Daqing Oilfield General Hospital

BACKGROUND: China has a large population of older people, but has not yet undertaken a comprehensive study on the prevalence, risk factors, and management of both dementia and mild cognitive impairment (MCI). METHODS: For this national cross-sectional study, 46 011 adults aged 60 years or older were recruited between March 10, 2015, and Dec 26, 2018, using a multistage, stratified, cluster-sampling method, which considered geographical region, degree of urbanisation, economic development status, and sex and age distribution. 96 sites were randomly selected in 12 provinces and municipalities representative of all socioeconomic and geographical regions in China. Participants were interviewed to obtain data on sociodemographic characteristics, lifestyle, medical history, current medications, and family history, and then completed a neuropsychological testing battery administered by a psychological evaluator. The prevalence of dementia (Alzheimer's disease, vascular dementia, and other dementias) and MCI were calculated and the risk factors for different groups were examined using multivariable-adjusted analyses. FINDINGS: Overall age-adjusted and sex-adjusted prevalence was estimated to be 6·0% (95% CI 5·8-6·3) for dementia, 3·9% (3·8-4·1) for Alzheimer's disease, 1·6% (1·5-1·7) for vascular dementia, and 0·5% (0·5-0·6) for other dementias. We estimated that 15·07 million (95% CI 14·53-15·62) people aged 60 years or older in China have dementia: 9·83 million (9·39-10·29) with Alzheimer's disease, 3·92 million (3·64-4·22) with vascular dementia, and 1·32 million (1·16-1·50) with other dementias. Overall MCI prevalence was estimated to be 15·5% (15·2-15·9), representing 38·77 million (37·95-39·62) people in China. Dementia and MCI shared similar risk factors including old age (dementia: odds ratios ranging from 2·69 [95% CI 2·43-2·98] to 6·60 [5·24-8·32]; MCI: from 1·89 [1·77-2·00] to 4·70 [3·77-5·87]); female sex (dementia: 1·43 [1·31-1·56]; MCI: 1·51 [1·43-1·59]); parental history of dementia (dementia: 7·20 [5·68-9·12]; MCI: 1·91 [1·48-2·46]); rural residence (dementia: 1·16 [1·06-1·27]; MCI: 1·45 [1·38-1·54]); fewer years of education (dementia: from 1·17 [1·06-1·29] to 1·55 [1·38-1·73]; MCI: from 1·48 [1·39-1·58] to 3·48 [3·25-3·73]); being widowed, divorced, or living alone (dementia: from 2·59 [2·30-2·90] to 2·66 [2·29-3·10]; MCI: from 1·58 [1·44-1·73] to 1·74 [1·56-1·95]); smoking (dementia: 1·85 [1·67-2·04]; MCI: 1·27 [1·19-1·36]), hypertension (dementia: 1·86 [1·70-2·03]; MCI: 1·62 [1·54-1·71] for MCI), hyperlipidaemia (dementia: 1·87 [1·71-2·05]; MCI: 1·29 [1·21-1·37]), diabetes (dementia: 2·14 [1·96-2·34]; MCI: 1·44 [1·35-1·53]), heart disease (dementia: 1·98 [1·73-2·26]; MCI: 1·17 [1·06-1·30]), and cerebrovascular disease (dementia: 5·44 [4·95-5·97]; MCI: 1·49 [1·36-1·62]). Nine of these risk factors are modifiable. INTERPRETATION: Dementia and MCI are highly prevalent in China and share similar risk factors. A prevention strategy should be developed to target the identified risk factors in the MCI population to thwart or slow down disease progression. It is also crucial to optimise the management of dementia and MCI as an important part of China's public health system. FUNDING: Key Project of the National Natural Science Foundation of China, National Key Scientific Instrument and Equipment Development Project, Mission Program of Beijing Municipal Administration of Hospitals, Beijing Scholars Program, Beijing Brain Initiative from Beijing Municipal Science & Technology Commission, Project for Outstanding Doctor with Combined Ability of Western and Chinese Medicine, and Beijing Municipal Commission of Health and Family Planning.

INTRODUCTION: The socioeconomic costs of Alzheimer's disease (AD) in China and its impact on global economic burden remain uncertain. METHODS: We collected data from 3098 patients with AD in 81 representative centers across China and estimated AD costs for individual patient and total patients in China in 2015. Based on this data, we re-estimated the worldwide costs of AD. RESULTS: The annual socioeconomic cost per patient was US $19,144.36, and total costs were US $167.74 billion in 2015. The annual total costs are predicted to reach US $507.49 billion in 2030 and US $1.89 trillion in 2050. Based on our results, the global estimates of costs for dementia were US $957.56 billion in 2015, and will be US $2.54 trillion in 2030, and US $9.12 trillion in 2050, much more than the predictions by the World Alzheimer Report 2015. DISCUSSION: China bears a heavy burden of AD costs, which greatly change the estimates of AD cost worldwide.

