bluuebunny/crossref_metadata_2025 huggingface dataset:
Hole Cleaning in Horizontal Wells Using Viscoelastic Fluids-An Experimental Study of Drilling Fluid Properties on the Bed Erosion Dynamics
Authors: Hirpa Mehmet Meric , Kuru Ergun
Published: February 2020

An experimental study was conducted to investigate how the fluid elastic properties would influence, the frictional pressure drops, the critical velocity for the onset of the bed erosion, and turbulent flow characteristics (i.e. Reynolds stress, axial and radial turbulence intensity profiles) of the polymer fluid flow over the stationary sand bed deposited in horizontal pipeline.

A 9m long horizontal flow loop (pipe ID: 95 mm) equipped with particle image velocimetry (PIV) system was used for the experiments. The polymer fluids, which had almost identical shear viscosity characteristics while showing significantly different elastic properties (quantified in terms of relaxation time) were used together with 30/50 mesh size industrial sands in the bed erosion experiments. Polymer fluids were prepared by mixing three different grades (i.e. 5×105, 8×106, 20×106 g/gmol) of partially hydrolysed polyacrylamide (HPAM) polymer.

After determining the critical velocities for the onset of the bed erosion using both fluids, the frictional pressure drops at critical and several subcritical velocities were recorded for both fluids. Additionally, instantaneous near bed velocities were measured by using the PIV technique. Further analyses of the velocity data obtained by PIV technique, we were able to determine the turbulent flow features such as Reynolds stress, axial and radial turbulence intensity profiles.

Results showed that the fluid elasticity affects the bed erosion dynamics significantly. Generally, frictional pressure drops, and critical velocities for the bed erosion all increased with the increasing fluid elasticity.

This paper presents results of an experimental study where the PIV technique was used to investigate the bed erosion dynamics due to the turbulent flow of elastic polymer fluid over the stationary sand beds. Fluids were prepared using a special technique, which allowed us to alter the fluid elastic properties while keeping the shear viscosity constant. By conducting experiments under controlled conditions, for the first time in drilling literature, we were able to quantify the individual effect of the fluid elasticity (independent from shear viscosity) on the critical flow rate for bed erosion and the turbulent flow characteristics of polymer fluid flow over the stationary sand bed.
Time, Pressure and Temperature Dependent Rheological Properties of Drilling Fluids and their Automatic Measurements
Authors: Cayeux Eric
Published: February 2020

The rheological properties of drilling fluids are very important for the precise estimation of the frictional pressure losses during drilling operations. The first experiences of inline rheometers at the rig site have shown that the rheological properties vary substantially with time. Yet, most inline instruments measure these properties at only one condition of pressure and temperature. This paper describes how the pressure, temperature and shear history dependence of the rheological behavior can be measured continuously.

The measurement of rheological properties of drilling fluids is complexified by the fact that they are thixotropic, i.e. the rheological properties depend on the shear history applied to the fluid. For an inline rheometer, any change of pipe diameter, or the introduction of a fluid sample in a cavity, introduces a shear variation. Therefore, inline rheometers need to account for the side effects of thixotropy on the results. Instead of trying to reduce the thixotropic effects, the new rheometer focuses on measuring these thixotropic properties so that steady state values can be extrapolated.

Most published studies of thixotropic fluids indicate that thixotropic fluids need a long recovery period to reach steady state conditions after a change from high to low shear rates, but that a change of shear rates from low to high is recovered very quickly. However, the thixotropic behavior of drilling fluids differs from other thixotropic fluids, as it needs considerable time to recover both from high to low and low to high shear step changes. The measured time constants for these effects are long (several minutes), therefore making it difficult to design an inline rheometer that eliminates thixotropic effects.

Furthermore, gel duration has not only an impact on the stress overshoot when an increasing shear strain is applied to a gelled fluid, it also impacts the rheological behavior for several minutes after viscous flow is established. The new inline rheometer is designed to exhibit explicitly these effects in order to measure directly the gel strength as a function of gel duration and the time constants that characterize the remnant effects of gelling on viscous properties.

The impact of the shear history on rheological measurements is important to obtain precise estimations of the rheological properties of drilling fluids. With an automatic inline rheometer that can provide time, pressure and temperature rheological properties, it is then possible to obtain more precise results from advanced drilling hydraulic models running in real-time, with less manual configuration efforts.
Dynamic RT Modelling and 3D Visualization of Critical Safety Parameters on Drillfloor During Drilling, Running Liners & Screens and Cementing of Challenging Offshore Wells
Authors: Rommetveit Rolv , Nabavi Josef , Ødegård Sven Inge , Gholami Mayani Maryam , Syltøy Svein , Lauve Marit , Jordal Ole Henrik , Kolltveit Tore
Published: February 2020

As part of the digitalization and utilization of Automated Monitoring during drilling operations, real-time dynamic modelling of downhole combined with 3D dynamic visualization have been implemented on the drillfloor in offshore rigs. The objectives have been to give the driller instant feedback on the ECD and other effects of the operations and allow for a safer and smoother operation within the limits of the well.

