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Effect of existence state of asphaltenes on the asphaltenes-wax interaction in wax deposition

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Petroleum Science 2023年第1期20卷 507-514页

作者： yun Lei Han Wang Shuang-Shuang Li Xue-Qian Liu Hao-Ran Zhu yu-Ming Gao Hao-Ping peng peng-fei yu Jiangsu Key Laboratory of Oil and Gas Storage&Transportation Technology Changzhou UniversityJiangsu213164China

Asphaltenes are the most elusive substances in waxy crude oil,especially the complex structures,which leads to significant precipitation and aggregation characteristics of asphaltenes,and affects the asphaltenes-wax *** this study,the concept of the existence state of asphaltenes was introduced to semi-quantitatively investigate the precipitation and aggregation characteristics of *** this basis,the influence of the existence state of asphaltenes on wax deposition was studied by coldfinger device and high-temperature gas chromatography,and the composition and properties of the deposits were *** main findings were made:(1)As the asphaltene concentration increases,the existence state of asphaltenes gradually transitions from dispersed state to aggregated state,and the asphaltene concentration of 0.30 wt%in this study is the starting point of the transition.(2)The existence state of asphaltenes in crude oil does affect the process of wax deposition,as shown in the fact that the dispersed asphaltenes promote the occurrence of wax deposition,while the aggregated asphaltenes can inhibit wax deposition.(3)In the presence of the aggregated asphaltenes,that is,when the asphaltene concentration is higher than 0.30 wt%,the shedding phenomenon of deposit layer was observed,and with the increase of aggregated asphaltenes,the deposit layer fell off earlier.(4)With the increase of the dispersed asphaltenes,the wax appearance temperature(WAT)and wax content of the deposits all showed an increasing trend,while with the appearance of the aggregated asphaltenes,the above situation was *** findings of this study can help for better understanding of the interaction between the asphaltenes and wax in wax deposition.

关键词： Asphaltenes Precipitation/aggregation Existence state of asphaltenes Deposition

Mutation analysis of related genes in hamartoma polyp tissue of Peutz-Jeghers syndrome

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World Journal of Gastroenterology 2020年第16期26卷 1926-1937页

作者： Zhi Zhang Fu-Xiao Duan Guo-Li Gu peng-fei yu Air Force Clinical College(Air Force Medical Center)of Anhui Medical University Beijing 100142China Department of General Surgery the General Hospital of Northern Theater Command PLAShenyang 110016Liaoning ProvinceChina Department of General Surgery Air Force Medical CenterPLABeijing 100142China

BACKGROUND Peutz-Jeghers syndrome(PJS)is a rare disease with clinical manifestations of pigmented spots on the lips,mucous membranes and extremities,scattered gastrointestinal polyps,and susceptibility to *** clinical heterogeneity of PJS is obvious,and the relationship between clinical phenotype and genotype is still *** To investigate the mutation status of hereditary colorectal tumor-associated genes in hamartoma polyp tissue of PJS patients and discuss its relationship with the clinicopathological data of *** Twenty patients with PJS were randomly selected for this study and were treated in the Air Force Medical Center(former Air Force General Hospital)PLA between 2008 and *** hamartoma polyp tissues were used for APC,AXIN2,BMPR1A,EPCAM,MLH1,MLH3,MSH2,MSH6,MUTYH,PMS1,PMS2,PTEN,SMAD4,and LKB1/STK11 gene sequencing using next-generation sequencing *** correlations between the sequencing results and clinical pathological data of PJS were *** Fourteen types of LKB1/STK11 mutations were detected in 16 cases(80.0%),of which 8 new mutations were found(3 types of frameshift deletion mutations:c.243delG,c.363_364delGA,and c.722delC;2 types of frameshift insertions:c.144_145insGCAAG,and c.454_455insC;3 types of splice site mutations:c.464+1G>T,c.464+1G>A,and c.598-1G>A);9 cases(45.0%)were found to have 18 types of heterozygous mutations in the remaining 13 genes except LKB1/*** these,MSH2:c.792+1G>A,MSH6:c.3689C>G,c.4001+13C>CTTAC,PMS1:c.46C>t,and c.922G>A were new *** The genetic mutations in hamartoma polyp tissue of PJS are complex and ***,other gene mutations in PJS hamartoma polyp tissue were observed,with the exception of LKB1/STK11 gene,especially the DNA mismatch repair gene(MMR).Colorectal hamartoma polyps with LKB1/STK11 mutations were larger in diameter than those with other gene mutations.

