bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of hydrocarbon transport systems and migration in slope areas of Qikou Sag, Bohai Bay Basin
Authors: Deng Yan , Zhao Changyi , Jiang Wenya
Published: October 2019

The transport system plays an important role in hydrocarbon accumulation in slope area. The geochemical characteristics of the reservoir indicate that the oil and gas in this area generally have the tendency of migration and accumulation from the hydrocarbon generation center to the high part of slope. According to the relationship between source kitchens and traps, the hydrocarbon migration is divided into three types: inside source accumulation, near source vertical migration and outside source accumulation, controlled by the differential pressure between source rock and reservoir, dominant pathway-cap assembly and dominant migration phase respectively. The main types of migration pathway in the slope area are sand bodies, faults and unconformities, and the matching relationship between them controlled the direction and mode of oil and gas migration and accumulation in the slope area. The hydrocarbon migration and accumulation of middle-shallow layer in the low-middle slope are controlled by the dominant pathways and the matching relationship between faults and cap rocks, the hydrocarbon migration and accumulation in the middle slope are controlled by the favorable sedimentary facies, and the hydrocarbon migration and accumulation in the high slope are controlled by the distribution of sand bodies and favorable structures.
Geochemical characteristics and organic matter enrichment of the Late Ordovician-Early Silurian black shale in Nanchuan area, Sichuan Basin
Authors: He Long , Wang Yupeng , Chen Duofu
Published: October 2019

The enrichment of organic matter in black shale is a controversial issue among the researchers and critical problem in the exploration of shale gas. In order to understand the relationship between sedimentary environment and organic matter accumulation in black shale of Wufeng Formation. Longmaxi Formation and limestone of Guanyinqiao Bed, multiple geochemical method, such as organic carbon, major and trace elements, are tested from the Nanchuan section. Research results show that the organic carbon is enriched in the middle to upper part of Wufeng Formation and the bottom of Longmaxi Formation. Ba and P contents exhibit a high primary productivity during Late Ordovician-Early Silurian in Sichuan basin. Redox proxies (V/Cr, Ni/Co) indicate that Wufeng Formation deposited in an anoxic environment and Longmaxi Formation deposited in euxinic condition, but Guanyinqiao Bed was predominated by oxic-dysoxic environment during the sedimentation. The poor relation between TOC and Ba, suggests primary productivity are not the major factors controlling the enrichment of organic matter, but an anoxic environment is the predominant condition causing the accumulation and preservation of organic matter suggested by a positive correlation between TOC and redox proxies.
Geochemical characteristics and genesis of tight sandstone gas in Xinguang area, Junggar Basin
Authors: Li Erting , Xiang Baoli , Mi Julei , Liu Cuimin , Ma Wanyun , Zhou Ni , Rouzi Dilidaer , Li Ji
Published: October 2019

Based on the study of natural gas geochemical characteristics, combined with carbon isotope composition distribution of n-alkanes in condensate oil associated with tight sandstone natural gas, the source of natural gas in Jiamuhe Formation tight sandstone reservoir from Xinguang area of Zhongguai uplift in Junggar Basin was determined. The result shows, hydrocarbon generation potential of three sets of source rocks in Permian is: Fengcheng Formation > Lower Wuerhe Formation > Jiamuhe Formation. Lower Wuerhe Formation source rocks generate oil and gas. And C7 light hydrocarbons composition of the natural sandstone reservoir of Jiamuhe Formation in Xinguang area is dominated by n-heptane, with content more than 40%, content of methylcyclohexane is less than 40%, and carbon isotope distribution of ethane is between -29.0‰ and -27.0‰. which shows the gas origin from sapropelic source rock. The carbon isotope composition distribution of n-alkanes in condensate oil associated with the tight sandstone natural gas of Jiamuhe Formation is “valley” type, which is consistent with source rock of Lower Wuerhe Formation, indicating that the condensate oil from Xinguang area is derived from Lower Wuerhe Formation source rock. According to comprehensive analysis, the tight sandstone gas of Jiamuhe Formation in Xinguang area of Junggar Basin is mainly derived from high-mature Lower Wuerhe Formation source rock.
Fractional composition and evolution of residual oil from coal of Early Permian Shanxi Formation (P1s), Ordos Basin (China)
Authors: Liao Lingling , Wang Yunpeng , Lu Jialan
Published: October 2019

To explore the residual oil contents and its fractional compositions changes with thermal stress, experiment of a whole coal sample from lower Permian Shanxi formation (P1sh) of Ordos Basin (China) was conducted in the grain-based micro-scale sealed vessel to explore the residual oil contents, fractional compositions and evolution at different temperatures and maturities. The residual oil of Shanxi coal reach the maximum at Ro=0.92% which was only 47.87 mg/g TOC. In oil window, the residual oil of Shanxi coal is mainly composed of asphaltenes, aromatics and resins with less saturates, showing lower oil prospective. In wet and dry gas windows, the residual oil becomes lower due to oil expulsion and cracking into gases. The main fractional compositions of residual oil are mainly aromatics and resins, which are gas-prone and can be the source of coal-bed methane at higher maturity stages.
Distribution and characteristics of paleo-oil reservoirs in Cambrian Longwangmiao Formation in Anyue area of Sichuan Basin, China
Authors: Ma Xingzhi , Liu Shaobo , Fan Junjia , Yang Fan , Meng Qingyang
Published: October 2019

