bluuebunny/crossref_metadata_2025 huggingface dataset:
An analysis of the urbanization contribution to observed terrestrial stilling in the Beijing–Tianjin–Hebei region of China
Authors: Wang Jun , Feng Jinming , Yan Zhongwei , Qiu Yuan , Cao Lijuan
Published: February 2020

Decreases in terrestrial near-surface wind speed (NSWS) were documented in many regions over the past decades. Various drivers have been proposed for this terrestrial stilling, such as weakening of ocean-land pressure gradients related to climate change and increased surface roughness linked to vegetation growth; but none have been robustly established as the cause. A plausible reason for this quandary is that the local impact of urbanization on NSWS has been overlooked. Here, we used homogenized NSWS records from in situ weather stations and a satellite-based dynamic urban–rural classification scheme to quantitatively assess the contribution of urbanization to observed terrestrial stilling during 1980–2016 over the Beijing–Tianjin–Hebei region of China. Results suggested that urbanization contributed approximately 8% to the observed decrease in the regional NSWS in urban areas, implying that urbanization played a minor role in terrestrial stilling, even in this rapidly developing region. The largest NSWS changes related to urbanization occurred in winter, followed by spring, autumn, and summer. Urbanization reduced the days with relatively strong winds but increased the days with light and gentle winds. We found that except for the Japanese 55 year reanalysis (JRA-55) dataset, none of the common reanalysis products reproduced the observed NSWS trends in urban or rural areas. However, this could be because of JRA-55’s intrinsic negative bias in NSWS trends over land. Thus, regional terrestrial NSWS trends derived from reanalysis products deserve careful examination.
Focus on leakage and spillovers: informing land-use governance in a tele-coupled world
Authors: Meyfroidt P , Börner J , Garrett R , Gardner T , Godar J , Kis-Katos K , Soares-Filho B S , Wunder S
Published: February 2020

Governing land use to achieve sustainable outcomes is challenging, because land systems manifest complex land use spillovers—i.e. processes by which land use changes or direct interventions in land use (e.g. policy, program, new technologies) in one place have impacts on land use in another place. The ERL issue ‘Focus on Leakage: informing Land-Use Governance in a Tele-coupled World’ builds on discussions in an international expert workshop conducted in Berlin in November 2017 to explore innovative ways to improve our understanding of how governance interventions, new technologies and other factors can affect land-use change both directly and indirectly through spillovers. This editorial starts by clarifying the definitions and relationships between land-use spillover, indirect land use change—a form of spillover where land use change in one place is caused by land use change in another place—leakage—a form of land use spillover, which is caused by an environmental policy (e.g. a conservation or restoration intervention), and the spillover reduces the overall benefits and effectiveness of this intervention—, and land use displacement processes. We then use this terminology to summarize the individual contributions of this special issue and conclude with lessons learned as well as directions for future research.
Occurrence of Antibiotic Resistance Genes in a Small Township Wastewater Treatment Plant and the Receiving River
Authors: Chen M X , Zhang Y Q , Chang J L , Ma X G , Lei T , Yang J , Jiang T
Published: February 2020

Six ARGs (tetX, sul1, qnrS, blaTEM, ermB and intl1) were quantified by qPCR, along with concentrations of inorganic nitrogen (ammonia, nitrite, nitrate), total phosphorous (TP) and chemical oxygen demand (COD). The sewage treatment facilities had elimination effects on the six target genes; absolute abundance decreased from 104–107 copies/mL in the influent to 103–105 copies/mL in effluent, and the removal efficiencies were 74.27–96.51%; the highest removal performance was for tetX. The main treatment units for eliminating ARGs were the aeration tank and the secondary sedimentation tank. Absolute abundances of ARGs in the effluent and downstream water were 3.24–18.83 and 1.86–8.55 times higher than that in the upstream river, respectively. The absolute abundances of different target ARGs were positively correlated (R = 0.6762 ± 0.1777), indicating similar elimination mechanisms, and a positive correlation between ARGs and ammonia nitrogen (R = 0.5025 ± 0.2711). Raw wastewater contained numerous ARGs, which were partially removed by the WWTP. However, there remained a high absolute abundance of ARGs in effluent, causing an increase in water-phase ARGs in the receiving river. Hence, effluent was an important pollution point source for the receiving river.
Heavy Metals Pollution Characteristics and Ecological Risk Assessment of the Sediments of Anrongjing River in Taizhou City
Authors: Jia B J , He S F , Huang Z , Liao J L , Zhang J P
Published: February 2020

In order to study the heavy metals pollution in the river channel of the city, this paper based on the results of the sediments detections of Anrongjing River in Taizhou, using the single pollution index method, the potential ecological risk index method, the cluster analysis method and other methods to evaluate the content, the degree of pollution, the distribution, ecological risk assessment, etc. of heavy metals. The results show that Cu, Zn, Pb and Cd in the sediments are seriously polluted. Viewed from the plane, the main pollution areas are the upstream, the two tributaries and the tributaries and main river crossings. Viewed from the vertical, the heavy metals pollution roughly decreases with increasing sediments depth. The results of heavy metals ecological risk assessment show that the potential ecological hazards of Cu and Cd are serious, the pollution of Cd and Cu in the source, the two tributaries and tributaries and main river crossings are the most serious.
Effects of Tillage Systems on Labile Fractions of Soil Organic Nitrogen of a Freeze-Thaw Agricultural Area in Northeast China
Authors: Lai Xuehui , Ren Xiaoli , Zhu Kaijin , Yan Cai , Yu Juan
Published: February 2020

