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Temporary plugging agent transport behavior within visualized multi-fracture created during TPDF in a horizontal well: An experimental study
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作者 Yu-Shi Zou Dian-Yu Li +4 位作者 Can Yang Yan-Chao Li Shi-Cheng Zhang Long-Qing Zou Xin-Fang Ma 《Petroleum Science》 2025年第9期3671-3687,共17页
Temporary plugging and diversion fracturing(TPDF)is widely used to promote the uniform and complex distribution of multi-clustered hydraulic fractures(HFs)in a horizontal well of the unconventional formations.However,... Temporary plugging and diversion fracturing(TPDF)is widely used to promote the uniform and complex distribution of multi-clustered hydraulic fractures(HFs)in a horizontal well of the unconventional formations.However,the migration behavior of temporary plugging agent(TPA),as a function of the concentration and particle size of TPA and cluster-perforation numbers,etc.,determining the effectiveness of this technique,remains unclear.Therefore,this study conducted innovatively a series of TPDF simulation experiments on transparent polymethyl methacrylate(PMMA)specimens(cubic block of 30 cm×30 cm×30 cm)to explore visually the migration behavior of TPA in multi-clustered HFs in a horizontal well.A laboratory hydraulic sandblasting perforation completion technique was implemented to simulate the multi-cluster perforations.All the distributions of wellbore,perforations,HFs,and TPA can be seen clearly inside the PMMA specimen post the experiment.The results show that there are four characteristic plugging positions for the TPA:mouth of HF,middle of HF,tip of HF,and the intersection of HFs.Small particle size TPA tends to migrate to the fracture tip for plugging,while large particle size TPA tends to plug at the fracture mouth.The migration of the TPA is influenced obviously by the morphology of the fracture wall.A smooth fracture wall is conducive to the migration of the TPA to the far end of HFs,but not conducive to generating the plugging zone and HF diversion.In contrast,a"leaf vein"fracture of rough wall is conducive to generating the plugging layer and the diversion of HFs,but not conducive to the migration of the TPA to the far end of HFs.The migration ability of TPA in a"shell"pattern is intermediate between the two above cases.Increasing TPA concentration can encourage TPA to migrate more quickly to the characteristic plugging position,and thereby to promote the creation of effective plugging and subsequently the multi-stage diversion of the HFs.Nevertheless,excessive concentration may cause the TPA to settle prematurely,affecting the propagation of the HFs to the far end.Increasing the number of clusters to a certain extent can encourage TPA to migrate into the HFs and form plugging,and promote the diversion.An evaluation system for the migration ability of granular TPA has been established,and it was calculated that when there is no plugging expectation target,the comprehensive migration ability of small particle size TPA is stronger than that of large particle size TPA.This research provides theoretical foundation for the optimization of temporary plugging parameters. 展开更多
关键词 temporary plugging and diversion fracturing(TPDF) Polymethyl methacrylate(PMMA) Multi-cluster perforation temporary plugging agent migration Visualization Plugging position
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Designing Temporary Installations beneath Toronto’s Gardiner Expressway to Enhance Thermal Comfort during Shoulder Seasons
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作者 Niloufar Mohsenivafa Afshin Ashari Nadia Amoroso 《Journal of Environmental Science and Engineering(B)》 2025年第3期103-122,共20页
Urban underutilized spaces,often the secondary by-products of large infrastructure projects,are often overlooked,despite their potential to enhance city life.With meaningful design interventions,these neglected areas ... Urban underutilized spaces,often the secondary by-products of large infrastructure projects,are often overlooked,despite their potential to enhance city life.With meaningful design interventions,these neglected areas can be transformed into inclusive public environments that offer social,environmental,and cultural value.This research investigates how modular,temporary installations beneath Toronto’s Gardiner Expressway,in Canada,can enhance thermal comfort and foster community engagement during the shoulder seasons.Using a multi-step methodology,including literature review,thermal comfort guidelines,site-specific climate analysis,and precedent studies,the research identifies key design strategies tailored to the unique microclimatic and social conditions of under-bridge spaces.The study culminates in the proposal of a flexible system of movable panels that provide wind protection,solar control,and opportunities for gathering,interaction,and rest.By reimagining these unnoticed infrastructure zones as adaptable,climate-responsive public spaces,this research contributes to sustainable urban design and highlights the importance of design strategies that address the challenges of a warming and increasingly variable climate. 展开更多
关键词 Thermal comfort under bridge public space temporary installation climate adaptation modular design MICROCLIMATE seasonal design