The Anyue gas field is a giant marine gas field with the largest reserves of a single reservoir and the oldest strata in China. In this area, the proved gas reserves in the Cambrian Longwangmiao Formation are 4, 404×108 m3, which are believed to originate from crude oil cracking according to substantial evidences. The paleo-oil reservoirs in the area have been destroyed, and their fluid properties, scale and other characteristics are unclear, despite of the distribution preliminarily determined. In this paper, the paleo-oil reservoirs in the Cambrian Longwangmiao Formation in the Moxi–Gaoshiti area were analyzed thoroughly through conventional microscopic observation, together with quantitative grain fluorescence (QGF), total scanning fluorescence (TSF), and micro-laser Raman analysis. The study results indicate that the Longwangmiao Formation contains bitumen, which is mainly distributed in four types of pore space, i.e. vein-like fractures, dissolution pores, intergranular pores, and intercrystalline pores. The bitumen in vein-like fractures was formed mostly in relation to hydrocarbon migration, while the bitumen in dissolution pores, intergranular pores and intercrystalline pores was formed by in-situ cracking of petroleum, mostly as a result of thermal alteration. The QGF index suggests the existence of paleo-oil reservoirs in certain scale in the study area, and the high QGF-E intensity indicates the property of residual bitumen. The laser Raman spectroscopy reveals the maturity of the extensive solid bitumen in reservoir rocks. The well-cross section illustrates that the paleo-oil reservoirs are mainly layered, have experienced mostly in-situ cracking, and match with the present gas reservoirs.
Differences and genesis of shale oil properties between the upper and lower sections of the Lucaogou Formation in the Jimsar Sag
Authors: Ren Jiangling , Jin Jun , Xiang Baoli , Ma Wanyun , Zhou Ni , Liao Jiande
Published: October 2019

The Lucaogou Formation is a set of saline lake sediments with high abundance of organic matter and good parent material type in the Jimsar Sag, Junggar Basin. It belongs to the best source rock. The Lucaogou Formation sandstone and shale are thinly interbedded, and the upper and lower reservoirs are oil-bearing as a whole, with source-storage integration characteristics. The upper part of the shale oil and the lower part of the shale oil in the Lucaogou Formation are more heavily oily, and the lower part of the oil is heavier. Fine geochemical analysis shows that the crude oil in the upper part of the Lucaogou Formation is formed in a sedimentary environment with certain reduction, while the lower crude oil is formed in a highly reducing and salinized environment; The parent material in the upper and lower shale oil sources in the Lucaogou Formation is mainly algae and lower aquatic organisms, but the lower aquatic organisms in the lower part are obviously dominant, and the upper and lower raw materials are significantly different. The difference of the characteristics of the shale oil in the upper and lower parts of the Lucaogou Formation is closely related to the sedimentary environment of the source rock and the source material. At the same time, the special source of the lower part of the Lucaogou Formation produces hydrocarbons in the early stage of the lower evolution stage, which makes the oil quality of the crude oil become heavier obviously.
The Burial and Thermal Histories of Wufeng-Longmaxi Shale of Well Anye-1, Zheng’an Area, North Guizhou
Authors: Shi Shuyong , Wang Yunpeng , Sun Yu , Liu Min
Published: October 2019

Great breakthrough had taken place in the field of shale gas exploration of Wufeng-Lonmgaxi shale in Zheng’an Area, North Guizhou. In this paper, we reconstruct the one-dimensional geological model of Well Anye-1 by using PetroMod software. The burial history shows that the Wufeng-Longmaxi shale of Well Anye-1 mainly experienced four erosion movements. It reached the maximum burial depth (5331 m) at the late Cretaceous and the current burial depth is 2331 m. The thermal history shows that the shale started to generated oil (Ro>0.55 %) at the middle Devonian, entered into the wet gas stage (Ro=1.30-2.00%) at middle Jurassic and the dry gas stage (Ro>2.00 %) at the end of early Cretaceous, and now the thermal maturity is around 2.07 %Ro.
Geochemical characteristics and accumulation model of Devonian natural gas in Northwestern Sichuan Basin, China
Authors: Xie Z Y , Yang C L , Zhang L , Dong C Y , Guo J Y , Guo Z Q , Wang Z H , Hao A S
Published: October 2019

Gas exploration has made major breakthrough firstly in Devonian strata in northwest Sichuan Basin, and its natural gas source have attracted much attention. In this work we developed comprehensive researches on natural gas geochemistry, reservoir bitumen and related source rock biomarkers of Devonian. Result shows: Natural gas in Devonian is secondary cracking gas dominated by hydrocarbon gas. It is major in sapropel type gas and comes from the source rock of Qiongzhusi Formation of Lower Cambrian and Middle Permian, mainly from the former. There are two reservoir accumulation model for gas in Devonian: lower source to upper reservoir and upper source to lower reservoir. Result is of important guidance significance for the exploration deployment of natural gas in this area.
Hydrocarbon generation potential of residual kerogens in high-over matured shale rocks and its contribution to shale gas reserves
Authors: Xu J B , Wei Z W , Deng Q , Cheng B , Faboya O L , Liao Z W
Published: October 2019