The basic elements of this technology are

A digital twin of the well with all relevant data and properties included. A set of integrated transient models (hydraulics, surge & swab, displacement, mechanical friction). These models are driven by the RT data from operation and compute critical safety parameters which are presented for the driller. A diagnostic module analyzing differences between measured and modelled parameters and trends. A 3D Virtual Well which visualize the downhole well, the risk matrix, the diagnostics and messages as well as the ECDs at critical positions in the well.

The 3D System has been utilized during drilling of several very challenging ERD and Multi-Lateral wells on two platforms in the North Sea. The system was also used during tripping in and out of the well, and during running of casing and liners. During these operations there is no PWD data available, and the modelled ECD values proved especially useful. The Trip-risk log from the Geologist was included in the 3D View during these operations, and the Driller could then see on the 3D when a risk was coming up.

This paper will present the experiences from using the dynamic 3D & modelling system on several wells. The feedback from the Drillers and Drilling manager have been positive, and the results are very promising.
Automated Sliding: Efficiencies Achieved in the Next Stage of Drilling Automation
Authors: Hausher Aaron , Kern Sarah , Chmela William , Cantwell Jeremy , Mims Kevin
Published: February 2020

In the current drilling climate, efficiency is king: do more with less. This motivation drives disruptive technological innovations in automation of the drilling process. Drilling automation can contribute to this efficiency specifically by automating the sliding process. The paper discusses a case history involving one operator's deployment and results of an automated sliding system.

The goal for automating the sliding process was to reduce personnel on location, drive consistency, increase wellbore quality, and shift the focus from an ROP-focused mindset. The operator had initially used bit guidance software for approximately one year, which was a significant backbone component of the automated sliding system. The automated sliding software was installed and tested on the rig, and then deployed on a six-well pad for initial observation and analysis.

After deployment, the automated sliding system successfully completed slides in all four surface sections on the pad. The first complete well on the pad, drilled to total depth, successfully completed slides in the vertical, curve and lateral sections. The rate of automated sliding exceeded initial goals, and the rig proceeded to drill several more wells at near-100% utilization rates. The automated decision-making system compiled detailed drilling set points and specifications used to form the most consistent and efficient method to drill the well, formation by formation. The total number of third party directional drillers was reduced, increasing overall safety and lowering costs.

Automating the sliding process, with this degree of accuracy and lack of human intervention through automated decision-making, represents a significant step change in the drilling industry milestones on the road to full automation. Best practices regarding adoption and deployment of automation technology will contribute to ensuring success in the ever-increasing field of drilling automation.
Revisiting the Classical Problem of Transient Temperature Prediction in Complex Deepwater Wellbores with a New Semi-Analytical Approach
Authors: Chandrasekhar Sharat
Published: February 2020

Transient temperatures in arbitrarily complex wellbores are preicted by using a semi-analytical approach based on the Laplace Transformation of the set of governing equations from the flowing stream across the multiple layers of the wellbore and out into the formation. We investigate flowing and shut-in (static) scenarios consider sequentially linked thermal operations. The methodology can be applied to subsea deviated wellbores with variable lithology and geothermal gradients, and without invoking any of the several simplifying that have characterized previous studies.

Wellbore temperatures are extracted from the solutions of the coupled heat transfer equations in the wellbore and the formation by inverting a set of Laplace transforms with sequential updating to capture the temporal variation of natural convection in fluid-filled annuli. Natural convection in these annuli and in the static fluid conduit during a shut-in period is explicitly modeled by taking considering the non-Newtonian behaviour of typical annular fluids. The transient heat transfer in the formation is determined by a time dependent temperature boundary condition at the wellbore-formation interface, and a zero heat flux boundary condition at a farfield location that is spatially consistent with the duration of the specified thermal operation. The former boundary condition is analytically treated by the Duhamel superposition principle. Having obtained the analytical solution to the formation heat transfer, the efficiency of the Gaver-Stehfest function sampling algorithm to invert the Laplace transforms is demonstrated.

The methodology is demonsrated by applying it to a complex deepwater 30,000 ft MD deviated well in the Gulf of Mexico. The S-shaped trajectory traverses a thick salt layer with variable geothermal gradients. We show that in comparsion to finite-difference methods, the semi-analytical approach (using Laplace Transforms) can use much larger time sub-intervals to provide a given level numerical accuracy. This aspect of numerical efficiency arises as a consequence of the inherent numerical stability of the approach. This results in a reduction in computational time by several orders of magnitude without a corresponding sacrifice in accuracy. Production, Injection and Shut-In operations are modeled. The advantages of the present approach are more pronounced for short term scenarios such as drill-stem tests where the transients have not yet decayed to a steady state. Even though complex subsea wellbores are the focus of the approach, the formulation can be applied to an arbitrary wellbore configuration including land-based and platform wells.
Using MPD and Conventional Methods to Address a Well Control Event in a Deepwater Exploration Well
Authors: Moghazy Sharief , Van Noort Roger , Kozlov Anton , Haq Inam , Silva Thiago , Hester Clayton , Gabaldon Oscar
Published: February 2020

This paper presents a case where Managed Pressure Drilling (MPD) was used to drill a challenging exploration well through a pore pressure ramp and to address a well control event in conjunction with conventional methods when an influx was encountered

The MPD system was used to drill using primary and secondary indicators, such as background gas, cuttings shape, and changes in ROP to determine if onset of the pore pressure ramp was imminent. The MPD system provided a means to measure the flow in versus the flow out of the well and chokes to add surface back-pressure (SBP) to adjust the bottomhole pressure. The MPD operators monitored the trends as drilling continued and reacted if any indications of a pore pressure ramp were experienced.

