bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reservoir Connectivity, Water Washing and Oil to Oil Correlation: An Integrated Geochemical & Petroleum Engineering Approach
Authors: Ghassal Bandar I. 
Published: March 2019

Abstract
Oil Fingerprinting by gas chromatography techniques are among the most sensitive and accurate tools utilized to study reservoir compartmentalization and oil to oil correlations. The greatest challenge of the technique, however, lies in recognizing and identifying if any oils have undergone post-generative alteration processes such as water washing or biodegradation that may prohibit accurate correlation. These effects, even when subtle, may alter or transform oils resulting in misleading interpretations and invalid outcomes. Understanding the controls on the oil composition is critical for all fingerprinting studies and can promote new characterization methods to ensure any negative post-generative alteration effects are mitigated.
The study aims to illustrate the use of various geochemical fingerprinting methods to assess the reservoir connectivity between two oil accumulations. Furthermore, the effect of water washing on the oil compositions, and its relationship with gas to oil ratio (GOR) and salinity were investigated.
A total of 11 oil samples from an Ordovician siliciclastic formation across 10 locations in a field were analyzed for API gravity light hydrocarbons (C5-C7) and whole-oil fingerprinting (C8 to C20) gas chromatography (GC) characterization methods. Light hydrocarbons (LHC) analysis used to correlate different oils to their sources was interpreted using five specially selected source dependent ratios plotted in a C7 star diagram. If the oils have a similar pattern, this indicates a similar source and vice versa.
The results suggest that the oils can be correlated to two different source rocks that charged the study area from independent northeast and southwest directions. A second set of light hydrocarbon ratios sensitive to water washing and biodegradation effects suggested a noticeable water washing trend increasing to the north. The whole-oil fingerprinting analysis employs a multivariate statistical model across all the samples to determine the most variant 12 ratios from the chromatograms to construct a specialized star diagram. From this analysis, five separate reservoir compartments were identified. It was further observed that a set of samples from a specific compartment differed in one of the 12 ratios. This ratio was plotted against the water washing transformation ratio from LHC and revealed a strong positive correlation. The difference in this ratio is attributed to water washing. Both parameters suggest that water washing possesses strong negative correlations with total dissolved salts (TDS) of the formation water and gas to oil ratio (GOR). These relationships accentuate the potential of utilizing the geochemical ratios to predict the GOR and consequently improve the production planning. The study shed the lights on the potential utilization of new rapid and cost-effective geochemical methods to predict some production engineering parameters.
Effects of Resin-Fluid Interaction on Fracturing Fluid Stability, Proppant Flowback, and Preventive Control Methods
Authors: Songire Sumit , Prakash Chetan , Belakshe Ravikant 
Published: March 2019

Abstract
Hydraulic fracturing is often performed using resin-coated proppants to minimize proppant flowback during hydrocarbon production, whether the resin is precoated or coated on-the-fly as the treatment is pumped. Resin-fracturing fluid interaction can have a negative effect on fluid stability or resin consolidation, or both. This paper examines the effects of resin-fluid interactions on fluid stability, proppant consolidation strength, and strategies to mitigate the effects.
Components of resins can change the fracturing fluid stability by interacting with crosslinker or breaker, or by changing the fluid pH. To offset the effect of a resin, the breaker/crosslinker/buffer concentration should be tuned while pumping resin-coated proppant. Similarly, resin-fluid interaction can decrease consolidation strength by disturbing resin-curing kinetics or reducing grain-to-grain contact, which can increase the possibility of proppant flowback during production. The influence of resins on fracturing fluid stability was evaluated by conducting rheology testing. The effect of fracturing fluids on the consolidation strength of resin was evaluated by comparing unconfined compressive strength (UCS) of proppant packs.
The stability of zirconate and borate crosslinked guar fluids, when treated with coated on the fly liquid resin-coated proppant (LRCP), was lower than non-treated fluids at 260°F as a result of breaker activation by the resin components. The desired fluid stability was attained by lowering breaker concentration in liquid resin-treated fluid. During another round of testing, a second type of LRCP, based on different chemical functionality, increased the stability of synthetic polymer fluid at 400°F. Likewise, a rise in fluid stability was observed when guar fluid was treated with resin pre-coated proppant (RCP) at 200 and 250°F. The improved fluid stability is associated with reduction in active breaker concentration in the presence of furan resin and RCP. The UCS value of the proppant pack prepared from fracturing fluid-treated RCP was ~16 to 45% lower than the proppant pack without this fluid treatment. Additionally, the UCS value of proppant pack prepared using fracturing fluid-treated LRCP decreased by ~30%. However, the measured UCS value of LRCP pack with fracturing fluid exposure was higher than the RCP pack measured value even without exposure to this fluid.
Incorporating LRCP instead of using RCP during fracturing operations could address the proppant flowback issue and possibly result in higher conductivity of propped fractures. It could help ensure economic production rates and prevent costs associated wellbore cleanup, downhole tool damage, erosion and damage to the tubular, chokes, valves and separators, and refracturing of the well. Ultimately, it could help maintain a lower cost per barrel of oil equivalent (BOE).
Magnitude of diabetic retinopathy in newly diagnosed type 2 diabetes patients in Menelik II Hospital, Addis Ababa
Authors: Wodajo Rebecca Getachew , Woyessa Dereje Negussie , Shiferaw Bezawit Gezahegn 
Published: March 2019