A low matured shale rock from Lucaogou Formation in the Santanghu Basin was thermally simulated using semi-open system pyrolysis experiment in attempt to evaluate its late gas generation potential. The Rock-Eval results showed that the residual kerogen in the high-over matured shale rocks still possess some hydrocarbon generation potential. The amount of the pyrolyzable hydrocarbons (S2) generated from the residual kerogen ranged from 0.57 to 1.02 mg HC/g rock. The S2 and hydrogen index (HI) values began to diminish at EasyRo
> 1.45%. About 1 m3/t rock of methane was estimated from Lucaogou Formation at high-over maturity stage. This indicates that the hydrocarbon generation potential of residual kerogens in the high-over matured shale rocks have a significant contribution to shale gas reserves.
Improvement of Fatigue Strength of Additive Manufactured Metals by Solid-Liquid-Gas Interfacial Phenomena Induced by Pulse Laser
Authors: Soyama Hitoshi
Published: October 2019

Although additive manufactured (AM) metals are attractive materials, the fatigue strength of AM metals are considerably weak comparing with that of wrought materials. The mechanical surface treatment such as shot peening can improve the fatigue strength of metallic materials. Recently, a novel mechanical surface treatment using solid-liquid-gas interfacial phenomena induced by pulse laser has been developed. In the present paper, in order to demonstrate the improvement of fatigue strength of AM metals by solid-liquid-gas interfacial phenomena, titanium alloy Ti6Al4V manufactured by electron beam melting EBM was treated by submerged pulse laser and tested by a plane bending fatigue test. The key factors were investigated by evaluating the relation between the fatigue properties and mechanical properties of the surface treated by submerged laser peening, cavitation peening and shot peening.
Corrosion Study on Ni-based Alloy in Acidic Environment
Authors: Shi Yuejuan , Liu Yanling , Wang Xuepeng , Zhou Yongxing , Ma Jun , Zhang Shuai
Published: October 2019

Ni-based alloys have excellent corrosion resistance and are widely used in the petrochemical industry. In this study, the effects of sulfuric acid concentration on the corrosion resistance of Ni-based alloys were analyzed by software simulation and electrochemical tests. The results show that the corrosion rate of the alloy is gradually increased with the increase of sulfuric acid concentration, and the influence of sulfuric acid concentration on the corrosion rate of 304 stainless steel is greater than that of nickel-based alloy. In a 10% sulfuric acid solution, the corrosion rate of the four nickel-base alloy samples is only one-twentieth of that of the 304 stainless steel substrate.
Finite Element Analysis of Overhead Pipeline Truss Bridge under Thermal Fluid Loads
Authors: Lin Guantang , Huang Si , Niu Qifeng , Xu Zhengnan , Zhang Cong , Chen Yinghong
Published: October 2019

The subject used in this study is an overhead pipeline truss bridge which sits in a chemical industrial park. The overhead pipeline truss bridge is a part of a pipeline system consisting of 10 sets of columns, 4 layers of pipe racks and 27 pipelines that transports flowing media under various temperature and pressure conditions. An integrated ANSYS finite element model was built considering the factors such as gravity, medium temperature, and flow load, etc. The results of the distributions of displacement, axial force, shear force, bending moment and stress of the overhead pipeline truss bridge were calculated. The primary stress and secondary stress were checked to judge the reliability of the overhead pipeline truss bridge. It concluded that the computation model and calculation used in this study is feasible and effective. The feature in this paper is to explore a practical method and to provide a solid technological foundation for the safety operation and assessment of overhead pipeline truss bridge.
Research on Improved Localization and Navigation Algorithm for Automatic Guided Vehicle
Authors: Liu Xiaohui , Wei Wu , Gao Yong , Wei Xiaoqin
Published: October 2019

Aiming at the problem of inaccurate positioning caused by the wheel slippage or “kidnapping” movement of the robot in the positioning navigation, an improved autonomous positioning navigation strategy based on the robot operating system (ROS) is proposed. Firstly, combined with adaptive Monte Carlo localization (AMCL) algorithm and laser-based point-and-line iterative closest/corresponding point (PLICP) pose estimation algorithm, the accuracy and robustness of positioning are effectively improved. Then, based on the path planning strategy combining A* algorithm and dynamic window algorithm (DWA), an improved navigation failure recovery method is proposed and integrated into the ROS navigation framework, which can effectively improve the efficiency of robot positioning navigation and task execution. Finally, the mobile robot model TurtleBot is used as the experimental platform. The simulation experiment and field test demonstrate that the improved algorithm is superior to the original algorithm. The improved algorithm can adapt to the inaccuracy of the odometer and can achieve accurate localization and navigation in long-distance environment.
Research on Coplanar Orbit Maneuvering in the Context of on-Orbit Service
Authors: Koryanov Vsevolod V , Zhang Budang
Published: October 2019

The concept of on-orbit service is introduced, and the development process of on-orbit service is briefly reviewed. The optimal transfer plan of orbit transfer and rendezvous is studied in the context of on-orbit service. The circular orbit motion with perturbation is used to study the near-circle orbit maneuver, and the general equation of coplanar maneuver is established based on the cylindrical coordinate system. The influences of the orbital parameters and the difference initial phase between the coaxial orbits on the optimal transfer orbit are calculated by Matlab simulation.
Dialectical Understanding of Information in the Context of the Artificial Intelligence Problems
Authors: Suleimenov Ibragim E , Gabrielyan Oleg A , Bakirov Akhat S , Vitulyova Yelizaveta S
Published: October 2019