The impact of tillage systems is obvious in the nitrogen mineralization. Few studies have focused on the relationship between labile fraction of soil organic nitrogen (SON) and crop nitrogen absorption under different tillage systems in freeze-thaw agricultural area. In this study, the effects of conventional tillage (CT) and no-tillage (NT) on the labile fractions of soil organic nitrogen and the relationships with the potentially mineralizable nitrogen (N0) at different soil depths in seeding, jointing, filling and maturity seasons over four years (2010, 2011, 2015 and 2016) were explored. It has been demonstrated that the labile fractions of SON and N0 in NT were higher than in CT at 0-5, 0-10 and 0-20cm. N0 was positively and highly related to the medium particulate organic carbon (mPOM-C) (P<0.01) under CT and NT, whereas highly significant and negative correlations (P<0.01) between N0 and medium particulate organic nitrogen (mPOM-N) were detected under both tillage systems at 0-5 and 0-10cm. The difference in these correlations between tillage systems had been found to be the most notable at the 0-5cm depth. The higher SON fractions content would contribute to the nitrogen mineralization potential because of freeze-thaw conditions during the crop growing season.
Exponential Decay Model of TVOC Emission from Indoor Building Materials
Authors: Zhang Y , Niu Y R , Liu Y , Wu Y F , Jiang J X , Guan H Y , Guo Z B
Published: February 2020

Total volatile organic compounds (TVOC) are mainly derived from indoor building materials and are one of the main causes of indoor air pollution. This paper presents a research on simulating the TVOC release of building materials in the environmental chamber. In this work, a simple and practical prediction model of exponential decay is established to study the transport and the emission behaviors under the effect of convective mass transfer theory. Based on this theory, the model considers the porous structure of indoor building materials and assumes that concentration of TVOC at the boundary of building material obeys exponential distribution. This paper focuses on two kinds of indoor building materials, interior wall coatings and wood coatings. Numerical simulation and experimental parameters are obtained by environmental chamber method. By modelling the emission of TVOCs, and comparing the present model with the classical model, the validity of the present model can be confirmed. Besides, from the results of the fitting, it can be seen that the new exponential decay predition model has a better agreement with the experimental data, and which can describe the release characteristics and transmissionmechanisms of TVOCs more accurately, and the root mean square error is much less than the classical model.
Study on the Electricity Generation Characteristics of Microbial Fuel Cell with Different Substrates
Authors: Jin Y Z , Wu Y C , Li B Q , Zhu H D , Li Y P , Zhuang M Z , Fu H Y
Published: February 2020

We use anhydrous sodium acetate, glucose, lactose and Colocasia antiquorum Schott as anode substrate to study the periodic curve of battery voltage and stable output voltage of different substrates, The results showed that the four kinds of microbial fuel cells with sodium acetate, glucose, lactose and pretreated Colocasia antiquorum Schott as anode substrate had the following power generation periods: 23.98 d, 20.15 d, 18.84 d and 23.52 d, respectively, and the stable voltage at the two ends of the resistance of microbial fuel cells with four different anode substrates are 0.77 V, 0.75 V, 0.65 V and 0.70 V respectively. We found at the same carbon source concentration, MFC with sodium acetate as the substrate has the best electricity production characteristics. When the pretreated Colocasia antiquorum Schott is used as anode substrate, the time for cell voltage to rise from initial value to stable value is the shortest, and as a carbon source, it can also play a dominant role in the process of electric energy collection and utilization.
CO2 Mitigation in Fujian Province: an Input-output based Network Utility Analysis Method
Authors: Wang G. Y. , Liu J. , Ding Y. K. , Chen L. R. , Li Y. P.
Published: February 2020

This paper proposes an input-output based network utility analysis model to diagnose urban CO2 emissions metabolism. It is applied to Fujian Province to demonstrate its feasibility. The direct and indirect CO2 emissions of six major sectors are calculated using the input-output table. It is revealed that the total carbon emissions of the industrial sector were higher than other sectors, accounting for 74% of Fujian Province total carbon emissions. And the indirect emissions generated during the consumption process in the industrial sector were also the largest, with 0.43×109 tons of emissions. The wholesale and retail catering sector had the smallest carbon emissions, with only 14.9×106 tons of emissions. In addition, carbon emissions in all industries were on the rise. Then, network utility analysis is employed to define the various relationships between different sectors. It is found that the mutual relationship between various sectors in Fujian Province has developed from 1 pair of competition relationships to 3 pairs of competition relationships, which has reduced from 13 pairs of exploitation relationships to 12 pairs of exploitation relationships. The results can help to provide integral reference for policy makers to propose the effective mitigation strategies. The study found that Fujian’s carbon emission metabolism system is different from other metabolic systems in terms of industry structure. The competitive relationship represents the mutual suppression of carbon emissions between sectors, which further provides a good opportunity for carbon reduction.
Creating of Risk Maps
Authors: Brumarova L , Brumar J , Pokorny J
Published: February 2020