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Temporary bilateral uterine artery occlusion in the control of hemorrhage:A case report and review of literature
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作者 Yu-Liang Song Chun-Feng Wang 《World Journal of Clinical Cases》 2025年第18期21-28,共8页
BACKGROUND Intramural pregnancy is rare,with an unclear etiology and pathophysiology.Surgical,medical,and expectant management options are available for this condition.However,most reported cases are managed surgicall... BACKGROUND Intramural pregnancy is rare,with an unclear etiology and pathophysiology.Surgical,medical,and expectant management options are available for this condition.However,most reported cases are managed surgically.Despite the risks of massive intraoperative bleeding and acute and long-term complications,uterine artery embolization is often selected.Temporary occlusion of the bilateral uterine arteries during surgery is associated with fewer complications.CASE SUMMARY We reported the case of a patient who was diagnosed with intramural pregnancy approximately one month after medical abortion.We performed laparoscopic resection with hysteroscopy.Since the lesion had abundant blood flow,we temporarily blocked the bilateral uterine arteries to prevent massive intraop-erative bleeding.The surgical process went smoothly.The postoperative course was uneventful.CONCLUSION Temporary occlusion of the bilateral uterine arteries in the treatment of intramural pregnancy may prevent excessive uterine bleeding during surgery. 展开更多
关键词 Intramural pregnancy HYSTEROSCOPY Laparoscopic surgery Uterine artery temporary occlusion Case report
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Effects of Acetic Acid Bacteria (Gluconacetobacter hansenii GK-1) on Fatigue Induced by Temporary Mental Stress: A Randomized, Double-Blind, Placebo-Controlled Study
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作者 Wei Wang Mariko Oe +6 位作者 Mengwei Yuan Keiko Kuriyama Yumi Takeda Mamoru Kimura Ryosuke Matsuoka Kiichi Sugiyama Naoki Miura 《Food and Nutrition Sciences》 2025年第1期44-54,共11页
Objective: This study assessed the effects of consuming acetic acid bacteria (Gluconacetobacter hansenii GK-1) for 12 weeks on fatigue induced by temporary mental stress. Methods: This randomized, double-blind, placeb... Objective: This study assessed the effects of consuming acetic acid bacteria (Gluconacetobacter hansenii GK-1) for 12 weeks on fatigue induced by temporary mental stress. Methods: This randomized, double-blind, placebo-controlled, parallel-group study included 100 healthy male and female adults aged 20 - 64 years. Participants consumed either the G. hansenii GK-1 supplement (9 × 10⁹ cells/day) or a placebo daily for 12 weeks. The impact of temporary mental stress on fatigue in G. hansenii GK-1 was assessed using a Visual Analog Scale (VAS) before the study began and after 12 weeks of supplementation. Results: Subjective fatigue measured by Visual Analog Scale (VAS) showed a significant decrease in fatigue induced by temporary mental stress after 12 weeks of consumption in the G. hansenii GK-1 group compared with the placebo group. No adverse events were attributed to G. hansenii GK-1. These findings confirm that continuous oral ingestion of G. hansenii GK-1 by healthy Japanese adults reduces feelings of fatigue caused by temporary mental stress. 展开更多
关键词 Acetic Acid Bacteria Gluconacetobacter hansenii GK-1 FATIGUE temporary Mental Stress Double-Blind Study
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Enhancing uniformity of multi-fracture propagation by temporary plugging and diversion fracturing in a horizontal well with multicluster perforations
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作者 Xin Chang Shi-Long Teng +2 位作者 Xing-Yi Wang Yin-Tong Guo Chun-He Yang 《Petroleum Science》 2025年第9期3688-3708,共21页
Multi-stage and multi-cluster fracturing(MMF)is a crucial technology in unconventional oil and gas development,aiming to enhance production by creating extensive fracture networks.However,achieving uniform expansion o... Multi-stage and multi-cluster fracturing(MMF)is a crucial technology in unconventional oil and gas development,aiming to enhance production by creating extensive fracture networks.However,achieving uniform expansion of multi-cluster hydraulic fractures(HFs)in MMF remains a significant challenge.Field practice has shown that the use of temporary plugging and diversion fracturing(TPDF)can promote the balanced expansion of multi-cluster HFs.This study conducted TPDF experiments using a true triaxial fracturing simulation system setting a horizontal well completion with multi-cluster jetting perforations to investigate the equilibrium initiation and extension of multi-cluster fractures.The influence of key parameters,including cluster spacing,fracturing fluid viscosity,differential stress,and fracturing fluid injection rate,on fracture initiation and propagation was systematically examined.The results indicate that while close-spaced multi-cluster fracturing significantly increases the number of HFs,it also leads to uneven extension of HFs in their propagation.In contrast,TPDF demonstrates effectiveness in mitigating uneven HF extension,increasing the number of HFs,and creating a larger stimulated reservoir volume,ultimately leading to improved oil and gas well productivity.Moreover,under conditions of high differential stress,the differential stress within the formation exerts a stronger guiding effect in HFs,which are more closely aligned with the minimum principal stress.Low-viscosity fluids facilitate rapid and extensive fracture propagation within the rock formation.High-volume fluid injection,on the other hand,more comprehensively fills the formation.Therefore,employing lowviscosity and high-volume fracturing is advantageous for the initiation and extension of multi-cluster HFs. 展开更多