Abstract
Background: Diabetes mellitus (DM) is one of the most common non-communicable diseases with an increasing incidence worldwide. Diabetic retinopathy (DR), one of the chronic micro vascular complications, is a major global cause of total blindness. As the global prevalence of diabetes increases, so will the numbers of people with diabetic retinopathy. Hence, this study aims to determine the magnitude and severity of DR in newly diagnosed type 2 DM patients in Menelik II Hospital. Method: institutional based cross sectional study was conducted on newly diagnosed Type 2 DM patients. Data were analyzed using Statistical Package for Social Science (SPSS) 20 version computer software. Result: A total of 111 patients with newly diagnosed type II diabetes participated in this study. The female to male ration was 1: 1.84. The mean age of study participants was 50.5 (± 10.6years) with a range of 30-70 years. Majority of respondents (47.7%) completed secondary school while 18.0% were unable to read and write. The average BMI of participants was 25.0 ± 3.6kg/m2, 37 (33.3%) were overweight, 11(9.9%) were obese. Average FBS at diagnosis was 265.25 (0±99.4 mg/dl) for all patients and about 24.3% of the total study population had hypertension. Diabetic retinopathy was detected in 24 (21.6%) patients out of whom 7(29.16%) had mild NPDR, 8 (33.33%) moderate NPDR 5(20.8%)severe NPDR (20.8%) and 4 (16.7%)PDR . Conclusion: The prevalence of diabetic retinopathy at time of diagnosis among type II diabetes showed 21.6%. This high number of undiagnosed DR indicate early and regular screening for diabetic retinopathy among diabetic patients and more aggressive management of modifiable risk factors could reduce the numbers of people who develop vision-threatening retinopathy.
The effect of implementing an aseptic practice bundle for anaesthetists to reduce postoperative infections. Protocol for a stepped wedge, cluster randomised, multi-site trial. The Anaesthetists Be Cleaner (ABC) Study.
Authors: Merry Alan F , Gargiulo Derryn , Bissett Ian , Cumin David , English Kerry , Frampton Christopher , Hamblin Richard , Hannam Jacqueline , Moore Matthew , Reid Papaarangi , Roberts Sally , Taylor Elsa , Mitchell Simon J 
Published: March 2019

Abstract
Background

Postoperative infection is a serious problem in New Zealand, and internationally with considerable human and financial costs. Also, in New Zealand, certain factors that contribute to postoperative infection are more common in Māori and Pacific populations. To date, most efforts to reduce postoperative infection have focused on surgical aspects of care and on antibiotic prophylaxis, but recent research shows that anaesthesia providers may also have an impact on infection transmission. These providers sometimes exhibit imperfect hand hygiene and frequently transfer the blood or saliva of their patients to their work environment. In addition, intravenous medications may become contaminated while being drawn up and administered to patients. Working with relevant practitioners and other experts, we have developed an evidence-informed bundle to improve key aseptic practices by anaesthetists with the aim of reducing postoperative infection. The key elements of the bundle are the filtering of compatible drugs, context-relevant hand hygiene practices, and enhanced maintenance of clean work surfaces.

