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Emerging insights into the function of very long chain fatty acids at cerebellar synapses

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Neural Regeneration Research 2025年第6期20卷 1709-1710页

作者： Martin-Paul Agbaga Mohiuddin Ahmad Department of Cell Biology and Ophthalmology University of Oklahoma Health Sciences Centerand Dean McGee Eye InstituteOklahoma CityOKUSA

Very long chain-saturated and-polyunsaturated fatty acids(VLC-SFA and VLC-PUFA, respectively) are a functionally important class of fatty acids containing 28 carbons or more in their acyl chain. They are synthesized by the elongation of very long fatty acids-4(ELOVL4) enzyme, expressed mainly in the brain, retina, skin, testes, and meibomian gland, where these fatty acids are found(Agbaga et al., 2008). Further, these organs exhibit tissuespecific VLC-PUFA and VLC-SFA biosynthesis and incorporation into complex lipids for specific functions. In the brain, skin, and Meibomian glands, the ELOVL4 mainly makes VLC-SFA, which are incorporated into complex sphingolipids. In the retina, the ELOVL4 makes VLC-PUFA that are incorporated into phosphatidylcholine, that are critical for visual function, while in testes and sperm, the VLC-PUFA are incorporated into sphingolipids that are critical for fertility(Yeboah et al., 2021).

关键词： functions function insight

Geochemistry and Geologic Analysis in Shale Gas Play

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中国石油勘探 2009年第3期14卷 34-40页

作者： Wenwu Xia Mike D. Burnaman John Shelton Harding Shelton Group Oklahoma City oklahoma 73102

The understanding from the conventional geochemistry and geology analysis is very different when trying to apply them to shale gas plays. This paper is a summary for U.S. shale gas plays on geochemistry and geologic analysis application, and real field data from active U.S. shale gas plays is used in the discussion of different concepts.

关键词：天然气地质勘探地球化学石油

Modern Shale Gas Horizontal Drilling： Review of Best Practices for Exploration Phase Planning and Execution

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中国石油勘探 2009年第3期14卷 41-50页

作者： Nathaniel Harding Stephen Smith John Shelton Mike D. Burnaman Harding Shelton Group Oklahoma City Oklahoma 73102

The challenging characteristics of shale formations often require horizontal drilling to economically develop their potential. While every shale gas play is unique, there are several best practices for the proper planning and execution of a horizontal well. In planning a horizontal well, the optimal method and technology for building inclination and extending the lateral section must be determined. Properly specified logging-while-drilling tools are essential to keep the wellbore within the target formation. Planning must also focus on casing design. Doing so will help ensure stability and enable reliable and productive completions. Shales pose a challenge for these elements of well planning due to their thin strata and potentially low mechanical competence when foreign fluids are introduced. Once a plan is developed, executing it is even more important to prove a viable exploration program. Fast, efficient drilling with wellbore control and minimal torque and drag should be the priority. This may be achieved by focusing on fluid hydraulics and rheology and bottom hole assembly. Managed pressure drilling (MPD) will help fast drilling, well control and stability. If MPD can be combined with new generation rotary steerable systems that allow the drill string to maintain rotation, impressive efficiencies are possible. Modern drilling parameter analysis represents the newest opportunity for executing shale gas horizontal wells. A method for ROP analysis to improve operational parameters and equipment selection is also proposed.

关键词：页岩天然气石油地质勘探

Shale Gas Well Completions and Maximizing Gas Recoveries

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中国石油勘探 2009年第3期14卷 65-86页

作者： Michael D. Burnaman Stephen Smith Wenwu Xia Harding Shelton Group Oklahoma City Oklahoma 73102

It is shown that stress fields within the earth are the principle control for hydraulic fracture direction in horizontal shale gas wells. Hydraulic fracturing is a process of increasing permeability within gas shales and involves a sophisticated organization of technology, good planning and proper management of equipment over a very short time period to be successful. The direction and extent of the induced fractures can be determined in near real-time at the well site via application of earthquake seismology theory in a now common process known as frac mapping. Next to the horizontal lateral azimuth, the total volume of slurry pumped into the well is a major factor in determining well EURs. Vertical fracture growth can be controlled and is important in concentration of the slurry within the main zone target zone that has the high TOC and porosity. Cemented casing with perforations is currently the most used method for zone isolation. New open-hole sleeve packers may eventually provide more flexibility in fracture design while also providing a means for refracturing multi-stage fractured horizontal wells, a technique not now commonly available. Multi-Stage fracture design requires incorporating rock properties with fracturing effect simulations and then verifying results using 3D reservoir simulations. Maximizing the gas recovery factors and EURs can be accomplished through use of closely spaced laterals with inter-fingered fracture stages and exploiting the stress shadow fracturing phenomenon. Even greater EURs may be possible if the wells can be refractured thereby opening up additional permeability channels. Shale gas development has progressed in an environmentally sensitive manner within the U.S. and will continue in this manner. During the past ten years, all of these technologies have been either newly developed or were the advancement of existing technology with modifications. The opportunity exists to take these proven technologies to other areas of the wor

关键词：石油天然气勘探开发

Shale Gas Play Screening and Evaluation Criteria

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中国石油勘探 2009年第3期14卷 51-64页

作者： Michael D. Burnaman Wenwu Xia John Shelton Harding Shelton Group Oklahoma City Oklahoma 73102

The uniqueness of shale gas plays is contrasted with conventional oil and gas exploration. Based on our ten year history in shale gas exploration, a practical 17 point list of criteria to use for screening shale gas projects and ranking that encompasses geoscience, geochemistry, reservoir engineering, drilling, completions and production operations is developed and explained. Other considerations that will impact shale gas development are identified and discussed. Some key methodologies to incorporate in the evaluation process are also proposed. The outcome of this proposed screening process, if rigorously applied, should quickly identify the projects that have the most likely chance for success for recommendation to management. Examples from active shale gas plays in the United States are used to support these criteria and references to relevant recent publications and presentations are provided.

