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Dissolvable temporary barrier:a novel paradigm for flexible hydrogel patterning in organ-on-a-chip models
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作者 Ding Wang Qinyu Li +5 位作者 Chenyang Zhou Zhangjie Li Kangyi Lu Yijun Liu Lian Xuan Xiaolin Wang 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第2期153-166,共14页
A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as organ-on-a-chipmodels.The hydrogel patterningwith awell-controlled... A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as organ-on-a-chipmodels.The hydrogel patterningwith awell-controlled spatial distribution is typically achieved by embedding sophisticated microstructures to act as a boundary.However,these physical barriers inevitably expose cells/tissues to a less physiologically relevant microenvironment than in vivo conditions.Herein,we present a novel dissolvable temporary barrier(DTB)strategy that allows robust and flexible hydrogel patterning with great freedom of design and desirable flow stimuli for cellular hydrogels.The key aspect of this approach is the patterning of a water-soluble rigid barrier as a guiding path for the hydrogel using stencil printing technology,followed by a barrier-free medium perfusion after the dissolution of the DTB.Single and multiple tissue compartments with different geometries can be established using either straight or curved DTB structures.The effectiveness of this strategy is further validated by generating a 3D vascular network through vasculogenesis and angiogenesis using a vascularized microtumor model.As a new proof-of-concept in vasculature-on-a-chip,DTB enables seamless contact between the hydrogel and the culture medium in closed microdevices,which is an improved protocol for the fabrication ofmultiorgan chips.Therefore,we expect it to serve as a promising paradigm for organ-on-a-chip devices for the development of tumor vascularization and drug evaluation in the future preclinical studies. 展开更多
关键词 Dissolvable temporary barrier Hydrogel patterning Microfluidics Organ-on-a-chip Vascularization
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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
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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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HVOF-sprayed HAp/S53P4 BG composite coatings on an AZ31 alloy for potential applications in temporary implants
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作者 Carlos A.Poblano-Salas John Henao +6 位作者 Astrid L.Giraldo-Betancur Paola Forero-Sossa Diego German Espinosa-Arbelaez Jorge A.González-Sánchez Luis R.Dzib-Pérez Susana T.Estrada-Moo Idelfonso E.Pech-Pech 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期345-360,共16页
Bioactive thermal spray coatings produced via high-velocity oxygen fuel spray(HVOF)from hydroxyapatite(HAp)and bioactive glasses(BG)have the potential to be employed on temporary implants due to the ability of both HA... Bioactive thermal spray coatings produced via high-velocity oxygen fuel spray(HVOF)from hydroxyapatite(HAp)and bioactive glasses(BG)have the potential to be employed on temporary implants due to the ability of both HAp and BG to dissolve and promote osseointegration,considering that both phases have different reaction and dissolution rates under in-vitro conditions.In the present work,75%wt.HAp-25%wt.S53P4 bioactive glass powders were HVOF-sprayed to obtain HAp/S53P4 BG composite coatings on a bioresorbable AZ31 alloy.The study is focused on exploring the effect of the stand-off distance and fuel/oxygen ratio variation as HVOF parameters to obtain stable structural coatings and to establish their effect on the phases and microstructure produced in those coatings.Different characterization techniques,such as scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy,were employed to characterize relevant structural and microstructural properties of the composite coatings.The results showed that thermal gradients during coating deposition must be managed to avoid delamination due to the high temperature achieved(max 550℃)and the differences in coefficients of thermal expansion.It was also found that both spraying distance and oxygen/fuel ratio allowed to keep the hydroxyapatite as the main phase in the coatings.In addition,in-vitro electrochemical studies were performed on the obtained HAp/S53P4 BG composite coatings and compared against the uncoated AZ31 alloy.The results showed a significant decrease in hydrogen evolution(at least 98%)when the bioactive coating was applied on the Mg alloy during evaluation in simulated body fluid(SBF). 展开更多
关键词 Coatings Composites Thermal spray Temporary implants Hydrogen evolution
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Qualitative exploration of home life experiences and care needs among elderly patients with temporary intestinal stomas
