bluuebunny/crossref_metadata_2025 huggingface dataset:
Delivering the First Horizontal Well Under the Harsh Economic Conditions in an Offshore Brownfield in Malaysia
Authors: Kumaran Prashanth Nair , Charbernaud Thierry , Ibrahim Ramli , Kadir Zairi , Kamat Dahlila , Yaakob Mohd Taufiq , Mandal Dipak , Ataei Abdolrahim , Maldonado Jorge , Abdul Rahman Mohd Ramziemran , Iskenova Gulnara , Ceccarelli Tomaso Umberto , Djarkasih Fredy , Abdul Rahman Nor Nabilah , Mohd Salim Ahmad Syahrir , Moreno Juan Carlos , Cavallini Alberto
Published: October 2018

A West Baram Delta prolific mature oil field has been developed through 150+ wells since 1975 in Malaysia. In 2015, an exploration well drilled in neighboring block, successfully found ~500ft TVT of gross oil, 50% less than expected due to structural changes. With lower than expected hydrocarbon in place, the project team was forced to re-evaluate the development and identified key strategies to minimize the number of wells to drill while ensuring healthy project economics. Optimizing reserves and ensuring future accessibility while minimizing number of wells and cost, were the key challenges. Rather than developing all sands with highly deviated well, the team designed an extended reach horizontal well targeting a single key reservoir containing 60% of block STOIIP. Team decided to drill from an existing platform with no pilot hole but opted for real time reservoir mapping technology for well placement. The well was designed with no smart completion due to surface power limitation. First time in the region a dual defensive sand control mechanism was selected, Gravel Pack & Sand Screens. The 1st ever horizontal well was drilled S field meeting its objective at Q4-2017 and exceeding forecasted initial rates. With a long horizontal open hole section and being the only well in the block, a major challenge was to delay water coning and to control water cut once water breaks through. This was achieved with the installation of 8 Inflow Control Devices (ICDs). Real-time reservoir mapping while drilling was used successfully to land the well and then optimize the production section in good quality sands despite structural uncertainty. The well, designed with 60° maximum inclinations, ensures routine well intervention to be done using slickline (i.e. gas lift valve change). Any major intervention would still require coil tubing with usage of barge. The horizontal profile overcomes the limitation of power supply for automation that would be faced with high angle deviated well hence saved significant surface modification cost. The out of box solution of optimized field development plan for complex offshore Brownfield with limited facilities modification, while being cost conscious but technically sound concept proven to provide the answer for sustainable production growth in S Field at low oil price environment. The success of this well has changed the team mindset to relook and propose similar design wells in previously deemed uneconomical FDPs within the S Field.
Experimental Investigation of Crude Oil Emulsion Stability: Effect of Oil and Brine Compositions, Asphaltene, Wax, Toluene-insolubles, Temperature, Shear-stress, and Water-cut
Authors: Uetani Takaaki , Kai Jyunichi , Hitomi Tomoko , Seino Hitoshi , Shinbori Kiyomasa , Yonebayashi Hideharu
Published: October 2018

This paper presents the results of a laboratory case study that was initiated to understand the main causes of the crude oil emulsion for an onshore oil field in Japan. The factors investigated on the influence of emulsion stability were oil and brine compositions, content of asphaltene, wax and toluene-insolubles, temperature, shear-stress, and water-cut. The results showed the emulsion was stabilized by multiple factors, indicating that multiple preventative approaches are required to sustain stable production, free of emulsion.
The Impact of Pore Structure on Carbonate Stimulation Treatment Using VES-Based HCl
Authors: Sibarani Tiurma Theresa , Ziauddin Murtaza , Nasr-El-Din Hisham A. , Zakaria Ahmed S.
Published: October 2018

This study investigates the performance of viscoelastic surfactant (VES)-based HCl stimulation fluids as a function of carbonate rock type and quantifies the response of the acid to different pore-structures. A pore-structure evaluation during stimulation design could lead to a successful field treatment.

Coreflood tests were conducted using several types of limestone cores with permeabilities ranging from 2.5 to 155 md. Intergranular pores were dominant in the Indiana limestone and Austin chalk samples investigated, whereas moldic pores were dominant in the Pink desert, Edwards yellow, Winterset, and Edwards white cores. Tracer experiments characterized the pore structure in each carbonate sample, and the tracer fluid was injected at 5 cm3/min and 75°F into the cores with dimensions of 6 in. length and 1.5 in. diameter. The tracer effluent data was used to measure accessible porosity (flowing fraction) for each core sample. After the tracer, the VES acid was injected at rates from 1 to 10 cm3/min and 150°F to determine pore volume to breakthrough (PVbt). The wormhole patterns were analyzed using computed tomography (CT) scan images, and the pattern complexity was examined by fractal dimension analysis.

A better pore connectivity showed for Indiana limestone compared to Edwards yellow, Winterset limestone, and Edwards white. The flowing fractions were 1, 0.86, 0.61, and 0.53 for Indiana limestone, Edwards yellow, Winterset limestone, and Edwards white, respectively. The PVbt of Indiana limestone ranged from 0.62 to 0.92. Cores with lower pore connectivity, such as Edwards yellow, had PVbt ranging from 0.52 to 0.81, Winterset limestone from 0.34 to 0.49, and Edwards white from 0.21 to 0.36. These results revealed that higher flowing fractions are required with a higher PVbt. Rocks that have the same dominant pore-structures usually exhibit similar wormhole behavior.