The pressure ramp was encountered, and the flow out exceeded the flow in. The driller applied more surface back pressure to control the influx and reduce the influx size. The well could not be controlled within the allowable back pressure limitations as outlined by the MPD Operations Matrix, so the well was shut in on the Subsea Blow-Out Preventer (SSBOP). The well was controlled with conventional well control methods, using the Driller's Method. The mud weight was increased to the extent that it was not enough to hydrostatically kill the well, but sufficient to allow operations to resume within a new MPD Operational Matrix adding back pressure to keep BHP overbalanced to the formation. This application of MPD reduced the impact of the influx event and allowed the rig to safely continue drilling and meet the well objectives without losing the hole section.
World's First Cement Replacement with Metal Expandable Annular Sealing on a Highly Laminated, Deep Water Injector in West Africa
Authors: Hallaire Maximilien , Bagal Joseph , Hazel Paul , Vasques Ricardo , Prasad Bala , Onadeko Gbenga
Published: February 2020

The field is developed within a complex environment, located within deep water and operated from a TLP / FPU facility. The wells are targeting 2 reservoir structures at 4000m TVD, requiring long and deviated wells to achieve field coverage. The reservoir is highly laminated with complex lithology requiring approximately 3:2 producers to injectors. Existing lower completion design utilizes a combination of cement and metal expandable annular sealing technology, to ensure zonal isolation and annular sealing (liner to formation) during the high-pressure stimulation and to ensure sealing over the life of well for zonal water shut off requirements. The oil reservoir is located approximately 20m TVD above a highly-pressurized water zone, making the oil producers challenging to drill and cement. Existing wells were drilled with a long shoe track into the water zone creating a possible flow path for the water to migrate along the annulus if annular sealing is not achieved.

As part of a global efficiency drive, the operator issued a challenge to the service industry, to reduce the DRILLEX of these wells whilst maintaining the beneficial productivity index that has been achieved within the highly heterogeneous carbonate field, being prone to asphaltenes. One of the implemented solutions was cement replacement across the reservoir. The benefits of this solution impacted several areas; it removed the need for drilling 100m of rat hole, under reaming of the 6 ½″ hole, clean out of the 6 ½″ hole and most significantly, eliminating cementing of the 4 ½″ liner. This led to a substantial cost savings and reduction of rig time and because it simplified the operations, the operational risks were also reduced.

The scope of work to deliver the solution included the design, development and qualification of the metal expandable annular sealing system. The project included validation of both sealing and anchoring of the cement-less liner within the open hole. The solution was also required to maintain the synergies with the perforation, acid stimulation and diversion techniques to achieve the required Productivity Index (PI) and Injectivity Index (II). The first deployment was within a well that was converted from producer to water injector. This would help validate the technology for further deployment on oil producers. The lower liner with the metal expandable annular sealing system was deployed from the rig whilst the activation (expansion) and subsequent acid stimulation were completed offline. Production and injectivity data were analysed and compared to the PI / II to the prior cemented and perforated well designs.

This paper will discuss the project scope of work, first deployment of the metal expandable sealing system, data analysis and an estimate of the risk and cost reduction delivered.
High-Viscosity Liquid/Gas Flow Pattern Transitions in Upward Vertical Pipe Flow
Authors: Al-Safran Eissa , Ghasemi Mohammad , Al-Ruhaimani Feras
Published: February 2020

High-viscosity liquid two-phase upward vertical flow in wells and risers presents a new challenge for predicting pressure gradient and liquid holdup due to the poor understanding and prediction of flow pattern. The objective of this study is to investigate the effect of liquid viscosity on two-phase flow pattern in vertical pipe flow. Further objective is to develop new/improve existing mechanistic flow-pattern transition models for high-viscosity liquid two-phase-flow vertical pipes. High-viscosity liquid flow pattern two-phase flow data were collected from open literature, against which existing flow-pattern transition models were evaluated to identify discrepancies and potential improvements. The evaluation revealed that existing flow transition models do not capture the effect of liquid viscosity, resulting in poor prediction. Therefore, two bubble flow (BL)/dispersed bubble flow (DB) pattern transitions are proposed in this study for two different ranges of liquid viscosity. The first proposed transition model modifies Brodkey's critical bubble diameter (Brodkey 1967) by including liquid viscosity, which is applicable for liquid viscosity up to 100 mPa·s. The second model, which is applicable for liquid viscosities above 100 mPa·s, proposes a new critical bubble diameter on the basis of Galileo's dimensionless number. Furthermore, the existing bubbly/intermittent flow (INT) transition model on the basis of a critical gas void fraction of 0.25 (Taitel et al. 1980) is modified to account for liquid viscosity. For the INT/annular flow (AN) transition, the Wallis transition model (Wallis 1969) was evaluated and found to be able to predict the high-viscosity liquid flow pattern data more accurately than the existing models. A validation study of the proposed transition models against the entire high-viscosity liquid experimental data set revealed a significant improvement with an average error of 22.6%. Specifically, the model over-performed existing models in BL/INT and INT/AN pattern transitions.
A convolutional neural network-based system to classify patients using FDG PET/CT examinations
Authors: Kawauchi Keisuke , Furuya Sho , Hirata Kenji , Katoh Chietsugu , Manabe Osamu , Kobayashi Kentaro , Watanabe Shiro , Shiga Tohru
Published: February 2020