关键词 Non-uniformity of fracture propagation temporary plugging and diversion FRACTURING Multi-cluster hydraulic fracturing Fracture propagation
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Plugging behaviors of temporary plugging particles in hydraulic fractures 被引量:4
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作者 GUO Jianchun ZHAN Li +5 位作者 LU Qianli QI Tianjun LIU Yuxuan WANG Xin CHEN Chi GOU Xinghao 《Petroleum Exploration and Development》 SCIE 2023年第2期464-472,共9页
Using the visualized experimental device of temporary plugging in hydraulic fractures, the plugging behaviors of temporary plugging particles with different sizes and concentrations in hydraulic fractures were experim... Using the visualized experimental device of temporary plugging in hydraulic fractures, the plugging behaviors of temporary plugging particles with different sizes and concentrations in hydraulic fractures were experimentally analyzed under the conditions of different carrier fluid displacements and viscosities. The results show that the greater the carrier fluid viscosity and displacement, the more difficult it is to form a plugging layer, and that the larger the size and concentration of the temporary plugging particle, the less difficult it is to form a plugging layer. When the ratio of particle size to fracture width is 0.45, the formation of the plugging layer is mainly controlled by the mass concentration of the temporary plugging particle and the viscosity of the carrier fluid, and a stable plugging layer cannot form if the mass concentration of the temporary plugging particle is less than 20 kg/m^(3)or the viscosity of the carrier fluid is greater than 3 mPa·s. When the ratio of particle size to fracture width is 0.60, the formation of the plugging layer is mainly controlled by the mass concentration of the temporary plugging particle, and a stable plugging layer cannot form if the mass concentration of the temporary plugging particle is less than 10 kg/m^(3). When the ratio of particle size to fracture width is 0.75, the formation of the plugging layer is basically not affected by other parameters, and a stable plugging layer can form within the experimental conditions. The formation process of plugging layer includes two stages and four modes. The main controlling factors affecting the formation mode are the ratio of particle size to fracture width, carrier fluid displacement and carrier fluid viscosity. 展开更多
关键词 hydraulic fracture temporary plugging and diversion temporary plugging particle plugging characteristics construction parameters combination
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Fracture propagation law of temporary plugging and diversion fracturing in shale reservoirs under completion experiments of horizontal well with multi-cluster sand jetting perforation 被引量:2
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作者 ZOU Yushi LI Yanchao +3 位作者 YANG Can ZHANG Shicheng MA Xinfang ZOU Longqing 《Petroleum Exploration and Development》 SCIE 2024年第3期715-726,共12页
This study conducted temporary plugging and diversion fracturing(TPDF)experiments using a true triaxial fracturing simulation system within a laboratory setting that replicated a lab-based horizontal well completion w... This study conducted temporary plugging and diversion fracturing(TPDF)experiments using a true triaxial fracturing simulation system within a laboratory setting that replicated a lab-based horizontal well completion with multi-cluster sand jetting perforation.The effects of temporary plugging agent(TPA)particle size,TPA concentration,single-cluster perforation number and cluster number on plugging pressure,multi-fracture diversion pattern and distribution of TPAs were investigated.A combination of TPAs with small particle sizes within the fracture and large particle sizes within the segment is conducive to increasing the plugging pressure and promoting the diversion of multi-fractures.The addition of fibers can quickly achieve ultra-high pressure,but it may lead to longitudinal fractures extending along the wellbore.The temporary plugging peak pressure increases with an increase in the concentration of the TPA,reaching a peak at a certain concentration,and further increases do not significantly improve the temporary plugging peak pressure.The breaking pressure and temporary plugging peak pressure show a decreasing trend with an increase in single-cluster perforation number.A lower number of single-cluster perforations is beneficial for increasing the breaking pressure and temporary plugging peak pressure,and it has a more significant control on the propagation of multi-cluster fractures.A lower number of clusters is not conducive to increasing the total number and complexity of artificial fractures,while a higher number of clusters makes it difficult to achieve effective plugging.The TPAs within the fracture is mainly concentrated in the complex fracture areas,especially at the intersections of fractures.Meanwhile,the TPAs within the segment are primarily distributed near the perforation cluster apertures which initiated complex fractures. 展开更多