Prior to this study, the performance of VES fluids had only been studied on carbonate rocks with well-connected intergranular porosity. The results of this study show that porosity distribution of the rock affects the response to acids.
Fines Migration as an EOR Method During Low Salinity Waterflooding
Authors: Al-Sarihi Abdullah , Zeinijahromi Abbas , Genolet Luis , Behr Aron , Kowollik Patrick , Bedrikovetsky Pavel
Published: October 2018

This study presents a novel mechanism of enhancing oil recovery by fines migration during low salinity waterflooding. Formation damage is isolated from other low salinity mechanisms in the experimental tests performed in this work. Therefore, the reduction in residual oil saturation is attributed to fines migration mechanism only that is caused by improved microscale sweep efficiency via water flux diversion due to fine particles straining. Corefloods were performed on Berea cores with high clay content, Bentheimer cores with low clay content, and artificial clean sand cores with no clay to investigate the effect of clay presence on residual oil saturation. HSW and LSW took place after drainage displacements that resulted in the same initial conditions of connate water saturation and oil relative permeability. Non-polar oil is used to ensure water-wetness in the cores and to avoid possible wettability alteration by low salinity waterflooding. Single phase corefloods were also performed to study the effect of piecewise decreasing salinity on permeability. The results show a permeability decline with low salinity water injection in the single phase tests of clay-rich cores accompanied by fine particles production and pH increase. The same effect is observed in the two phase tests. In addition, incremental oil production is observed along with the permeability decrease and fines production. This is due to detachment of clay particles by weakened attraction as a result of LSW, which leads to fines migration and straining in water filled pores. Therefore, water flux diversion into trapped oil pores takes place, which displaces the residual oil in these pores. A relationship between formation damage, βΔσ, and residual oil saturation has been introduced and it can be applied in reservoir simulation for LSW.
Numerical Simulation of Well Production Performance Considering Pre-Darcy Flow Using EDFM
Authors: Xu Jianchun , Sun Baojiang , Zhang Wei , Cheng Hongjie , Fu Weiqi
Published: October 2018

Numerical simulation of well production performance for tight oil/gas reservoirs is a hot issue during recent years. Embedded discrete facture model (EDFM) is an effective numerical simulation tool as its advantages and becomes popular. Now it is widely used in multistage fractured horizontal well performance prediction. In this paper, we will extend EDFM to study the well production performance when considering Pre-Darcy flow. Firstly, the two phases flow model is established. The conservation equations are derived for different media, i.e., fracture and matrix. For the flow in fracture, the Darcy's law is used. In the matrix, the Pre-Darcy flow is considered. Then, the solution workflow is showed and the verification is presented. The simulation results of the extended model are compared with that of local grid refined (LGR) method. Finally, the test cases are presented. We show the difference of oil/water production rate when considering Darcy flow and Pre-Darcy flow. The pressure and saturation distribution are also compared. The results show big difference will happen when using different flow model.
Economic Evaluation and Uncertainty Assessment of Lost Circulation Treatments and Materials in the Hartha Formation, Southern Iraq
Authors: Alkinani Husam H. , Al-Hameedi Abo Taleb , Dunn-Norman Shari , Flori Ralph E. , Hilgedick Steven A. , Amer Ahmed S. , Alsaba Mortadha T.
Published: October 2018

It is recognized that there is no single solution to lost circulation, and most treatment and trial-and-error. However, the screening guide presents a high-level ‘go to’ document with coherent guidelines, which engineers can utilize in making decisions regarding lost circulation treatments in major oil fields. The aim of this work is to describe how mud engineers can use the decision tree analysis (DTA) to evaluate and select the best treatments path for mitigating mud losses.

Lost circulation events of Southern Iraq oil fields were statistically analyzed to determine treatment effectiveness. Also, the cost of each treatment, as well as the NPT that is associated with the treatment, is considered in this study. Data from over 1000 wells were gathered from various sources and reports; the

treatments were classified by scenario -partial, severe, and complete losses - as well as cost, efficiency, and formation types. This paper is developed based on probabilities, expected monetary value (EMV), and decision tree analysis (DTA) to recommend the best-lost circulation treatments path for each type of losses.

Traditionally, lost circulation in Southern Iraq area has been treated in a multitude of ways without consistent methodology. This analysis identifies and ranks the most effective treatments to create a "best" method/product recommendation and a flowchart suggesting additional measures in treating losses to optimize success and reduce overall cost and NPT. This paper presents the best treatment for each scenario - partial loss, severe losses and complete losses - both for product selection and engineering.

This paper utilizes probability and economics in the decision-making process. This is the first study that considers a detailed probability and cost to treat the lost circulation problem. Thousands of treatment scenarios for each type of losses are conducted, and the EMVs for all scenarios are calculated. For each type of losses, the lowest EMV treatment strategy- that is practically applicable in the field and makes sense- is selected to be used to treat each type of losses to minimize NPT and cost. If the losses didn't stop after utilizing the proposed treatment strategies, it is recommended to use liner hanger to isolate the losses zone and then continue drilling.