Background: As the number of PET/CT scanners increases and FDG PET/CT becomes a common imaging modality for oncology, the demands for automated detection systems on artificial intelligence (AI) to prevent human oversight and misdiagnosis are rapidly growing. We aimed to develop a convolutional neural network (CNN)-based system that can classify whole-body FDG PET as 1) benign, 2) malignant or 3) equivocal. Methods: This retrospective study investigated 3,485 sequential patients with malignant or suspected malignant disease, who underwent whole-body FDG PET/CT at our institute. All the cases were classified into the 3 categories by a nuclear medicine physician. A residual network (ResNet)-based CNN architecture was built for classifying patients into the 3 categories. In addition, we performed a region-based analysis of CNN (head-and-neck, chest, abdomen, and pelvic region). Results: There were 1,280 (37%), 1,450 (42%), and 755 (22%) patients classified as benign, malignant and equivocal, respectively. In the patient-based analysis, CNN predicted benign, malignant and equivocal images with 99.4%, 99.4%, and 87.5% accuracy, respectively. In region-based analysis, the prediction was correct with the probability of 97.3% (head-and-neck), 96.6% (chest), 92.8% (abdomen) and 99.6% (pelvic region), respectively. Conclusion: The CNN-based system reliably classified FDG PET images into 3 categories, indicating that it could be helpful for physicians as a double-checking system to prevent oversight and misdiagnosis.
Effect of inspiratory muscle-loaded exercise training on peak oxygen uptake and ventilatory response during incremental exercise under normoxia and hypoxia
Authors: Ogawa Takeshi , Nagao Maiko , Fujii Naoto , NIshiyasu Takeshi
Published: February 2020

Background: Although numerous studies have reported the effect of inspiratory muscle training for improving exercise performance, the outcome of whether exercise performance is improved by inspiratory muscle training is controversial. Therefore, this study investigated the influence of inspiratory muscle-loaded exercise training (IMLET) on peak oxygen uptake (VO2peak), respiratory responses, and exercise performance under normoxic (N) and hypoxic (H) exercise conditions. We hypothesised that IMLET enhances respiratory muscle strength and improves respiratory response, thereby improving VO2peak and work capacity under H condition.Methods: Sixteen university track runners (13 men and 3 women) were randomly assigned to the IMLET (n=8) or exercise training (ET) group (n=8). All subjects underwent 4 weeks of 20-min 60% VO2peak cycling exercise training, thrice per week. IMLET loaded 50% of maximal inspiratory pressure during exercise. At pre- and post-training periods, subjects performed exhaustive incremental cycling under normoxic (N; 20.9 ± 0%) and hypoxic (H; 15.0 ± 0.1%) conditions. Results: Although maximal inspiratory pressure (PImax) significantly increased after training in both groups, the extent of PImax increase was significantly higher in the IMLET group (from 102 ± 20 to 145 ± 26 cmH2O in IMLET; from 111 ± 23 to 127 ± 23 cmH2O in ET; P<0.05). In both groups, VO2peak and maximal work load (Wmax) similarly increased both under N and H conditions after training (P<0.05). Further, the extent of Wmax decrease under H condition was lower in the IMLET group at post-training test than at pre-training (from -14.7 ± 2.2% to -12.5 ± 1.7%; P<0.05). Maximal minute ventilation in both N and H conditions increased after training than in the pre-training period. Conclusions: Our IMLET enhanced the respiratory muscle strength, and the decrease in work capacity under hypoxia was reduced regardless of the increase in VO2peak.
High Contribution and Impact of Resistant Gram Negative Pathogens Causing Surgical Site infections at a Multi-Hospital Healthcare System in Saudi Arabia, 2007-2016
Authors: El-Saed Aiman , Balkhy Hanan , Alshamrani Majid M. , Aljohani Sameera , Alsaedi Asim , Nasser Wafa Al , Gammal Ayman El , Almohrij Saad A. , Alyousef Ziyad , Almunif Sara , Alzahrani Mohammad
Published: February 2020