Risk assessment of defined types of hazards and their negative impacts in the territory is the basis for creating risk maps. Risk maps, following up the tasks from the concept of civil protection, will provide quality data for qualified decision-making in territorial planning. The article captures the process of creating risk maps in the Czech Republic in relation to territorial planning and sustainable development of the territory.
Impact of stormwater runoff in the urbanized area
Authors: Csicsaiova R , Marko I , Stanko S , Skultetyova I , Hrudka J
Published: February 2020

The development of urbanized areas leads to abiding negative changes in the landscape. The percentage of impermeable surfaces in the cities is increasing. Currently, efforts are being made to replace paved surfaces with alternative materials that contribute to reducing surface runoff. The aim of this paper is to get acquainted briefly with legislation dealing with the issue of rainwater management, with standards ensuring the correct design of rainwater infiltration devices and with the quality requirement of infiltrated water. In the second part, the paper summarizes the knowledge from the given area.
Evaluation of genotoxicity in industrial waste waters
Authors: Chlebkova L , Vaclavik V , Dvorsky T , Zajac R
Published: February 2020

This article presents the results of a research dealing with the detection of mutagenic activity of two samples used in the textile industry, Methylene Blue synthetic dye and Inotex real dye bath before, during and at the end of the biodegradation process by means of ligninolytic fungus Irpex lacteus. There is evidence that Methylene Blue synthetic dye was detected as an indirect mutagen prior to the biodegradation process. However, the biodegradation intermediate product was evaluated as a direct mutagen and the final product of biodegradation no longer induced any mutagenic activity. Inotex dye bath samples were assessed as non-mutagenic.
Identification of dry and wet years in eastern Slovakia using indices
Authors: Nagy P , Zelenakova M , Kapostasova D , Hlavata H , Simonova D
Published: February 2020

The aim of the paper was to evaluate dry and wet periods in selected climatic stations in eastern Slovakia using the drought indices. We evaluated drought occurrence using the following indexes: standardized precipitation index (SPI), streamflow drought index (SDI), drought reconnaissance index (RDI) and standardized evapotranspiration index (SPEI) in a 12-month step over the period 1960-2015. The evaluation of the results showed alternation of wet and dry periods. The result of the work is identification of the dry and wet years according the separate indexes during the evaluated period.
An alternative method of removing Cr (VI) from aquatic solution using chemically modified cone biomass and Fomitopsis pinicola
Authors: Pertile E , Zamarsky P
Published: February 2020

We report the adsorption of Cr (VI) ions from aqueous solution by forest waste. Two adsorbents were prepared from cone biomass and Fomitopsis pinicola. To study the kinetics of both were used three particular size (<0.5, 0.5-1, 1-2 mm). It was found that adsorbents chemically modified with a HCl (activation 2mol/L, activated for 60 min) demonstrated better Cr(VI) removal capabilities as compared to pure adsorbents in terms of their adsorption rate. The optimum conditions for removal of Cr(VI) were found to be particular size <0,5 mm, pH=1, contact time 10 min, adsorbent dosage 20g/L, concentration of Cr(VI) 100 mg/L, temperature 25 ± 1°C, rpm 200. The percent removal at these optimum conditions was found to be 100 % for both biosorbents. The Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The maximum uptake capacities for 40.98 mg/g and 45.05 mg/g for cone biomass and Fomitopsis pinicola, respectively. To study the effect of other ions on the Cr (VI) removal by both biosorbents, electroplating industry wastewater was collected from an industry. Overall, the experimental results suggest that cone biomass and Fomitopsis pinicola could be used as low cost alternative adsorbents for the treatment of low concentration Cr (VI) containing wastewater.
Bending Strength of Polyester Composites Reinforced with Stitched Random Orientation and Plain Weave Abaca Fiber
Authors: Iqbal M , Aminanda Y , Firsa T , Ali M
Published: February 2020

This paper discusses the bending strength of Fiber Reinforced Polymer (FRP) composite made from polyester resin matrix and abaca fiber. The abaca fiber was prepared in the form of stitched random orientation and plain weave woven fabric. The abaca FRP composite was produced by using hand-lay-up method with the variation of weight percentage of the fiber. The weight density of the FRP composite was measured to determine the effect of fiber percentage to the weight density of the composite panel. The three points bending test was performed in order to examine the maximum bending force and flexural strength of the abaca FRP composite. The result of the experiment shows that the fiber weight percentage gave significant effect to the weight density and flexural strength of the abaca composite. Furthermore, the comparison between the two types of fiber form shows that the abaca plain weave woven fiber produces higher flexural strength compare to stitched random orientation woven fiber at all levels of fiber contents.
Determination of Changes in the Parameters of Electrical Machines after Repairs to Prevent an Unacceptable Increase in Vibration of the Building Structure
Authors: Belyi A
Published: February 2020