It is shown that the implementation of breakthrough progress in artificial intelligence cannot be accomplished without a radical modernization of the methodological framework for research in this area. This upgrade can be performed only with the use of conceptual and methodological apparatus of dialectics. Its consistent application to objects, in either case connected with ideas about the intellect, results in the formulation of the dialectic symmetry principle. The first practical steps for the implementation of the proposed concept in practice are associated with the creation of a new education paradigm, which operates, including ideas that “education” being understood as a public institution, is not reducible to individual learning. Education in modern conditions can and should be viewed primarily as a tool to influence public consciousness, or more precisely, its subsystems.
Experimental Study on the Effect of Two Equal-Sized Holes Lying at Different Angles in a CFRP Plate under Bending
Authors: Bunyawanichakul Phacharaporn , Limpitipanich Paiboon , Siribodhi Pongwit
Published: October 2019

A bending test method was designed to investigate the failure characteristics of drilling carbon-fiber reinforced composite (CFRP) plates. The CFRP plates were fabricated and drilled to join other parts for use in aircraft structures (riveting or bolting). Each sample had two equal-sized holes at 0, θ, or -θ degrees at a fixed distance of 36 mm in the longitudinal direction. The sample dimensions were identified following a study on tensile testing singleholed samples based on the ASTM D5961 standard. The tensile test focused on three cases of laminate: [0]14, [22.5]14, and [45]14. The maximum mean forces for [0]14, [22.5]14, and [45]14 laminate configurations were 6.32, 6.59, and 7.12 kN respectively. These results were implemented into a bending test which included two configurations of laminate: [0]14 and [45]14 and two equal-sized holes with a variable distance of 0 and 9 mm in the transverse direction of the plate. The bending test configuration is presented in this paper. The results revealed different load-bearing capabilities in each of the three types of specimen configuration. Samples with two holes lying at ±9 degree affected the overall strength in the [45]14 case, and as in [0]14 there was no difference between the eccentricity and the aligned holes. In [45]14, the eccentricity decreased the maximum allowable force by 1.57 percent in the normal eccentricity case and by 15.94 percent in the alternate eccentricity case compared to the aligned case.
Development and Application of Image-base Plantar Measurement System
Authors: Lo Hsien-Chung , Pan Guo-Xiang , Chang Hui-Ling , Chang Chong-Ching
Published: October 2019

The foot pain affects daily life function about 14-4b2% of adults over the age of 45 years old, since feet bear all the weight of the body. The most foot problems come from a great impact on the human body. It affects not only bone structures, but also the organs. Plantar information can be checked through the plantar pressure and arch index. The plantar pressure distribution is related to the walking balance, while the arch index can understand the foot bone structure. The paper aims to develop a system of plantar self-detection which is economical and easy to carry and operate. The system has built up two parts: one is the image capture equipment; another is the data analysis software. The portable scanning platforms can obtain high-resolution image, scanning work area is 216x356mm which the resolution is 1200dpi image. It only needs 10 seconds, using the wireless transmission to the plantar image through the pad for data analysis, calculated the plantar pressure distribution and arch index. The whole system price is less than one-tenth of the market selling pressure pad, providing a general system which is designed for plantar self-detection.
Patterns of floral morphology in relation to climate and floral visitors
Authors: Weber Urs K , Nuismer Scott L , Espíndola Anahí
Published: October 2019

Background and Aims

The diversity of floral morphology among plant species has long captured the interest of biologists and led to the development of a number of explanatory theories. Floral morphology varies substantially within species, and the mechanisms maintaining this diversity are diverse. One possibility is that spatial variation in the pollinator fauna drives the evolution of spatially divergent floral ecotypes adapted to the local suite of pollinators. Another possibility is that geographic variation in the abiotic environment and local climatic conditions favours different floral morphologies in different regions. Although both possibilities have been shown to explain floral variation in some cases, they have rarely been competed against one another using data collected from large spatial scales. In this study, we assess floral variation in relation to climate and floral visitors in four oil-reward-specialized pollination interactions.

Methods

We used a combination of large-scale plant and pollinator samplings, morphological measures and climatic data. We analysed the data using spatial approaches, as well as traditional multivariate and structural equation modelling approaches.

Key Results

Our results indicate that the four species have different levels of specialization, and that this can be explained by their climatic niche breadth. In addition, our results show that, at least for some species, floral morphology can be explained by the identity of floral visitors, with climate having only an indirect effect.

Conclusions

Our results demonstrate that, even in very specialized interactions, both biotic and abiotic variables can explain a substantial amount of intraspecific variation in floral morphology.
Fat Hypertrophy as a Complication of Fat Transfer for Hemifacial Atrophy
Authors: Jeon Faith H K , Varghese Jajini , Griffin Michelle , Mosahebi Afshin , Butler Peter E , Withey Simon , Henderson Hugo
Published: October 2019

Fat hypertrophy is a less commonly known complication of autologous fat transfer. We present a 32-year-old female with left hemifacial atrophy associated with systemic sclerosis, who was treated with 7 fat transfer procedures to correct the facial asymmetry. A total of 236.5 mL of fat was injected to the hemiface over a 4-year period to achieve good symmetry. A progressively enlarging, painless, soft mass over the left parotid region was noted at 3 months after the final fat transfer procedure. Magnetic resonance imaging showed a markedly enlarged bulk of subcutaneous fat over the left cheek with no evidence of necrosis, edema, or pathologic enhancement. Concurrent weight gain was noted secondary to additional nutritional input. The patient’s aesthetic, symptomatic, and functional concerns led to the subsequent removal of 115 mL fat by liposuction.