Research Article| July 01, 2008 Cenozoic tectonic evolution of the Qaidam basin and its surrounding regions (Part 3): Structural geology, sedimentation, and regional tectonic reconstruction An Yin; An Yin * 1Structural Geology Group, School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China, Permanent Address: Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095-1567, USA *Email: yin@ess.ucla.edu Search for other works by this author on: GSW Google Scholar Yu-Qi Dang; Yu-Qi Dang 2Qinghai Oilfield Company, Dunhuang, Gansu Province, People's Republic of China Search for other works by this author on: GSW Google Scholar Min Zhang; Min Zhang 2Qinghai Oilfield Company, Dunhuang, Gansu Province, People's Republic of China Search for other works by this author on: GSW Google Scholar Xuan-Hua Chen; Xuan-Hua Chen 3Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing, People's Republic of China Search for other works by this author on: GSW Google Scholar Michael W. McRivette Michael W. McRivette 4Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095-1567, USA Search for other works by this author on: GSW Google Scholar Author and Article Information An Yin * 1Structural Geology Group, School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China, Permanent Address: Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095-1567, USA Yu-Qi Dang 2Qinghai Oilfield Company, Dunhuang, Gansu Province, People's Republic of China Min Zhang 2Qinghai Oilfield Company, Dunhuang, Gansu Province, People's Republic of China Xuan-Hua Chen 3Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing, People's Republic of China Michael W. McRivette 4Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095-1567, USA *Email: yin@ess.ucla.edu Publisher: Geological Society of America Received: 24 Mar 2007 Revision Received: 11 Aug 2007 Accepted: 14 Aug 2007 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2008 Geological Society of America GSA Bulletin (2008) 120 (7-8): 847–876. https://doi.org/10.1130/B26232.1 Article history Received: 24 Mar 2007 Revision Received: 11 Aug 2007 Accepted: 14 Aug 2007 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation An Yin, Yu-Qi Dang, Min Zhang, Xuan-Hua Chen, Michael W. McRivette; Cenozoic tectonic evolution of the Qaidam basin and its surrounding regions (Part 3): Structural geology, sedimentation, and regional tectonic reconstruction. GSA Bulletin 2008;; 120 (7-8): 847–876. doi: https://doi.org/10.1130/B26232.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The Qaidam basin is the largest topographic depression inside the Tibetan plateau. Because of its central position, understanding the tectonic origin of the Qaidam basin has important implications for unraveling the formation mechanism and growth history of the Tibetan plateau. In order to achieve this goal, we analyzed regional seismic-reflection profiles across the basin and a series of thickness-distribution patterns of Cenozoic strata at different time slices. The first-order structure of the basin is a broad Cenozoic synclinorium, which has an amplitude ranging from >16 km in the west to <4 km in the east. The synclinorium has expanded progressively eastward across the Qaidam region: from the western basin against the Altyn Tagh fault at 65–50 Ma to the eastern basin at 24 Ma. The half-wavelength of the regional fold complex changes from ~170 km in the west to ~50 km in the east. The formation of the synclinorium was induced by an older thrust system initiated ca. 65–50 Ma in the northern margin and a younger thrust system initiated ca. 29–24 Ma in the southern basin margin. Cenozoic upper-crustal shortening decreases eastward across basin from >48% in the west to <1% in the east; the associated strain rates vary from 3.2 × 10−15 s−1 to 1.3 × 10−17 s−1. The eastward decrease in upper-crustal shortening requires a progressive shift in crustal-thickening mechanisms across Qaidam basin, from dominantly upper-crustal shortening in the west to dominantly lower-crustal shortening in the east. Although sedimentation began synchronously at 65–50 Ma across the entire basin, the initiation ages of the southern and northern basin-bounding structures are significantly different; deformation started at 65–50 Ma in the north and at 29–24 Ma in the south. This information and the existing inference that the uplift of the Eastern Kunlun Range south of Qaidam basin began after 30–20 Ma imply that the Paleogene (65–24 Ma) Qaidam and Hoh Xil basins on both sides of the Eastern Kunlun Range may have been parts of a single topographic depression, >500 km wide in the north-south direction between the Qilian Shan and Fenghuo Shan thrust belts in the north and south. The development of this large Paleogene basin in central Tibet and its subsequent destruction and partitioning by the Neogene uplift of the Eastern Kunlun Range requires a highly irregular sequence of deformation, possibly controlled by preexist-ing weakness in the Tibetan lithosphere. 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ABSTRACT Through tectonostratigraphic analysis of the nonmarine, intracontinental Songliao basin in northeast China, four episodes of deformation are recognized: mantle upwelling, rift, postrift thermal subsidence and structural inversion. The episodes are related to regional geodynamics and plate motions. Each episode is associated with a specific stratigraphic signature. The first period of deformation occurred during the Middle and Late Jurassic when asthenospheric upwelling heated, thinned and stretched the lithosphere. These events may have been caused by the narrowing of the Okhotsk Sea through subduction. This deformation is characterized by doming, extension, widespread volcanism and intrusion, and erosion. Volcanics interfinger with alluvial fan and alluvial plain facies systems tracts. The second rifting episode began in the latest Jurassic and continued into the Early Cretaceous. It resulted in the formation of a large number of isolated, NNE‐trending fault blocks of ‘basin‐and‐range’ style. Rifting may have been caused by the formation and subduction of the Izanagi and Pacific Plates. Coal‐bearing fluvial, floodplain, lacustrine and fan‐delta strata and widespread volcanic rocks filled the fault‐block basins. Volcanic strata hundreds to several thousand meters thick in the Huoshiling and Yingcheng Formations record multiple intrusive events during the rifting stage in the basin. These events were concurrent with episodes of intrusion and volcanic eruption in northeast China. The third phase of regional postrift deformation and subsidence, which began with the Lower Cretaceous Denglouku Formation, was caused by lithospheric cooling and extension, modulated by multiple compressional events. Subsidence in the Songliao basin permitted accumulation of thick postrift deposits, in contrast with other Cretaceous basins in Mongolia and northeast Asia. Three compressional episodes, which episodically interrupted the long‐term cooling subsidence, originated from development of the Okhotsk suture and subduction of the Pacific plate. In the Early Cretaceous, pronounced compression originated from closure of Okhotsk Sea, forming the mountain ranges of Daxinganling, which provided sediment to the northern part of the basin. In the Late Cretaceous, the intensity of compression from the Pacific margin increased through time, causing westward migration of depocentres and uplift in the east until the end of Cretaceous. Postrift strata, typically 3000–4000 m thick with a maximum thickness of 6000 m, extend beyond the rift blocks and onlap the basin margins to form a large uniform basin. Early thermal subsidence strata include alluvial fan, fluvial, floodplain, shallow lacustrine and delta facies tracts, overlain by large deltaic and lacustrine facies. Late postrift environments featured by large lakes in the basin centre rimmed by delta, fluvial and floodplain environments. Reflection seismic profiles show that strong structural inversion, including folding and uplift, began at the end of the Nenjiang Formation and culminated at the end of the Cretaceous. The main compressional stress field changed from NW to NWW at the end of the Cretaceous, which caused changes in the direction of folding. During the rifting stage, several sets of gas‐bearing reservoirs formed in association with coal‐bearing source rocks in fluvial and deltaic strata with reservoir‐quality volcanics and fluvial and fan‐delta sandstone. Thick, widespread mudstone deposited in deep lakes during the postrift stage contains abundant organic matter, and is an important source rock and regional cap rock. Good reservoirs occur in deltaic and fluvial strata. Because of the episodic compressional events that alternately caused subsidence and uplift, reservoirs are sandwiched between source rocks, providing direct fluid communication from source to reservoir.