This article discusses the improvement of control methods for electrical machines after repair. These methods allow during testing of an electric machine to determine deviations of parameters that can lead to an increase in the level of vibration and subsequent failure of both the machine itself and the elements of building structures.
Study on Rotor Eddy Current Losses in High-speed Permanent Magnet Brushless Machines for Aircraft Applications
Authors: Hu Yaohua , Zhu Shushu
Published: February 2020

To improve the power density of aviation electric drive system, the high-speed permanent magnet machines has more and more popular in the air compressor, radial compressor, and electro-hydrostatic actuator applications. Two methods have studied to reduce the rotor eddy current losses in high-speed permanent magnet machines in this paper. Firstly, rotor eddy current losses at different stator slot openings are investigated, the stator core loss are considered simultaneously. Secondly, to reduce the magnet eddy current loss in carbon fiber retaining sleeve, the copper shield is added between permanent and carbon fiber, and the rotor eddy current losses at different copper shield width are studied.
Research and Design of the Control Law of Passive Side-Stick System with Human Factor Fault
Authors: Ziyu Yao , Xizhong Yang , Xuyi Qiu
Published: February 2020

For modern commercial civil aircraft, failure tolerant control (FTC) method is the basic strategy. Human factor fault is becoming more and more important for the design of the active control technology for the electrical flight control system or fly-by-wire system (EFCS or FBW). This paper focuses on the problem caused by the human factor with passive side-stick equipment. A new design concept was proposed based on the Boeing and Airbus experience and a control law of feedforward structure with alarm functions was designed in MATLAB\simulink. The functions were tested in a flight simulation platform in a desktop simulator based on the open-loop dynamic model. The results showed that each part of the control law worked well and the functions were effective. The human factor failure problem of dual inputs was well solved. The work provided a reference for the designer in the civil aviation field especially for those of the developing modern commercial aircrafts.
Assembly Method for Satellite Device Installation based on HoloLens
Authors: Zhang Wei , Zhang Qiang , Liu Zhe , Zhang Chengli , Wang Wei , Yin Chengshuang
Published: February 2020

As the satellite design changes from the traditional 2D mode to the 3D digital mode, the satellite assembly also enters the 3D assembly mode. An effective and accurate device installation process information transmission method from designers to operators is not formed, and accidents with incorrect polarity in device installation often occur. In order to improve efficiency and quality of satellite device installation, modelling method of R point of device is regulated and a system based on HoloLens is designed. With the help of the system, the code and R point are clear at a glance, so an ordinary operator can verify the polarity correctness of the device installation and the efficiency can be doubled.
Modal Analysis of Variable Structure of Gate Rotor of CP-type Single-screw Structure
Authors: Song Xiaofeng , Wang Wei , Wu Yuting , Ma Chongfang
Published: February 2020

Single screw technology, due to its superiority of structure, has been widely used in many fields of gas compression, refrigeration, power and so on at present. However, specialized research on the dynamics of single screw structure has not been systematic or in-depth yet. As for single screw compressors and expanders, the dynamics of the gate rotor are the key factors influencing its performance, and the variable-structure modal analysis of the gate rotor is an important task to study its dynamic characteristics. In this paper, the modal parameters of the CP-type single-screw structure gate rotor are compared by modal simulation and modal experiment, and the accuracy of the finite element method is verified. And mainly carried out the simulation modal analysis of the gate rotor variable structure. The results show that the change of structural parameters is an important factor affecting the natural frequency of the gate rotor mode. The variable structure modal analysis can be used to provide reference for the structural optimization of the gate rotor.
Tiltrotors Position Tracking Controller Design Using Deep Reinforcement Learning
Authors: Huo Yujia , Li Yiping , Feng Xisheng
Published: February 2020

In this paper, a quad-tiltrotors air-water trans-domain robot is introduced. The nonlinear dynamic behaviours with uncertainties require a robust controller for multi-tasks. For this robot, controllers are designed using deep reinforcement learning method solving position and attitude control when operating as a UAV in the air. A ROS combining Gazebo simulation platform is designed to train the robot. The simulation results show the tiltrotors robot gets capabilities of spots tracking as a quad-rotors, and trajectory tracking as both the quad-rotors and tiltrotors.
Simulation Analysis of Influence of the Blade Elasticity on Propeller Performance
Authors: Tan Yuhang , Peng Weicai , Shen Lijiao
Published: February 2020

The blade elasticity can influence hydrodynamic and structural performance of the propeller. The elasticity of the propeller is considered in the hydrodynamic simulation based on the CFD/FEM fluid-structure interaction method. And the hydrodynamic results of the elastic are compared with the rigid. Which show that the accuracy of elastic hydrodynamic prediction improved significantly compared with the rigid. In addition, the hydrodynamic prediction considering the elasticity also shows the transient fluid flow considering the influence of blade vibration. The study indicates considering blade elasticity can significantly improve the accuracy of propeller hydrodynamic prediction, and the prediction of fluid pulsation and propeller response can be used to analyse the flow noise and structural vibration.
Numerical Simulation Method for Wave Surface Landing of Seaplane
Authors: Feng Sun , Mingzhen Wang , Jiaxu Zhang , Qi Hu
Published: February 2020

