The casing deformation prevention technology based on the optimization of cement slurry is proposed to reduce the casing deformation of shale oil and gas wells during hydraulic fracturing. In this paper, the fracture ...The casing deformation prevention technology based on the optimization of cement slurry is proposed to reduce the casing deformation of shale oil and gas wells during hydraulic fracturing. In this paper, the fracture mechanism of hollow particles in cement sheath was firstly analyzed by discrete element method, and the effect of hollow particles in cement on casing deformation was investigated by laboratory experiment method. Finally, field test was carried out to verify the improvement effect of the casing deformation based on cement slurry modification. The results show that the formation displacement can be absorbed effectively by hollow particles inside the cement transferring the excessive deformation away from casing. The particles in the uncemented state provide deformation space during formation slipping. The casing with diameter of 139.7 mm could be passed through by bridge plug with the diameter of 99 mm when the mass ratio of particle/cement reaches 1:4. According to the field test feedback, the method based on optimization of cement slurry can effectively reduce the risk of casing deformation, and the recommended range of hollow microbeads content in the cement slurry is between 15% and 25%.展开更多
The subsea production system is a vital equipment for offshore oil and gas production.The control system is one of the most important parts of it.Collecting and processing the signals of subsea sensors is the only way...The subsea production system is a vital equipment for offshore oil and gas production.The control system is one of the most important parts of it.Collecting and processing the signals of subsea sensors is the only way to judge whether the subsea production control system is normal.However,subsea sensors degrade rapidly due to harsh working environments and long service time.This leads to frequent false alarm incidents.A combinatorial reasoning-based abnormal sensor recognition method for subsea production control system is proposed.A combinatorial algorithm is proposed to group sensors.The long short-term memory network(LSTM)is used to establish a single inference model.A counting-based judging method is proposed to identify abnormal sensors.Field data from an offshore platform in the South China Sea is used to demonstrate the effect of the proposed method.The results show that the proposed method can identify the abnormal sensors effectively.展开更多
Microbes well-adapted to the Arctic Ocean are promising for producing novel compounds,due to their fancy strategies for adaptation and being under-investigated.Two new phenazine alkaloids(1 and 2)and one new phenoxa-z...Microbes well-adapted to the Arctic Ocean are promising for producing novel compounds,due to their fancy strategies for adaptation and being under-investigated.Two new phenazine alkaloids(1 and 2)and one new phenoxa-zine(3)were isolated from Nocardiopsis dassonvillei 502F,a strain originally isolated from Arctic deep-sea sediments.AntiSMASH analysis of the genome of Nocardiopsis dassonvillei 502F revealed the presence of 16 putative biosynthetic gene clusters(BGCs),including a phenazine BGC.Most of the isolated compounds were evaluated for their antibacterial,antiallergic,and cytotoxic activities.Among them,compounds 4 and 5 exhibited potent in vitro cytotoxic activities against osteosarcoma cell line 143B with IC_(50) values 0.16 and 20.0μM,respectively.Besides,the results of antiallergic activities of compounds 6-8 exhibited inhibitory activities with IC_(50) values of 10.88±3.05,38.88±3.29,and 2.44±0.17μg/mL,respectively(IC_(50)91.6μM for the positive control loratadine).展开更多
Parkinson's disease(PD) can be classified into three motor-based subtypes: postural instability/gait difficulty(PIGD), tremor dominant(TD), and indeterminate.The neuropathophysiological mechanisms of the three mot...Parkinson's disease(PD) can be classified into three motor-based subtypes: postural instability/gait difficulty(PIGD), tremor dominant(TD), and indeterminate.The neuropathophysiological mechanisms of the three motor subtypes are different, which may lead to different responses to therapy.Sixty-nine patients with idiopathic Parkinson's disease(Hoehn–Yahr stage ≤ 3) were screened from 436 patients with Parkinsonism recruited through outpatient services and the internet.According to the Movement Disorder Society Unified Parkinson's Disease Rating Scale(MDS-UPDRS) TD/PIGD ratio, the patients were divided into PIGD(TD/PIGD ≤ 0.09;n = 36), TD(TD/PIGD ≥1.15;n = 19), and indeterminate(TD/PIGD = 0.90–1.15;n = 14) groups.All patients received 2 weeks of multidisciplinary intensive rehabilitation treatment(MIRT) during hospitalization, as well as a remote home rehabilitation health education class.Compared with the scores at admission, all patients showed significant improvements in their MDS-UPDRS