Level of Evidence: 5
mCSM-AB2: guiding rational antibody design using graph-based signatures
Authors: Myung Yoochan , Rodrigues Carlos H M , Ascher David B , Pires Douglas E V
Published: October 2019

Motivation

A lack of accurate computational tools to guide rational mutagenesis has made affinity maturation a recurrent challenge in antibody (Ab) development. We previously showed that graph-based signatures can be used to predict the effects of mutations on Ab binding affinity.

Results

Here we present an updated and refined version of this approach, mCSM-AB2, capable of accurately modelling the effects of mutations on Ab–antigen binding affinity, through the inclusion of evolutionary and energetic terms. Using a new and expanded database of over 1800 mutations with experimental binding measurements and structural information, mCSM-AB2 achieved a Pearson’s correlation of 0.73 and 0.77 across training and blind tests, respectively, outperforming available methods currently used for rational Ab engineering.

Availability and implementation

mCSM-AB2 is available as a user-friendly and freely accessible web server providing rapid analysis of both individual mutations or the entire binding interface to guide rational antibody affinity maturation at http://biosig.unimelb.edu.au/mcsm_ab2

Supplementary information

Supplementary data are available at Bioinformatics online.
Genomic data reveal similar genetic differentiation in aquifer species with different dispersal capabilities and life histories
Authors: Jordan Steve , Hand Brian K , Hotaling Scott , Delvecchia Amanda G , Malison Rachel , Nissley Clark , Luikart Gordon , Stanford Jack A
Published: October 2019

Little is known about the life histories, genetic structure and population connectivity of shallow groundwater organisms. We used next-generation sequencing (RAD-seq) to analyse population genomic structure in two aquifer species: Paraperla frontalis (Banks, 1902), a stonefly with groundwater larvae and aerial (winged) adults; and Stygobromus sp., a groundwater-obligate amphipod. We found similar genetic differentiation in each species between floodplains separated by ~70 river km in the Flathead River basin of north-west Montana, USA. Given that Stygobromus lacks the above-ground life stage of P. frontalis, our findings suggest that connectivity and the magnitude of genetic structure cannot be definitively assumed from life history differences.
Consistent community detection in multi-layer network data
Authors: Lei Jing , Chen Kehui , Lynch Brian
Published: October 2019

We consider multi-layer network data where the relationships between pairs of elements are reflected in multiple modalities, and may be described by multivariate or even high-dimensional vectors. Under the multi-layer stochastic block model framework we derive consistency results for a least squares estimation of memberships. Our theorems show that, as compared to single-layer community detection, a multi-layer network provides much richer information that allows for consistent community detection from a much sparser network, with required edge density reduced by a factor of the square root of the number of layers. Moreover, the multi-layer framework can detect cohesive community structure across layers, which might be hard to detect by any single-layer or simple aggregation. Simulations and a data example are provided to support the theoretical results.
Subclinical leaflet thrombosis is associated with impaired reverse remodelling after transcatheter aortic valve implantation
Authors: Szilveszter Bálint , Oren Daniel , Molnár Levente , Apor Astrid , Nagy Anikó I , Molnár Andrea , Vattay Borbála , Kolossváry Márton , Karády Júlia , Bartykowszki Andrea , Jermendy Ádám L , Suhai Ferenc I , Panajotu Alexisz , Maurovich-Horvat Pál , Merkely Béla
Published: October 2019

Aims

Cardiac CT is increasingly applied for planning and follow-up of transcatheter aortic valve implantation (TAVI). However, there are no data available on reverse remodelling after TAVI assessed by CT. Therefore, we aimed to evaluate the predictors and the prognostic value of left ventricular (LV) reverse remodelling following TAVI using CT angiography.

Methods and results

We investigated 117 patients with severe, symptomatic aortic stenosis (AS) who underwent CT scanning before and after TAVI procedure with a mean follow-up time of 2.6 years after TAVI. We found a significant reduction in LV mass (LVM) and LVM indexed to body surface area comparing pre- vs. post-TAVI images: 180.5 ± 53.0 vs. 137.1 ± 44.8 g and 99.7 ± 25.4 vs. 75.4 ± 19.9 g/m2, respectively, both P < 0.001. Subclinical leaflet thrombosis (SLT) was detected in 25.6% (30/117) patients. More than 20% reduction in LVM was defined as reverse remodelling and was detected in 62.4% (73/117) of the patients. SLT, change in mean pressure gradient on echocardiography and prior myocardial infarction was independently associated with LV reverse remodelling after adjusting for age, gender, and traditional risk factors (hypertension, body mass index, diabetes mellitus, and hyperlipidaemia): OR = 0.27, P = 0.022 for SLT and OR = 0.22, P = 0.006 for prior myocardial infarction, OR = 1.51, P = 0.004 for 10 mmHg change in mean pressure gradient. Reverse remodelling was independently associated with favourable outcomes (HR = 0.23; P = 0.019).