BACKGROUND Despite being largely preventable, surgical site infections (SSIs) are still one of the most frequent healthcare-associated infections. The presence of resistant pathogens can further augment their clinical and economic impacts. The objective was to estimate the distribution and resistance in SSI pathogens in Saudi Arabia and to compare them to the US National Healthcare Safety Network (NHSN) hospitals. METHODS Targeted SSI surveillance was prospectively conducted on several surgical procedures done between 2007 and 2016 in four hospitals of Ministry of National Guard Health Affairs. Definitions and methodology of SSI and bacterial resistance were based on NHSN. RESULTS A total 492 pathogens causing 403 SSI events were included. The most frequent pathogens were Staphylococcus aureus (22.8%), Pseudomonas aeruginosa (20.1%), Klebsiella spp. (12.2%), and Escherichia coli (12.2%), with marked variability between surgeries. Approximately 30.3% of Staphylococcus aureus was methicillin-resistant (MRSA), 13.0% of Enterococcus spp. was vancomycin-resistant (VRE), and 5.5% of Enterobacteriaceae were carbapenem resistant (CRE). The highest multidrug-resistant (MDR) GNPs were Acinetobacter spp. (58.3%), Klebsiella spp. (20.4%) and Escherichia coli (16.3%). MRSA was significantly less frequent while cephalosporin-resistant Klebsiella spp., MDR Klebsiella spp., and MDR Escherichia coli were significantly more frequent in our hospitals compared with NHSN hospitals. CONCLUSION GNPs in a tertiary care setting in Saudi Arabia are responsible for more than 60% of SSI with more resistant patterns than Western countries. This information may be critical to secure resources and ensure support for caregivers and healthcare leaders in implementing antimicrobial stewardship programs and evidence-based SSI preventive practices.
Secular trend analysis of antibiotic consumption in China’s hospitals 2011-2018, a retrospective analysis of sales data
Authors: Wushouer Haishaerjiang , Zhou Yue , Zhang Xi , Fu Mengyuan , Fan Daiming , Shi Luwen , Guan Xiaodong
Published: February 2020

Background: This study was aimed to explore the secular trends of antibiotic sales over an 8-year period. Methods: We retrospectively analysed aggregated monthly surveillance data on antibiotic sales to 586 hospitals from 28 provinces in China from January 2011 to December 2018. Information including generic name, sales amount, dosage form, strength, the route of administration, and geographical data were collected. Population weighted antibiotic sales were expressed in DDD per 1,000 inhabitants per day (DID). WHO’s ‘Access, Watch, Reserve’ categorization was also adopted to analyse antibiotic sales. Results: Between 2011 and 2018, total antibiotic sales in China’s hospitals increased by 39.6% (from 4.8 DID in 2010 to 6.7 DID in 2018). Antibiotic sales were stable or had moderately decreased in 13 provinces, while in the other 15 provinces they had substantially increased. Cephalosporins were the most consumed antibiotics, accounting for 26.9% of the total antibiotic sales (1.8 DID/6.7 DID). In 2018, antibiotics in the Access category comprised 19.4% of the total sales (1.3 DID/6.7 DID), where antibiotics in the Watch category comprised the largest proportion of 71.6% (4.8 DID/6.7 DID). Population-weighted antibiotic sales were greater in secondary hospitals than in tertiary hospitals (7.3 DID vs 6.6 DID). The antibiotics sales of oral form were almost two times the sales of parenteral forms in secondary hospitals, whereas in tertiary hospitals the amounts were about the same. Conclusions: Although efforts were made towards restricting antibiotics in the past decade by the Chinese government, antibiotic sales demonstrated an upward trend during the study period. More efforts are needed to explore whether the antibiotics are prudently used.
The EMPOWER-SUSTAIN e-Health Intervention to improve patient activation and self-management behaviours among individuals with Metabolic Syndrome in primary care: study protocol for a pilot randomised controlled trial
Authors: Daud Maryam Hannah , Ramli Anis Safura , Abdul-Razak Suraya , Isa Mohamad Rodi , Yusoff Fakhrul Hazman , Baharudin Noorhida , Mohamed-Yassin Mohamed Syarif , Badlishah-Sham Siti Fatimah , Nikmat Azlina Wati , Jamil Nursuriati , Mohd-Nawawi Hapizah
Published: February 2020

Background: Epidemiological studies from various parts of the world have clearly demonstrated that Metabolic Syndrome (MetS) is an increasing global health problem, not only in the western societies but also in the Asian populations. Web-based and mobile phone-based self-management applications have been proven to be effective in improving self-management behaviour in patients with MetS components i.e. diabetes or hypertension. However, evidence is lacking in terms of its effectiveness specifically for patients with MetS. The aim of this pilot study is to evaluate the feasibility and potential effectiveness of the EMPOWER-SUSTAIN © Self-Management e-Health Intervention in improving patient activation and self-management behaviours among patients with MetS. This paper presents the study protocol. Methods: A pilot randomised controlled trial will be conducted in a university primary care clinic. A total of 232 patients aged 18-60 years old with MetS will be recruited; 116 will be randomised to receive the EMPOWER-SUSTAIN © intervention for 6 months and another 116 patients will continue with usual care. The EMPOWER-SUSTAIN © intervention is a multifaceted chronic disease management strategy based on the Chronic Care Model and persuasive technology theory. It consists of training primary care physicians, nurse and patients to use the EMPOWER-SUSTAIN web-based self-management mobile app © , strengthening patient-physician relationship and reinforcing the use of relevant clinical practice guidelines to guide management and prescribing. The primary outcome is the mean change in patient activation score using the Patient Activation Measure ® short form Malay version (PAM ® -13-M) questionnaire. The secondary outcomes include the change in waist circumference, body mass index, blood pressure, patients’ physical activity level, eating behavior, patients’ perception on chronic illness care, satisfaction in patient-physician interaction and perceived absolute 10-year cardiovascular disease risk. Feasibility of implementing the intervention will be evaluated. These include acceptability of the intervention, estimating the likely rate of participant recruitment and retention, appropriateness of the outcome measures, calculation of sample size, and its potential effectiveness. Conclusion: To our knowledge, this is the first study in Malaysia that aims to determine the feasibility of a multifaceted e-health intervention, as well as to indicate more useful aspects of this intervention for further exploration in a larger trial.
Overexpression of GmNFYA5 confers drought tolerance to transgenic Arabidopsis and soybean plants
Authors: Ma Xiao-Jun , Yu Tai-Fei , Li Xiao-Hui , Cao Xin-You , Ma Jian , Chen Jun , Zhou Yong-Bin , Chen Ming , Ma You-Zhi , Zhang Jun-Hua , Xu Zhao-Shi
Published: February 2020