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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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Laser speckle contrast imaging to predict the effect of temporary spinal cord stimulation in postherpetic neuralgia patients: A prospective observational study
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作者 Xiang Huang Dacheng Tang +3 位作者 Pan Chen Lumiao Chen Xiaohong Li Xiaoping Wang 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2024年第1期69-75,共7页
Temporary spinal cord stimulation(tSCS)can effectively reduce the pain and severity of postherpetic neuralgia(PHN).However,there are no effective and objective methods for predicting the effects of tSCS on PHN.Laser s... Temporary spinal cord stimulation(tSCS)can effectively reduce the pain and severity of postherpetic neuralgia(PHN).However,there are no effective and objective methods for predicting the effects of tSCS on PHN.Laser speckle contrast imaging(LSCI)is frequently used in neurology to evaluate the effectiveness of treatment.To assess the accuracy of LSCI in predicting the impact of tSCS on PHN,14 adult patients receiving tSCS treatments for spinal nerve-innervated(C6-T2)PHN participated in this observational study.Visual analog scale(VAS)assessments and LSCI bloodflow images of the-ngers were recorded after the tSCS procedure.The results showed that the VAS scores of all patients decreased signi-cantly.Moreover,the bloodflow index(BFI)values were signi-cantly higher than they were before the procedure.Increased bloodflow and pain alleviation were positively correlated.The-ndings indicated that spinal nerve PHN(C6-T2)was signi-cantly reduced by tSCS.Pain alleviation by tSCS was positively correlated with increased bloodflow in the hand.The effect of tSCS on PHN may thus be predicted using an independent and consistent indicator such as LSCI. 展开更多
关键词 Laser speckle contrast imaging temporary spinal cord stimulation postherpetic neuralgia
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Comparative study between Embosphere®and Marine gel®as embolic agents for chemoembolization of hepatocellular carcinoma
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作者 Hyo-Cheol Kim Jin Woo Choi 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第1期102-109,共8页
BACKGROUND While gelatin sponge particles and calibrated microspheres are commonly used as embolic materials in conventional transarterial chemoembolization(cTACE),direct comparisons between these embolic agents are r... BACKGROUND While gelatin sponge particles and calibrated microspheres are commonly used as embolic materials in conventional transarterial chemoembolization(cTACE),direct comparisons between these embolic agents are rare.AIM To compare the efficacy and safety of superselective cTACE using Embosphere®or Marine gel®in patients with early-stage hepatocellular carcinoma(HCC).METHODS This retrospective study included 70 patients with small(<4 cm)HCC who underwent cTACE with Embosphere®(n=33)or Marine gel®(n=37)as the embolic agent at a single center between March 2021 and July 2022.The radiologic images and clinical data were retrospectively reviewed,with an emphasis on tumor response,procedure-related complications,and local tumor recurrence.The primary index tumor was assessed on a 1-mo follow-up image,and local progression-free survival was obtained using the Kaplan-Meier method and was compared by the log-rank test.RESULTS The median tumor size of both groups was 1.5 cm,and 69 patients achieved a complete response one month after cTACE.The cumulative local recurrence rate at 12 mo was 15.5%in the Embosphere®group and 14.4%in the Marine gel®group.The local progression-free survival was not significantly different between the two groups(P=0.83).In the multivariate analysis,high serum alphafetoprotein was the only significant poor prognostic factor for local tumor progression(P=0.01).Postembolization syndrome occurred in 36.4%of the Embosphere®group and 35.1%of the Marine gel®group,and there were no cases of biloma,biliary duct dilation,or liver abscess in either group.CONCLUSION Calibrated gelatin sponge particles(Marine gel®)and calibrated microspheres(Embosphere®)have similar outcomes in terms of tumor response for superselective cTACE of small HCC. 展开更多
关键词 Hepatocellular carcinoma CHEMOEMBOLIZATION Temporary embolic material Permanent embolic material Tumor response
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Discussion on Land Use Mode Reform in Coal Opencast Mining
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作者 Hong ZHANG Lin LIN 《Asian Agricultural Research》 2024年第1期25-28,共4页