Research Article| July 01, 2008 Cenozoic tectonic evolution of Qaidam basin and its surrounding regions (Part 1): The southern Qilian Shan-Nan Shan thrust belt and northern Qaidam basin An Yin; An Yin 1Structural Geology Group, School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China Permanent address: Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095-1567, USA E-mail: yin@ess.ucla.edu Search for other works by this author on: GSW Google Scholar Yu-Qi Dang; Yu-Qi Dang 2Qinghai Oilfield Company, Dunhuang 736202, Gansu Province, People's Republic of China Search for other works by this author on: GSW Google Scholar Li-Cun Wang; Li-Cun Wang 2Qinghai Oilfield Company, Dunhuang 736202, Gansu Province, People's Republic of China Search for other works by this author on: GSW Google Scholar Wu-Ming Jiang; Wu-Ming Jiang 2Qinghai Oilfield Company, Dunhuang 736202, Gansu Province, People's Republic of China Search for other works by this author on: GSW Google Scholar Su-Ping Zhou; Su-Ping Zhou 2Qinghai Oilfield Company, Dunhuang 736202, Gansu Province, People's Republic of China Search for other works by this author on: GSW Google Scholar Xuan-Hua Chen; Xuan-Hua Chen 3Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, People's Republic of China Search for other works by this author on: GSW Google Scholar George E. Gehrels; George E. Gehrels 4Department of Geosciences, University of Arizona, Tucson, Arizona 85721-0071 Search for other works by this author on: GSW Google Scholar Michael W. McRivette Michael W. McRivette 5Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095-1567, USA Search for other works by this author on: GSW Google Scholar Author and Article Information An Yin 1Structural Geology Group, School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China Permanent address: Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095-1567, USA Yu-Qi Dang 2Qinghai Oilfield Company, Dunhuang 736202, Gansu Province, People's Republic of China Li-Cun Wang 2Qinghai Oilfield Company, Dunhuang 736202, Gansu Province, People's Republic of China Wu-Ming Jiang 2Qinghai Oilfield Company, Dunhuang 736202, Gansu Province, People's Republic of China Su-Ping Zhou 2Qinghai Oilfield Company, Dunhuang 736202, Gansu Province, People's Republic of China Xuan-Hua Chen 3Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, People's Republic of China George E. Gehrels 4Department of Geosciences, University of Arizona, Tucson, Arizona 85721-0071 Michael W. McRivette 5Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095-1567, USA E-mail: yin@ess.ucla.edu Publisher: Geological Society of America Received: 17 Jan 2007 Revision Received: 11 Aug 2007 Accepted: 14 Aug 2007 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2008 Geological Society of America GSA Bulletin (2008) 120 (7-8): 813–846. https://doi.org/10.1130/B26180.1 Article history Received: 17 Jan 2007 Revision Received: 11 Aug 2007 Accepted: 14 Aug 2007 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation An Yin, Yu-Qi Dang, Li-Cun Wang, Wu-Ming Jiang, Su-Ping Zhou, Xuan-Hua Chen, George E. Gehrels, Michael W. McRivette; Cenozoic tectonic evolution of Qaidam basin and its surrounding regions (Part 1): The southern Qilian Shan-Nan Shan thrust belt and northern Qaidam basin. GSA Bulletin 2008;; 120 (7-8): 813–846. doi: https://doi.org/10.1130/B26180.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Cenozoic Qaidam basin, the largest active intermountain basin inside Tibet, figures importantly in the debates on the history and mechanism of Tibetan plateau formation during the Cenozoic Indo-Asian collision. To determine when and how the basin was developed, we conducted detailed geologic mapping and analyses of a dense network of seismic reflection profiles from the southern Qilian Shan-Nan Shan thrust belt and northern Qaidam basin. Our geologic observations provide new constraints on the timing and magnitude of Cenozoic crustal thickening in northern Tibet. Specifically, our work shows that the southernmost part of the Qilian Shan-Nan Shan thrust belt and contractional structures along the northern margin of Qaidam basin were initiated in the Paleocene-early Eocene (65–50 Ma), during or immediately after the onset of the Indo-Asian collision. This finding implies that stress was transferred rapidly through Tibetan lithosphere to northern Tibet from the Indo-Asian convergent front located >1000 km to the south. The development of the thrust system in northern Qaidam basin was driven by motion on the Altyn Tagh fault, as indicated by its eastward propagation away from the Altyn Tagh fault. The eastward lengthening of the thrust system was spatially and temporally associated with eastward expansion of Qaidam basin, suggesting thrust loading was the main control on the basin formation and evolution. The dominant structure in northern Qaidam basin is a southwest-tapering triangle zone, which started to develop since the Paleocene and early Eocene (65–50 Ma) and was associated with deposition of an overlying southwest-thickening, growth-strata sequence. Recognition of the triangle zone and its longevity in northern Qaidam basin explains a long puzzling observation that Cenozoic depocenters have been located consistently along the central axis of the basin. This basin configuration is opposite to the prediction of classic foreland-basin models that require the thickest part of foreland sediments deposited along basin edges against basin-bounding thrusts. Restoration of balanced cross sections across the southern Qilian Shan-Nan Shan thrust belt and northern Qaidam basin suggests that Cenozoic shortening strain is highly inhomogeneous, varying from ~20% to >60%, both vertically in a single section and from section to section across the thrust belt. The spatially variable strain helps explain the conflicting paleomagnetic results indicating different amounts of Cenozoic rotations in different parts of Qaidam basin. The observed crustal shortening strain also implies that no lower-crustal injection or thermal events in the mantle are needed to explain the current elevation (~3000–3500 m) and crustal thickness (45–50 km) of northern Qaidam basin and the southern Qilian Shan-Nan Shan thrust belt. Instead, thrusting involving continental crystalline basement has been the main mechanism of plateau construction across northern Qaidam basin and the southern Qilian Shan-Nan Shan region. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Abstract Objective To evaluate sintilimab versus placebo in combination with chemotherapy (cisplatin plus paclitaxel or cisplatin plus 5-fluorouracil) as first line treatment of unresectable locally advanced, recurrent, or metastatic oesophageal squamous cell carcinoma. Design Multicentre, randomised, double blind, phase 3 trial. Setting 66 sites in China and 13 sites outside of China between 14 December 2018 and 9 April 2021. Participants 659 adults (aged ≥18 years) with advanced or metastatic oesophageal squamous cell carcinoma who had not received systemic treatment. Intervention Participants were randomised 1:1 to receive sintilimab or placebo (3 mg/kg in patients weighing &lt;60 kg or 200 mg in patients weighing ≥60 kg) in combination with cisplatin 75 mg/m 2 plus paclitaxel 175 mg/m 2 every three weeks. The trial was amended to allow investigators to choose the chemotherapy regimen: cisplatin plus paclitaxel or cisplatin plus 5-fluorouracil (800 mg/m 2 continuous infusion on days 1-5). Main outcome measures Overall survival in all patients and in patients with combined positive scores of ≥10 for expression of programmed cell death ligand 1. Results 659 patients were randomly assigned to sintilimab (n=327) or placebo (n=332) with chemotherapy. 616 of 659 patients (93%) received sintilimab or placebo in combination with cisplatin plus paclitaxel and 43 of 659 patients (7%) received sintilimab or placebo in combination with cisplatin plus 5-fluorouracil. At the interim analysis, sintilimab with chemotherapy showed better overall survival compared with placebo and chemotherapy in all patients (median 16.7 v 12.5 months, hazard ratio 0.63, 95% confidence interval 0.51 to 0.78, P&lt;0.001) and in patients with combined positive scores of ≥10 (17.2 v 13.6 months, 0.64, 0.48 to 0.85, P=0.002). Sintilimab and chemotherapy significantly improved progression free survival compared with placebo and chemotherapy in all patients (7.2 v 5.7 months, 0.56, 0.46 to 0.68, P&lt;0.001) and in patients with combined positive scores of ≥10 (8.3 v 6.4 months, 0.58, 0.45 to 0.75, P&lt;0.001). Adverse events related to treatment occurred in 321 of 327 patients (98%) in the sintilimab-chemotherapy group versus 326 of 332 (98%) patients in the placebo-chemotherapy group. Rates of adverse events related to treatment, grade ≥3, were 60% (196/327) and 55% (181/332) in the sintilimab-chemotherapy and placebo-chemotherapy groups, respectively. Conclusions Compared with placebo, sintilimab in combination with cisplatin plus paclitaxel showed significant benefits in overall survival and progression free survival as first line treatment in patients with advanced or metastatic oesophageal squamous cell carcinoma. Similar benefits of sintilimab with cisplatin plus 5-fluorouracil seem promising. Trial registration ClinicalTrials.gov NCT03748134 .

