation around the injection wells being more significant than that around the production wells.The deflection of geostress direction around injection wells is also large.The technology for EOR through multi-field reconstruction and combination of displacement and imbibition employs water injection wells converted to production and large-scale fracturing techniques to restructure the artificial fracture network system.Through a full lifecycle energy replenishment method of pre-fracturing energy supplementation,energy increase during fracturing,well soaking for energy storage,and combination of displacement and imbibition,it effectively addresses the issue of easy channeling of the injection medium and difficult energy replenishment after large-scale fracturing.By intensifying the imbibition effect through the coordination of multiple wells,it reconstructs the combined system of displacement and imbibition under a complex fracture network,transitioning from avoiding fractures to utilizing them,thereby improving microscopic sweep and oil displacement efficiencies.Field application in Block Yuan 284 of the Huaqing Oilfield in the Ordos Basin has demonstrated that this technology increases the recovery factor by 12 percentage points,enabling large scale and efficient development of tight oil.