III score, walking ability, balance, and posture control at discharge.Moreover, the MDS-UPDRS III score improvement was greater in the PIGD group than in the TD group.The follow-up data, collected for 3 months after discharge, showed that overall symptom improvement in each group was maintained for 1–3 months.Furthermore, there were no significant differences in the duration or grade effects of symptom improvement among the three groups.These findings suggest that 2 weeks of MIRT is effective for improving motor performance in all three motor subtypes.Patients in the PIGD group had a better response after hospitalization than those in the TD group.This study was approved by the Institutional Ethics Committee of Beijing Rehabilitation Hospital of Capital Medical University of China(approval No.2018 bkky022) on May 7, 2018 and registered with the Chinese Clinical Trial Registry(registration No.Chi CTR1900020771) on January 19, 2019.展开更多
In this study,a novel safety integrity level(SIL)determination methodology of safety instrumented systems(SISs)with parameter uncertainty is proposed by combining multistage dynamic Bayesian networks(DBNs)and Monte Ca...In this study,a novel safety integrity level(SIL)determination methodology of safety instrumented systems(SISs)with parameter uncertainty is proposed by combining multistage dynamic Bayesian networks(DBNs)and Monte Carlo simulation.A multistage DBN model for SIL determination with multiple redundant cells is established.The models of function inspection test interval and function inspection test stages are alternately connected to form the multistage DBNs.The redundant cells can have different M out of N voting system architectures.An automatic modeling of conditional probability between nodes is developed.The SIL determination of SISs with parameter uncertainty is constructed by using the multistage DBNs and Monte Carlo simulation.A high-pressure SIS in the export of oil wellplatform is adopted to demonstrate the application of the proposed approach.The SIL and availability of the SIS and its subsystems are obtained.The influence of single subsystem on the SIL and availability of the SIS is studied.The influence of single redundant element on the SIL and availability of the subsystem is analyzed.A user-friendly SIL determination software with parameter uncertainty is developed on MATLAB graphical user interface.展开更多
Slip is one of the most critical components for the frac plug,which would lodge into the casing and lock the frac plug in place during the setting and anchoring process.However,fracture failure of slip significantly a...Slip is one of the most critical components for the frac plug,which would lodge into the casing and lock the frac plug in place during the setting and anchoring process.However,fracture failure of slip significantly affects the hydraulic fracturing effects and has attracted tremendous attention.In this paper,a three-dimensional contact model is applied to explore the setting process of slip.The effects of key structural parameters such as apex angle,inclination angle,and wedge angle on the contact characteristics of slip are systematically investigated.Numerical results indicate that the maximum contact stress appears at the contact area between slip tooth and the casing’s inner wall.Besides,the maximum contact stress generally increases with the increase of apex angle and inclination angle,while decrease linearly with the rise in the wedge angle.Experimental results show that the slip teeth get blunt and appear severe plastic deformation,which arises from stress concentration.Comparison of biting area indicates that the experimental results are about 21.3%larger,which still have a reasonable agreement with the numerical results.These obtained results can guide the parametric selection of plug slip and other similar components.展开更多
Objective:To observe the clinical effect of electroacupuncture"Tongmin point"combined with heat-sensitive moxibustion on knee osteoarthritis and its effect on blood lipid level,polyprotein polysaccharide enz...Objective:To observe the clinical effect of electroacupuncture"Tongmin point"combined with heat-sensitive moxibustion on knee osteoarthritis and its effect on blood lipid level,polyprotein polysaccharide enzyme-4(a disintegrin and metalloprotease with thrombospondin motifs,ADAMTS-4,matrix metalloproteinase-3(matrix metalloproteinase-3,);and MMPs-3)Impact.Methods:80 patients were randomly divided into two groups,40 cases per group,Treatment and control groups,The treatment group was given electroacupuncture combined with heat-sensitive moxibustion,Six times a week,Continuous treatment for 4 weeks;The control group was given intraarticular sodium hyaluronate,Once a week,continuous treatment for 4 weeks.Results:During the treatment period,Visual analogue scale visual analogue scale,VAS)show a downward trend,Intra-group comparisons,Differences were statistically significant(P<0.05);After 2 weeks of treatment,4 weeks of treatment and 2 weeks of follow-up,All the