One challenge in drilling wells in Southern Iraq oil fields is the inconsistency of approaches to the lost circulation problem. Therefore, the result of this data analysis provides a path forward for Southern Iraq area lost circulation events and suggests probable methods that can be used in similar formations globally. Additionally, the methodology can be adapted to studying other types of formations and drilling challenges have the same geological properties in any major oil field.
Transient Modelling and Sensitivity Analysis of Influxes in Backpressure MPD Systems
Authors: Gomes Dalila , Frøyen Johnny , Fjelde Kjell , Bjørkevoll Knut
Published: October 2018

A transient flow model capable of modeling gas solubility will be used to perform a sensitivity analysis of kick behavior in a subsea backpressure MPD system when using oil based mud. The parameters of interest are choke pressures, pit volume, and return rates. At HPHT conditions, gas kicks can be entirely dissolved in oil based mud. However, when being circulated upwards, free gas will emerge at a certain depth. The required choke pressure to maintain a constant bottomhole pressure depends on the amount of gas released from the mud and where this occurs. Another parameter that impacts both choke pressure and return flow is the geometry, whether we have a wide riser for subsea MPD or are considering an MPD operation from a fixed installation with a narrower geometry. In this paper, the riser geometry will be varied. The paper will contribute in showing how transient models can assist in the planning of MPD operations. It will also provide insight into influx behavior and its impact on surface parameters with focus on oil based mud.
Investigating the Influence of Wettability and Direction on Supercritical CO2 Trapping for Supercritical CO2-Brine Imbibition Process at Pore Scale for Bentheimer Sandstone
Authors: Jahan Farjana , Ahmed Shakil , Hossain Mofazzal
Published: October 2018

Wetting properties of various reservoir rocks strongly influence the efficiency and security of geological storage of carbon dioxide in deep saline aquifers. Numerical simulation of Carbon Capture and Storage (CCS) has become a considerable research option now-a-days due to less time and cost-effective outcomes compare to traditional laboratory based experiments. This study provides a Computational Fluid Dynamics (CFD) methodology for the pore-scale displacement mechanism of supercritical CO2 under different wetting conditions and quantify the effect of wettability and direction of flow on supercritical CO2 trapping.

A 3-Dimensional visualization software is used to build surface mesh from the micro-pores of the Bentheimer sandstone. A module of a commercial CFD software is used to generate volume mesh from the surface mesh and another module from the same CFD software is used to perform imbibition processes (supercritical CO2/brine) through the Bentheimer sandstone. Full Navier-Stokes equations are solved by using Eulerian-Eulerian multiphase transient flow approach. Free surface flow model is used to integrate the effect of capillary forces. This model determines the pressure gradient at the two-phase interface. The flow is assumed to be laminar, isothermal and there is no mass transfer between phases.

The initial condition of the imbibition processes was obtained from a drainage process for a strongly water-wet system. For this, a Bentheimer sandstone was completely filled with brine and supercritical CO2 was injected. The simulation was stopped when brine was drained by supercritical CO2 and the system reached the steady state conditions. This phase distribution was used as an initial boundary condition for the imbibition processes. The imbibition processes were performed in two opposite direction for different contact angles (100° and 110°). The effect of wettability and direction of brine on supercritical CO2 trapping were observed. The residual saturation of supercritical CO2 was significantly different in two opposite direction of brine flow. In the reverse imbibition process, normalized residual supercritical CO2 saturation values are increased but, the amount of normalized trapped supercritical CO2 values are decreased. It was mainly due to the amount of normalized free supercritical CO2 saturation values (which were equal to the difference between normalized residual supercritical CO2 saturation and normalized free supercritical CO2 saturation values).
Review of Water Saturation Calculation Methods in Shale Gas Reservoir
Authors: Yu Hongyan , Wei Xiaolong , Wang Zhenliang , Rezaee Reza , Zhang Yihuai , Lebedev Maxim , Iglauer Stefan
Published: October 2018

The gas content in shale reservoir is of great importance in reservoir evaluation. Shale reservoir has various gas including free gas, adsorpted gas and soluted gas. Free gas take an important part for the total gas content. Hence, we investigated three equations for water saturation calculating and compared and improved them based on theoretical analysis in order to find a siutable one for the shale reservoir characterization. The results indicate that the Archie formula has several limitations applied to complex pore structure, which leads to high water saturation. Since the Archie formula was proposed by experimental data in pure sandstone without enough consideration about the clay of shale reservoir. The Waxman-Smits is suitable to shale gas reservoirs through theoretical analysis, but there are several uncertain parameters. The conductivity of formation water is necessary parameter in calculation of formation water saturation, but calculating the conductivity of formation water is difficult in shale gas reservoir because of its intricate characterization of pore structure and conductivity. Waxman-Smits model take account for the clay conductivity, but there are several uncertain parameters which are hard to obtained, resuting high error. For instance, the equivalent conductivity of exchange cations (B) and the capacitance of exchange anions (Qv) can not be defined accurately relied on experimental calculation, which causes indefinite influence on results. Thus, we concluded that selecting the improved Indonesia equation is a better method to calculate water saturation. This study provided a comprehensive analysis and an accurate way for water satruartion evaluation in shale reservoir.
Modelling of Inflow Control Devices: From the Flow Loop to the Simulator
Authors: Dimitrov Sankoff Roumen , Bijani Behrooz , Di Martino Gianluca , Watson Julie , Scott Marshall Craig
Published: October 2018

The intent of this work is to outline the workflow that engineers can apply in the selection and modelling of inflow control devices (ICDs) for use in completion design. It provides a step-by-step guide and examples of how to address the key challenges in the field of modelling of ICDs, namely: the choice of ICD technology that is most suitable for the particular well; the process of building a custom ICD performance model and import into the reservoir simulator; considerations in setting up the simulation model; and, verification of the results.

