bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased ROP by 18% in Norway and in Other Applications through Optimizing Cutter Geometry from Laboratory Tests, Numerical Models and Field Tests
Authors: Izbinski Konrad , Cardoe Jennifer , Bomidi John 
Published: February 2019

Abstract
The oil-and-gas drilling industry has been utilizing modified PDC cutter geometry for improving performance. One of the first reinforcements of beliefs in positive effects of edge geometry changes was in report by Lin et al. in 1992 from conducting laboratory experiments on cutters. Currently, certain geometries are being favored based on limited testing and analysis of the design space. The detailed effect of geometry on attributes such as strength, cutting, wear and the tie to performance has not been fully understood.
This paper reports results of laboratory studies, numerical models, and field runs towards building such understanding. Single cutter edge-loading tests, pressurized cutting and wear tests were carried out alongside full-scale PDC bit tests and field runs. Improved analysis techniques were utilized to extract meaningful information from the tests. Numerical models were used to exploit the design space for the geometry.
The optimized geometry was selected with greater than 50% strength improvement as indicated by the numerical model. For the optimized geometry, pressurized single cutter lab tests indicated greater than 25% performance improvement in several aspects. Of the field runs in various applications, the largest dataset was in Norway with an ROP increase of 18% among greater than 187 bits run. This study is part of a holistic approach to understanding the thermo-mechanical behavior of PDC cutter drilling as it applies to improving design as demonstrated and drilling practices.
The improved cutter geometry has helped customers drill further and faster, which has helped reduce the cost of drilling. There are still improvements that can be made to cutter geometries that will push performance even further. The methods discussed in this paper will help expedite the learning process and help build better insights.
Field-Verified Modeling Compares Weight Transfer Methods in Horizontal Wells
Authors: Jesus Garcia , Sarah Banks , John McCormick , Robert Brosig 
Published: February 2019

Abstract
This paper describes a field-verified model that predicts weight transfer effects for three common techniques—axial vibration tools (AVTs), non-rotating protectors (NRPs) and pipe rocking from the surface (top drive oscillations). Friction has a large effect on drilling horizontal wells, especially while slide drilling. This paper discusses the use of as-drilled well data to assess the individual and collective effects of these drag-reduction methods. Prior to drilling the wells, these methods can be used in torque and drag engineering software models to more accurately predict challenges and feasible lateral lengths. Using these modeling techniques, it is demonstrated through several case histories that operators can effectively plan horizontal wells with longer lateral lengths; in other words, it can be analyzed if drilling the well is technically possible and economically feasible.
Experimental Studies on Cement Sheath Integrity During Pressure Cycling
Authors: Vrålstad Torbjørn , Skorpa Ragnhild , Werner Benjamin 
Published: February 2019

Abstract
Cement sheaths are among the most important barrier elements in petroleum wells. However, the cement may lose its integrity due to repeated pressure variations in the wellbore, such as during pressure tests and fluid injections. Typical cement sheaths failure mechanisms are formation of radial cracks and microannuli, and such potential leak paths may lead to loss of zonal isolation and pressure build-up in the annulus. To prevent such barrier failures, it is important to study and understand cement sheath failure mechanisms.
This paper describes a series of experiments where we have used a tailor-built laboratory set-up to study cement sheath integrity during pressure cycling, where the set-up consists of down-scaled samples of rock, cement and casing. Cement integrity before and during casing pressurization is characterized by X-ray computed tomography (CT), which provides 3D visualization of radial cracks formed inside the cement and rock. We have studied how contextual well conditions, such as rock stiffness, casing stand-off and presence of mudfilm, influence cement sheath integrity.
The results confirm that the rock stiffness and casing stand-off determine how much casing pressure the cement can withstand before radial cracks are formed in the cement sheath, where the rock stiffness is significantly more important than casing stand-off. Furthermore, it is seen that the radial cracks in the cement sheath continue into the rock as well. However, when a thin mudfilm is present at the rock surface, the cracks stop at the cement-rock interface, and the cement sheath withstands less pressure before failure. The bonding towards the rock is thus of importance.
Understanding Hydraulics and Friction Loss in Extremely Narrow Annuli for Deepwater MPD Operations
Authors: Patil Harshad , Deshpande Kedar , Smelker Keith , Naphade Pravin 
Published: February 2019