scores in the treatment group were lower than those in the control group(P<0.05).After treatment in two groups(The Western Ontario and Mc Master Universities Osteoarthritis Index,)of osteoarthritis index,University of Western Ontario WOMAC)The scores of each item decreased significantly,treatment group was better than the control group(P<0.05).After four weeks of treatment,(Total cholesterol,)Total cholesterol TC,triglycerides(Triglyceride,);and TG,LDL(Low density lipoprotein,);and LDL-C)A decrease in content,High density lipoprotein High density lipoprotein,HDL-C)Increased content,and the improvement was better than that of the control group(P<0.05).After treatment,the ADAMTS-4,MMPs-3 content decreased,Intergroup comparisons,Differences were statistically significant(P<0.05);The effective rate in the treatment group was 87.5%,The control rate was 60%,treatment group was more effective(P<0.05).Conclusions:Electroacupuncture"Tongmin point"combined with heat-sensitive moxibustion can obviously improve the symptoms of knee osteoarthritis patients,Regulate blood lipids,High security,It is worth popularizing in clinic.展开更多
Four new polyketide decalin derivatives,penicisteck acids A-D(1-4),and three new nitrogenous compounds(7-9)z together with eight previously reported compounds,were isolated from the mangrove endophytic fungus Penicill...Four new polyketide decalin derivatives,penicisteck acids A-D(1-4),and three new nitrogenous compounds(7-9)z together with eight previously reported compounds,were isolated from the mangrove endophytic fungus Penicillium steckii SCSIO 41025.展开更多
Objective To compare bone mineral density （BMD） between users of intramuscular depot medroxyprogesterone acetate（DMPA ） and nonhormonal control subjects. Methods The study included 68 women aged between 25 and 40 ...Objective To compare bone mineral density （BMD） between users of intramuscular depot medroxyprogesterone acetate（DMPA ） and nonhormonal control subjects. Methods The study included 68 women aged between 25 and 40 years using depot medroxyprogesterone acetate for 24 months and 59 women aged between 25 and 40 years using nonhormonal contraception as control subjects. BMD of the lumbar spine and femoral neck were obtained using dual energy X-ray absorptiometry. Results At 24 months of treatment, as compared with baseline, the mean BMD in lumbar spine and femoral neck was decreased by 5.5% and 5.9%, respectively. Lumbar spine and femoral neck BMD in women who used DMPA were significantly decreased compared with the subjects in nonuser （P〈0.001）. Conclusion These results show BMD declined during using DMPA in women aged 25 -40 years old.展开更多
Neurocysticercosis is the most common parasitic infection of the central nervous system.We present a case report of a neurocysticercosis patient with multiple cysts,who presented with new onset generalized tonic-cloni...Neurocysticercosis is the most common parasitic infection of the central nervous system.We present a case report of a neurocysticercosis patient with multiple cysts,who presented with new onset generalized tonic-clonic seizures.A 4-cycle treatment of 2 different antihelminthic drugs with dexamethasone and sodium valproate led to clinical improvement without any adverse reactions.The manifestations of neurocysticercosis are protean and the diagnosis should be considered whenever multiple cysts are seen on computed tomography or magnetic resonance imaging.The antihelminthic treatment of neurocysticercosis should be individualized,especially for patients with multiple cysts.展开更多
基金the supports of project funded by China Postdoctoral Science Foundation(2023M743886)Project of Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province(YSK2023004)youth project funded by Shaanxi Province Natural Science Basic Research Program(2024JC-YBQN-0522)。
文摘The casing deformation prevention technology based on the optimization of cement slurry is proposed to reduce the casing deformation of shale oil and gas wells during hydraulic fracturing. In this paper, the fracture mechanism of hollow particles in cement sheath was firstly analyzed by discrete element method, and the effect of hollow particles in cement on casing deformation was investigated by laboratory experiment method. Finally, field test was carried out to verify the improvement effect of the casing deformation based on cement slurry modification. The results show that the formation displacement can be absorbed effectively by hollow particles inside the cement transferring the excessive deformation away from casing. The particles in the uncemented state provide deformation space during formation slipping. The casing with diameter of 139.7 mm could be passed through by bridge plug with the diameter of 99 mm when the mass ratio of particle/cement reaches 1:4. According to the field test feedback, the method based on optimization of cement slurry can effectively reduce the risk of casing deformation, and the recommended range of hollow microbeads content in the cement slurry is between 15% and 25%.