The paper highlights the risk of using empirical ICD models, available in reservoir simulators, in the early stages of evaluating inflow control technology. It then demonstrates that the decision on whether or not an inflow control is required, and what type, can be made without resorting to these built-in empirical models in reservoir simulators.

The paper introduces a new approach to evaluation, comparison and modelling of inflow control devices of different types and geometry. Focused on simplicity and accuracy, the method of ICD characterisation is described, as is how to use this characterisation to generate input to the reservoir simulator. A method for verification of the output from the reservoir simulator is also presented.

The application of this modelling approach is illustrated through a case study on evaluating inflow control technology in a mature oil reservoir.
Bio Enhanced Energy Recovery Technology for Clean and Efficient Energy Production
Authors: Clemens Langbauer , Herbert Hofstätter , Albina Mukhamedzianova
Published: October 2018

The demand for environmentally friendly and efficient oil and gas production, especially in unconventional reservoirs, is continuously increasing. Conventional hydraulic fracturing jobs use numerous different harmful (U.S. Environmental Protection Agency, 2016) chemicals to stabilize the fracturing fluid and to maintain its proppant caring capacity. The Bio-Enhanced Energy Recovery (BEER®) fracturing technology is a new technology for clean and efficient energy recovery in tight oil and shale gas reservoirs using biological substances, without the use of environmentally harmful chemicals.

This paper shows the potential of the BEER® technology in a tight gas sandstone reservoir with the help of the 3D simulator GOHFER® and laboratory tests. The technology itself consists of two essential parts. On the one hand, a biological hydraulic fracturing fluid to create the fracture and to carry the proppants is just a mixture of a few harmless components. On the other hand, special proppants, based on silicon dioxide, are applied to keep the fracture open.

Experiments and lab tests have shown the high potential of the fluid. Fluid rheology, caring capacity, breaking behavior and other relevant properties are examined. The investigations of the proppants result in a very high compressive strength, narrow size range, perfect sphericity at a much lower price, compared to the common commercially available products. Based on those results by the usage of the simulator GOHFER®, the fracturing job efficiency of the BEER® technology is comparable to the performance of the standard fracturing technology. Reservoir properties, the treatment job design, the 3D fracture geometry and post-treatment production enhancement are investigated. A sensitivity analysis of gross fracture length, propped cut-off fracture length, and fracture conductivity confirms the significant potential of this technology.

The results presented here indicate that the proposed technology is indeed suitable for performing environmentally friendly and clean hydraulic fracturing jobs, resulting in higher production rates at much lower costs than the conventional technology.
Novel Nano-Surfactant Formulation to Overcome Key Drawbacks in Conventional Chemical EOR Technologies
Authors: Mashat Afnan , Gizzatov Ayrat , Abdel-Fattah Amr
Published: October 2018

This article reports on a novel simple method for transforming the high-salinity-incompatible petroleum sulfonates into a persistently stable oil-swollen micelles, referred to here as nanosurfactant. We present and discuss the effect of three different nanosurfactant formulations on the interfacial tension (IFT) between high-salinity water and crude oil, their phase behavior, and the effect of their dilution on IFT to assess their ability to reduce mobilize oil after injection into high-salinity and temperature reservoirs.

The three nanosurfactant formulations were prepared in high-salinity water following a direct-mixing procedure in which solutions in fresh water of 5 wt% petroleum sulfonate in mineral oil and three 4 wt% zwitterionic co-surfactants were mixed with high-salinity water at room temperature to give a combined concentration of all active ingredients of 0.2 wt%. The IFT between crude oil and different nanosurfactant formulations was measured using a spinning drop interfacial tensiometer at 90°C. IFT was measured every 5 minutes while the oil drop was spinning at ~4000 rpm. The phase behavior was investigated by monitoring the turbidity and UV absorbance changes in a system of crude oil atop of the nanosurfactant formulation over time at 100°C without any mechanical mixing.

The particle size of the three nanosurfactant formulations is in the range of 40 to 80 nm, depending on the co-surfactant used. All formulations were persistently stable, colloidally, and chemically under high-salinity (~56,000 ppm) and temperature (100°C) for more than four months. All formulations showed substantial reduction in IFT with crude oil compared to high-salinity water alone. Dilution with high-salinity water up to five times further reduced the IFT, suggesting improved performance after injection into the reservoir. This behavior was consistent with the observed gradual decrease in surface tension of the nanosurfactant formulation as its concentration decreases toward the CMC value. Phase behavior experiments showed enhanced formation of homogeneous micelles at 100°C without the aid of any mixing. Our results demonstrate the ability of nanosurfactants to solubilize oil under typical carbonate reservoir conditions. Their colloidal nature allows them to migrate deeper in the reservoir compared to conventional surfactants due to size exclusion and chromatographic effects.