Abstract
Estimating hydraulic frictional loss in narrow annuli is challenging, especially for deepwater offshore wells with extremely narrow drilling margins. The challenge arises from annuli that are formed by big bore packers like Gravel Pack Packers, where the annular clearance isextremely small. In cases where open hole completions are run with MPD (Managed Pressure Drilling), the well typically would be displaced to heavier weight fluids before the packer is set and MPD is isolated. This paper illustrates the complications and limitations for estimating friction loss due to the narrow annuli when using drilling hydraulic programs.
Accurate estimation of hydraulic friction loss is extremely essential when using MPD system to maintain BHP(bottomhole pressure) while drilling, tripping, cementing etc. While drilling, the hydraulic models would typically be calibrated to PWD (pressure while drilling) in the BHA (bottomhole assembly), but when running liners, casings or completion systems, the lack of PWD complicates hydraulics and friction loss estimations. This phenomenon is accentuated when displacing the well from lighter drilling fluids to heaviercompletion fluids,especially when the completion fluid reaches the narrow annuli and displays sudden increase in frictional loss value due to the hydraulic model limitations.
This paper focuses on the limitations of estimating the frictional loss in narrow annulus created by the Gravel Pack Packers,when predicted using the drillinghydraulicmodels, and proposes a solution for mitigating such anomalies in calculations. To assess the sudden changes in the pressure loss estimations, the paper further utilizes CFD (Computational Fluid Dynamics) and the frictional loss estimations in these narrow annuli. As an outcome of the study, the paper proposes unique solutions to estimate the frictional pressure loss due to narrow annuli.
Effectiveness of rituximab in neuromyelitis optica: A meta-analysis
Authors: Gao Fulin , Chai Bingyan , Gu Cheng , Wu Ruipeng , Dong Tong , Yao Yuping , Zhang Yi 
Published: February 2019

Abstract
Background: Neuromyelitis optica (NMO) is a severe inflammatory autoimmune disorder of the central nervous system and often results in paralysis or blindness. Rituximab (RTX) is a mouse–human chimeric monoclonal antibody specific for the CD20 antigen on B lymphocytes and used to treat many autoimmune diseases. Disability and relapses were measured using the Expanded Disability Status Scale (EDSS) and annualized relapse rate (ARR) ratio to evaluate the effectiveness of RTX. This review performed a meta-analysis of the efficacy of RTX in NMO.
Methods: We searched through the databases of PubMed, Embase, and Cochrane Library. We compiled 26 studies, in which 18 used ARR ratio, 22 used EDSS score, and 14 used both variables. Differences in the ARR ratio and EDSS score before and after RTX therapy were used as the main efficacy measures. Publication bias was evaluated after the consistency test, and a sensitivity analysis was performed with mean difference (MD) of the efficacy of RTX.
Results: A meta-analysis of 26 studies with 577 participants was conducted. Antibodies against aquaporin-4 autoantibody were recorded in 435 of 577 (75.39%) patients with NMO. RTX therapy resulted in a mean (WMD) −1.56 (95% CI, −1.82 to −1.29) reduction in the mean ARR ratio and a mean (WMD) −1.16 (95% CI, −1.36 to −0.96) reduction in the mean EDSS score. A total of 330 of 528 patients (62.9%) reached the relapse-free state. A total of 95 of 577 (16.46%) patients had adverse reactions.
Conclusions: RTX has acceptable tolerance, reduces the relapse frequency, and improves disability in most patients with NMO. Future studies should focus on reducing the health-care costs, improving the functional outcomes, and reducing the adverse effects associated with RTX treatment.
Autophagy protects against retinal cell death in mouse model of cytomegalovirus retinitis
Authors: Mo Juan , Atherton Sally S , Wang Liya , Liu Susu 
Published: February 2019