基金supported by the National Key Research and Development Program of China (No.2022YFC2806102)the National Natural Science Foundation of China (No.52171287,52325107)+3 种基金High-tech Ship Research Project of Ministry of Industry and Information Technology (No.2023GXB01-05-004-03,No.GXBZH2022-293)the Science Foundation for Distinguished Young Scholars of Shandong Province (No.ZR2022JQ25)the Taishan Scholars Project (No.tsqn201909063)the Fundamental Research Funds for the Central Universities (No.24CX10006A)。
文摘The subsea production system is a vital equipment for offshore oil and gas production.The control system is one of the most important parts of it.Collecting and processing the signals of subsea sensors is the only way to judge whether the subsea production control system is normal.However,subsea sensors degrade rapidly due to harsh working environments and long service time.This leads to frequent false alarm incidents.A combinatorial reasoning-based abnormal sensor recognition method for subsea production control system is proposed.A combinatorial algorithm is proposed to group sensors.The long short-term memory network(LSTM)is used to establish a single inference model.A counting-based judging method is proposed to identify abnormal sensors.Field data from an offshore platform in the South China Sea is used to demonstrate the effect of the proposed method.The results show that the proposed method can identify the abnormal sensors effectively.
基金the Guangdong Basic and Applied Basic Research Foundation(2021A1515011523,2021B1515120046,2022B1515120075)National Key Research and Development Program of China(2022YFC2807501)+2 种基金National Natural Science Foundation of China(grant no.41976224)Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(2021JJLH0097,2021CXLH0013)Hainan Provincial Natural Science Foundation of China(823CXTD393)。
文摘Microbes well-adapted to the Arctic Ocean are promising for producing novel compounds,due to their fancy strategies for adaptation and being under-investigated.Two new phenazine alkaloids(1 and 2)and one new phenoxa-zine(3)were isolated from Nocardiopsis dassonvillei 502F,a strain originally isolated from Arctic deep-sea sediments.AntiSMASH analysis of the genome of Nocardiopsis dassonvillei 502F revealed the presence of 16 putative biosynthetic gene clusters(BGCs),including a phenazine BGC.Most of the isolated compounds were evaluated for their antibacterial,antiallergic,and cytotoxic activities.Among them,compounds 4 and 5 exhibited potent in vitro cytotoxic activities against osteosarcoma cell line 143B with IC_(50) values 0.16 and 20.0μM,respectively.Besides,the results of antiallergic activities of compounds 6-8 exhibited inhibitory activities with IC_(50) values of 10.88±3.05,38.88±3.29,and 2.44±0.17μg/mL,respectively(IC_(50)91.6μM for the positive control loratadine).