Background: Crop productivity is challenged by abiotic stresses, among which drought stress is the most common. NF-Y genes, especially NF-YA genes, regulate tolerance to abiotic stress.
Results: Soybean NF-Y gene GmNFYA5 was identified to have the highest transcript level among all 21 NF-YA genes in soybean ( Glycine max L.) under drought stress. Drought-induced transcript of GmNFYA5 was suppressed by the ABA synthesis inhibitor naproxen (NAP). GmNFYA5 transcript was detected in various tissues at vegetative and reproductive growth stages with higher levels in roots and leaves than in other tissues, which was consist with the GmNFYA5 promoter:GUS fusion assay. Overexpression of GmNFYA5 in transgenic Arabidopsis plants caused enhanced drought tolerance in seedlings by decreasing stomatal aperture and water loss from leaves. Overexpression and suppression of GmNFYA5 in soybean resulted in increased and decreased drought tolerance, respectively, relative to plants with an empty vector (EV). Transcript levels of ABA-dependent genes ( ABI2 , ABI3 , NCED3 , LEA3 , RD29A , P5CS1 , GmWRKY46 , GmNCED2 and GmbZIP1 ) and ABA-independent genes ( DREB1A , DREB2A , DREB2B , GmDREB1 , GmDREB2 and GmDREB3 ) in transgenic plants overexpressing GmNFYA5 were higher than those of wild-type plants under drought stress; suppression of GmNFYA5 transcript produced opposite results. GmNFYA5 probably regulated the transcript abundance of GmDREB2 and GmbZIP1 by binding to the promoters in vivo.
Conclusions: Our results suggested that overexpression of GmNFYA5 improved drought tolerance in soybean via both ABA-dependent and ABA-independent pathways.
Keywords: ABA sensitivity, Glycine max , Nuclear Factor YA, resistance mechanisms
Is menopause still evolving? Evidence from a longitudinal study of multiethnic populations and its relevance to women's health
Authors: Chan Shirley , Gomes Alyssa , Singh Rama Shankar
Published: February 2020

To reflect on the impact of changing patterns of delayed marriage and reproduction and to seek evidence as to whether menopause is still evolving, characteristics of the menopause transition were investigated within and between ethnic populations in this study. A cross-sectional analysis was conducted using data on 747 middle-aged women obtained from the Study of Women’s Health Across the Nation (SWAN) from 1996 to 2008. The ethnic groups included: Afro-American, Chinese, Japanese, Caucasian, and Hispanic. Perimenopause age and duration, menopause age, and hormonal indicators of menopause were examined across five ethnicities. We found a similar window of menopause age within populations, but no significant difference in perimenopause and menopause age between populations. The rate of increase of follicle-stimulating hormone and testosterone differed significantly in Hispanics and African-Americans during the menopause transition period. The broad window of variation in age at menopause within the population (45-60 years) and the absence of significant differences between populations, in combination with population variation in menopause symptoms, suggest that menopause is a relatively recently evolved and still evolving trait. Under the mate choice theory of menopause, menopause is the result of the accumulation of infertility mutations in older women due to men’s preference for younger mates. We propose a shifting mate choice-shifting menopause model which posits that, as the age of mate choice/marriage shifts to older age, so will the age at menopause, and that menopause is a transient phase of female fertility; it can de-evolve, be delayed, if not disappear completely. Integrated longitudinal menopausal studies linked with genomics and hormonal studies on diverse ethnic populations can provide valuable information bearing on women’s health and personalized medicine.
Identification of a virulence tal gene in the cotton pathogen, Xanthomonas citri pv. malvacearum strain Xss-V2-18
Authors: Haq Fazal , Xie Shiwang , Huang Kunxuan , Shah Syed Mashab Ali , Ma Wenxiu , Cai LuLu , Xu Xiameng , Xu Zhengyin , Wang Sai , Zou Lifang , Zhu Bo , Chen Gongyou
Published: February 2020