ABSTRACT The lacustrine shale of the Upper Cretaceous Qingshankou Formation is the principal prospective unconventional target lithology, acting as source, reservoir, and seal. Lithofacies and associated storage capacity are two significant factors in shale oil prospectivity. This paper describes an investigation of the lower Qingshankou Formation lacustrine shale based on detailed description and analysis of cores, shale lithofacies characteristics, depositional setting, and stacking patterns. Seven lithofacies are recognized based on organic matter content, sedimentary structure, and mineralogy, all exhibiting rapid vertical and lateral changes controlled by the depositional setting and basin evolution. An overall trend from shallow-water to deep-water depositional environments is interpreted from the characteristics of the infilling sequences, characterized by increasing total organic carbon (TOC) and total clay content and decreasing layer thickness (i.e., from bedded to laminated then to massive sedimentary structures). Periods of deposition during shallowing cycles show a reverse trend in the sedimentary characteristics described above. The sedimentary rocks in the studied interval show three complete short-term cycles, each one containing progressive and regressive system tracts. Massive siliceous mudstones with both high and moderate TOC are considered to have the best hydrocarbon generation potential. Laminated siliceous mudstones, bedded siltstones, and calcareous mudstones with moderate and low TOC could have the same high hydrocarbon saturations as the high-TOC massive siliceous mudstones, but these lithologies contain more brittle minerals than the massive mudstones. Several siltstone samples show low or zero saturation of in situ hydrocarbons; this is considered to be related to a combination of fair to poor hydrocarbon generation potential and extremely low permeability, limiting migration. Moderate-TOC laminated siliceous mudstones were also observed to have connective pore-fracture networks. It can be demonstrated that successive thick sequences of moderate-TOC laminated siliceous mudstones, showing high volumes of hydrocarbon in situ, a high mineral brittleness index, and good permeability, combine to form shale oil exploration “sweet spots.”