Nanosurfactants are novel oil-swollen micelles of the inexpensive and abundant petroleum sulfonate salts that are efficient in reducing IFT under typical carbonate reservoir conditions. The formulation method can be extended to other surfactants and chemical treatments that are incompatible with high-salinity water at high temperatures. Their nanoparticle character and colloidal behavior suggest their ability to migrate and penetrate deep in the reservoir. Nanosurfactants can therefore help overcome some of the most critical drawbacks in conventional chemical EOR technologies.
Supramolecular & Oil Displacement Fluid for Hydraulic Fracturing
Authors: Cui Weixiang , Zou Honglan , Wang Chunpeng , Yang Jiang , Yan Jun
Published: October 2018

This paper studied a new fracturing fluid based on a supramolecular complex between associative polymer and viscoelastic surfactant (VES). The combination of VES and associative polymer synergistically enhances the viscosity several times more than that of the individual components alone. The fluid system was optimized by experimental design. The microstructure of wormlike micelle and complex formation was verified by electron microscopy. The proppant transport test in a large-scale fracture simulator showed good proppant suspension ability. After fracturing, the nano- surfactant molecule in the liquid have a high surface energy, which can play a good oil displacement effect in the crack.

The fluid has 50% lower formation damage than that of conventional guar. The fluid was prepared with less additives and formed gel instantly, which can be mixed on the fly in the field. The gel can be completely broken with almost no residue. By flooding and [1]nuclear magnetic resonance experiments results, compared to the conventional fracturing fluid and water, oil displacement efficiency can be increased by 12% to 20%, more micro-pores in the oil and gas drive for higher pressure stimulation effect for tight oil reservoir. Field application of the new fracturing fluid in 10 tight gas wells showed the enhancement of gas production over 100%. The fluid has 20% lower friction pressure than that of guar fluid. Hence, the new supramolecular fluid is an effective fracturing fluid.

Supramolecular fracturing fluid provides a new fracturing system with less formation damage to fracturing operation. This paper will be beneficial to all engineers and technologists who are currently working at tight gas stimulation applications.
Defining and evaluating the social value of regional water resources in terms of emergy
Authors: Wu Zening , Di Danyang , Lv Cuimei , Guo Xi , Wang Huiliang
Published: October 2018

The social value of water resources must be considered when reforming water prices, improving water policy, protecting water resources and devising allocation methods. However, current social value theories for water resources are often unsound. The social value of water resources is defined here based on social system theory. Energy flow within a combined social–ecological system is analyzed, and an emergy analysis method for ecological economics is introduced for unified quantification and to improve the accounting method of the social value of water resources. Taking Zhengzhou in east-central China as an example, the social value of water resources is calculated for 2015. The water resources' total social emergy was 6.04 × 1021 solar equivalent joules (sej) and the unit value was 6.58 × 1012 sej/m3. This corresponds to 3.88$/m3, indicating that the social value of water resources is enormous. This paper proposes that the social value of water is an important component of its ecological economic value, and its social value should therefore be considered by water policy makers. Research of this type can be effective in helping to protect water resources and encourage efficient water use.
Rapid detection of Cyanobacteria by recombinase polymerase amplification combined with lateral flow strips
Authors: Li Jingjing , Wang Chunming , Yu Xin , Lin Huirong , Hui Chen , Shuai Li , Zhang Shenghua
Published: October 2018

Cyanobacteria are one of the major groups of algae causing algal blooms. In this study, we developed a rapid method for detecting Cyanobacteria using a recombinase polymerase amplification (RPA) method coupled with lateral flow (LF) strips. After releasing cyanobacterial DNA from cells using a freeze-cracking method, DNA was amplified using the RPA method. Next, the RPA products were detected using the LF test. LF-RPA successfully amplified the DNA of eight cyanobacterial species and detected their presence in the sample with high specificity, distinguishing them from five non-cyanobacterial species. The method could detect cyanobacterial DNA in water samples containing as low as 0.01 cell/mL Cyanobacteria, making the method more sensitive than polymerase chain reaction (PCR), which required cell densities of at least 104 cell/mL. LF-RPA could amplify and detect cyanobacterial DNA at any temperature in the range 30–45 °C in just 30 min and without the need for a thermal cycler. The method developed in this study is simple, rapid, and effective for on-site testing of Cyanobacteria, which may become a routine measurement in efforts to detect and treat harmful algal blooms.
β-Adrenergic Over-Stimulation and Cardio-Myocyte Apoptosis: Two Receptors, One Organelle, Two Fates?
Authors: Branco Ana F. , Moreira Ana C. , Cunha-Oliveira Teresa , Couto Renata , Sardao Vilma A. , Rizvanov Albert A. , Palotas Andras , Oliveira Paulo J.
Published: October 2018