关键词：石油天然气勘探开发

Significance of Shale Gas Development

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中国石油勘探 2009年第3期14卷 29-33页

作者： John Shelton Mike D. Burnaman Wenwu Xia Nathaniel Harding Harding Shelton Group Oklahoma City Oklahoma 73102

Natural gas production from shale formations is growing exponentially in the United States. This paper introduces the five major shale formations in the United States and the technologies used to produce them. The Barnett, Haynesville, Fayetteville, Woodford, and Marcellus combined hold an estimated 978 trillion cubic feet of total gas reserves. These findings along with recent technological advances in horizontal drilling and completion methods have transformed the natural gas exploration and production industry in the U.S. and have fundamentally changed the U.S. energy picture. Specifically this paper states that the United States through the utilization of natural gas from shale can reduce its carbon emissions and can become more energy self-sufficient. Finally, the Harding & Shelton Group states in this paper that the opportunity to locate and produce shale gas in China is very similar to that which has taken place in the United States.

关键词：页岩石油天然气地质勘探

Light hydrocarbon geochemistry:insight into oils/condensates families and inferred source rocks of the Woodford–Mississippian tight oil play in North-Central oklahoma,USA

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Petroleum Science 2020年第3期17卷 582-597页

作者： Ting Wang Dong-Lin Zhang Xiao-Yong Yang Jing-Qian Xu Coffey Matthew You-Jun Tang Key Laboratory of Exploration Technologies for Oil and Gas Resources(Yangtze University) Ministry of EducationWuhan 430100HubeiChina School of Geology and Geophysics.University of oklahoma NormanOK 73019USA Devon Energy Corporation Oklahoma CityOK 73102USA

The Woodford–Mississippian"Commingled Production"is a prolific unconventional hydrocarbon play in oklahoma,*** tight reservoirs feature variations in produced fluid chemistry usually explained by different possible source *** chemical variations are regularly obtained from bulk,molecular,and isotopic *** this study,we present a new geochemical investigation of gasoline range hydrocarbons,biomarkers,and diamondoids in oils from Mississippian carbonate and Woodford Shale.A set of oil/condensate samples were examined using high-performance gas chromatography and mass *** result of the condensates from the Anadarko Basin shows a distinct geochemical fingerprint reflected in light hydrocarbon characterized by heptane star diagrams,convinced by biomarker characteristics and diamantane isomeric *** possible source rocks were identified,the Woodford Shale and Mississippian mudrocks,with a variable degree of *** maturity based on light hydrocarbon parameters indicates that condensates from the Anadarko Basin are of the highest maturity,followed by"Old"Woodford-sourced oils and central oklahoma tight *** geochemical parameters shed light on petroleum migration within Devonian–Mississippian petroleum systems and mitigate geological risk in exploring and developing petroleum reservoirs.

关键词： Tight oil-Tight condensate Woodford Shale Mississippia n limestone Light hydrocarb on geochemistry Anadarko Basin

Exploring novel candidate genes from the Mouse Genome Informatics database: Potential implications for avian migration research

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Integrative Zoology 2016年第4期11卷 240-249页

作者： Andrea CONTINA Eli S.BRIDGE Jeffrey F.KELLY oklahoma Biological Survey University of OklahomaNormanOklahomaUSA Department of Biology University of OklahomaNormanOklahomaUSA

To search for genes associated with migratory phenotypes in songbirds,we selected candidate genes through annotations from the Mouse Genome Informatics database and assembled an extensive candidate-gene ***,we implemented a next-generation sequencing approach to obtain DNA sequences from the Painted Bunting *** focused on those sequences that were conserved across avian species and that aligned with candidate genes in our mouse *** genotyped short sequence repeats from the following candidate genes:ADRA1d,ANKRD17,CISH and *** studied the possible correlations between allelic variations occurring in these novel candidate migration genes and avian migratory phenotypes available from the published lit*** found that allele variation at MYH7 correlated with a calculated index of speed of migration(km/day)across 11 species of *** highlight the potential of the Mouse Genome Informatics database in providing new candidate genes that might play a crucial role in regulating migration in birds and possibly in other *** research effort shows the benefits and limitations of working with extensive genomic datasets and offers a snapshot of the challenges related to cross-species validation in behavioral and molecular ecology studies.

关键词： avian migration candidate gene approach Mouse Genome Informatics MYH7 songbirds

Structural Features of Human Memapsin 2 （β-Secretase） and Their Biological and Pathological Implications

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Acta Biochimica et Biophysica Sinica 2004年第12期36卷 787-792页

作者： Jordan TANG Protein Studies Program oklahoma Medical Research Foundation University of oklahoma Health Science Center oklahoma City oklahoma 73104 USA

Memapsin 2 (β-secretase) is the membrane-anchored aspartic protease that initiates the cleavage of β-amyloid precursor protein (APP) leading to the production of amyloid-β (Aβ), a major factor in the pathogenesis of Alzheimer’s disease (AD). Since memapsin 2 is a major target for the development of inhibitor drugs for AD, it has been intensively studied during the past five years. Here we discuss the struc- tural features of the catalytic/specificity apparatus, transmembrane domain, cytosolic domain and the impli- cations of these features in the physiological and pathological roles of this protease.

关键词： memapsin 2 β-secretase Alzheimer’s disease β-amyloid β-amyloid precursor protein aspartic protease endocytosis cellular trafficking.