Through reviewing the development history of tight oil and gas in China, summarizing theoretical understandings in exploration and development, and comparing the geological conditions and development technologies objectively in China and the United States, we clarified the progress and stage of tight oil and gas exploration and development in China, and envisaged the future development orientation of theory and technology, process methods and development policy. In nearly a decade, relying on the exploration and development practice, science and technology research and management innovation, huge breakthroughs have been made. The laws of formation, distribution and accumulation of tight oil and gas have been researched, the development theories such as “multi-stage pressure drop” and “man-made reservoirs” have been established, and several technology series have been innovated and integrated. These technology series include enrichment regions selection, well pattern deployment, single well production and recovery factor enhancement, and low cost development. As a result, both of reserves and production of tight oil and gas increase rapidly. However, limited by the sedimentary environment and tectonic background, compared with North America, China's tight oil and gas reservoirs are worse in continuity, more difficult to develop and poorer in economic efficiency. Moreover, there are still some gaps in reservoir identification accuracy and stimulating technology between China and North America. In the future, Chinese oil and gas companies should further improve the resource evaluation method, tackle key technologies such as high-precision 3D seismic interpretation, man-made reservoir, and intelligent engineering, innovate theories and technologies to enhance single well production and recovery rate, and actively endeavor to get the finance and tax subsidy on tight oil and gas.

Summary At elevated temperatures in aqueous solution, partially hydrolyzed polyacrylamides (HPAMs) experience hydrolysis of amide side groups. However, in the absence of dissolved oxygen and divalent cations, the polymer backbone can remain stable so that HPAM solutions were projected to maintain at least half their original viscosity for more than 8 years at 100°C and for approximately 2 years at 120°C. Within our experimental error, HPAM stability was the same with and without oil (decane). An acrylamide-AMPS copolymer [with 25% 2-acrylamido-2-methylpropane sulphonic acid (AMPS)] showed similar stability to that for HPAM. Stability results were similar in brines with 0.3% NaCl, 3% NaCl, or 0.2% NaCl plus 0.1% NaHCO3. At temperatures of 160°C and greater, the polymers were more stable in brine with 2% NaCl plus 1% NaHCO3 than in the other brines. Even though no chemical oxygen scavengers or antioxidants were used in our study, we observed the highest level of thermal stability reported to date for these polymers. Our results provide considerable hope for the use of HPAM polymers in enhanced oil recovery (EOR) at temperatures up to 120°C if contact with dissolved oxygen and divalent cations can be minimized. Calculations performed considering oxygen reaction with oil and pyrite revealed that dissolved oxygen will be removed quickly from injected waters and will not propagate very far into porous reservoir rock. These findings have two positive implications with respect to polymer floods in high-temperature reservoirs. First, dissolved oxygen that entered the reservoir before polymer injection will have been consumed and will not aggravate polymer degradation. Second, if an oxygen leak (in the surface facilities or piping) develops during the course of polymer injection, that oxygen will not compromise the stability of the polymer that was injected before the leak developed or the polymer that is injected after the leak is fixed. Of course, the polymer that is injected while the leak is active will be susceptible to oxidative degradation. Maintaining dissolved oxygen at undetectable levels is necessary to maximize polymer stability. This can be accomplished readily without the use of chemical oxygen scavengers or antioxidants.

After the preliminary basic research on the problems encountered during the production period of Gulong shale oil in the Songliao Basin, NE China, and the scientific exploration, the special characteristics of Gulong shale oil in terms of reservoir space, phase distribution, flow pattern, and mineral evolution are proposed. The main results are as follows : (1) The source of organic matter, mechanism of hydrocarbon generation and expulsion, and key factors affecting shale oil abundance; (2) The types and structural characteristics of the reservoir and their contribution to porosity and permeability; (3) The mineral origin and evolution of minerals and their influence on reservoir availability, sensitivity, and compressibility; (4) The rock mechanical characteristics and fracture propagation law of Gulong shale; (5) The shale oil products, phase change law and main control factors of adsorption and desorption conversion of Gulong shale oil; (6) The mechanism of shale oil-liquid, solid-liquid gas interaction and enhanced oil recovery. Three key research suggestions are proposed to realize the large-scale economic utilization of the Gulong shale oil as follows: (1) Deepen research on the mechanism of oil and gas generation and discharge, storage and transportation, to guide the selection of geological sweet spots of shale oil; (2) Deepen research on the compressibility and fracture initiation mechanism to support the selection of engineering sweet spots and optimization of engineering design; (3) Deepen research on the fluid interaction mechanism under reservoir conditions, os us to guide the optimization of development schemes and the selection of EOR technologies. A successful development of Gulong shale oil requires global experts and scholars to contribute multidisciplinary innovative ideas and technical ideas to solve production problems.