Background: Bacterial blight of cotton (BBC), which is caused by the bacterium Xanthomonas citri pv. malvacearum (Xcm), is a destructive disease in cotton. Transcription activator-like effectors (TALEs), encoded by tal-genes, play critical roles in the pathogenesis of xanthomonads. Characterized strains of cotton pathogenic Xcm harbor 8-12 different tal genes and only one of them is functionally decoded. Further identification of novel tal genes in Xcm strains with virulence contributions are prerequisite to decipher the Xcm-cotton interactions.
Results: In this study, we identified six tal genes in Xss-V2-18, a highly-virulent strain of Xcm from China, and assessed their role in BBC. RFLP-based Southern hybridization assays indicated that Xss-V2-18 harbors the six tal genes on a plasmid. The plasmid-encoded tal genes were isolated by cloning BamHI fragments and screening clones by colony hybridization. The tal genes were sequenced by inserting a Tn5 transposon in the DNA encoding the central repeat region (CRR) of each tal gene. Xcm TALome evolutionary relationship based on TALEs CRR revealed relatedness of Xss-V2-18 to MSCT1 and MS14003 from the United States. However, Tal2 of Xss-V2-18 differs at two repeat variable diresidues (RVDs) from Tal6 and Tal26 in MSCT1 and MS14003, respectively, inferred functional dissimilarity. The suicide vector pKMS1 was then used to construct tal deletion mutants in Xcm Xss-V2-18. The mutants were evaluated for pathogenicity in cotton based on symptomology and growth in planta. Four mutants showed attenuated virulence and all contained mutations in tal2. One tal2 mutant designated M2 was further investigated in complementation assays. When tal2 was introduced into Xcm M2 and expressed in trans, the mutant was complemented for both symptoms and growth in planta, thus indicating that tal2 functions as a virulence factor in Xcm Xss-V2-18.
Conclusions: Overall, the results demonstrated that Tal2 is a major pathogenicity factor in Xcm strain Xss-V2-18 that contributes significantly in BBC. This study provides a foundation for future efforts aimed at identifying susceptibility genes in cotton that are targeted by Tal2.
Predictors of health-related quality of life in Chinese patients receiving treatment for neovascular age-related macular degeneration: A Prospective Longitudinal study
Authors: Bian Wei , Wan Junli , Tan Mingqiong , Su Jun , Yuan Yi , Wang Zonghua , Li Shiying
Published: February 2020

Objectives Age-related macular degeneration (AMD) is currently the leading cause of irreversible visual impairment in developed countries and seriously affect the health-related quality of life (HRQoL) of patients. However, the majority of the researches in this area employ cross-sectional design, and the longitudinal researches investigating changes in HRQoL and influence factors are limited. The aim of the study was to use longitudinal study design to investigate descriptive trends in HRQoL and predictive factors in Chinese AMD patients receiving treatment of vascular endothelial growth factor inhibitors (anti-VEGF) at baseline and follow-ups.Methods A sample of 142 AMD patients from the outpatient clinic of the Southwest Eye Hospital, a tertiary major hospital in the southwest of China. Each patient completed a self-administered questionnaire assessing demographics,clinical features, HRQoL, depression, anxiety, coping style, social support and self-efficacy at baseline, 1, 3, 6 and 12 months’ follow-up.Results The total score of HRQoL was fluctuated with the highest score at 6 months follow-up and the lowest score at baseline. Multivariable linear regression showed the predictors of HRQoL are best-corrected visual acuity (BCVA), income, depression andvisual acuity (VA) of the treated eye at baseline; BCVA, income and depression at 1 month follow-up; duration, area of residence, gender, VA of the treated eye, BCVA, income, anxiety, social support, self-efficacy, depression at 3 months follow-up; gender, BCVA, income, anxiety, social support, self-efficacy, depression, negative coping and positive coping at 6 months follow-up; BCVA, social support, self-efficacy and depression at 12 months follow-up.Conclusions The HRQoL and its predictive factors in Chinese AMD patients receiving treatment of anti-VEGF were fluctuated over time. It is suggested that the medical staff should get more information when planning precise care for improving HRQoL of the patients.
Nurses' Viewpoints on the Quality of Care: A Qualitative Study in Timor-Leste
Authors: Luan Bernadethe Marheni , Lopes Paulo , Soares Domingos
Published: February 2020

Background Research on quality of care revealed nurse-to-patient ratio and skill mix served as key elements in quality of care. However, those studies were done in countries where nursing workforce had reasonable proportion of professional nurses with bachelor degrees. Findings of these researches may overlook challenges in health system as well as the nature of nursing service in small island low-income countries that has a huge proportion of auxiliary nurses. Working in under-sourced places, nurses in Timor-Leste might have different viewpoints on what aspect contribute to quality of care. Methods Focus group discussions (FGDs) were done in 2017, in three districts that included staff nurses and senior nurses from three levels of health care facilities: primary, secondary, and tertiary. Data were analyzed using content analysis method. Results Two themes were emerged from the FGDs data: “patients as the center of the service” and “gaps in providing quality of care”. Aside from attributes of quality care such as equality, efficiency, and patient-centeredness in the delivery of care, the first theme also covered the importance of employing nurses’ value system in order to uphold quality of care. The second theme included quality care milieu amplifying distinctive factors facing health system in under-resources places. Problems related with facility infrastructure, equipment and supplies, financing, management, and staffing were narrated. While an inadequacy or a deficiency of these factors implies the country’s struggles to maintain a functioning health care facility, it incapacitated nurses to improve quality of care. Conclusions Compared to nurses in countries with better skill mix, nurses in under-resources places and small island low-income countries face different challenging situations that go beyond nursing realm, forcing nurses to describe quality care uniquely. Findings from this study provide evidence that it is urgent to develop policies of human resources for health (HRH) within the context of the health policies that contributes to professional management of the largest cadre, thus strengthens their ability to improve patient care service.
Impact of Q.Clear reconstruction algorithm on the interpretation of PET/CT images in patients with lymphoma
Authors: Wyrzykowski Michał , Siminiak Natalia , Kaźmierczak Maciej , Ruchała Marek , Czepczyński Rafał
Published: February 2020