Neuro-hormonal regulation of cardiac function via cathecol-amines results in increased heart rate and contractility. A persistent adrenergic tone, however, is an insult to the heart, affecting its regular homeostasis, altering morphology and gene expression patterns, as well as inducing apoptosis of cardio-myocytes. At the same time as being the main oxygen consumers, mitochondria are also key to the energy production required for the heart to maintain its vital functions and to integrate a series of signaling pathways that define the life and death of the cell. As α-adrenergic receptors (α-AR) orchestrate multiple biochemical events that can either trigger or inhibit cell death, mitochondria can act as a referee in the entire process. In fact, α-AR subtypes α1 and α2 activate various down-stream pathways which differently modulate intracellular calcium levels and production of mitochondrial reactive oxygen species (ROS). The delicate balance between an adaptive (cardio-protective) response resulting in increased contractility and activation of survival pathways, vs. cell death caused by calcium and ROS-induced mitochondrial disruption, along with evidence of their clinical and potential therapeutic translations, are reviewed in this communication.
Pharmacoinformatic Approaches to Design Novel Inhibitors of Protein Kinase B Pathways in Cancer
Authors: Akhtar Noreen , Jabeen Ishrat
Published: October 2018

Background:

Protein kinase B (PKB/Akt) belongs to the AGC superfamily of related serine/
threonine kinases with three structurally homologous mammalian isoforms, Akt1 (PKBα), Akt2
(PKBβ), and Akt3 (PKBγ). Besides sharing a similar structural topology, the difference in their
physiological functions and tissue distribution makes Akt a cardinal node in diverse signaling pathways
involving cell growth, survival, and proliferation. Various immunohistochemical studies have
reported that the constitutive hyperactivation of Akt signaling is responsible for several types of human
cancer, poor prognosis, as well as chemotherapeutic and radiotherapeutic resistance. Thus, inhibition
of Akt activation represents a promising concept to induce cell apoptosis in various cancers
and evade chemotherapeutic resistance. However, development of potent and selective inhibitors of
Akt kinases as suitable antagonists remained gloomy and thus, only handful of compounds were selected
for the clinical investigation but none of them could reach the market for routine clinical usage
to circumvent cell proliferation and resistance to chemotherapeutic agents in cancer. Recent reports
on achieving isoform selectivity by designing inhibitors against PH domain of Akt, together
with availability of crystal structures of the PH domain of Akt1, open the possibility of structurebased
design.

Methods:

In this article, various biological regulatory networks by which Akt and its substrates
regulate cell growth and survival and several SAR and QSAR strategies in combination with molecular
docking studies on selective inhibitors of Akt subtypes have been highlighted to further
probe the selectivity of ligand-Akt subtypes interactions.

Results:

Structure-based drug design studies revealed that the interactions of structurally diverse
compounds with Glu121, Ala123, Asn171, Asp184, Glu228 and Ala230 amino acid residues in CAT
domain and Arg23, Arg25, Lys30, Asn54 and Arg86 amino acid residues within PH domain play an
important role in attaining significant inhibitory potency.

Conclusion:

Isoform selective inhibition of Akt might have clinical significance and thus, should be
taken into account in future investigations. Moreover, an up to date isoform selective chemical data
is required to further validate already reported isoform selective binding hypothesis.
Does Physician Gender Impact the Clinical Productivity and Salaries of Obstetrician-Gynecologists?
Authors: Zhang Cindy Y. , Cole Diane M. , Adams Marci G. , Silver Richard K.
Published: October 2018

Background:

Male medical student interest in the field of obstetrics-gynecology has
significantly decreased in the last three decades. A perceived patient preference for female obstetrician-
gynecologists (Ob-Gyn) and subsequent gender differences in clinical productivity and compensation
may influence this trend.

Objective:

To explore how provider gender affects clinical productivity and salary among obstetrics-
gynecology generalists.

Methods:

An analysis of productivity and salary data for generalist Ob-Gyns employed by an academic
integrated health system was performed. Gross charges, net collections, physician payroll
information, work relative value units (wRVUs), new and existing patient encounter volumes and
clinical full-time equivalent (FTE) status were compared year over year by physician gender using a
repeated measures ANOVA test.

Results:

On average, male providers earned a numerically higher salary in each year studied,
but when the entire timeframe was evaluated, there was no significant difference in salary nor
total productivity between women and men (p=0.19 and 0.15, respectively). There was a gender
difference in how total productivity was achieved, with women seeing twice as many new patients
(p= 0.0025), and men achieving higher average wRVUs per patient encounter (p=0.02).

Conclusions:

There was no significant difference in total productivity and there was no significant
difference in salaries between male and female Ob-Gyns. However, there were differences in the
type of care that contributed to productivity by gender. Female providers saw a higher proportion of
new patient encounters, while male providers accrued a higher wRVU per encounter, likely as a
result of higher procedure volumes. These findings are an encouraging sign that men are not disadvantaged
in terms of productivity in obstetrics-gynecology and that compensation models such as
the one in this system can promote fair payment in mixed-gender physician groups.
Determination of Menbutone Residues in Edible Swine Tissues Based on Solid-Phase Extraction and RP-HPLC
Authors: Zhou Liya , Zhang Ping , Liu Jiangbo , Wu Xiaobo , Luo Lei , Xu Xingran , Luo Yonghuang
Published: October 2018

Background:

Menbutone is widely used as a veterinary choleretic drug in many countries.
There was no publicly available analysis method for the determination of menbutone residues in swine
tissues. It is necessary to establish a method to control the maximum residue limit and ensure food
safety of the public.

Objective:

The aim of this study is to establish an analytical method for the simultaneous determination
of menbutone in muscle, fat, liver and kidney tissues from swine.