A seaplane is an aircraft that takes off and land on the water. The water surface is divided into a static surface and a wave surface. The numerical simulation technology of seaplane landing on wave surface is carried out. The accuracy of the simulation method of static water is verified by the comparison of simulation and experiment. The numerical wave generation is realized based on the pseudo-physical method, and the wave surface landing simulation is realized by combining the numerical simulation method with the numerical wave-making method. It is found that the pseudo-physical wave-making method can realize numerical wave-making and the precision is adjustable; then the water-water simulation of the wave surface is realized.
Method of Probe Radius Compensation for Optical Complex Surface Measurement
Authors: Chen L J , Kang Y D
Published: February 2020

When surface measuring with a contact method, the data obtained by the LM50 laser interferometer is the data of the center of the probe actually, not the real measurement point. Therefore, based on the theory of NURBS and the theory of Delaunay triangulation, a method of “enveloping surface - triangulation” is proposed, and the normal vector of the measuring points of the surface is derived so that the radius of the probe is compensated accurately and quickly. After triangular segmentation, the normal vector of each triangle around a measuring point has an influence on the normal vector of the vertex, so it is necessary to calculate the weight function of each triangulation. In this paper, the influence of the edge length and the angle factor on the vertex normal vector is considered, and the calculation of the vertex normal vector is improved in the triangulation, and the programming and calculation are simplified on the premise of guaranteeing the accuracy.
Effect of Load Ratio on the Mechanical Field around Crack Front of Dissimilar Metal Weld Joints
Authors: Wenna Jia , Lingyan Zhao , Jinxuan He , Bashir Rehmat
Published: February 2020

Stress corrosion cracking (SCC) of the dissimilar metal weld (DMW) joints in nuclear power equipment has been paid more attention in recent years. Besides the geometric size, load level, multiaxial stress state and mechanical heterogeneity, the relaxation and redistribution of residual stress make it very difficult to directly study the influence of residual stresses on the actual welded components. To study the effect of load ratio on residual stress around the crack front in the weld zone of DMW joints, the distributions of residual stress and stress triaxiality under different load ratios are simulated and discussed. The analyses show that the stress becomes larger with the increasing load ratio. The stress is tensile stress near the crack front. While the stress becomes compressive stress when it is far away from the crack front. The external load rotio has great effect on the stress around the circumferential direction at the crack front. The higher load ratio are more likely to cause the crack propagation. In the region of crack angle θ=80-120 °, the load ratio has little effect on the stress triaxiality.
Non-vacuum electron beam welding and cutting of cupper
Authors: Hassel T , Beniyash A , Klimov G
Published: February 2020

Due to its physical properties, like high thermal and electrical conductivity copper is an indispensable material in many branches of industries. However the welding and cutting of copper and its alloys is challenging due to this properties and tendency to absorb gases resulting some defects like porosity or hot cracking. To prevent these, different requirements concerning the welding process have to be fulfilled. One requirement is the use of a highly concentrated heat input. The electron beam in atmosphere (NVEBW)is a suitable tool, which meets this requirement. This publication presents the advantages of NVEBW welding and cutting of copper. The experimental results of low-voltage (NVEBW) of copper will be shown and discussed too. The first portion studied the effects of varying power, travel speed and work distance on mechanical and electrical properties and structure of weldment at 175 kV accelerating voltage. The second portion studied the possibility of application of low-voltage 60kV NVEBW for welding of copper and influence of impurities in the copper on the welding parameters. The third portion studied the process of NVEB cutting of copper using the suction created by a local vacuum underneath the work piece. Experimental results of cutting with extremely high cutting speeds such as15m/min for 1.5 mm thick and 9m/min for 6mm thick copper will be representing.
Using ontological and architectural approaches for the vehicle fleet management in the enterprise engineering context
Authors: Kurganov V M , Gryaznov M V , Dorofeev A N , Nastasyak O B , Pervukhin D V
Published: February 2020

The transport activities at a large industrial enterprise are usually an auxiliary process. Therefore, its optimization with information technologies is often neglected. As a result, the cost accounting for the transportation of goods for various purposes is often a weighty problem due to inconsistent information flows. The method considered in this article combines the ontological and architectural approaches for the enterprise activities modeling intended to equalize occasionally a somewhat significant gap between business expectations and TMS functionality.
An organoid-based carcinogenesis model induced by in vitro chemical treatment
Authors: Naruse Mie , Masui Ryoichi , Ochiai Masako , Maru Yoshiaki , Hippo Yoshitaka , Imai Toshio
Published: February 2020