关键词 shale temporary plugging and diversion fracturing multi-cluster sand jetting perforation distribution of temporary plugging agent fracture propagation law
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Theoretical Study on the Temporary Cavity Caused by a High Speed Projectile When Wounding Living Organisms 被引量:2
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作者 安波 蒋浩征 李杨 《Journal of Beijing Institute of Technology》 EI CAS 2001年第3期272-277,共6页
Analyzes and calculates the process of development of a temporary cavity in the muscle directly after a projectile wounds organisms at a high speed. The muscle is taken as a non compressible Voigt Kelvin viscoel... Analyzes and calculates the process of development of a temporary cavity in the muscle directly after a projectile wounds organisms at a high speed. The muscle is taken as a non compressible Voigt Kelvin viscoelastic fluid model, on the assumption of moving in a radial direction and on spherical symmetry, a theoretical model proposed using the basic equations of the non Newtonian fluid mechanics. The model can well describe the pulsation process of the temporary cavity and changes of pressure in the cavity. The calculated results are in correspondence with the experimental results. The model can be applied in the quantitative analysis of a temporary cavity. 展开更多
关键词 temporary cavity WOUND injury viscoelastic fluid
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A comprehensive review on biocompatible Mg-based alloys as temporary orthopaedic implants:Current status,challenges,and future prospects 被引量:17
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作者 Darothi Bairagi Sumantra Mandal 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第3期674-722,共49页
Mg and its alloys are drawing huge attention since the last two decades as a viable option for temporary implants applications.A commendable progress has already been made in the development of these alloys.The biodeg... Mg and its alloys are drawing huge attention since the last two decades as a viable option for temporary implants applications.A commendable progress has already been made in the development of these alloys.The biodegradable nature of Mg,appreciable biocompatibility of elemental Mg,and its close resemblance to natural bone in terms of density and elastic modulus make them highly preferable option amongst other available alternatives in this field.This review article presents an overview covering the recent advancements made in the field of Mg-based biodegradable implants for orthopaedic implant applications.The paper focuses on alloy development and fabrication techniques,the state of the art of important Mg-based alloy systems in terms of their mechanical properties,in-vitro and in-vivo degradation behaviour and cytotoxicity.Further,the paper reviews the current progress achieved in the clinical transition of Mg-based alloys for orthopaedic fixtures.The review also includes the degradation mechanisms of the alloys in physiological environment and highlights the mismatch existing between the rate of bone healing and alloy degradation due to rapid corrosion of the alloys in such environment,which has still restricted their widespread application.Finally,the surface coating techniques available for the alloys as an effective way to reduce the degradation rate are reviewed,followed by a discussion on the future research prospects. 展开更多
关键词 Mg-based alloys BIOMATERIALS temporary implants BIOCOMPATIBILITY Degradation behaviour orthopaedic fixtures.
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Open abdomen in gastrointestinal surgery:Which technique is the best for temporary closure during damage control? 被引量:12
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作者 Marcelo A F Ribeiro Junior Emily Alves Barros +3 位作者 Sabrina Marques de Carvalho Vinicius Pereira Nascimento José Cruvinel Neto Alexandre Zanchenko Fonseca 《World Journal of Gastrointestinal Surgery》 SCIE CAS 2016年第8期590-597,共8页
AIM To compare the 3 main techniques of temporary closure of the abdominal cavity,vacuum assisted closure(vacuum-assisted closure therapy- VAC),Bogota bag and Barker technique,in damage control surgery.METHODS After s... AIM To compare the 3 main techniques of temporary closure of the abdominal cavity,vacuum assisted closure(vacuum-assisted closure therapy- VAC),Bogota bag and Barker technique,in damage control surgery.METHODS After systematic review of the literature,33 articles were selected to compare the efficiency of the three procedures.Criteria such as cost,infections,capacity of reconstruction of the abdominal wall,diseases associated with the technique,among others were analyzed.RESULTS The Bogota bag and Barker techniques present as advantage the availability of material and low cost,what is not observed in the VAC procedure.The VAC technique is the most efficient,not only because it reduces the tension on the boarders of the lesion,but also removes stagnant fluids and debris and acts at cellular level increasing cell proliferation and division.Bogota bag presents the higher rates of skin laceration and evisceration,greater need for a stent for draining fluids and wash-ups,higher rates of intestinal adhesion to the abdominal wall.The Barker technique presents lack of efficiency in closing the abdominal wall and difficulty on maintaining pressure on the dressing.The VAC dressing can generate irritation and dermatitis when the drape is applied,in addition to pain,infection and bleeding,as well as toxic shock syndrome,anaerobic sepsis and thrombosis.CONCLUSION The VAC technique,showed to be superior allowing a better control of liquid on the third space,avoiding complications such as fistula with small mortality,low infection rate,and easier capability on primary closure of the abdominal cavity. 展开更多