Methods:

MBT residue was extracted by acetonitrile from the tissues then purified by using a C18 solid
phase extraction (SPE) cartridge and an alkaline alumina (ALA) SPE cartridge. MBT was detected by
RP-HPLC and separation was achieved on a Shim-pack VP-ODS C18 HPLC column using phosphoric
acid solution (0.5%, v/v) and acetonitrile (45/55, v/v) at a flow rate of 1.0 mL/min. The effluent was
monitored at 235 nm, and the column temperature was set to 30°C.

Results:

MBT eluted at 6.3 min and no interfering peak nearby was observed. This linearity within the
concentration range of 0.02 (LOQ) and 12 µg/mL (r2>0.9999, n=6). The accuracy ranged from 74.07 to
110.83% of the actual values. Intra and inter-day precision were within 15.11%. In the application
study, MBT was detectable in continuously dosing MBT 10 µg/g/day to healthy swine for 7 days.

Conclusion:

The proposed method has specificity, accuracy, and sensitivity, with an excellent linear
relationship that successfully applied to swine tissues.
New Amino-steroid-anthracenone with Biological Activity Against Ischemia-reperfusion Injury in a Wistar Rat Model
Authors: Lauro Figueroa-Valverde , Marcela Rosas-Nexticapa , Virginia Mateu-Armand , Socorro Herrera-Meza , Francisco Díaz-Cedillo , Elizabeth Montano-Tapia , Elodia García-Cervera , Eduardo Pool-Gómez , Lenin Hau-Heredia , Rolando García-Martínez , Maria Lopez-Ramos , Regina Cauich-Carrillo , Perla Parra-Galindo
Published: October 2018

Objective:

The main objective of this study was to evaluate the biological activity of an ASA (Amino-Steroid-Anthracenone derivative) against heart failure caused by the ischemia- reperfusion injury (translated as infarct area).

Methods:

Biological activity exerted by ASA (0.001-100 nM) on infarct area was determined using an ischemia-reperfusion injury model. In addition, to characterize the molecular mechanism involved in the effect exerted by ASA on left ventricular pressure, some drugs such as estrone (0.001-100 nM), tamoxifen (1 nM), butoxamine (1 nM) and ZM-241385 (1 nM) were used.

Results:

The experimental data showed that ASA decreased the infarction area significantly (p= 0.05) compared to estrone. Other results indicated that ASA decreased left ventricular pressure and this effect was inhibited by ZM-241385. In addition, ASA increased cAMP levels in a time-dependent manner compared to control conditions.

Conclusion:

The results showed that ASA decreases ischemia-reperfusion injury (translated as infarct area)viaA2adenosine receptor activation and these phenomena involve changes in cAMP levels.
Correlations between Capsular Changes and ROM Restriction in Frozen Shoulder Evaluated by Plain MRI and MR Arthrography
Authors: Kanazawa Kenji , Hagiwara Yoshihiro , Sekiguchi Takuya , Suzuki Kazuaki , Koide Masashi , Ando Akira , Yabe Yutaka
Published: October 2018

Background:

Evaluation of the Range Of Motion (ROM) is one of the important procedures for shoulder disorders. The purpose of this study was to investigate correlations between capsular changes and ROM restrictions evaluated by both plain magnetic resonance imaging (MRI) and Magnetic Resonance Arthrography (MRA) in the same patients with frozen shoulder.

Methods:

Between March 2015 and June 2016, 24 patients with frozen shoulders (13 male and 11 female patients, mean age 60.5) with severe ROM restriction who underwent both MRI and MRA on the same affected side were evaluated. We evaluated 1) ROM, 2) the coracohumeral ligament (CHL) thickness, 3) the joint capsule thickness in the axillary recess (humeral and glenoid sides), 4) the area of the axillary recess, and 5) the capsular area of the axillary recess.

Results:

Positive correlations were found between the axillary area and forward flexion (FF) (R = 0.43, P = 0.035), lateral elevation (LE) (R = 0.66, P<0.001), external rotation (ER)(R = 0.43, P = 0.035), 90° abduction with external rotation (AER)(R = 0.56, P = 0.004), and hand behind the back (HBB)(R = 0.6, P = 0.002) on MRA. Negative correlations were found between the joint capsule at the glenoid side and ER and HBB in both MRI and MRA.

Conclusion:

The axillary area was significantly correlated with ROM restriction in FF, LE, ER, AER, and HBB on MRA. Thickness of the joint capsule at the glenoid side is an important factor for ROM restriction in frozen shoulder.

Level of Evidence:

Level 3, Study of Diagnostic Test.
Visual Social Media Use Moderates the Relationship between Initial Problematic Internet Use and Later Narcissism
Authors: Reed Phil , Bircek Nazli I. , Osborne Lisa A. , Viganò Caterina , Truzoli Roberto
Published: October 2018

Background:

Little is known about the temporal directionality of relationships between problematic internet use and personality disorders such as narcissism.

Objective:

Although these two constructs are related at a single time, no existent study has determined whether initial problematic internet use is more strongly associated with subsequent narcissism, or vice versa. So, the aim of the research is to verify if problematic internet use predicts the narcissism or vice versa.