Conclusion

TAVI resulted in a significant LVM regression on CT. The presence of SLT showed an inverse association with LV reverse remodelling and thus it may hinder the beneficial LV structural changes. Reverse remodelling was associated with improved long-term prognosis.
Three-valve endocarditis in a patient with bioprosthetic aortic valve replacement and intravenous drug use: a case report
Authors: Javaid Awad , Sehgal Sumit , Dazley Jason
Published: October 2019

Background

Here, we outline the case of a US Veteran’s Health Administration (VA) patient with a history of recent bioprosthetic aortic valve replacement (AVR) and recent intravenous drug use (IVDU) who was found to have three-valve infective endocarditis (IE) resulting in septic shock. We highlight this case because it represents an uncommon case of three-valve IE in the setting of recent bioprosthetic valve replacement and IVDU, and it raises the need for continued awareness of mental health and drug rehabilitation in the US military veteran population.

Case summary

A 62-year-old gentleman with recent bioprosthetic AVR presented with dyspnoea and lower extremity oedema and was found to have a heart failure exacerbation. He developed sepsis and was found to have three-valve endocarditis, as well as aortic root abscess and pacemaker lead infection. He was treated with broad-spectrum antibiotics and evaluated for surgical intervention. After discussion with the surgical team, the patient decided not to pursue surgery due to prohibitively high perioperative mortality risk. The patient was transferred to hospice and expired within 2 weeks.

Discussion

Three-valve IE is sparingly documented in published literature and can be difficult to treat. Providers must be cognizant of prosthetic valve endocarditis as an uncommon but known complication of valve replacement surgery. Intravenous drug use is a common risk factor for endocarditis and is prevalent in the US military veteran population. Prosthetic valve endocarditis should be treated with broad-spectrum antibiotics, and in general, if it leads to new significant valvular abnormalities, the valve should be replaced.
Coal Smoke, City Growth, and the Costs of the Industrial Revolution
Authors: Hanlon W Walker
Published: October 2019

This article provides the first rigorous estimates of how industrial air pollution from coal burning affects long-run city growth. I introduce a new theoretically grounded strategy for estimating this relationship and apply it to data from highly polluted British cities from 1851 to 1911. I show that local industrial coal use substantially reduced long-run city employment and population growth. Moreover, a counterfactual analysis suggests that plausible improvements in coal-use efficiency would have led to a higher urbanisation rate in Britain by 1911. These findings contribute to our understanding of the effects of air pollution and the environmental costs of industrialisation.
Molecular studies of NAD- and NADP-glutamate dehydrogenases decipher the conundrum of yeast–hypha dimorphism in zygomycete Benjaminiella poitrasii
Authors: Pathan Ejaj K , Ghormade Vandana , Panwar Sneh Lata , Prasad Rajendra , Deshpande Mukund V
Published: October 2019

Benjaminiella poitrasii, a zygomycete, shows glucose- and temperature-dependent yeast (Y)–hypha (H) dimorphic transition. Earlier, we reported the biochemical correlation of relative proportion of NAD- and NADP-glutamate dehydrogenases (GDHs) with Y–H transition. Further, we observed the presence of one NAD-GDH and two form-specific NADP-GDH isoenzymes in B. poitrasii. However, molecular studies are necessary to elucidate the explicit role of GDHs in regulating Y–H reversible transition. Here, we report the isolation and characterization of one NAD (BpNADGDH, 2.643 kb) and two separate genes, BpNADPGDH I (Y-form specific, 1.365 kb) and BpNADPGDH II (H-form specific, 1.368 kb) coding for NADP-GDH isoenzymes in B. poitrasii. The transcriptional profiling during Y–H transition showed higher BpNADPGDH I expression in Y cells while expression of BpNADPGDH II was higher in H cells. Moreover, the yeast-form monomorphic mutant (Y-5) did not show BpNADPGDH II expression under normal dimorphism triggering conditions. Transformation with H-form specific BpNADPGDH II induced the germ tube formation in Y-5, which confirmed the cause–effect relationship between BpNADPGDH genes and morphological outcome in B. poitrasii. Interestingly, expression of H-form specific BpNADPGDH II also induced germ tube formation in human pathogenic, non-dimorphic yeast Candida glabrata, which further corroborated our findings.
Education as a Moderator of the Relationship Between Episodic Memory and Amyloid Load in Normal Aging
Authors: Joannette Maude , Bocti Christian , Dupont Pénélope Sévigny , Lavallée Marie Maxime , Nikelski Jim , Vallet Guillaume T , Chertkow Howard , Joubert Sven
Published: October 2019