关键词 TRAUMA Damage control ABDOMINAL COMPARTMENT syndrome temporary ABDOMINAL CLOSURE
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Development of degradable pre-formed particle gel(DPPG)as temporary plugging agent for petroleum drilling and production 被引量:8
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作者 Dao-Yi Zhu Xing-Yu Fang +3 位作者 Ren-Xian Sun Zeng-Hao Xu Yang Liu Ji-Yang Liu 《Petroleum Science》 SCIE CAS CSCD 2021年第2期479-494,共16页
Temporary plugging agent(TPA)is widely used in many fields of petroleum reservoir drilling and production,such as temporary plugging while drilling and petroleum well stimulation by diverting in acidizing or fracturin... Temporary plugging agent(TPA)is widely used in many fields of petroleum reservoir drilling and production,such as temporary plugging while drilling and petroleum well stimulation by diverting in acidizing or fracturing operations.The commonly used TPA mainly includes hard particles,fibers,gels,and composite systems.However,current particles have many limitations in applications,such as insufficient plugging strength and slow degradation rate.In this paper,a degradable pre-formed particle gel(DPPG)was developed.Experimental results show that the DPPG has an excellent static swelling effect and self-degradation performance.With a decrease in the concentration of total monomers or cross-linker,the swelling volume of the synthesized DPPG gradually increases.However,the entire self-degradation time gradually decreases.The increase in 2-acrylamide-2-methylpropanesulfonic acid(AMPS)in the DPPG composition can significantly increase its swelling ratio and shorten the self-degradation time.Moreover,DPPG has excellent high-temperature resistance(150°C)and high-salinity resistance(200,000 mg/L NaCl).Core displacement results show that the DPPG has a perfect plugging effect in the porous media(the plugging pressure gradient was as high as 21.12 MPa),and the damage to the formation after degradation is incredibly minor.Therefore,the DPPG can be used as an up-and-coming TPA in oil fields. 展开更多
关键词 temporary plugging agents Pre-formed particle gel(PPG) Degradable PPG Petroleum drilling Petroleum production
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Modified sewage sludge as temporary landfill cover material 被引量:7
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作者 Jun He Feng Li +1 位作者 Yong Li Xi-lin Cui 《Water Science and Engineering》 EI CAS CSCD 2015年第3期257-262,共6页
In order to study the feasibility of modified sewage sludge as landfill cover material and its performance in a complex landfill environment, strength and hydraulic conductivity tests were conducted. The permeability ... In order to study the feasibility of modified sewage sludge as landfill cover material and its performance in a complex landfill environment, strength and hydraulic conductivity tests were conducted. The permeability requirements for daily and interim covers were analyzed first. Based on saturated-unsaturated seepage calculations, it is suggested that approximately 1.0×10^-4 cm/s and 1.0 × 10^-5 cm/s are the appropriate values for the hydraulic conductivities of daily and interim covers, respectively. The strength and permeability requirements of the mixtures, when used as an interim cover, can be met at a sludge:lime:cement:silt:tire-derived aggregate (TDA) weight ratio of 100:15:5:70:15. Results also demonstrate that the solid content ratio of modified sewage sludge, which should be greater than 60% when modified sewage sludge is used as a temporary cover material, is crucial to both strength and hydraulic performance. In addition, as the duration of soaking of modified sewage sludge in synthetic leachate increases, the unconfined compressive strength increases, and the hydraulic conductivity decreases slightly or fluctuates between 1.0×10^-5 cm/s and 1.0 × 10^-6 cm/s, still meeting the requirements for an interim cover. The reduction in hydraulic conductivity of modified sewage sludge under the effect of synthetic leachate, as well as the long-term and environmental performance of the modified sewage sludge, should be examined in future studies. 展开更多
关键词 Modified sewage sludge temporary cover Hydraulic conductivity Unconfined compressive strength SOAKING
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Impact of Intraoperative Blood Pressure Control and Temporary Parent Artery Blocking on Prognosis in Cerebral Aneurysms Surgery 被引量:4
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作者 Min Xu Zheng-song Gu +5 位作者 Cun-zu Wang Xiao-feng Lu Ding-chao Xiang Zhi-cheng Yuan Qiao-yu Li Min Wu 《Chinese Medical Sciences Journal》 CAS CSCD 2016年第2期89-94,共6页