The existing land supply mode of opencast mining is"land requisition first,then transfer",which lacks an effective recovery and withdrawal mechanism,and the reclaimed mining land is difficult to withdraw.Acc... The existing land supply mode of opencast mining is"land requisition first,then transfer",which lacks an effective recovery and withdrawal mechanism,and the reclaimed mining land is difficult to withdraw.According to the regular rules of coal opencast mining and the periodic characteristics of land use,this paper puts forward a new mode of temporary land use for coal opencast mining.It is conducive to im-proving the quality and scale of land use and reclamation utilization of opencast coal mining,and is of great significance for exploring and for-mulating reasonable land use policies for mineral resources development projects. 展开更多
关键词 Opencast mine Temporary land use Land requisition RECLAMATION Withdrawal mechanism
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Clinical Efficacy of GBR Technique Combined with Temporary Bridgework-Guided Gingival Contouring in Treating Upper Anterior Tooth Loss with Labial Bone Defects
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作者 Yu Ma Jirui Ma 《Journal of Clinical and Nursing Research》 2024年第6期171-176,共6页
Objective:To investigate the clinical effect of the guided bone regeneration(GBR)technique combined with temporary bridgework-guided gingival contouring in treating upper anterior tooth loss with labial bone defects.M... Objective:To investigate the clinical effect of the guided bone regeneration(GBR)technique combined with temporary bridgework-guided gingival contouring in treating upper anterior tooth loss with labial bone defects.Methods:From July 2023 to April 2024,80 patients with upper anterior tooth loss and labial bone defects were admitted to the hospital and selected as evaluation samples.They were divided into an observation group(n=40)and a control group(n=40)using a numerical table lottery scheme.The control group received treatment with the GBR technique,while the observation group received treatment with the GBR technique combined with temporary bridges to guide gingival contouring.The two groups were compared in terms of clinical red aesthetic scores(PES),labial alveolar bone density,labial bone wall thickness,gingival papillae,gingival margin levels,and patient satisfaction.Results:The PES scores of patients in the observation group were higher than those in the control group after surgery(P<0.05).The bone density of the labial alveolar bone and the thickness of the labial bone wall in the observation group were higher than those in the control group.The levels of gingival papillae and gingival margins were lower in the observation group after surgery(P<0.05).Additionally,patient satisfaction in the observation group was higher than in the control group(P<0.05).Conclusion:The GBR technique combined with temporary bridge-guided gingival contouring for treating upper anterior tooth loss with labial bone defects can improve the aesthetic effect of gingival soft tissue,increase alveolar bone density and the thickness of the labial bone wall,and enhance patient satisfaction.This approach is suitable for widespread application in healthcare institutions. 展开更多
关键词 Upper anterior teeth loss Labial bone defects Guided bone regeneration(GBR)technique Temporary bridgework-guided gingival contouring
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Emergency internal iliac artery temporary occlusion after massive hemorrhage during surgery of cesarean scar pregnancy:A case report 被引量:1
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作者 Ji-Ping Xie Lin-Lin Chen +3 位作者 Wen Lv Wu Li Hui Fang Guang Zhu 《World Journal of Clinical Cases》 SCIE 2023年第17期4065-4071,共7页
BACKGROUND Cesarean scar pregnancy(CSP)is rare but may result in uterine rupture during pregnancy or massive hemorrhage during abortion procedures.Awareness of this condition is increasing,and most patients with CSP a... BACKGROUND Cesarean scar pregnancy(CSP)is rare but may result in uterine rupture during pregnancy or massive hemorrhage during abortion procedures.Awareness of this condition is increasing,and most patients with CSP are now diagnosed early and can be managed safely.However,some atypical patients are misdiagnosed,and their surgical risks are underestimated,increasing the risk of fatal hemorrhage.CASE SUMMARY A 27-year-old Asian woman visited our institution because of abnormal pregnancy,and she was diagnosed with a hydatidiform mole through transvaginal ultrasound(TVS).Under hysteroscopy,a large amount of placental tissue was found in the scar of the lower uterine segment,and a sudden massive hemorrhage occurred during the removal process.The bilateral internal iliac arteries were temporarily blocked under laparoscopy,and scar resection and repair were rapidly performed.She was discharged in good condition 5 d after the operation.CONCLUSION Although TVS is widely used in the diagnosis of CSP,delays in the diagnosis of atypical CSP remain.Surgical treatment following internal iliac artery temporary occlusion may be an appropriate management method for unanticipated massive hemorrhage during CSP surgery. 展开更多