Methods

We will seek support for implementation of the bundle from senior anaesthesia and hospital leadership and departmental “champions”. Anaesthetic teams and recovery room staff will be educated about the bundle and its potential benefits through presentations, written material, and exemplar videos. We will implement the bundle in operating rooms where hip or knee arthroplasty or cardiac surgery procedures are undertaken in a five-site, stepped wedge, cluster randomised, quality improvement design. We will compare outcomes between approximately 5,000 cases before and 5,000 cases after implementation of our bundle. Outcome data will be collected from existing national and hospital databases. Our primary outcome will be days alive and out of hospital to 90 days, which is expected to reflect all serious postoperative infections. Our secondary outcome will be the rate of surgical site infection. Aseptic practice will be observed in sampled cases in each cluster before and after implementation of the bundle.

Discussion

If effective, our bundle may offer a practical clinical intervention to reduce postoperative infection and its associated substantial human and financial costs.

Trial registration

Australian New Zealand Clinical Trials Network Registry: ACTRN12618000407291
Thermoregulation of Prodigiosin Biosynthesis by Serratia marcescens is Controlled at the Transcriptional Level and Requires HexS
Authors: ROMANOWSKI ERIC G. , LEHNER KARA M. , MARTIN NATALIE C. , PATEL KRIYA R. , CALLAGHAN JAKE D. , STELLA NICHOLAS A. , SHANKS ROBERT M.Q. 
Published: March 2019

Abstract
Several biotypes of the Gram-negative bacterium Serratia marcescens produce the tri-pyrole pigment and secondary metabolite prodigiosin. The biological activities of this pigment have therapeutic potential. For over half a century it has been known that biosynthesis of prodi giosin is inhibited when bacteria are grown at elevated temperatures, yet the fundamental mechanism underlying this thermoregulation has not been characterized. In this study, chromosomal and plasmid-borne luxCDABE transcriptional reporters revealed reduced transcription of the prodigiosin biosynthetic operon at 37°C compared to 30°C indicating transcriptional control of pigment production. Moreover, induced expression of the prodigiosin biosynthetic operon at 37°C was able to produce pigmented colonies and cultures demonstrating that physiological conditions at 37°C allow prodigiosin production and indicating that post-transcriptional control is not a major contributor to the thermoregulation of prodigiosin pigmentation. Genetic experiments support the model that the HexS transcription factor is a key contributor to thermoregulation of pigmentation, whereas CRP plays a minor role, and a clear role for EepR and PigP was not observed. Together, these data indicate that thermoregulation of prodigiosin production at elevated temperatures is controlled largely, if not exclusively, at the transcriptional level.
In Vitro and In Vivo Activity of Zabofloxacin and Other Fluoroquinolones Against MRSA Isolates from A University Hospital in Egypt
Authors: MOHAMED NELLY M. , ZAKARIA AZZA S. , EDWARD EVA A. , ABDEL-BARY AMANY 
Published: March 2019

Abstract
The widespread of infections caused by methicillin-resistant Staphylococcus aureus (MRSA), has necessitated the search for alternative therapies; introduction of new agents being a suggestion. This study compares the in vitro and in vivo activities of zabofloxacin, a novel fluoroquinolone, with moxifloxacin, levofloxacin and ciprofloxacin against clinical isolates of MRSA from patients hospitalized in the Alexandria Main University hospital; a tertiary hospital in Alexandria, Egypt, where zabofloxacin has not been yet introduced. The strains tested showed the highest percentage of susceptibility to zabofloxacin (61.2%) among the tested fluoroquinolones with the most effective MIC50 and MIC90 (0.25 and 2 µg/ml, respectively). Time-kill curve analysis revealed a rapid bactericidal activity of zabofloxacin after 6 h of incubation with a quinolone-resistant isolate and complete killing when tested against a quinolone-sensitive isolate with inhibition of regrowth in both cases. PCR amplification and sequencing of QRDRs in selected strains revealed the following amino acid substitutions: Ser-84→Leu in GyrA, Ser-80→Phe in GrlA and Pro-451→Ser in GrlB. The in vivo studies demonstrated that zabofloxacin possessed the most potent protective effect against systemic infection in mice (ED50: 29.05 mg/kg) with lowest count in the dissected lungs (3.66 log10 CFU/ml). The histopathological examination of lung specimens of mice treated with zabofloxacin displayed least congestion, inflammation, oedema and necrosis with clear alveolar spaces and normal vessels. In conclusion, zabofloxacin was proved to possess high in vitro and in vivo efficacy encompassing its comparators and could be considered as a possible candidate for the treatment of infections caused by MRSA. To our knowledge, this is the first study evaluating the in vitro and in vivo activity of zabofloxacin against Egyptian MRSA clinical isolates.
DEVELOPMENT OF CHAIN-TYPE EXPONENTIAL ESTIMATORS FOR POPULATION VARIANCE IN TWO-PHASE SAMPLING DESIGN IN PRESENCE OF RANDOM NON-RESPONSE
Authors: Singh G. N. , Kumar Amod , Vishwakarma Gajendra K. 
Published: March 2019