Abstract When flooding with viscous Polymers, due to the increase in viscosity and decrease in permeability (for polymers that absorb on the rock surface), the mobility ratio compared to water flooding becomes more favorable. Therefore the volumetric sweep efficiency increases and the recovery of the reservoir on a macro scale increases also. Most people think that polymer flooding does not increase the recovery at a micro scale. But numerous results in this work do not support this conclusion. From cores in the lab, the effect of flooding with viscous-elastic polymers on different types of residual oil after water flooding was studied. The different types of residual oil are: 1) oil film on the rock surface; 2) oil in "dead ends"; 3) oil in pores throats retained by capillary forces; 4) oil un-swept in micro scale heterogeneous portions of the core. It could be seen that all types of micro-scale residual oil were reduced after flooding with viscous-elastic polymers. Due to the elastic nature of the polymer, the velocity distribution in the pores are quite different from Newtonian Fluids and the polymer could also exert a very strong "pulling effect" on different types of residual oil. The study pointed out that the relationship between Capillary Number and Recovery of cores for Newtonian Fluids does not apply to fluids with elastic properties. In the study, it was seen that the increase in micro scale recovery was related to the elastic properties of the polymer fluids. Different polymer fluids had quite different elastic properties. Some had practically no elasticity. Therefore, when selecting polymers for flooding, its elastic properties must be considered. The difference in incremental recovery can be more than 6 % OOIP (original oil in place), which is substantial, it can make a polymer flood successful (both technically and economically) or not. The above conclusions can also be confirmed by pressure coring data and field results of large scale polymer (PAM) flooding in Daqing Oil Field, which is obtaining an incremental oil recovery of more than 13% OOIP. This magnitude of incremental oil recovery can not be explained by just an increase in volumetric sweep efficiency. The above conclusions 1) can explain why some polymer floods were successful or not; 2) should be considered when selecting polymer floods and, 3) should be able to increase the incremental oil of future polymer floods. The rheology of viscous-elastic fluids in porous media is very much different from fluids with no elasticity. Much work needs to be done in this field. Many conclusion obtained by studies on Newtonian Fluids need to be re-assessed when used on visco-elastic fluids.

OBJECTIVE: To identify an optimal lifestyle profile to protect against memory loss in older individuals. DESIGN: Population based, prospective cohort study. SETTING: Participants from areas representative of the north, south, and west of China. PARTICIPANTS: Individuals aged 60 years or older who had normal cognition and underwent apolipoprotein E (APOE) genotyping at baseline in 2009. MAIN OUTCOME MEASURES: Participants were followed up until death, discontinuation, or 26 December 2019. Six healthy lifestyle factors were assessed: a healthy diet (adherence to the recommended intake of at least 7 of 12 eligible food items), regular physical exercise (≥150 min of moderate intensity or ≥75 min of vigorous intensity, per week), active social contact (≥twice per week), active cognitive activity (≥twice per week), never or previously smoked, and never drinking alcohol. Participants were categorised into the favourable group if they had four to six healthy lifestyle factors, into the average group for two to three factors, and into the unfavourable group for zero to one factor. Memory function was assessed using the World Health Organization/University of California-Los Angeles Auditory Verbal Learning Test, and global cognition was assessed via the Mini-Mental State Examination. Linear mixed models were used to explore the impact of lifestyle factors on memory in the study sample. RESULTS: 29 072 participants were included (mean age of 72.23 years; 48.54% (n=14 113) were women; and 20.43% (n=5939) were APOE ε4 carriers). Over the 10 year follow-up period (2009-19), participants in the favourable group had slower memory decline than those in the unfavourable group (by 0.028 points/year, 95% confidence interval 0.023 to 0.032, P<0.001). APOE ε4 carriers with favourable (0.027, 95% confidence interval 0.023 to 0.031) and average (0.014, 0.010 to 0.019) lifestyles exhibited a slower memory decline than those with unfavourable lifestyles. Among people who were not carriers of APOE ε4, similar results were observed among participants in the favourable (0.029 points/year, 95% confidence interval 0.019 to 0.039) and average (0.019, 0.011 to 0.027) groups compared with those in the unfavourable group. APOE ε4 status and lifestyle profiles did not show a significant interaction effect on memory decline (P=0.52). CONCLUSION: A healthy lifestyle is associated with slower memory decline, even in the presence of the APOE ε4 allele. This study might offer important information to protect older adults against memory decline. TRIAL REGISTRATION: ClinicalTrials.gov NCT03653156.

Paper includes discussion and reply published in May 2006 JPT. Distinguished Author Series articles are general, descriptive representations that summarize the state of the art in an area of technology by describing recent developments for readers who are not specialists in the topics discussed. Written by individuals recognized as experts in the area, these articles provide key references to more definitive work and present specific details only to illustrate the technology. Purpose: to inform the general readership of recent advances in various areas of petroleum engineering. Abstract Polymer flooding (PF) and alkaline/surfactant/polymer (ASP) flooding have been applied throughout the world for more than 20 years. However, few large-scale successes with these processes have been reported, except in China. To date, the PF process has been applied successfully in several major Chinese oil fields such as Daqing and Shengli. PF alone contributed approximately 250,000 BOPD of production in 2004 from these two fields. Incremental oil recoveries of up to 14% of the original oil in place (OOIP) have been obtained in good-quality reservoirs. Profile modifications by use of polymers and a crosslinker to form colloidal-dispersion gels (CDGs) also have been implemented successfully in large-scale production operations in China. Results show that the CDG process is more cost-effective than the PF process. Several ASP floods also have been pilot tested in various Chinese oil fields. Incremental recoveries of up to 25% OOIP have been reported, although commercial-scale applications have not been implemented. Plans to implement three large-scale projects have been made for 2006 in the Daqing oil field. This paper discusses the progress made in these processes in China over the last 20 years, including field results, new concepts, and economics. Introduction The PF concept in the U.S. has been to use a small slug at low polymer concentrations. The amount of polymer used is measured with a combination unit calculated by multiplying the concentration in parts per million (ppm) by the slug size in pore volume (Vp). The 1976 U.S. Natl. Petroleum Council (NPC) study used 125 ppm·Vp. The amount of polymer used in the 1984 NPC study was increased to 240 ppm·Vp, but it was still much less than that used in China. NPC projected incremental recoveries were in the range of 6 to 8% OOIP in successful projects, approximately 50% of that obtained in good-quality reservoirs in the Daqing oil field. Seven PF pilot tests were conducted in the Daqing oil field from 1972 through 1998. Continued research and field testing led to fieldwide expansion in 1996. There were 31 commercial-scale PF projects in Daqing in 2004, with 2,427 injection wells and 2,916 production wells. Currently, PF is implemented in a total area of 67,759 acres, as shown in Fig. 1. Oil production from PF has been maintained since 1999. The production reached 73.5 million bbl in 2004, approximately 23% of the total field production.