Animal carcinogenesis models induced by environmental chemicals have been widely used for basic and applied cancer research. However, establishment of in vitro or ex vivo models is essential for molecular mechanistic elucidation of early events in carcinogenesis, leading to clarification of the total mode of action. In the present study, to establish an organoid-based chemical carcinogenesis model, mouse organoids were treated in vitro with 4 genotoxic chemicals, e.g. ethyl methanesulfonate (EMS), acrylamide (AA), diethylnitrosamine (DEN) and 7,12-dimethylbenz[a]anthracene (DMBA) to examine their tumorigenicity after injection to nude mice. The four chemicals were reported to induce lung, liver or mammary carcinomas in mouse models. DMBA-treated mammary tissue-derived organoids with Trp53 heterozygous knockout exhibited tumorigenicity, but not those with wild-type Trp53, reflecting previous reports of corresponding animal models. Treatment of lung organoids with or without Trp53 knockout with EMS or AA resulted in carcinogenic histopathological characteristics, and the activation of oncogenic kinases was demonstrated in the nodules from the nude mouse subcutis. DEN-treated liver (biliary tract) organoids also had an increased number of similar changes. In conclusion, an ex vivo model for chemical carcinogenesis was established using normal mouse tissue-derived organoids. This model will be applied to detect early molecular events, leading to clarification of the mode of action of chemical carcinogenesis.
Clinical Pharmacology of Janus Kinase Inhibitors in Inflammatory Bowel Disease
Authors: Lefevre Pavine L C , Vande Casteele Niels
Published: February 2020

Inflammatory bowel disease, including ulcerative colitis and Crohn’s disease, are chronic inflammatory disorders of the gastrointestinal tract which are characterised, in part, by an imbalance in the production of several pro- and anti-inflammatory cytokines. Although various agents are effective for inducing and maintaining remission, approximately 20% of patients are treatment-refractory and require surgery. Parenterally administered monoclonal antibody-based biologics are associated with adverse effects resulting in treatment discontinuation and/or immunogenicity, leading to loss of response to therapy. Approximately 50% of patients who initially respond to treatment with tumour necrosis factor antagonists lose response to therapy within the 1st year of treatment. Incidence of immunogenicity tends to decrease over time, but once present can persist for years, even after treatment discontinuation. Nonimmunogenic oral small molecule therapies, including Janus kinase inhibitors, are currently being developed and have demonstrated efficacy in early phase clinical trials, which has already led to regulatory approval of tofacitinib for the treatment of patients with moderate-to-severe ulcerative colitis. Differentiation of T cells into T helper cells, which are mediators of the inflammatory response in inflammatory bowel disease, is mediated by the Janus kinase signal transducer and activator of the transcription signalling pathway. Absorption and distribution of Janus kinase inhibitors occurs at the site of action in the gastrointestinal tract, and newer compounds are being developed with limited systemic absorption, potentially reducing the risk of adverse effects. The current review describes the clinical pharmacology of approved Janus kinase inhibitors, as well as those in clinical development for the treatment of inflammatory bowel disease.
Alteration of CTCF-associated chromatin neighborhood inhibits TAL1-driven oncogenic transcription program and leukemogenesis
Authors: Li Ying , Liao Ziwei , Luo Huacheng , Benyoucef Aissa , Kang Yuanyuan , Lai Qian , Dovat Sinisa , Miller Barbara , Chepelev Iouri , Li Yangqiu , Zhao Keji , Brand Marjorie , Huang Suming
Published: February 2020

Aberrant activation of the TAL1 is associated with up to 60% of T-ALL cases and is involved in CTCF-mediated genome organization within the TAL1 locus, suggesting that CTCF boundary plays a pathogenic role in T-ALL. Here, we show that −31-Kb CTCF binding site (−31CBS) serves as chromatin boundary that defines topologically associating domain (TAD) and enhancer/promoter interaction required for TAL1 activation. Deleted or inverted −31CBS impairs TAL1 expression in a context-dependent manner. Deletion of −31CBS reduces chromatin accessibility and blocks long-range interaction between the +51 erythroid enhancer and TAL1 promoter-1 leading to inhibition of TAL1 expression in erythroid cells, but not T-ALL cells. However, in TAL1-expressing T-ALL cells, the leukemia-prone TAL1 promoter-IV specifically interacts with the +19 stem cell enhancer located 19 Kb downstream of TAL1 and this interaction is disrupted by the −31CBS inversion in T-ALL cells. Inversion of −31CBS in Jurkat cells alters chromatin accessibility, histone modifications and CTCF-mediated TAD leading to inhibition of TAL1 expression and TAL1-driven leukemogenesis. Thus, our data reveal that −31CBS acts as critical regulator to define +19-enhancer and the leukemic prone promoter IV interaction for TAL1 activation in T-ALL. Manipulation of CTCF boundary can alter TAL1 TAD and oncogenic transcription networks in leukemogenesis.
High density of unrepaired genomic ribonucleotides leads to Topoisomerase 1-mediated severe growth defects in absence of ribonucleotide reductase
Authors: Cerritelli Susana M , Iranzo Jaime , Sharma Sushma , Chabes Andrei , Crouch Robert J , Tollervey David , El Hage Aziz
Published: February 2020