Background Q.Clear is a new Bayesian penalised-likelihood PET reconstruction algorithm. It has been documented that Q.Clear increases SUVmax values of different malignant lesions. Purpose. As SUVmax values are crucial for interpretation of PET/CT images in patients with lymphoma, particularly when early and final response to treatment is evaluated, aim of the study was to systematically analyze the impact of the use of Q.Clear on interpretation of PET/CT in patients with lymphoma. Methods 280 18 F-FDG PET/CT scans in patients with lymphoma performed for staging (sPET), for early treatment response (iPET), after the end of treatment (ePET) and when a lymphoma relapse was suspected (rPET) were retrospectively analyzed. Scans separately reconstructed with two algorithms: Q.Clear and OSEM were compared. Results The lymphoma stage was concordantly diagnosed in 69/70 patients with both algorithms in sPET. Discordant assessment of Deauville score (p<0.001) was found in 11 cases (15.7%) of 70 iPET scans and in 11 cases of 70 ePET scans. An upgrade from negative to positive scan by Q.Clear resulted in case of 3 (4.3%) iPET scans and 7 (10.0%) ePET scans that resulted in alteration of management. Results of all 70 r-PET scans were concordant. SUVmax values of the target lymphoma lesions measured with Q.Clear were higher than with OSEM in 88.8% scans. Conclusion Although the Q.Clear algorithm may alter interpretation of PET/CT only in a small proportion of patients, we recommend to use standard OSEM reconstruction for assessment of treatment response.
Auditory feedback alters postural control and functional ability in patients with chronic stroke
Authors: Lim Hee Sung , Ryu Jiseon , Ryu Sihyun
Published: February 2020

Background: This study aimed to investigate the effect of white noise on dynamic balance in patients with stroke and the pre- and post-intervention changes in dynamic balance during walking by analyzing the anterior-posterior (A-P) and medial-lateral (M-L) center of pressure (CoP) range and velocity, center of mass (CoM), and A-P/M-L inclination angle using CoM-CoP and to establish the basis for using auditory feedback as an effective means of exercise intervention by bringing changes in dynamic balance abilities of patients with chronic stroke and retain the necessary abilities for maintaining independent and functional daily living.Methods: Nineteen patients with chronic stroke (age: 61.2±9.8 years, height: 164.4±7.4 cm, weight: 61.1±9.4 kg, paretic side (R/L): 11/8, duration: 11.6±4.9 years) were included as study participants. Auditory feedback used white noise, and all participants listened for 20 minutes mixing six types of natural sounds with random sounds. The dynamic balancing ability was evaluated during the walking, and the variables were the center of pressure (CoP), the center of mass (CoM), CoP-CoM inclined angle.Results: There is a significant increase in the A-P CoP range, A-P inclination angle, and gait speed on the paretic and non-paretic sides following white noise intervention (p<.05). In addition, the changes in CoP velocity on the paretic and non-paretic sides increased in both the A-P and M-L directions but not significantly.Conclusion: Our findings confirmed the positive effect of using white noise as auditory feedback through a more objective and quantitative assessment using CoP-CoM inclination angle as an evaluation indicator for assessing dynamic balance in patients with chronic stroke. The A-P and M-L inclination angle can be employed as a useful indicator for evaluating other exercise programs and intervention methods for functional enhancement of patients with chronic stroke in terms of their effects on dynamic balance and effectiveness.
Malaria patterns across altitudinal zones of Mount Elgon following intensified control and prevention programs in Uganda
Authors: Aggrey Siya , Anthony Egeru , John Kalule Bosco , Akim Lukwa Tafadzwa , Benard Ssentongo
Published: February 2020

Background Malaria remains a major tropical vector-borne disease of immense public health concern owing to its debilitating effects in sub-Saharan Africa. In the recent past, the high altitude areas in Eastern Africa have been reported to experience dramatic cases of malaria. However, its patterns following intensified control and prevention interventions remains and the changing climate remains widely unexplored in these regions. This study thus analyzed malaria patterns across altitudinal zones of Mount Elgon, Uganda. Methods Times-series data on malaria cases (2011 - 2017) from five level III local health centers occurring across three altitudinal zones; low, mid and high altitude was utilized. Inverse Distance Weighted (IDW) interpolation regression and Mann Kendall trend test were used to analyze malaria patterns. Autoregressive Integrated Moving Average (ARIMA) model was used to project malaria patterns for a seven year period. Results On average, 66±69/1000 individuals suffered from malaria on a monthly basis. This was most pronounced in the months of May-August 89±88/1000 compared to the months of November-February (40±33/1000). Malaria patterns varied with season and altitude and declined over time across the three altitudinal zones. Observed cases, revealed an annual average of 587±750/1000; 345±321/1000 and 338±351/1000 cases in lower, mid and high altitudes respectively. Conclusions Despite observed decline in malaria cases across the three altitudinal zones, the high altitude zone became a malaria hotspot as cases variably occurred in the zone. The projections of malaria revealed declining patterns of malaria cases in all the altitudinal zones. Malaria control interventions thus ought to be strengthened and strategically designed to achieve no malaria cases across all the altitudinal zones. Integration of climate information within malaria interventions can also strengthen eradication strategies of malaria in such differentiated altitudinal zones.