Abstract
Background: Extensive death of uninfected bystander neuronal cells is an important component of the pathogenesis of cytomegalovirus retinitis (CMV). Our previous results have shown that there is a functional relationship between autophagy and apoptosis during MCMV infection of retinal pigment epithelium (RPE). The purpose of this study was to determine whether autophagy plays a significant role in the death of retinal cells during MCMV retinitis.
Methods: The retinas of adult BALB/c mice were infected with MCMV via supraciliary injection. Rapamycin was injected to MCMV-infected BALB/c mice intraperitoneally. Immunohistochemistry and western blot were performed to observe the spread pattern of virus in retinas and the levels of targeted proteins. Plaque assay was performed to determine the virus titer in different groups. Nestin-cre; Atg5flox/flox mice were genotyped and infected with MCMV. Immunohistochemistry was performed to observe the type of virus-infected cells and apoptosis in retinas during MCMV retinitis.
Results: In MCMV mouse model, MCMV infection in our nuclear layer (ONL) and inner nuclear layer (INL) in the retinas caused cleaved caspase 3 positive apoptosis, which is not co-localized with early antigen (EA) positive virus infected cells in rapamycin treated group. Rapamycin treatment increased the levels of LC3B-II by inhibiting mTOR and decreased the levels of cleaved caspase-3 during MCMV retinitis. However, virus propagation was not affected by rapamycin. In Nestin-cre; Atg5flox/flox mice, RPE and glial cells were the main targets of viral infection, and number of EA positive retinal cells and TUNEL positive retinal cells was significantly increased compared to Nestin-cre; Atg5flox/+ mice though there was no difference of virus propagation between Nestin-cre; Atg5flox/flox mice and Nestin-cre; Atg5flox/+ mice.
Conclusions: Autophagy protects retinal cells from MCMV infection induced apoptosis through mTOR-mediated signaling pathway.
Cryptosporidium in the Philippines
Authors: Labana Ryan Vidal 
Published: February 2019

This short review provides an overview regarding the research findings on the occurrence of Cryptosporidium in the Philippines. It seeks to set conjecture about its possible role on the increasing waterborne disease incidences in the country. Intensive search of journal articles was done among major databases, online. The first report of Cryptosporidium infection in the country was in 1985. Past more than 30 years, Cryptosporidium is not yet well-understood in the Philippines, but an increasing research interest has been observed among Filipinos in the past few years. Recently, waterborne transmission of the infection appeared in the studies to be more potent than zoonotic and person-to-person transmissions. An improvement on the detection methods was also observed, giving an improved knowledge on the molecular diversity of Cryptosporidium in the country. Despite these improvements, the paucity of the data regarding the impact of Cryptosporidium to the public health in the Philippines is still apparent. One Health approach is recommended to fully understand the interconnections between human, animal, and environment as reservoirs of the infective stage of the parasite. Dedication of the researchers in understanding their geographical distribution, molecular diversity, and environmental and climatic behaviour will eventually uncover the public health implications of Cryptosporidium in the country.
Comparative Study of the in vitro Antioxidant Properties of Methanolic Extracts of Chromolaena odorata and Ageratum conyzoides used in Wound Healing
Authors: Oso Babatunde , Abey Nosarieme , Oyeleke Oyedotun , Olowookere Boyede 
Published: February 2019

This study sought to evaluate the potential antioxidative potencies of Chromolaena odorata and Ageratum conyzoides, commonly used herbs in Nigeria for wound first aid and healing. The antioxidant potentials were evaluated by measuring their abilities to scavenge radicals, reduce oxidised iron and quench the formation of lipid peroxides. The findings showed that the extract of Ageratum conyzoides exhibited significantly higher (p<0.05) antioxidant potential than the extract of Chromolaena odorata. The study therefore suggests that Ageratum conyzoides has higher potential for therapeutic value than Chromolaena odorata in terms of antioxidant potential.
Adverse Effects of Mineralocorticoid Receptor Antagonist Administration
Authors: Kallistratos Manolis S. , Pittaras Andreas , Theodoulidis Iakovos , Grassos Charris , Poulimenos Leonidas E. , Manolis Athanasios J. 
Published: February 2019

Background:
Mineralocorticoid receptor antagonists consist of a class of drugs with pleiotropic beneficial
effects in several cardiovascular diseases. However, physicians frequently overlook their use due to the
adverse effects of such agents.