Cellular levels of ribonucleoside triphosphates (rNTPs) are much higher than those of deoxyribonucleoside triphosphates (dNTPs), thereby influencing the frequency of incorporation of ribonucleoside monophosphates (rNMPs) by DNA polymerases (Pol) into DNA. RNase H2-initiated ribonucleotide excision repair (RER) efficiently removes single rNMPs in genomic DNA. However, processing of rNMPs by Topoisomerase 1 (Top1) in absence of RER induces mutations and genome instability. Here, we greatly increased the abundance of genomic rNMPs in Saccharomyces cerevisiae by depleting Rnr1, the major subunit of ribonucleotide reductase, which converts ribonucleotides to deoxyribonucleotides. We found that in strains that are depleted of Rnr1, RER-deficient, and harbor an rNTP-permissive replicative Pol mutant, excessive accumulation of single genomic rNMPs severely compromised growth, but this was reversed in absence of Top1. Thus, under Rnr1 depletion, limited dNTP pools slow DNA synthesis by replicative Pols and provoke the incorporation of high levels of rNMPs in genomic DNA. If a threshold of single genomic rNMPs is exceeded in absence of RER and presence of limited dNTP pools, Top1-mediated genome instability leads to severe growth defects. Finally, we provide evidence showing that accumulation of RNA/DNA hybrids in absence of RNase H1 and RNase H2 leads to cell lethality under Rnr1 depletion.
Cognitive impairment, endothelial biomarkers and mortality in maintenance haemodialysis patients: a prospective cohort study
Authors: Freire de Medeiros Camilla Maroni Marques , Diógenes da Silva Bruna Rafaele , Costa Bruno Gabriele , Sartori Vinicius Farina , Meneses Gdayllon Cavalcante , Bezerra Gabriela Freire , Martins Alice Maria Costa , Libório Alexandre Braga
Published: February 2020

Background

Haemodialysis (HD) patients have a high prevalence of cardiovascular disease risk factors as well as cognitive impairment. The objective of the present study was to evaluate the interrelationship between cognitive impairment, endothelium-related biomarkers and cardiovascular/non-cardiovascular mortality.

Methods

A total of 216 outpatients were recruited from three centres in a dialysis network in Brazil between June 2016 and June 2019. Sociodemographic and clinical data were obtained by applying a patient questionnaire, reviewing medical records data and conducting patient interviews. Cognitive function was assessed using the Cambridge Cognitive Examination. Plasma endothelium-related biomarkers [syndecan-1, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion protein-1 (VCAM-1) and angiopoietin-2 (AGPT2)] were measured. Patients were followed for 30 months. Cox proportional hazards regression models were used to assess the associations of the cognitive function scores and each endothelium-related biomarker with cardiovascular/non-cardiovascular mortality.

Results

Cognitive function was associated with cardiovascular mortality {each standard deviation [SD] better cognitive score was associated with a 69% lower risk for cardiovascular mortality [hazard ratio (HR) 0.31 [95% confidence interval (CI) 0.17–0.58]} but not with non-cardiovascular mortality. Moreover, cognitive function was also correlated with all endothelial-related biomarkers, except VCAM-1. ICAM-1, AGPT2 and syndecan-1 were also associated with cardiovascular mortality. The association between cognitive function and cardiovascular mortality remained significant with no HR value attenuation [fully adjusted HR 0.32 (95% CI 0.16–0.59)] after individually including each endothelial-related biomarker in the Cox model.

Conclusions

In conclusion, cognitive impairment was associated with several endothelium-related biomarkers. Moreover, cognitive impairment was associated with cardiovascular mortality but not with non-cardiovascular mortality, and the association between cognitive impairment and cardiovascular mortality in HD patients was not explained by any of the endothelial-related biomarkers.
ALMA band 8 observations of DLA 2233+131 at z = 3.150
Authors: Ogura Kazuyuki , Umehata Hideki , Taniguchi Yoshiaki , Matsuda Yuichi , Kashikawa Nobunari , Sheth Kartik , Murata Katsuhiro , Kajisawa Masaru , Kobayashi Masakazu A R , Murayama Takashi , Nagao Tohru
Published: February 2020

We present our ALMA Band 8 observations of a damped Ly$\alpha$ absorption (DLA) system at $z = 3.150$ observed in the spectrum of the quasar Q2233+131 at $z = 3.295$. The optical counterpart of this DLA has been identified and it shows a double-peaked Ly$\alpha$ emission line. Since one possible origin of DLAs at high redshift is an outflowing gas from star-forming galaxies, DLA 2233+131 provides a good laboratory to investigate the nature of high-z DLAs. Motivated by this, we have carried out ALMA band 8 observations to study the [C ii] line in this system. However, we do not detect any significant emission line in the observed pass bands. Instead, we have serendipitously found three submm continuum sources in the observed sky area. One appears to be the quasar Q2233+131 itself while the other two sources are newly identified submm galaxies (SMGs), called SMG1 and SMG2 in this paper. They are located at a separation of ${4{^{\prime \prime }_{.}}7}$ and ${8{^{\prime \prime }_{.}}1}$ from Q2233+131, respectively. Their 646 μm fluxes are $6.35\:$mJy and $6.43\:$mJy, respectively, being higher than that of Q2233+131, $3.62\:$mJy. Since these two SMGs are not detected in the optical images obtained with the Hubble Space Telescope and the Subaru Telescope, they have a very red spectral energy distribution. It is, therefore, suggested that they are high-redshift galaxies or very dusty galaxies at intermediate redshift, although we cannot rule out the possibility that they are optically very faint SMG analogs at low redshift. Follow-up observations will be necessary to explore the nature of this interesting region.
A Preliminary Model for the Migration of Sulfide Droplets in a Magmatic Conduit and the Significance of Volatiles
Authors: Yao Zhuosen , Mungall James E , Qin Kezhang
Published: February 2020