Methods:

Seventy-four university student participants were studied over a four-month period, and completed the Narcissism Personality Inventory, and Problematic Internet Use Questionnaire, at baseline and follow-up.

Results:

The results demonstrated a relationship between problematic internet use and narcissism at baseline. Time-lagged correlations demonstrated that problematic internet use at baseline was positively related to narcissism four-months later, but not vice versa for social media users whose use was primarily visual. This relationship did not hold for social media users whose use was primarily verbal.

Conclusion:

These results suggest that problematic internet use may serve to discharge narcissistic personality traits for those who use social media in a visual way, but not for those who do not engage in that form of internet use.
The Challenge of Genome Sequence Assembly
Authors: Collins Andrew
Published: October 2018

Background:

Although whole genome sequencing is enabling numerous advances in many fields achieving complete chromosome-level sequence assemblies for diverse species presents difficulties. The problems in part reflect the limitations of current sequencing technologies. Chromosome assembly from ‘short read’ sequence data is confounded by the presence of repetitive genome regions with numerous similar sequence tracts which cannot be accurately positioned in the assembled sequence. Longer sequence reads often have higher error rates and may still be too short to span the larger gaps between contigs.

Objective:

Given the emergence of exciting new applications using sequencing technology, such as the Earth BioGenome Project, it is necessary to further develop and apply a range of strategies to achieve robust chromosome-level sequence assembly. Reviewed here are a range of methods to enhance assembly which include the use of cross-species synteny to understand relationships between sequence contigs, the development of independent genetic and/or physical scaffold maps as frameworks for assembly (for example, radiation hybrid, optical motif and chromatin interaction maps) and the use of patterns of linkage disequilibrium to help position, orient and locate contigs.

Results and Conclusion:

A range of methods exist which might be further developed to facilitate cost-effective large-scale sequence assembly for diverse species. A combination of strategies is required to best assemble sequence data into chromosome-level assemblies. There are a number of routes towards the development of maps which span chromosomes (including physical, genetic and linkage disequilibrium maps) and construction of these whole chromosome maps greatly facilitates the ordering and orientation of sequence contigs.
Nocturnal Blood Pressure Decrease in Hypertensive Patients and Normotensives- Association with Obstructive Sleep Apnoea and Renal Function
Authors: Hornstrup Bodil G. , Rosenbaek Jeppe B. , Hoffmann-Petersen Nikolai , Gjoerup Pia H. , Wessels Jost , Lauridsen Thomas G. , Pedersen Erling B. , Bech Jesper N.
Published: October 2018

Background:

Blunted nocturnal Blood Pressure (BP) decrease is seen in patients with hypertension and obstructive sleep apnoea (OSA). The influence of OSA and renal function on nocturnal BP decrease is not fully clarified.

Objective:

In this case control study of hypertensive patients and healthy controls, we aimed to analyse the relationship between nocturnal BP decrease on one hand and presence of OSA, renal function, plasma levels of syndecan and vasoactive hormones, and urinary sodium excretion on the other.

Methods:

In 75 hypertensive patients and 56 controls, we performed brachial and central 24h ambulatory BP measurement and cardio respiratory monitoring. We measured syndecan, renin, angiotensinII, aldosterone, vasopressin, and brain natriuretic peptide in plasma and 24h urinary excretion of sodium, aquaporin2, and a component of the epithelial sodium channel (u-ENaCγ).

Results:

Nocturnal BP decrease was lower in patients than controls, brachial (13% versus 17%,p=0.001) and central (8% versus 10%,p=0.019). Moderate-to-severe OSA was present in 13% of patients, 2% of controls (p<0.005). Neither brachial nor central nocturnal BP decrease was associated with OSA, renal function, plasma levels of vasoactive hormones, syndecan-1, or urinary sodium excretion. P-syndecan and u-ENaCɣ were higher in patients than controls.

Conclusion:

Both brachial and central nocturnal BP decrease was lower in patients than in controls. Neither brachial nor central nocturnal BP decrease was associated with the presence of OSA, renal function, or plasma levels of vasoactive hormones. Increased syndecan in plasma in hypertensive patients suggested damage to the endothelial glycocalyx.
Design and Implementation of a Real-time Publish/Subscribe Middleware
Authors: Zheng Pengyi
Published: October 2018

Background:

Middleware has been widely adopted as an efficient approach to facilitate the development process of large-scale distributed systems. Although this approach can achieve simplified system design and reduced time consumption, it has a strong demand for real-time task processing and data transmitting. Traditional middleware, which lacks the real-time performance guarantee mechanism, cannot be adopted by the distributed systems with strict time restrictions.

Methods:

In order to meet the real-time requirements of distributed systems, the functional requirements of middleware are studied, and a real-time publish/subscribe middleware is designed and implemented in this paper. A hierarchical design is adopted to build this middleware from a model layer, a communication layer and a support layer. The middleware has the data synchronization on distributed objects, Ethernet-based publish/subscribe mechanism and the real-time performance guarantee mechanism.

Results:

Experiments show that the proposed middleware satisfies the needs of distributed applications, and ensures that the end-to-end data communication delay is less than 1 millisecond, which meets the real-time requirements of data transmission in distributed systems.

Conclusion:

In this paper, we design and implement a real-time middleware based on the publish/ subscribe mechanism.