The current study explored whether education, a proxy of cognitive reserve, modifies the association between episodic memory (EM) performance and βeta-amyloid load (Aβ), a biomarker of Alzheimer’s disease, in a cohort of cognitively normal older adults. One hundred and four participants (mean age 73.3 years) evenly spread out in three bands of education were recruited. Participants underwent neuropsychological assessment, structural MRI as well as PET imaging to quantify Aβ load. Moderation analyses and the Johnson–Neyman technique were carried out to examine the interaction of education with Aβ load to predict EM performance. Linear regressions were then performed within each group of education to better illustrate the interaction effect (all analyses were controlled for age and sex). The interaction between education and Aβ load was significant (p < .05) for years of education, reaching a cutoff point of 13.5 years, above which the relationship between Aβ load and EM was no longer significant. Similarly, significant associations were found between Aβ and EM among participants with secondary (p < .01) and pre-university education (p < .01), but not with a university degree (p = .253). EM performance is associated with Aβ load in cognitively normal older individuals, and this relationship is moderated by educational attainment.
Factor Structures of Reasons for Immigration Among Older Asian and Latino Immigrants in the United States
Authors: Park Soohyun , Kim Giyeon
Published: October 2019

Backgrounds and Objectives

Although reasons for immigration are significant predictors of immigrants’ health, factor structures of reasons for immigration are still unclear among older immigrants. The present study examined the factor structure of reasons for immigration among older Asian and Latino immigrants in the United States.

Research Design and Methods

Drawn from the National Latino and Asian American Study, 396 Latino and 298 Asian immigrants over 55 years of age were selected for analysis. Exploratory factor analysis was conducted for nine items concerning reasons for immigration in each immigrant group.

Results

Three factors were extracted from both Asian and Latino immigrant elders: (a) “voluntary reasons” to pursue development, (b) “involuntary reasons” due to uncontrollable situations, and (c) “semivoluntary reasons” regarding family/medical duties. While immigration to join family members was located in the “semivoluntary reasons” factor among older Asian immigrants, it was located in the “voluntary reasons” factor among older Latino immigrants.

Discussion and Implications

These findings suggest that three underlying factors of reasons for immigration should be understood considering the different characteristics of two racial/ethnic groups of immigrants. In addition, a migratory reason to join the family should be considered differently for elderly Asian and Latino immigrants. This three-factor framework of reasons for immigration can help clinicians provide more culturally sensitive interventions for older minority immigrants.
SwiftOrtho: A fast, memory-efficient, multiple genome orthology classifier
Authors: Hu Xiao , Friedberg Iddo
Published: October 2019

Background

Gene homology type classification is required for many types of genome analyses, including comparative genomics, phylogenetics, and protein function annotation. Consequently, a large variety of tools have been developed to perform homology classification across genomes of different species. However, when applied to large genomic data sets, these tools require high memory and CPU usage, typically available only in computational clusters.

Findings

Here we present a new graph-based orthology analysis tool, SwiftOrtho, which is optimized for speed and memory usage when applied to large-scale data. SwiftOrtho uses long k-mers to speed up homology search, while using a reduced amino acid alphabet and spaced seeds to compensate for the loss of sensitivity due to long k-mers. In addition, it uses an affinity propagation algorithm to reduce the memory usage when clustering large-scale orthology relationships into orthologous groups. In our tests, SwiftOrtho was the only tool that completed orthology analysis of proteins from 1,760 bacterial genomes on a computer with only 4 GB RAM. Using various standard orthology data sets, we also show that SwiftOrtho has a high accuracy.

Conclusions

SwiftOrtho enables the accurate comparative genomic analyses of thousands of genomes using low-memory computers. SwiftOrtho is available at https://github.com/Rinoahu/SwiftOrtho
Defective cell adhesion function of solute transporter, SLC4A11, in endothelial corneal dystrophies
Authors: Malhotra Darpan , Jung Martin , Fecher-Trost Claudia , Lovatt Matthew , Peh Gary S L , Noskov Sergei , Mehta Jodhbir S , Zimmermann Richard , Casey Joseph R
Published: October 2019

Corneal endothelial cell (CEnC) loss is often associated with blinding endothelial corneal dystrophies: dominantly inherited, common (5%) Fuchs endothelial corneal dystrophy (FECD) and recessive, rare congenital hereditary endothelial dystrophy (CHED). Mutations of SLC4A11, an abundant corneal solute transporter, cause CHED and some cases of FECD. The link between defective SLC4A11 solute transport function and CEnC loss is, however, unclear. Cell adhesion assays using SLC4A11-transfected HEK293 cells and primary human CEnC revealed that SLC4A11 promotes adhesion to components of Descemet’s membrane (DM), the basement membrane layer to which CEnC bind. An antibody against SLC4A11 extracellular loop 3 (EL3) suppressed cell adhesion, identifying EL3 as the DM binding site. Earlier studies showed that some SLC4A11 mutations cause FECD and CHED by impairing solute transport activity or cell surface trafficking. Without affecting these functions, FECD-causing mutations in SLC4A11-EL3 compromised cell adhesion capacity. In an energy-minimized SLC4A11-EL3 three-dimensional model, these mutations cluster and are buried within EL3 structure. A GST fusion protein of SLC4A11-EL3 interacts with principal DM protein, COL8A2, as identified by mass spectrometry. Engineered SLC4A11-EL3-containing protein, STIC (SLC4A11-EL3 Transmembrane-GPA Integrated Chimera), promotes cell adhesion in transfected HEK293 cells and primary human CEnC, confirming the cell adhesion role of EL3. Taken together, the data suggest that SLC4A11 directly binds DM to serve as a cell adhesion molecule (CAM). These data further suggest that cell adhesion defects contribute to FECD and CHED pathology. Observations with STIC point toward a new therapeutic direction in these diseases: replacement of lost cell adhesion capacity.
Editorial on Hirten et al
Authors: Fleshner Phillip
Published: October 2019