关键词 Internal iliac artery temporary occlusion Cesarean scar pregnancy Uterine artery embolization MISDIAGNOSIS HYSTEROSCOPY LAPAROSCOPY Case report
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Plugging behaviors of temporary plugging particles in hydraulic fractures
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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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Estrada index of dynamic random graphs
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作者 SHANG Yi-lun 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第2期159-165,共7页
The Estrada index of a graph G on n vertices is defined by EE(G)=∑^(n)_(i=1)^(eλ_(i)),whereλ_(1),λ_(2),···,λ_(n)are the adjacency eigenvalues of G.We define two general types of dynamic graphs evol... The Estrada index of a graph G on n vertices is defined by EE(G)=∑^(n)_(i=1)^(eλ_(i)),whereλ_(1),λ_(2),···,λ_(n)are the adjacency eigenvalues of G.We define two general types of dynamic graphs evolving according to continuous-time Markov processes with their stationary distributions matching the Erd¨os-R´enyi random graph and the random graph with given expected degrees,respectively.We formulate some new estimates and upper and lower bounds for the Estrada indices of these dynamic graphs. 展开更多
关键词 Estrada index temporary graph Markov process EIGENVALUE
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Complex fracture propagation model and plugging timing optimization for temporary plugging fracturing in naturally fractured shale
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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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Open abdomen in gastrointestinal surgery:Which technique is the best for temporary closure during damage control? 被引量:10
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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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A comprehensive review on biocompatible Mg-based alloys as temporary orthopaedic implants:Current status,challenges,and future prospects 被引量:6
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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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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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Quantitative investigation of multi-fracture morphology during TPDF through true tri-axial fracturing experiments and CT scanning 被引量:6
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作者 Ming-Hui Li Fu-Jian Zhou +3 位作者 Jin-Jun Liu Li-Shan Yuan Guo-Peng Huang Bo Wang 《Petroleum Science》 SCIE CAS CSCD 2022年第4期1700-1717,共18页
Due to the reservoir heterogeneity and the stress shadow effect, multiple hydraulic fractures within one fracturing segment cannot be initiated simultaneously and propagate evenly, which will cause a low effectiveness... Due to the reservoir heterogeneity and the stress shadow effect, multiple hydraulic fractures within one fracturing segment cannot be initiated simultaneously and propagate evenly, which will cause a low effectiveness of reservoir stimulation. Temporary plugging and diverting fracturing(TPDF) is considered to be a potential uniform-stimulation method for creating multiple fractures simultaneously in the oilfield. However, the multi-fracture propagation morphology during TPDF is not clear now. The purpose of this study is to quantitatively investigate the multi-fracture propagation morphology during TPDF through true tri-axial fracturing experiments and CT scanning. Critical parameters such as fracture spacing, number of perforation clusters, the viscosity of fracturing fluid, and the in-situ stress have been investigated. The fracture geometry before and after diversion have been quantitively analyzed based on the two-dimensional CT slices and three-dimensional reconstruction method. The main conclusions are as follows:(1) When injecting the high viscosity fluid or perforating at the location with low in-situ stress, multiple hydraulic fractures would simultaneously propagate. Otherwise, only one hydraulic fracture was created during the initial fracturing stage(IFS) for most tests.(2) The perforation cluster effectiveness(PCE) has increased from 26.62% during the IFS to 88.86% after using diverters.(3) The diverted fracture volume has no apparent correlation with the pressure peak and peak frequency during the diversion fracturing stage(DFS) but is positively correlated with water-work.(4) Four types of plugging behavior in shale could be controlled by adjusting the diverter recipe and diverter injection time, and the plugging behavior includes plugging the natural fracture in the wellbore, plugging the previous hydraulic fractures, plugging the fracture tip and plugging the bedding. 展开更多