Objective In cerebral aneurysm clipping and embolization, blood pressure control and temporaryparent artery blocking are common methods to prevent aneurysm rupture. Their influence on the prognosis isuncertain. In thi... Objective In cerebral aneurysm clipping and embolization, blood pressure control and temporaryparent artery blocking are common methods to prevent aneurysm rupture. Their influence on the prognosis isuncertain. In this study, we try to find out the association between methods above and prognostic indicators. 展开更多
关键词 cerebral ANEURYSM INTRAOPERATIVE blood pressure control PROGNOSIS temporary PARENT artery BLOCKING
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Urgent Tracheal Resection and Reconstruction Assisted by Temporary Cardiopulmonary Bypass:a Case Report 被引量:7
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作者 Hui Gao Bin Zhu +2 位作者 Jie Yi Tie-hu Ye Yu-guang Huang 《Chinese Medical Sciences Journal》 CAS CSCD 2013年第1期55-57,共3页
SEVERE tracheal stenosis can not only cause criti- cal medical problems such as severe shortness of breath, hypoxia, and even orthopnea, but also impose overwhelming challenges on thephysicians, particularly the anest... SEVERE tracheal stenosis can not only cause criti- cal medical problems such as severe shortness of breath, hypoxia, and even orthopnea, but also impose overwhelming challenges on thephysicians, particularly the anesthesiologist. Life-threa- tening airway obstruction can make the patient's gas ex- change extremely difficult. Though several options could be offered regarding the treatment of tracheal stenosis, normally, tracheal resection and following reconstruction is the first choice for severe airway stenosis.1 Successful surgical intervention relies on the close communication and cooperation between surgeons and anesthesiologists. 展开更多
关键词 tracheal resection tracheal reconstruction temporary cardiopulmonary bypass
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Complex fracture propagation model and plugging timing optimization for temporary plugging fracturing in naturally fractured shale 被引量:4
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作者 TANG Xuanhe ZHU Haiyan +1 位作者 CHE Mingguang WANG Yonghui 《Petroleum Exploration and Development》 2023年第1期152-165,共14页
In this paper,a viscoelasticity-plastic damage constitutive equation for naturally fractured shale is deduced,coupling nonlinear tensile-shear mixed fracture mode.Dynamic perforation-erosion on fluid re-distribution a... In this paper,a viscoelasticity-plastic damage constitutive equation for naturally fractured shale is deduced,coupling nonlinear tensile-shear mixed fracture mode.Dynamic perforation-erosion on fluid re-distribution among multi-clusters are considered as well.DFN-FEM(discrete fracture network combined with finite element method)was developed to simulate the multi-cluster complex fractures propagation within temporary plugging fracturing(TPF).Numerical results are matched with field injection and micro-seismic monitoring data.Based on geomechanical characteristics of Weiyuan deep shale gas reservoir in Sichuan Basin,SW China,a multi-cluster complex fractures propagation model is built for TPF.To study complex fractures propagation and the permeability-enhanced region evolution,intersecting and competition mechanisms between the fractures before and after TPF treatment are revealed.Simulation results show that:fracture from middle cluster is restricted by the fractures from side-clusters,and side-clusters plugging is benefit for multi fractures propagation in uniformity;optimized TPF timing should be delayed within a higher density or strike of natural fractures;Within a reservoir-featured natural fractures distribution,optimized TPF timing for most clustered method is 2/3 of total fluid injection time as the optimal plugging time under different clustering modes. 展开更多
关键词 shale gas naturally fractured shale temporary plugging fracturing fracture propagation plugging timing discrete fracture network finite element method
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Qualitative exploration of home life experiences and care needs among elderly patients with temporary intestinal stomas 被引量:3
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作者 Si-Meng Wang Jian-Ling Jiang +5 位作者 Rui Li Juan-Juan Wang Chun-Hong Gu Jia Zeng Xiao-Hui Wei Mei Chen 《World Journal of Gastroenterology》 SCIE CAS 2024年第22期2893-2901,共9页
BACKGROUND This study employed a phenomenological research approach within qualitative research to explore the challenges encountered by elderly individuals with temporary colostomies in managing their daily lives and... BACKGROUND This study employed a phenomenological research approach within qualitative research to explore the challenges encountered by elderly individuals with temporary colostomies in managing their daily lives and care needs.Protecting the anus surgery combined with temporary colostomy has emerged as a prevalent treatment modality for low rectal cancer.However,the ileostomy is susceptible to peri-stoma skin complications,as well as fluid,electrolyte,and nutritional imbalances,posing challenges to effective management.The successful selfmanagement of patients is intricately linked to their adjustment to temporary colostomy;nonetheless,there remains a dearth of research examining the factors influencing self-care among temporary colostomy patients and the obstacles they confront.AIM To investigate the lived experiences,perceptions,and care requirements of temporary colostomy patients within their home environment,with the ultimate goal of formulating