Objectives:
To determine the adverse effects of mineralocorticoid receptor antagonists and to suggest clinically
meaningful options. We present data on the two most administered agents of this class: spironolactone and eplerenone.

Method:
We conducted an in-depth review of the existing international literature to draft a mini review about the
mineralocorticoid receptor antagonists-related side effects.

Result:
Mineralocorticoid receptor antagonists are associated with increased risk of hyperkalemia and acute deterioration
of renal function. Of note, these adverse effects are dose-dependent, more common during the initial
period of treatment, and are usually reversed after the withdrawal of therapy. Sex-related adverse events are noted
mainly in spironolactone while switching to eplerenone could attenuate those.

Conclusion:
Mineralocorticoid receptor antagonists therapy is significantly limited due to their side effects. The
development of novel non-steroidal mineralocorticoid receptor antagonists could substantially widen the use of
such agents.
10-Phenyltriazoyl Artemisinin is a Novel P-glycoprotein Inhibitor that Suppresses the Overexpression and Function of P-glycoprotein
Authors: Lee Dong-Hwan , Hasanuzzaman Md. , Kwon Daeho , Choi Hye-Young , Kim So Myoung , Kim Dong Jin , Kang Dong Ju , Hwang Tae-Ho , Kim Hyung-Hoi , Shin Ho Jung , Shin Jae-Gook , Oh Sangtae , Lee Seokjoon , Kim So Won 
Published: February 2019

Background:
The effect of drugs on ATP-binding cassette transporters, especially permeabilityglycoprotein
(P-gp), is an important consideration during new anti-cancer drug development.

Objective:
In this context, the effects of a newly synthesized artemisinin derivative, 10-(4-phenyl-1H-1,2,3-
triazol)-artemisinin (5a), were evaluated on P-gp expression and function.

Methods:
Reverse transcript polymerase chain reaction and immunoblotting techniques were used to determine
the effect of 5a on P-gp expression in LS174T cells. In addition, the ability of 5a to work as either a substrate or
an inhibitor of P-gp was investigated through different methods.

Results:
The results revealed that 5a acts as a novel P-gp inhibitor that dually suppresses the overexpression and
function of P-glycoprotein. Co-treatment of LS174T cell line, human colon adenocarcinoma cell line, with 5a and
paclitaxel recovered the anticancer effect of paclitaxel by controlling the acquired drug resistance pathway. The
overexpression of P-gp induced by rifampin and paclitaxel in a colorectal cell line was suppressed by 5a which
could be a novel inhibitory substrate inhibiting the transport of paclitaxel by P-gp.

Conclusion:
The results revealed that 5a can be classified as a type B P-gp inhibitor (with both substrate and
inhibitor activities) with an additional function of suppressing P-gp overexpression. The results might be clinically
useful in the development of anticancer drugs against cancers with multidrug resistance.
Hematological Parameters as Prognostic Biomarkers in Patients with Cardiovascular Diseases
Authors: Monteiro Júnior José Gildo de Moura , de Oliveira Cipriano Torres Dilênia , Filho Dário Celestino Sobral 
Published: February 2019

:Cardiovascular diseases are the major causes of preventable health loss from disease in the world and lead to functional disturbances including hematological parameters. The inflammatory and hypoxemic nature of cardiovascular diseases causes a stimulus in the bone marrow and, depending on the intensity of this stimulus, there is a release of immature cells or increase of other cells in the bloodstream. Therefore, their presence in the circulation is an important variable used to diagnose, stratify and predict diseases.:In the last five decades, with the advent of automated counting of immature cells in the peripheral blood, the hemogram was transformed into a clinical tool of great importance in hospital surveillance for demonstrating this daily variability in the hematopoietic response according to the existing injury in the patient. Studies have shown that the presence of nucleated red blood cells and increases in mean platelet volume, immature granulocytes and neutrophil to lymphocyte ratio in the systemic circulation are independent prognostic biomarkers.:This review article has as main objective to demonstrate the association of these hematological parameters to cardiovascular diseases, emphasizing their importance in clinical decision making.
Gray Scale Histogram Analysis of Carpal Tunnel Syndrome with Ultrasonography
Authors: Umay Sermin Tok , Analan Pinar Doruk 
Published: February 2019