基金supported by the National Key Research and Development Program Sub-project, No.2018 YFC0115405(to BYF)the Start-up Fund for Scientific Research Talents of Beijing Rehabilitation Hospital, Capital Medical University of China, No.2019 R-006(to ZHJ)。
文摘Parkinson's disease(PD) can be classified into three motor-based subtypes: postural instability/gait difficulty(PIGD), tremor dominant(TD), and indeterminate.The neuropathophysiological mechanisms of the three motor subtypes are different, which may lead to different responses to therapy.Sixty-nine patients with idiopathic Parkinson's disease(Hoehn–Yahr stage ≤ 3) were screened from 436 patients with Parkinsonism recruited through outpatient services and the internet.According to the Movement Disorder Society Unified Parkinson's Disease Rating Scale(MDS-UPDRS) TD/PIGD ratio, the patients were divided into PIGD(TD/PIGD ≤ 0.09;n = 36), TD(TD/PIGD ≥1.15;n = 19), and indeterminate(TD/PIGD = 0.90–1.15;n = 14) groups.All patients received 2 weeks of multidisciplinary intensive rehabilitation treatment(MIRT) during hospitalization, as well as a remote home rehabilitation health education class.Compared with the scores at admission, all patients showed significant improvements in their MDS-UPDRS III score, walking ability, balance, and posture control at discharge.Moreover, the MDS-UPDRS III score improvement was greater in the PIGD group than in the TD group.The follow-up data, collected for 3 months after discharge, showed that overall symptom improvement in each group was maintained for 1–3 months.Furthermore, there were no significant differences in the duration or grade effects of symptom improvement among the three groups.These findings suggest that 2 weeks of MIRT is effective for improving motor performance in all three motor subtypes.Patients in the PIGD group had a better response after hospitalization than those in the TD group.This study was approved by the Institutional Ethics Committee of Beijing Rehabilitation Hospital of Capital Medical University of China(approval No.2018 bkky022) on May 7, 2018 and registered with the Chinese Clinical Trial Registry(registration No.Chi CTR1900020771) on January 19, 2019.
基金supported by the National Natural Science Foundation of China(No.52171287,No.51779267,No.51707204)the National Key Research and Development Program of China(No.2019YFE0105100)+3 种基金the IKTPLUSS program of Research Council of Norway(No.309628)the Taishan Scholars Project(No.tsqn201909063)the Fundamental Research Funds for the Central Universities,that is,the Opening Fund of National Engineering Laboratory of Offshore Geophysical and Exploration Equipment(No.20CX02301A)the Science and Technology Support Plan for Youth Innovation of Universities in Shandong Province(No.2019KJB016)。
文摘In this study,a novel safety integrity level(SIL)determination methodology of safety instrumented systems(SISs)with parameter uncertainty is proposed by combining multistage dynamic Bayesian networks(DBNs)and Monte Carlo simulation.A multistage DBN model for SIL determination with multiple redundant cells is established.The models of function inspection test interval and function inspection test stages are alternately connected to form the multistage DBNs.The redundant cells can have different M out of N voting system architectures.An automatic modeling of conditional probability between nodes is developed.The SIL determination of SISs with parameter uncertainty is constructed by using the multistage DBNs and Monte Carlo simulation.A high-pressure SIS in the export of oil wellplatform is adopted to demonstrate the application of the proposed approach.The SIL and availability of the SIS and its subsystems are obtained.The influence of single subsystem on the SIL and availability of the SIS is studied.The influence of single redundant element on the SIL and availability of the subsystem is analyzed.A user-friendly SIL determination software with parameter uncertainty is developed on MATLAB graphical user interface.
基金financial support from the National Major Science and Technology Projects of China(Grant No.2017ZX05072)the Royal Society Newton International Fellowships(Grant No.NIF/R1/181640)the Marie SkłodowskaCurie Individual Fellowships under European Union’s Horizon 2020 research and innovation programme(Grant No.840264)
文摘Slip is one of the most critical components for the frac plug,which would lodge into the casing and lock the frac plug in place during the setting and anchoring process.However,fracture failure of slip significantly affects the hydraulic fracturing effects and has attracted tremendous attention.In this paper,a three-dimensional contact model is applied to explore the setting process of slip.The effects of key structural parameters such as apex angle,inclination angle,and wedge angle on the contact characteristics of slip are systematically investigated.Numerical results indicate that the maximum contact stress appears at the contact area between slip tooth and the casing’s inner wall.Besides,the maximum contact stress generally increases with the increase of apex angle and inclination angle,while decrease linearly with the rise in the wedge angle.Experimental results show that the slip teeth get blunt and appear severe plastic deformation,which arises from stress concentration.Comparison of biting area indicates that the experimental results are about 21.3%larger,which still have a reasonable agreement with the numerical results.These obtained results can guide the parametric selection of plug slip and other similar components.