Abstract
In this paper, an investigation has been carried out to deal with a unified approach of estimation procedures of population variance in two-phase sampling design under missing at random non-response mechanism circumstances. Using two auxiliary variables, we have developed different chain-type exponential estimators of finite population variance for two different set-ups and studied their properties under the different assumption of random non-response considered by Tracy and Osahan (1994). The comparisons of the proposed estimators have been made with some contemporary estimators of population variance under the similar realistic conditions. Numerical illustrations are presented to support the theoretical results. Results are analysed and suitable recommendations are put forward to the survey statisticians.
Aşağı Sakarya Nehri Su Kalitesinin Sulama Suyu Açısından Değerlendirilmesi
Authors: ÖZER Çiğdem , KÖKLÜ Rabia 
Published: March 2019

Aşağı
Sakarya Alt Havzası, Sakarya Nehrinin doğduğu noktadan itibaren maruz kaldığı
sanayi faaliyetlerinin ve yerleşim yerlerinden kaynaklanan atıksuların,
tarımsal ve kentsel yayılı kaynakların ve geçtiği jeolojik formasyonların
etkisi altındadır. Tüm bu kirletici yüklerin etkisine rağmen geçtiği bölgelerde
aynı zamanda tarımsal sulama maksadıyla da kullanılmaktadır. Bu nedenle, bu su
kaynağının içme ve endüstriyel kullanımı yanında özellikle tarımsal amaçlı
sürdürülebilir kullanımının önemi artmaktadır. Bu amaçla, çalışma kapsamında Aşağı Sakarya Nehrinin
tarımsal amaçlı sulama suyu bakımından kalitesi belirlenmiştir. Aşağı Sakarya
Nehri üzerinde Devlet Su İşleri (DSİ) tarafından işletilen 3 adet istasyona ait
su kalite verilerine ait farklı fiziko-kimyasal özellikler farklı sulama suyu
standartları açısından değerlendirilmiştir.
Bu standartlar temelinde sulama suyu kalitesi, Elektriksel iletkenlik (Eİ),
ve Toplam Sertlik (TS) değerleri ile Schoeller Diyagramı, Sodyum Adsorbsiyon
Oranı (SAR), Sodyum yüzdesi (%Na), Magnezyum Oranı (MR), Potansiyel Tuzluluk
(PS) ve Kelley indeksi (KI) gibi değerlendirme kriterleri kullanılarak
yorumlanmıştır.
Pharmaceuticals and Other Organic Chemicals in Selected North‐Central and Northwestern Arkansas Streams
Authors: Haggard Brian E. , Galloway Joel M. , Green W. Reed , Meyer Michael T. 
Published: March 2019