关键词 Hydraulic fracturing Temporary plugging and diverting fracturing(TPDF) Multiple fracture Tri-axial experiment CT scanning
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Development of degradable pre-formed particle gel(DPPG)as temporary plugging agent for petroleum drilling and production 被引量:5
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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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High-strength and self-degradable sodium alginate/polyacrylamide preformed particle gels for conformance control to enhance oil recovery 被引量:4
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作者 Xiao Zhang Jia-Nan Deng +11 位作者 Kai Yang Qian Li Sen-Yao Meng Xiu-Xia Sun Zhao-Zheng Song Yong-Dong Tian Sui-An Zhang Xin-Jia Liu Zhan-Yi Wang Xin-Yu Liu Gui-Wu Lu Zi-Long Liu 《Petroleum Science》 SCIE CAS CSCD 2022年第6期3149-3158,共10页
Excess water production has become an important issue in the oil and gas extraction process.Preformed particle gels(PPGs),show the capability to control the conformance and reduce excess water cut.However,conventional... Excess water production has become an important issue in the oil and gas extraction process.Preformed particle gels(PPGs),show the capability to control the conformance and reduce excess water cut.However,conventional PPGs have poor mechanical properties and their swollen particles are easily damaged by shearing force when passing through the fractures in formations,meanwhile PPGs can be also degraded into various byproducts,leading to permanent damage to the reservoir permeability after temporary plugging.Herein,a novel type of dual cross-linked PPGs(dPPGs)was designed and synthesized using sodium alginate(SA)and acrylamide(AAm),cross-linked with N,N’-methylenebisacrylamide(MBA)and Fe^(3+).Results show that dPPGs have excellent mechanical properties with a storage modulus up to 86,445 Pa,which is almost 20 times higher than other reported PPGs.Meanwhile,dPPGs can be completely degraded into liquid without any solid residues or byproducts and the viscosity of dPPGs degraded liquid was found to be lower than 5 mPa·s.A laboratory coreflooding test showed that the plugging efficiency of dPPGs was up to 99.83%on open fractures.The obtained results demonstrated that dPPGs could be used as economical and environment-friendly temporary plugging agent with high-strength,self-degradation,thermal stability,and salt stability,thus making it applicable to a wide range of conformance control to enhance oil recovery. 展开更多
关键词 Conformance control Sodium alginate Dual cross-linked Temporary plugging agent HIGH-STRENGTH Self-degradation
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Impact of Intraoperative Blood Pressure Control and Temporary Parent Artery Blocking on Prognosis in Cerebral Aneurysms Surgery 被引量:3
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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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Successful balloon-occluded retrograde transvenous obliteration for bleeding duodenal varices using cyanoacrylate 被引量:3
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作者 Rintaro Hashimoto Keitaro Sofue +2 位作者 Yoshito Takeuchi Kentaro Shibamoto Yasuaki Arai 《World Journal of Gastroenterology》 SCIE CAS 2013年第6期951-954,共4页
A 76-year-old woman with hepatitis C cirrhosis presented with tarry stools and hematemesis.An endoscopy demonstrated bleeding duodenal varices in the second portion of the duodenum.Contrast-enhanced computed tomograph... A 76-year-old woman with hepatitis C cirrhosis presented with tarry stools and hematemesis.An endoscopy demonstrated bleeding duodenal varices in the second portion of the duodenum.Contrast-enhanced computed tomography revealed markedly tortuous varices around the wall in the duodenum.Several afferent veins appeared to have developed,and the right ovarian vein draining into the inferior vena cava was detected as an efferent vein.Balloon-occluded retrograde transvenous obliteration (BRTO) of the varices using cyanoacrylate was successfully performed in combination with the temporary occlusion of the portal vein.Although no previous publications have used cyanoacrylate as an embolic agent for BRTO to control bleeding duodenal varices,this strategy can be considered as an alternative procedure to conventional BRTO using ethanolamine oleate when numerous afferent vessels that cannot be embolized are present. 展开更多
关键词 BLEEDING DUODENAL VARICES Balloon-occluded retrograde TRANSVENOUS OBLITERATION CYANOACRYLATE Combination therapy Temporary portal vein occlusion
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