a standardized management protocol.METHODS Over the period of June to August 2023,a purposive sampling technique was utilized to select 12 patients with temporary intestinal stomas from a tertiary hospital in Shanghai,China.Employing a phenomenological research approach,a semi-structured interview guide was developed,and qualitative interviews were conducted using in-depth interview techniques.The acquired data underwent coding,analysis,organization,and summarization following Colaizzi’s seven-step method.RESULTS The findings of this study revealed that the experiences and needs of patients with temporary intestinal stomas can be delineated into four principal themes:Firstly,Temporary colostomy patients bear various burdens and concerns about the uncertainty of disease progression;secondly,patients exhibit limited self-care capabilities and face information deficits,resulting in heightened reliance on healthcare professionals;thirdly,patients demonstrate the potential for internal motivation through proactive self-adjustment;and finally,patients express a significant need for emotional and social support.CONCLUSION Home-living patients with temporary intestinal stomas confront multifaceted challenges encompassing burdens,inadequate self-care abilities,informational deficits,and emotional needs.Identifying factors influencing patients’self-care at home and proposing strategies to mitigate barriers can serve as a foundational framework for developing and implementing nursing interventions tailored to the needs of patients with temporary intestinal stomas. 展开更多
关键词 ELDERLY temporary intestinal stomas Life experiences Intestinal ostomy complications Qualitative study
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Degradable preformed particle gel as temporary plugging agent for low-temperature unconventional petroleum reservoirs:Effect of molecular weight of the cross-linking agent 被引量:2
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作者 Hong-Jun Zhang Dao-Yi Zhu +8 位作者 Yong-Long Gong Jun-Hui Qin Xiao-Ning Liu Yuan-Hang Pi Qi Zhao Run-Tian Luo Wan-Sheng Wang Ke-Ke Zhi Zong-Jie Mu 《Petroleum Science》 SCIE CAS CSCD 2022年第6期3182-3193,共12页
The development of unconventional petroleum resources has gradually become an important succession for increasing oil production.However,the related engineers and researchers are paying more and more attention to the ... The development of unconventional petroleum resources has gradually become an important succession for increasing oil production.However,the related engineers and researchers are paying more and more attention to the application of temporary plugging agents(TPAs)for their efficient development.TPAs can expand the stimulated reservoir volume(SRV)and facilitate the flow of oil and gas to the bottom of the well.Particle-gels used as temporary plugging agents have the characteristics of the simple injection process,good deformation,high plugging strength,and complete self-degradation performance,which have been widely applied in recent years.In this paper,five samples of DPPG polymerized by different molecular weights of cross-linking agents were prepared.In addition,infrared spectroscopy analysis,differential calorimetry scanning(DSC)analysis,static particle gel swelling and degradation performance evaluation experiments,and dynamic temporary plugging performance experiments in cores were conducted at 34°C.Results show that as the molecular weight of the cross-linking agent(at 0.01 g)in the DPPG molecule decreased from 1,000 to 200 Da,the fewer cross-linking sites of DPPG,the looser the microscopic three-dimensional mesh structure formed.The swelling ratio increased from 7 to 33 times.However,the complete degradation time increased from 40 to 210 min.Moreover,the DSC results confirmed that the higher the molecular weight of the cross-linking agent,the worse is chemical stability and the more prone it to self-degradation.DPPG samples had good temporary plugging performance in reservoir cores.DPPGs prepared by the cross-linking agent with smaller molecular weight has a stronger swelling ratio,higher gel strength,and greater plugging strength in the core permeabilities.Moreover,the degraded DPPG is less damaging to the cores.However,their slower degradation rates take a slightly longer times to reach complete degradation.The results of this paper can provide new ideas and a theoretical basis for the development of particle gel-type temporary plugging agents(TPA)with controllable degradation time in low-temperature reservoirs.It can help to expand the application range of existing DPPG reservoir conditions. 展开更多
关键词 temporary plugging agent Preformed particle gel Degradable cross-linking agent Molecular weight Low-temperature reservoir
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Following Control for a UUV using Temporary Path Generation Guidance 被引量:2
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作者 Zheping Yan Dongnan Chi Jiajia Zhou Yufei Zhao 《Journal of Marine Science and Application》 2012年第2期236-243,共8页