关键词： Peutz-Jeghers syndrome STK11 gene LKB1 gene Sequencing Genetic analysis

Study on the thixotropy and structural recovery characteristics of waxy crude oil emulsion

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Petroleum Science 2021年第4期18卷 1195-1202页

作者： Li-Ping Guo Xue Han yun Lei Lei Wang peng-fei yu Shuang Shia Key Laboratory of Enhanced Oil Recovery Ministry of EducationNortheast Petroleum UniversityHeilongjiang163000China Jiangsu Key Laboratory of Oil and Gas Storage&Transportation Technology Changzhou UniversityJiangsu213164China Exploration and Development Research Institute Daqing Oil Field Company LtdDaqingHeilongjiang163712China

Waxy crude oil emulsion has thixotropic properties at the temperature near gel point,which is a macromechanical characterization of the structure failure and recovery of waxy crude oil *** this paper,the thixotropic behaviors of waxy crude oil emulsion near gel point were studied using hysteresis loop formed by stress linear increase and decrease,as well as the structural recovery *** influence of the loading conditions and water content on the thixotropy of waxy crude oil emulsion were analyzed with hysteresis loop *** concept of"structural recovery"was introduced to study the degree of structural recovery after different stewing,and influencing factors were taken into *** have shown that for waxy crude oil emulsion,the failure to fully restore of the structure after lysis is the cause of the formation of hysteresis loop,and the loading conditions will not affect the strength of thixotropy and the degree of structural ***,the dispersed phase droplets weaken the thixotropy and structure recovery characteristics of waxy crude oil emulsion,and the greater the water content,the weaker the *** findings can help to better understand the safe and economic operation of waxy crude oil-water pipeline transportation.

关键词： Waxy crude oil Emulsion Thixotropic properties Structural recovery Hysteresis loop

Numerical simulation and experimental verification of large-sized Zr-based bulk metallic glass ring-shaped parts in casting process

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Transactions of Nonferrous Metals Society of China 2022年第2期32卷 581-592页

作者： fei-long WANG Qiu-hong HAO peng-fei yu yu-jing YANG Ming-zhen MA Xin-yu ZHANG Ri-ping LIU State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China Wuhan Hgcyber Data System Co. Ltd.Wuhan 430223China Department of Physics Hebei Normal University of Science and TechnologyQinhuangdao 066004China

An outer ring of 29320 self-aliging roller bearing was used in an experimental study on the casting of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(22.5) amorphous *** simulations of mold filling and solidification processes were carried out to determine the velocity fields and temperature fields of the alloy melt during mold filling process as well as the temperature fields and temperature gradient fields in the course of the *** to the results,a cast with a complete shape can be obtained at 1200℃under the condition that the cooling rate is greater than the critical cooling *** ring-shaped part with a thickness of 25 mm,an equivalent diameter of 22 mm,and a mass of 1.32 kg was prepared by gravity casting in a copper mold.X-ray diffraction and differential scanning calorimetry data revealed that the produced cast had the amorphous structure.

关键词： bulk metallic glasses ring-shaped part casting forming numerical simulation mold filling solidification

Protective effect of mesenchymal stem cell-derived exosomal treatment of hippocampal neurons against oxygen-glucose deprivation/reperfusion-induced injury

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World Journal of Emergency Medicine 2022年第1期13卷 46-53页

作者： Xiao-fang Guo Shuang-shuang Gu Jun Wang Hao Sun yu-juan Zhang peng-fei yu Jin-song Zhang Lei Jiang Department of Emergency the First Affi liated Hospital of Nanjing Medical UniversityNanjing 210029China Key Laboratory of Modern Toxicology Ministry of EducationDepartment of ToxicologySchool of Public HealthNanjing Medical UniversityNanjing 211166China Key Laboratory of Modern Toxicology Ministry of EducationDepartment of Environmental GenomicsSchool of Public HealthNanjing Medical UniversityNanjing 211166China Center for Drug Safety Evaluation and Research Shanghai Institute of Materia MedicaShanghai 201203China