The significance of ulcers confined to the anastomotic line in Crohn’s disease patients remains unclear.
Alterations in Blood Chemistry Levels Associated With Nipah Virus Disease in the Syrian Hamster Model
Authors: Genzer Sarah C , Welch Stephen R , Scholte Florine E M , Harmon Jessica R , Coleman-McCray JoAnn D , Lo Michael K , Montgomery Joel M , Nichol Stuart T , Spiropoulou Christina F , Spengler Jessica R
Published: October 2019

Nipah virus (NiV; family Paramyxoviridae, genus Henipavirus) infection can cause severe respiratory and neurological disease in humans. The pathophysiology of disease is not fully understood, and it may vary by presentation and clinical course. In this study, we investigate changes in blood chemistry in NiV-infected Syrian hamsters that survived or succumbed to disease. Increased sodium and magnesium and decreased albumin and lactate levels were detected in animals euthanized with severe clinical disease compared with mock-infected controls. When subjects were grouped by clinical syndrome, additional trends were discernable, highlighting changes associated with either respiratory or neurological disease.
Europe Has Never Been Modern: Recasting Historical Narratives of Migration Control
Authors: Vigneswaran Darshan
Published: October 2019

Our understanding of contemporary international relations rests on flawed images of the past. One of the most problematic dimensions of this history is the idea that the core institutions and practices of modern territorial sovereignty originated in Europe before being gradually extended to other parts of the globe. A key dimension of this Euro-centric historiography is the story that the territorial sovereignty norm was invented in Europe in the seventeenth century, before Europeans honed it into a standard technique of state practice in the twentieth. This paper uses original archival research to critically interrogate the consensus position. The paper demonstrates that the dominant narrative significantly misconstrues the way rulers and governments sought to control migration across the longue durée. European rulers were more collectively seeking to transnationally promote migration at the same time as they individually acquired territorial sovereign control over it. Extra-European states were the first to deploy territorial immigration controls, and non-Europeans shaped the forms of mobility promotion Europeans would adopt. The paper uses these findings to make the case for a new chronology of European migration governance and for a critical institutionalist approach to the way we write the history of the global migration regime.
Appropriate empirical antibiotic use in the emergency department: full compliance matters!
Authors: Berrevoets Marvin A H , ten Oever Jaap , Hoogerwerf Jacobien , Kullberg Bart Jan , Atsma Femke , Hulscher Marlies E , Schouten Jeroen A
Published: October 2019

Background

Little is known about determinants of appropriate antibiotic use in the emergency department (ED). We measured appropriateness of antibiotic use for seven quality indicators (QIs) and studied patient-related factors that determine their variation.

Patients and methods

A retrospective analysis of 948 patients presumptively diagnosed as having an infection needing empirical antibiotic treatment in the ED was performed. Outcomes of seven previously validated QIs were calculated using computerized algorithms. We used logistic regression analysis to identify patient-related factors of QI performance and evaluated whether more appropriate antibiotic use in the ED results in better patient outcomes (length-of-stay, in-hospital mortality, 30 day readmission).

Results

QI performance ranged from 57.3% for guideline-adherent empirical therapy to 97.3% for appropriate route of administration in patients with sepsis. QI performance was positively associated with patients’ disease severity on admission (presence of fever, tachycardia and hypotension). Overall, the clinical diagnosis and thus the guidelines followed influenced QI performance. The difference in complexity between the guidelines was a possible explanation for the variation in QI performance. A QI performance sum score of 100% was associated with reduced in-hospital mortality. QI performance was not associated with readmission rates.

Conclusions

We gained insights into factors that determine quality of antibiotic prescription in the ED. Adherence to the full bundle of QIs was associated with reduced in-hospital mortality. These findings suggest that future stewardship interventions in the ED should focus on the entire process of antibiotic prescribing in the ED and not on a single metric only.
The development and electronic delivery of case-based learning using a fast healthcare interoperability resource system
Authors: Braunstein Mark L , Oancea Iulia , Barry Benjamin K , Darlington Sharon , Steel Jim , Hansen David P , Battock James , Cheung Daniel , Gan Gregory , Hooper Ben , Lundin Reilly , Nicol Duncan , O’Brien Joshua , Whittington Scott , Wilkinson Chris , Wong Tse Tse
Published: October 2019

HL7 International’s Fast Healthcare Interoperability Resources (FHIR) standard provides a common format for sharing health data (eg, FHIR resources) and a RESTful Application Programming Interface (eg, FHIR API) for accessing those resources via a FHIR server connected to an electronic health record system or any other system storing clinical data. Substitutable Medical Applications and Reusable Technologies (SMART) leverages FHIR to create an electronic health record (EHR) agnostic app platform. It utilizes the OAuth standard to provide for authorization and authentication. This paper describes the development and informal evaluation of Case Based Learning on FHIR (CBL on FHIR), a prototype EHR-connected FHIR/SMART platform to provide interactive digital cases for use in medical education. The project goals were to provide a more interactive form of CBL than is possible on paper to more realistically simulate clinical decision making and to expose medical students to modern informatics systems and tools for use in patient care.