A path following control algorithm for an unmanned underwater vehicle(UUV) using temporary path generation guidance was proposed in this paper.Owing to different initial states of the vehicle,such as position and or... A path following control algorithm for an unmanned underwater vehicle(UUV) using temporary path generation guidance was proposed in this paper.Owing to different initial states of the vehicle,such as position and orientation,the path following control in the horizontal plane may yield a poor performance.To deal with the negative effect induced by initial states,a temporary path generation was presented based on the relationship between the original reference path and the vehicle’s initial states.With different relative positions between the vehicle and reference path,including out of straight lines,as well as inside and outside a circle,the related temporary paths guiding the vehicle to the reference path were able to be generated in real time.The vehicle was guided to steer along the temporary path until it reached the tangent point at the reference path,where the controller was designed using the input-output feedback linearization method.Simulation results demonstrated that the proposed algorithm is effective under the three different situations mentioned above. 展开更多
关键词 nonlinear control path following control UUV temporary path generation input-output feedback linearization
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An Approach for Micropropagation of Blueberry (<i>Vaccinium corymbosum</i>L.) Plants Mediated by Temporary Immersion Bioreactors (TIBs) 被引量:2
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作者 Ariel D. Arencibia Carolina Vergara +3 位作者 Karla Quiroz Basilio Carrasco Carmen Bravo Rolando Garcia-Gonzales 《American Journal of Plant Sciences》 2013年第5期1022-1028,共7页
A new procedure for blueberry (Vaccinium corymbosum L.) micropropagation in programmed Temporary Immersion Bioreactors (TIBs based on two separate bottles) was developed for the commercial genotypes Biloxi, Sharp Blue... A new procedure for blueberry (Vaccinium corymbosum L.) micropropagation in programmed Temporary Immersion Bioreactors (TIBs based on two separate bottles) was developed for the commercial genotypes Biloxi, Sharp Blue and Brillita. Plant cultures were developed in a controlled environment with 0.4 MPa CO2 enrichment, sucrose-reduced medium, and light intensity of 60 mM m-2·s-1. Principal component analysis showed that component 1 (C1) grouped 64.08% of the total variability, while the first two components accounted for 86.97%. Representation of the principal components demonstrated three clusters corresponding with the blueberry genotypes, and within each cluster plants micropropagated in agar-base medium grouped separately from those plants multiplied in TIBs. Both plant number and total internodes traits (related to the productive efficiency) were demonstrated superior in blueberries propagated in TIBs. Additionally, when transferred to greenhouse conditions, blueberries propagated in TIBs showed higher adaptability and growing rates than those cultured by the conventional approach, altogether evidencing the occurrence of a photomixotrophic stage in the vitroplantlets cultured in TIBs. 展开更多
关键词 temporary Immersion Bioreactors VACCINIUM corymbosum L. Photomixotrophic BLUEBERRY MICROPROPAGATION
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Evaluation of Long-term Stability of Vertical Control in Hyperdivergent Patients Treated with Temporary Anchorage Devices 被引量:1
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作者 Jin-rong DENG Yan-ang LI +3 位作者 Xue-dong WANG Jing LI Yun DING Yan-heng ZHOU 《Current Medical Science》 SCIE CAS 2018年第5期914-919,共6页
This study aims to evaluate,the long-term stability of vertical control in hyperdivergent patients treated with temporary anchorage devices.The sample included 20 hyperdivergent patients without anterior open bite.The... This study aims to evaluate,the long-term stability of vertical control in hyperdivergent patients treated with temporary anchorage devices.The sample included 20 hyperdivergent patients without anterior open bite.The temporary anchorage devices were used to intrude the upper incisor and molars for vertical control.Lateral cephalograms were established prior to treatment,immediately after treatment,and during retention. The upper molars and incisors were intruded by 1.33 mm and 1.41 mm after treatment (P<0.05).U6-PP increased by 0.11 mm and 0.23 mm during the first and second stages of retention (P>0.05).U1-PP was found to possess a significant extrusion of 1.2 mm during the first stage (P<0.05),which increased by 0.68 mm during the second stage (P>0.05). The mandibular plane angle (MP-SN)decreased by 2.58 degrees following treatment, and underwent a relapse of 0.51 degree and 0.42 degree during the first and second stages of retention respectively (P>0.05).No significant soft tissue changes occurred,with the exception of increased upper lip length during the second stage (P<0.05).Maxillary anterior and posterior intrusions,counter clockwise rotation,of the mandibular plane,and improved profiles can be successfully achieved following treatment with vertical control. During the first stage of retention (less than three years),intruded molars and incisors both exhibited some extrusion,and molars had better long-term stability than incisors. During the second stage of retention (three to six years),the therapeutic effects appeared stable,with the exception of some increase in upper lip length.Rotated mandibular plane remained stable during the entire retention period. 展开更多
关键词 hyperdivergent temporary ANCHORAGE DEVICES MOLAR INTRUSION VERTICAL control
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