BACKGROUND:Individuals who survive a cardiac arrest often sustain cognitive impairments due to ischemia-reperfusion *** stem cell(MSC)transplantation is used to reduce tissue damage,but exosomes are more stable and highly conserved than *** study was conducted to investigate the therapeutic effects of MSC-derived exosomes(MSC-Exo)on cerebral ischemia-reperfusion injury in an in vitro model of oxygen-glucose deprivation/reperfusion(OGD/R),and to explore the underlying ***:Primary hippocampal neurons obtained from 18-day Sprague-Dawley rat embryos were subjected to OGD/R treatment,with or without MSC-Exo *** integration,cell viability,mitochondrial membrane potential,and generation of reactive oxygen species(ROS)were *** deoxynucleotidyl transferase-mediated 2’-deoxyuridine 5’-triphosphate nickend labeling(TUNEL)staining was performed to detect neuronal ***,mitochondrial function-associated gene expression,Nrf2 translocation,and expression of downstream antioxidant proteins were ***:MSC-Exo attenuated OGD/R-induced neuronal apoptosis and decreased ROS generation(P<0.05).The exosomes reduced OGD/R-induced Nrf2 translocation into the nucleus(2.14±0.65 vs.5.48±1.09,P<0.01)and increased the intracellular expression of antioxidative proteins,including superoxide dismutase and glutathione peroxidase(17.18±0.97 vs.14.40±0.62,and 20.65±2.23 vs.16.44±2.05,respectively;P<0.05 for both).OGD/R significantly impaired the mitochondrial membrane potential and modulated the expression of mitochondrial functionassociated genes,such as PINK,DJ1,LRRK2,Mfn-1,Mfn-2,and *** abovementioned changes were partially reversed by exosomal treatment of the hippocampal ***:MSC-Exo treatment can alleviate OGD/R-induced oxidative stress and dysregulation of mitochondrial function-associated genes in hippocampal ***,MSCExo might be a potential therapeutic strategy to preven

关键词： Mesenchymal stem cells Exosomes Oxygen-glucose deprivation/reperfusion Reactive oxygen species Mitochondria

Must Peutz-Jeghers syndrome patients have the LKB1/STK11 gene mutation?A case report and review of the literature

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World Journal of Clinical Cases 2018年第8期6卷 224-232页

作者： Fu-Xiao Duan Guo-Li Gu Hai-Rui Yang peng-fei yu Zhi Zhang Department of General Surgery Air Force General Hospital of Chinese PLA

Peutz-Jeghers syndrome(PJS) is an autosomal dominant inherited disease, which is characterized by mucocutaneous pigmentation and multiple gastrointestinal hamartoma polyps. The germline mutation of LKB1/STK11 gene on chromosome 19 p13.3 is considered to be the hereditary cause of PJS. However, must a patient with PJS have the LKB1/STK11 gene mutation? We here report a case of a male patient who had typical manifestations of PJS and a definite family history, but did not have LKB1/STK11 gene mutation. By means of high-throughput sequencing technology, only mutations in APC gene(c.6662 T > C: ***2221 Thr) and MSH6 gene(c.3488 A > T: ***1163 Val) were detected. The missense mutations in APC and MSH6 gene may lead to abnormalities in structure and function of their expression products, and may result in the occurrence of PJS. This study suggests that some other genetic disorders may cause PJS besides LKB1/STK11 gene mutation.

关键词： Peutz-Jeghers syndrome Gastrointestinal polyps High-throughput sequencing LKB1/STK11 APC MSH6 Hamartoma

Diffuse invasive signet ring cell carcinoma in total colorectum caused by ulcerative colitis:A case report and review of literature

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World Journal of Clinical Cases 2022年第5期10卷 1729-1737页

作者： Zhi Zhang peng-fei yu Guo-Li Gu yu-Hui Zhang yu-Ming Wang Zhi-Wei Dong Hai-Rui Yang Department of General Surgery Air Force Medical CenterChinese People's Liberation ArmyBeijing 100142China Graduate School Hebei North UniversityZhangjiakou 075000Hebei ProvinceChina Health Team 93656 Troop of Chinese People's Liberation ArmyBeijing 101113China

BACKGROUND Diffuse invasive signet ring cell carcinoma of the colorectum is extremely rare *** type of colorectal cancer has certain clinical,pathological and biological characteristics that are different from ordinary colorectal *** SUMMARY A 31-year-old young woman was admitted to the hospital for nearly 1 wk due to recurrent symptoms of mucopurulent bloody stools and abdominal *** colonoscopy showed a ring-shaped intestinal wall mass 10 cm from the rectum to the *** pieces of tumor tissue were removed for *** pathological results showed rectal mucinous *** patient underwent laparoscopic exploration under general anesthesia,and then laparoscopic total colorectal resection,ileal pouch–anal anastomosis and ileostomy were *** patient was switched to a FOLFOX+cetuximab *** the fifth cycle,the patient was unable to tolerate further treatment due to tumor progression and multiple organ dysfunction,and died at the end of May *** survival was 7 *** Carcinogenesis of ulcerative colitis is different from sporadic colon cancer,and the overall prognosis is extremely poor.