ABSTRACTRecently, our attention has focused on the low level detection of many antibiotics, pharmaceuticals, and other organic chemicals in water resources. The limited studies available suggest that urban or rural streams receiving wastewater effluent are more susceptible to contamination. The purpose of this study was to evaluate the occurrence of antibiotics, pharmaceuticals, and other organic chemicals at 18 sites on seven selected streams in Arkansas, USA, during March, April, and August 2004. Water samples were collected upstream and downstream from the influence of effluent discharges in northwestern Arkansas and at one site on a relatively undeveloped stream in north‐central Arkansas. At least one antibiotic, pharmaceutical, or other organic chemical was detected at all sites, except at Spavinaw Creek near Mayesville, Arkansas. The greatest number of detections was observed at Mud Creek downstream from an effluent discharge, including 31 pharmaceuticals and other organic chemicals. The detection of these chemicals occurred in higher frequency at sites downstream from effluent discharges compared to those sites upstream from effluent discharges; total chemical concentration was also greater downstream. Wastewater effluent discharge increased the concentrations of detergent metabolites, fire retardants, fragrances and flavors, and steroids in these streams. Antibiotics and associated degradation products were only found at two streams downstream from effluent discharges. Overall, 42 of the 108 chemicals targeted in this study were found in water samples from at least one site, and the most frequently detected organic chemicals included caffeine, phenol, para‐cresol, and acetyl hexamethyl tetrahydro naphthalene (AHTN).
The impact of phacoemulsification on corneal endothelial cells in patients with pseudoexfoliation syndrome
Authors: Potemkin V. V. , Varganova T. S. , Ageeva E. V. 
Published: March 2019

The effect of pseudoexfoliation syndrome (PEХ) on endothelial cells has been studied long enough. Yet the effect of phacoemulsification (PHACO) on endothelium in patients with PEХ is less explored.Purpose. To assess the impact of PHACO on corneal endothelial cell density (ECD) and on the coefficient of variation (CV) in patients with PEX.Material and methods. 30 patients (30 eyes) with PEX syndrome and 34 patients (34 eyes) with no such syndrome were examined before and after phacoemulsification.Results. In patients with PEX, the ECD after PHACO was significantly lower and CV was significantly higher (р < 0.05).Conclusion. PEX has a negative impact on endothelial cells, which leads to a pronounced cells loss after PHACO.
An objective study of negative accommodation
Authors: Tarutta E. P. , Tarasova N. A. , Markosyan G. A. , Kushnarevich N. Yu. , Larina T. Yu. 
Published: March 2019

Purpose: to study the dynamic refraction of myopic eyes at the time when the object is fixed in an open field at a distance of 5 m and determine habitual accommodation tone (HAT) in an open field. Material and methods. 130 patients (260 eyes) aged 6 to 23 years (ave. 11.26 ± 0.2 years) with an average refraction spherical equivalent of -4.16 ± 0.13 D were divided into 4 groups, depending on the degree of myopia. The HAT was measured by an automatic binocular open field (OP) autorefkeratometer Grand Seiko WR-5100K (Japan), while the HAT according to Yuri Rosenblum was determined by a conventional autorefractometer Nidek. Results. Comparing noncycloplegic and cycloplegic refraction using the two devices, we obtained different results. In the first case, we found the maximal difference of -0.15 D (-4.38 – (-4.23)), and in the second case, the minimal difference of -0.09 D (-4.16 – (-4.07)). Over the whole group, HAT according to Yuri Rosenblum averaged -0.21 ± 0.02 D. In patients with low myopia HAT was the highest and averaged -0.33 ± 0.03 D. In patients with moderate myopia an average HAT level was -0.23 ± 0.03, and in high myopia it was -0.19 ± 0.04 D. Patients with anisomyopia showed a significant difference of the tone between the fellow eyes: the eyes with lower refraction showed a HAT of -0.21 ± 0.03 D, while for the worse eye it was 0.06 ± 0,11 D (p < 0.05) (i.e. a negative accommodation tone). Over the whole contingent HAT OP averaged -0.17 ± 0.02 D: in patients with low myopia it averaged -0.22 ± 0.04 D, in those with moderate myopia, -0.27 ± 0.02 D, in high myopia — -0.09 ± 0.04 D. PTA OP patients with anisomyopia averaged -0.07 ± 0.03 D and demonstrated a significant difference between the eyes (-0.26 ± 0.03 D for the better eyes and 0.12±0.06 D — for the worse eyes, p < 0.01). A negative tone of accommodation of HAT OP in myopia occurs, on average, in 30% of patients; the frequency was maximal in high myopia (50 %) and minimal in moderate myopia (13.8 %). Conclusions. Objectively determined the weakening of the far dynamic refraction as compared with the static refraction (in terms of cycloplegia) was objectively determined. Thus, the existence of negative accommodation was confirmed.