A set of shale-dominated source rocks series were deposited during the heyday of lake basin development in the Member 7 of Triassic Yanchang Formation, Ordos Basin, and the thickness is about 110 m. Aimed at whether this layer can form large-scale oil enrichment of industrial value, comprehensive geological research and exploration practice have been carried out for years and obtained the following important geologic findings. Firstly, widely distributed black shale and dark mudstone with an average organic matter abundance of 13.81% and 3.74%, respectively, lay solid material foundation for the formation of shale oil. Secondly, sandy rocks sandwiched in thick organic-rich shale formations constitute an oil-rich “sweet spot”, the average thickness of thin sandstone is 3.5 m. Thirdly, fine-grained sandstone and siltstone reservoirs have mainly small pores of 2–8 μm and throats of 20–150 nm in radius, but with a large number of micro-pores and nano-throats, through fracturing, the reservoirs can provide good conductivity for the fluid in it. Fourthly, continued high-intensity hydrocarbon generation led to a pressure difference between the source rock and thin-layer reservoir of up to 8–16 MPa during geological history, driven by the high pressure, the oil charged into the reservoirs in large area, with oil saturation reaching more than 70%. Under the guidance of the above theory, in 2019, the Qingcheng Oilfield with geologic oil reserves of billion ton order was proved in the class I multi-stage superimposed sandstone shale reservoir of Chang 7 Member by the Changqing Oilfield Branch through implementation of overall exploration and horizontal well volume fracturing. Two risk exploration horizontal wells were deployed for the class II thick layer mud shale interbedded with thin layers of silt- and fine-sandstones reservoir in the Chang 73 submember, and they were tested high yield oil flows of more than 100 tons per day, marking major breakthroughs in petroleum exploration in class I shale reservoirs. The new discoveries have expanded the domain of unconventional petroleum exploration.

Importance: Acupuncture is used to induce ovulation in some women with polycystic ovary syndrome, without supporting clinical evidence. Objective: To assess whether active acupuncture, either alone or combined with clomiphene, increases the likelihood of live births among women with polycystic ovary syndrome. Design, Setting, and Participants: A double-blind (clomiphene vs placebo), single-blind (active vs control acupuncture) factorial trial was conducted at 21 sites (27 hospitals) in mainland China between July 6, 2012, and November 18, 2014, with 10 months of pregnancy follow-up until October 7, 2015. Chinese women with polycystic ovary syndrome were randomized in a 1:1:1:1 ratio to 4 groups. Interventions: Active or control acupuncture administered twice a week for 30 minutes per treatment and clomiphene or placebo administered for 5 days per cycle, for up to 4 cycles. The active acupuncture group received deep needle insertion with combined manual and low-frequency electrical stimulation; the control acupuncture group received superficial needle insertion, no manual stimulation, and mock electricity. Main Outcomes and Measures: The primary outcome was live birth. Secondary outcomes included adverse events. Results: Among the 1000 randomized women (mean [SD] age, 27.9 [3.3] years; mean [SD] body mass index, 24.2 [4.3]), 250 were randomized to each group; a total of 926 women (92.6%) completed the trial. Live births occurred in 69 of 235 women (29.4%) in the active acupuncture plus clomiphene group, 66 of 236 (28.0%) in the control acupuncture plus clomiphene group, 31 of 223 (13.9%) in the active acupuncture plus placebo group, and 39 of 232 (16.8%) in the control acupuncture plus placebo group. There was no significant interaction between active acupuncture and clomiphene (P = .39), so main effects were evaluated. The live birth rate was significantly higher in the women treated with clomiphene than with placebo (135 of 471 [28.7%] vs 70 of 455 [15.4%], respectively; difference, 13.3%; 95% CI, 8.0% to 18.5%) and not significantly different between women treated with active vs control acupuncture (100 of 458 [21.8%] vs 105 of 468 [22.4%], respectively; difference, -0.6%; 95% CI, -5.9% to 4.7%). Diarrhea and bruising were more common in patients receiving active acupuncture than control acupuncture (diarrhea: 25 of 500 [5.0%] vs 8 of 500 [1.6%], respectively; difference, 3.4%; 95% CI, 1.2% to 5.6%; bruising: 37 of 500 [7.4%] vs 9 of 500 [1.8%], respectively; difference, 5.6%; 95% CI, 3.0% to 8.2%). Conclusions and Relevance: Among Chinese women with polycystic ovary syndrome, the use of acupuncture with or without clomiphene, compared with control acupuncture and placebo, did not increase live births. This finding does not support acupuncture as an infertility treatment in such women. Trial Registration: clinicaltrials.gov Identifier: NCT01573858.

Summary This paper describes successful practices applied during polymer flooding at Daqing that will be of considerable value to future chemical floods, both in China and elsewhere. On the basis of laboratory findings, new concepts have been developed that expand conventional ideas concerning favorable conditions for mobility improvement by polymer flooding. Particular advances integrate reservoir-engineering approaches and technology that is basic for successful application of polymer flooding. These include the following: (1) Proper consideration must be given to the permeability contrast among the oil zones and to interwell continuity involving the optimum combination of oil strata during flooding and well-pattern design, respectively; (2) Higher polymer molecular weights, a broader range of polymer molecular weights, and higher polymer concentrations are desirable in the injected slugs; (3) The entire polymer-flooding process should be characterized in five stages—with its dynamic behavior distinguished by water-cut changes; (4) Additional techniques should be considered, such as dynamic monitoring using well logging, well testing, and tracers; effective techniques are also needed for surface mixing, injection facilities, oil production, and produced-water treatment; and (5) Continuous innovation must be a priority during polymer flooding.