关键词： Ulcerative colitis Colorectal cancer Signet ring cell carcinoma Case report

Investigation on synergistic deposition of wax and hydrates in waxy water-in-oil(W/O) flow systems

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Petroleum Science 2022年第4期19卷 1840-1852页

作者： Yang Liu Xiao-Fang Lv Qian-Li Ma Shi-Dong Zhou Bo-Hui Shi Hui Du yun Lei peng-fei yu Shang-fei Song Jing Gong Bing-Cai Sun Jiangsu Key Laboratory of Oil and Gas Storage and Transportation Technology Changzhou UniversityChangzhouJiangsu213164China Institute of Petroleum Engineering Technology Sinopec Northwest Oil Field CompanyUrumqiXinjiang830011China National Engineering Laboratory for Pipeline Safety/State Key Laboratory of Natural Gas Hydrate China University of Petroleum-BeijingBeijing102249China CNPC Safety and Environmental Protection Technology Research Institute Co.Ltd Beijing102206China

Elucidating the synergistic effect of wax and hydrates, involving formation, aggregation and deposition,is imperative to the operation and transportation safety for offshore petroleum fields. To understand the characteristics and mechanism of synergistic deposition of wax and hydrates, flow and deposition experiments of systems with different wax contents(0-2.89 wt%), initial flow rates, pressures and temperatures were conducted in a high pressure visual flow loop. According to the flow rate and pressure drop data as well as the visual window observation, four different types of plugging scenarios of waxhydrate coexisting systems with different flow properties and wall deposition state were summarized,including rapid plugging, transition plugging, gradual plugging type I and gradual plugging type *** with the wax-free system after hydrate formation, even with the addition of anti-agglomerant(AA) with the same concentration, wax-hydrate coexisting systems could not reach stable hydrate slurry flow state, indicating that the existence of wax deteriorated the performance of AA. Aside from the influence of wax crystals on hydrate agglomeration, it was found that wax deposition layer would alter the adhesion and bedding of hydrates, resulting in the variation of flow properties and wall deposition *** low wax content systems(0.75 wt%) where rapid plugging occurred, the synergistic effect between wax and hydrates promoted the formation of wax-hydrate coupling aggregates, resulting in severe local deposition when the coupling aggregates attained critical deposition size and consequently decreasing flow rate, forming a vicious circle of decreasing transportability. Since bedding of coupling aggregates was hindered by the uniformly coated wax deposition layer on pipe wall, gradual plugging rather than rapid plugging occurred in medium wax content systems(1-1.25 wt%), predominately caused by the gradual increment in viscosity of waxy hydrate slurry. For relative

关键词： Flow assurance Wax Hydrates Flow properties Synergistic deposition

Detection and analysis of common pathogenic germline mutations in Peutz-Jeghers syndrome

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World Journal of Gastroenterology 2021年第39期27卷 6631-6646页

作者： Guo-Li Gu Zhi Zhang yu-Hui Zhang peng-fei yu Zhi-Wei Dong Hai-Rui Yang Ying yuan Department of General Surgery Air Force Medical CenterChinese People's Liberation ArmyBeijing 100142China Graduate School Hebei North UniversityZhangjiakou 075000Hebei ProvinceChina Department of Medical Oncology Cancer InstituteThe Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009Zhejiang ProvinceChina

Different types of pathogenic mutations may produce different clinical phenotypes,but a correlation between Peutz-Jeghers syndrome(PJS)genotype and clinical phenotype has not been *** all patients with PJS have detectable mutations of the STK11/LKB1 gene,what is the genetic basis of clinical phenotypic heterogeneity of PJS?Do PJS cases without STK11/LKB1 mutations have other pathogenic genes?Those are clinical problems that perplex *** The aim was to investigate the specific gene mutation of PJS,and the correlation between the genotype and clinical phenotype of *** A total of 24 patients with PJS admitted to the Air Force Medical Center,PLA(formerly the Air Force General Hospital,PLA)from November 1994 to January 2020 were randomly selected for inclusion in the *** hundred thirty-nine common hereditary tumor-related genes including STK11/LKB1 were screened and analyzed for pathogenic germline mutations by high-throughput nextgeneration sequencing(NGS).The mutation status of the genes and their relationship with clinical phenotypes of PJS were *** Twenty of the 24 PJS patients in this group(83.3%)had STK11/LKB1 gene mutations,90%of which were pathogenic mutations,and ten had new mutation *** mutations in exon 7 of STK11/LKB1 gene were significantly lower than in other *** mutations are more common in exons 1 and 4 of STK11/LKB1,and their pathogenicity was significantly higher than that of missense *** also found SLX4 gene mutations in PJS *** PJS has a relatively complicated genetic *** in the sites responsible for coding functional proteins in exon 1 and exon 4 of STK11/LKB1 may be one of the main causes of *** of the SLX4 gene may be a cause of genetic heterogeneity in PJS.

关键词： Peutz-Jeghers syndrome Genotype Phenotype STK11 Mutation