Purpose: In this study, we aim to evaluate the diagnostic value of echogenicity ratio
with histogram analyses.
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Materials & Methods: This retrospective study was performed on 22 patients with 44 hands. The
patients had clinical presentations consistent with CTS, in at one hand. Quantitative ultrasound
scanning and image capture were completed using a diagnostic sonography machine. For gray
scale histogram analysis, image J software was used.

Results:
Mean flexor tendons histogram analysis echogenicity/Mean median nerve histogram
analysis echogenicity was significantly high for 1,7 cutoff value.

Conclusion:
Mean FTE/MNE ratio may be a useful sonographic parameter for CTS.
Elemental Impurities Determination by ICP-AES / ICP-MS: A review of Theory, Interpretation of Concentration Limits, Analytical Method Development Challenges and Validation Criterion for Pharmaceutical Dosage Forms
Authors: Katakam Lakshmi Narasimha Rao , Aboul-Enein Hassan Y. 
Published: February 2019

:
Inductively coupled plasma is a new technique employed for the determination of elemental
impurities in pharmaceutical ingredients viz. raw materials, drug substance, and drug product dosage
forms. New US FDA and EMA regulations came into effect from Jan 2018 as industry standard requirements
for the determination of inorganic elemental impurities using ICP-OES/AES or ICP-MS
analytical techniques. The method development was optimized for the determination of the listed elements
as per USP <232> <233> elemental impurities-limits and procedures. It also demonstrates the
validation of the method and verification/transfer of the method which also provides an insight into the
presence of free elemental atomics of the gaseous form of the sample (drug substance, drug product or
excipients), thus helping in determining the concentration of the element of interest. Also, the regulatory
guidance is very general and does not explain the sample specifications for the individual element concentrations.
Thus, this review emphasizes the routine instrumental maintenance, analytical method development
challenges, trends in the performance of analytical method validation and verification/
transfer activities of the various pharmaceutical dosage forms outlined with acceptance criterion.
Development of HPLC Method for the Purity Test by Design of Experiments and Determination of Activation Energy of Hydrolytic Degradation Reactions of Sofosbuvir
Authors: Petřík Jakub , Heřt Jakub , Řezanka Pavel , Vymyslický Filip , Douša Michal 
Published: February 2019

Background:
The present study was focused on the development of HPLC method for purity
testing of sofosbuvir by the Design of Experiments and determination of the activation energy of hydrolytic
degradation reactions of sofosbuvir using HPLC based on the kinetics of sofosbuvir degradation.

Methods:
Following four factors for the Design of Experiments were selected, stationary phase, an
organic modifier of the mobile phase, column temperature and pH of the mobile phase. These factors
were examined in two or three level experimental design using Modde 11.0 (Umetrics) software. The
chromatographic parameters like resolution, USP tailing and discrimination factor were calculated and
analysed by partial least squares. The chromatography was performed based on Design of Experiments
results with the mobile phase containing ammonium phosphate buffer pH 2.5 and methanol as an organic
modifier. Separation was achieved using gradient elution on XBridge BEH C8 at 50 °C and a
flow rate of 0.8 mL/min. UV detection was performed at 220 nm. The activation energy of hydrolytic
degradation reactions of sofosbuvir was evaluated using two different calculation methods. The first
method is based on the slope of dependence of natural logarithm of the rate constant on inverted thermodynamic
temperature and the second approach is the isoconversional method.

Results and Conclusion:
Calculated activation energies were 77.9 ± 1.1 kJ/mol for the first method
and 79.5 ± 3.2 kJ/mol for the isoconversional method. The results can be considered to be identical,
therefore both calculation methods are suitable for the determination of the activation energy of degradation
reactions.