Abstract In this paper, the visco-elastic characteristics of polyacrylamide solution have been studied experimentally. The mechanisms of the effect of polymer solution with visco-elastic characteristic on each type of residual oil after water flooding are analyzed and the mechanisms of polymer solution with visco-elastic characteristic increasing microscopic oil displacement efficiency are studied. By the analysis of microscopic experiments of percolating flow, corresponding relationships between the characteristic parameter describing the visco-elastic behavior of polymer solution and displacement efficiency of residual oil in "dead ends" are given. It is shown that the larger the visco-elastic behavior of polymer solution, the higher the displacement efficiency of residual oil in "dead ends". A phenomenon that is not seen during water flooding is observed during polyacrylamide solution flooding in the microscopic experiment of percolating flow, that is, residual oil can be pulled into "oil threads" by the polyacrylamide solution. So a new type of oil flow channel, i.e. "oil thread" channel, can be formed and residual oil flows downstream through the "oil thread" channel. The probability of forming a steady "oil thread" flow channel in polymer flooding is also analyzed theoretically and proved. The research indicates that the mechanism of polymer solution microscopically increasing oil recovery is due to the visco-elastic characteristic of the polymer solution, the sweeping force acting on the residual oil for the visco-elastic polymer solution is larger than that of water. The residual oil is not pushed out by the polymer solution but pulled out by the polymer solution. It is also found that every type of residual oil after water flooding can be decreased by visco-elastic polymer solution, and the larger the visco-elastic property, the stronger the capability of the polymer solution to "sweep out" the residual oil. In brief, the results indicate that polymer flooding can not only macroscopically increase the sweep efficiency but also microscopically increase the oil displacement efficiency and a new type of flow channel, "oil thread", can also be formed.Besides new understanding on the mechanism of the flow of fluid through porous media and the displacement of residual oil, the above results should be beneficial to designing new EOR methods to further increase the recovery of oil fields.

Abstract Emulsification plays an important role in enhancing oil recovery. Experiments and field applications of alkali/surfactant/polymer ( ASP ) flooding indicated that the amount of oil recovery in liquids with emulsions is 5% higher than that in liquids with no emulsions. Therefore, it is of great significance to study emulsion and its field application for enhanced oil recovery. This paper discusses the current status of emulsion for enhanced oil recovery, including the formation mechanism of emulsions in chemical flooding, rheological properties, stability, seepage characteristics, emulsion improving sweep volume, and displacement efficiency, along with future development plans of emulsion for enhanced oil recovery, especially surfactants for chemical flooding. In addition, the Pickering emulsion for application in enhanced oil recovery is also discussed. The development effects of emulsion flooding have been discussed for the Midway‐Sunset Oilfield, the emulsification characteristics of ASP flooding have been analyzed in Xing‐V and Xing‐ II of the Daqing Oilfield, and the experiences regarding emulsion for enhanced oil recovery have been summarized. The key research directions of emulsion for enhanced oil recovery are indicated.

Taking organic-rich shale in the first member of Cretaceous Qingshankou Formation in the Gulong Sag, northern Songliao Basin as an example, this study examined the lithofacies classification, petrological characteristics, pore size distribution and their implications on the enrichment of shale oil of lacustrine detrital fine-grained shale. The spatial variation of lithofacies, controlled by Milankovitch cycle and influenced by sediment provenance, has an obvious sequence. The fine-grained sedimentary rocks of studied section could be classified into seven lithofacies according to a three-step classification criterion that consists of total organic carbon (TOC), sedimentary structure and mineral composition. Among them, the laminated siliceous mudstone lithofacies with moderate TOC has high hydrocarbon generation potential and abundant reservoir space, making it the most favorable lithofacies for the enrichment of matrix shale oil. Under the background of abnormally high pressure, the laminated siliceous mudstone lithofacies with moderate TOC deposited between the top of SSC2 and the bottom of SSC3 is stable in lateral distribution in the delta-lacustrine transition zone, with continuous thickness greater than 30 m. The massive siliceous mudstone lithofacies with high and moderate TOC developed in the middle of the these two cycles can act as the roof and floor seal for shale oil, therefore, the study area has good conditions for forming matrix type shale oil reservoirs.

Oxidative stress contributes to the pathogenesis of diabetic nephropathy (DN). Nuclear factor erythroid 2-related factor 2 (NRF2) plays a key role in cellular defense against oxidative stress. NRF2 activators have shown promising preventive effects on DN. Sodium butyrate (NaB) is a known activator of NRF2. However, it is unknown whether NRF2 is required for NaB protection against DN. Therefore, streptozotocin-induced diabetic C57BL/6 Nrf2 knockout and their wild-type mice were treated in the presence or absence of NaB for 20 weeks. Diabetic mice, but not NaB-treated diabetic mice, developed significant renal oxidative damage, inflammation, apoptosis, fibrosis, pathological changes and albuminuria. NaB inhibited histone deacetylase (HDAC) activity and elevated the expression of Nrf2 and its downstream targets heme oxygenase 1 and NAD(P)H dehydrogenase quinone 1. Notably, deletion of the Nrf2 gene completely abolished NaB activation of NRF2 signaling and protection against diabetes-induced renal injury. Interestingly, the expression of Kelch-like ECH-associated protein 1, the negative regulator of NRF2, was not altered by NaB under both diabetic and non-diabetic conditions. Moreover, NRF2 nuclear translocation was not promoted by NaB. Therefore, the present study indicates, for the first time, that NRF2 plays a key role in NaB protection against DN. Other findings suggest that NaB may activate Nrf2 at the transcriptional level, possibly by the inhibition of HDAC activity.