A close relationship between Ni–Cu–(PGE) sulfide deposits and magmatic conduit systems has been widely accepted, but our present understanding still rests on empirical inductions that sulfide liquids are entrained during magma ascent and aggregated at hydrodynamic traps such as the opening of a conduit into a larger magma body. In this contribution, a preliminary quantitative model for the dynamics of mm-scale sulfide droplets in a vertical magmatic conduit is developed, examining such limiting parameters as the size, transport velocity and the magmas’ maximum carrying capacity for sulfide droplets. Addition of numerous dense sulfide droplets significantly reduces magma buoyancy and rapidly increases the bulk viscosity, and the resulting pressure gradient in the propagating conduit dyke restricts the maximum volume fraction of droplets that can be carried by ascending magma. For sulfide droplets alone, the maximum carrying capacity is low, but it will be improved dramatically by the addition of volatiles which reduces the density and viscosity of silicate melt. Potential volatile degassing during decompression further facilitates sulfide entrainment by reducing bulk magma density, and the formation of buoyant compound vapour-sulfide liquid bubble drops also greatly enhances the carrying capacity. The breakdown of compound drops by detachment of parts of the vapour bubble or sulfide droplet may occur at low pressure, which liberates sulfide liquids from rising compound drops, potentially to collect in traps in the conduit system. When sulfide-laden magma flows through a widening conduit, many droplets can be captured by the re-circulation flow just downstream of the expanding section, followed by sulfide liquid accumulation and enhanced chemical interaction via diffusive exchange with the recirculating magma, potentially resulting in an economic, high-tonnage ore body. We apply our models to the emplacement of sulfide-rich magmatic suspensions at Noril’sk and show that the disseminated mineralization in intrusions could have formed when magmas carrying re-suspended sulfide liquid entrained from pre-existing sulfide accumulations in the conduit system reached their limiting sulfide carrying capacity as dictated by buoyancy and were deflected into blind sills flanking the principal conduit for flood basalt volcanism.
Formation of the Vergenoeg F–Fe–REE Deposit (South Africa) by Accumulation from a Ferroan Silicic Magma
Authors: Brandt S , Klemd R , Haase K M , Fassbender M L , Vennemann T
Published: February 2020

Situated in the centre of the Paleoproterozoic Bushveld Large Igneous Province (LIP) of South Africa the Vergenoeg F–Fe–REE deposit is one of the largest, but at the same time most unusual, fluorite deposits on Earth. In situ major and trace element analyses of fayalite, magnetite, ilmenite, fluorapatite, fluorite and allanite from fayalite-rich rocks are combined with oxygen isotope data for fayalite, magnetite and ilmenite to unravel the complex evolution of the deposit. Textural and compositional characterization of the fayalite-rich rocks supports a magmatic formation as cumulates and an intense late hydrothermal overprint. Fayalite accumulated together with minor Ti-rich magnetite, ilmenite, fluorapatite and allanite from a highly evolved, H2O-poor felsic melt at low oxygen fugacity. Chondrite-normalized rare earth element (REE) patterns of fayalite and the recalculated parental melts, using fayalite–rhyolite partition coefficients, exhibit positive trends with strong enrichment of the heavy REE (HREE) relative to the light REE (LREE). Apart from the LREE depletion the patterns are similar to those of highly fractionated high-silica REE rhyolites that often occur in siliceous LIPs. We attribute the LREE depletion to crystallization of accessory allanite, the main host of the LREE in the cumulates. Chondrite-normalized REE patterns of the parental melt prior to fayalite accumulation, recalculated using allanite–rhyolite partition coefficients, resemble the composition of the rhyolites of the Rooiberg Group and therefore document a petrogenetic link to the Bushveld LIP. High δ18O values of fayalite (up to ≈7·4 ‰) are consistent with its crystallization in a rhyolitic melt that has formed by extensive fractionation from basic melts of the Rustenburg Layer Suite, the mafic member of the Bushveld LIP. Primary fluorite crystallized together with rare quartz, and a second generation of fayalite, magnetite and ilmenite from rare intercumulus melt in interstices between cumulate fayalite. Textural and mineral compositional data, as well as the generally negative δ18O values of magnetite (–2·9 to 0 ‰), are in agreement with the main magnetite–fluorite ore formation in Vergenoeg being related to a hydrothermal overprint, which was responsible for further F and Fe enrichments of the rocks. Fluorine-rich fluids, released from the crystallizing granites of the felsic member of the Bushveld LIP (Lebowa Granite Suite), caused the extensive alteration of fayalite to bowlingite and its replacement by Ti-poor magnetite and quartz. The hydrothermal overprint was associated with the widespread formation of secondary fluorite and minor fluorapatite. Our new petrogenetic model for the Vergenoeg deposit, as constrained from the primary fayalite cumulates, implies that the formation of the Vergenoeg deposit was directly linked to the evolution of the Bushveld LIP.