基金Clinical Medical Research Project of Wuhan Municipal Health and Family Planning Commission(No.WZ20Q12)Major project of the National Natural Science Foundation of China"Clinical Application Research on Different Functional States of Acupoints"(No.81590955)。
文摘Objective:To observe the clinical effect of electroacupuncture"Tongmin point"combined with heat-sensitive moxibustion on knee osteoarthritis and its effect on blood lipid level,polyprotein polysaccharide enzyme-4(a disintegrin and metalloprotease with thrombospondin motifs,ADAMTS-4,matrix metalloproteinase-3(matrix metalloproteinase-3,);and MMPs-3)Impact.Methods:80 patients were randomly divided into two groups,40 cases per group,Treatment and control groups,The treatment group was given electroacupuncture combined with heat-sensitive moxibustion,Six times a week,Continuous treatment for 4 weeks;The control group was given intraarticular sodium hyaluronate,Once a week,continuous treatment for 4 weeks.Results:During the treatment period,Visual analogue scale visual analogue scale,VAS)show a downward trend,Intra-group comparisons,Differences were statistically significant(P<0.05);After 2 weeks of treatment,4 weeks of treatment and 2 weeks of follow-up,All the scores in the treatment group were lower than those in the control group(P<0.05).After treatment in two groups(The Western Ontario and Mc Master Universities Osteoarthritis Index,)of osteoarthritis index,University of Western Ontario WOMAC)The scores of each item decreased significantly,treatment group was better than the control group(P<0.05).After four weeks of treatment,(Total cholesterol,)Total cholesterol TC,triglycerides(Triglyceride,);and TG,LDL(Low density lipoprotein,);and LDL-C)A decrease in content,High density lipoprotein High density lipoprotein,HDL-C)Increased content,and the improvement was better than that of the control group(P<0.05).After treatment,the ADAMTS-4,MMPs-3 content decreased,Intergroup comparisons,Differences were statistically significant(P<0.05);The effective rate in the treatment group was 87.5%,The control rate was 60%,treatment group was more effective(P<0.05).Conclusions:Electroacupuncture"Tongmin point"combined with heat-sensitive moxibustion can obviously improve the symptoms of knee osteoarthritis patients,Regulate blood lipids,High security,It is worth popularizing in clinic.
基金This work was supported by the Key-Area Research and Development Program of Guangdong Province(2O2OB1111O3OOO5)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guang-zhou)(GML2019ZD0406)+4 种基金the National Natural Science Foundation of China(Nos.U20A20101,22007019,81973235)the Special Fund for Bagui Scholars of Guangxi(05019055)the Natural Science Foundation of Guangxi(Nos.2020GXNSFBA159001,2020GXNSFGA297002)the Specific Research Project of Guangxi for Research Bases and Talents(AD20297003)the Open Project of CAS Key Laboratory of Tropical Marine Bio-resources and Ecology(LMB20211005).
文摘Four new polyketide decalin derivatives,penicisteck acids A-D(1-4),and three new nitrogenous compounds(7-9)z together with eight previously reported compounds,were isolated from the mangrove endophytic fungus Penicillium steckii SCSIO 41025.
文摘Objective To compare bone mineral density （BMD） between users of intramuscular depot medroxyprogesterone acetate（DMPA ） and nonhormonal control subjects. Methods The study included 68 women aged between 25 and 40 years using depot medroxyprogesterone acetate for 24 months and 59 women aged between 25 and 40 years using nonhormonal contraception as control subjects. BMD of the lumbar spine and femoral neck were obtained using dual energy X-ray absorptiometry. Results At 24 months of treatment, as compared with baseline, the mean BMD in lumbar spine and femoral neck was decreased by 5.5% and 5.9%, respectively. Lumbar spine and femoral neck BMD in women who used DMPA were significantly decreased compared with the subjects in nonuser （P〈0.001）. Conclusion These results show BMD declined during using DMPA in women aged 25 -40 years old.
文摘Neurocysticercosis is the most common parasitic infection of the central nervous system.We present a case report of a neurocysticercosis patient with multiple cysts,who presented with new onset generalized tonic-clonic seizures.A 4-cycle treatment of 2 different antihelminthic drugs with dexamethasone and sodium valproate led to clinical improvement without any adverse reactions.The manifestations of neurocysticercosis are protean and the diagnosis should be considered whenever multiple cysts are seen on computed tomography or magnetic resonance imaging.The antihelminthic treatment of neurocysticercosis should be individualized,especially for patients with multiple cysts.
