bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acoustic Imaging of Perforation Erosion in Hydraulically Fractured Wells for Optimizing Cluster Efficiency
Authors: Robinson Stephen , Littleford Thomas , Luu Tim , Wardynski Kacper , Evans Andrew , Horton Blake , Oman Michael 
Published: January 2020

Abstract
A new solid-state, high-resolution acoustic imaging technology has been applied in hydraulically fractured wells to image and quantify perforation erosion. The downhole device captures detailed full-lateral logs of horizontal wells, without the need for clear fluids to facilitate measurements. This paper discusses how the imaging technology functions, lab testing that validated the measurements, and field testing completed with several operators in a variety of reservoirs and basins.
This high-resolution, acoustic-based downhole imaging technology provided a 360-degree view inside a variety of wells. Instead of optics, the imaging technology used high-frequency sound waves to image a full lateral through opaque fluids at sub-millimetric levels. The imaging tool was conveyed on either tractor or e-coil to continuously log the wellbore between 15 and 30ft/min, completing a full azimuthal scan that imaged individual perforations regardless of orientation. A range of imaging techniques quantified and measured each perforation to determine the extent of erosion in each perforation, cluster, and stage sustained during the hydraulic fracturing process.
The acoustic imaging technology was initially tested in the lab with calibration jigs and perforated pipe samples to validate its accuracy. The technology was then field deployed by several operators and used to assess perforation erosion in extended horizontal wells by scanning the entire well from toe to heel and measuring thousands of perforations in a single log. The data gathered quantified the perforation diameter, perforation erosion range, perforation orientation dependency, cluster efficiency, perforation erosion bias, and discovered the presence of significant casing damage around areas where plugs were set. The image results showed the distribution, size, and measured diameter for each perforation in each cluster. The results noted toe or heel biases and how these changed in different well types and designs in different basins. The data allowed operators to reach conclusions regarding erosion and cluster efficiency across the entire lateral in various wells in the Montney, Permian, and Anadarko basins. Wells across North America were scanned in several other basins for comparison purposes using various completion designs from different operators.
The high-resolution acoustic imaging technology offers a robust 360-degree view of long horizontal wells and perforation measurements post-fracture. Over 35,000 perforations have been measured using the technology in the field across various well types with different designs. The technology has proven to be a valuable tool in improving and optimizing completion designs by providing detailed feedback on where designs are working effectively and where they can be improved.
More Bang for the Buck – Optimized Perforating Design for Unconventional Reservoirs
Authors: Wehunt C. Dean , Naik Sarvesh J. , Singh Amit K. 
Published: January 2020

Abstract
Effective fracture treatment distribution to stimulate and obtain production from all perforation clusters is a key goal for success in unconventional reservoirs. The objectives of this work were to assess the impacts of multi-cluster stage perforating design parameters and execution uncertainties on treatment slurry distribution, production, ultimate recovery, and offset well interference for unconventional reservoirs.
A stochastic perforation breakdown and slurry injection model and a conceptual reservoir simulator were used to investigate treatment slurry distribution, production, and ultimate recovery impacts. The design parameters in the analysis were clusters per stage, cluster spacing, maximum proppant concentrations, perforation diameter, and number of perforations per cluster for both fixed- and variable-shot cluster designs. Uncertainties evaluated included perforation breakdown percentage, perforation shot phasing for non-oriented carriers, perforation hole diameter growth from erosion, and formation permeability.
As part of the analysis, the authors defined and used a new dimensionless quantity—the Slurry Distribution Number (Nsd)—that potentially fills a gap as no standard industry definition exists for perforation cluster efficiency. Nsd successfully correlated perforating design changes with slurry distribution outcomes. The authors used the results to identify strategies to mitigate uncertainty impacts, obtain more predictable outcomes, and achieve improved production results.
Novel information is presented that can assist perforating design optimization for unconventional reservoirs. In addition to introducing Nsd, the authors show perforation carrier phasing and shot phasing within the casing are generally not the same for decentralized carrier systems. The authors demonstrate how to model the perforation breakdown and stage stimulation process using a combination of published geomechanics, perforation erosion, and perforation flow resistance models. Lastly, the authors describe future study opportunities for perforating uncertainties and design parameters.
Shale Frac Designs Move to Just-Good-Enough Proppant Economics
Authors: Melcher Howard , Mayerhofer Michael , Agarwal Karn , Lolon Ely , Oduba Oladapo , Murphy Jessica , Ellis Ray , Fiscus Kirk , Shelley Robert , Weijers Leen 
Published: January 2020

Abstract
Selecting appropriate proppants is an important part of hydraulic fracture completion design. Proppant selection choices have dramatically increased in recent years as regional sands have become the proppant of choice in many liquid-rich shale plays. But are these new proppants the best long-term choices to maximize production? Do they provide the best well economics?
The paper presents a brief historical perspective on proppant selection followed by various detailed studies of how different proppant types have been performing in various unconventional basins (Williston, Permian, Eagle Ford, Powder River and DJ) along with economic analyses. As the shale revolution pushed into lower-quality reservoirs, the concept of dimensionless conductivity has pushed our industry to use ever lower-quality materials – away from ceramics and resin-coated proppant to white sand in some Rocky Mountain plays and more recently from white sand to regional sand in the Permian and Eagle Ford plays.
Further, we compare early-to late-time production response and economics in liquid-rich wells where proppant type changed. The performance of various proppant types and mesh sizes is evaluated using a combination of different techniques, including big data multi-variate statistics, lab conductivity testing, detailed fracture and reservoir modeling, as well as direct well group comparisons. The results of these techniques are then combined with economic analyses to provide a perspective on proppant selection criteria. The comparisons are anchored to permeability estimates from production history matching and DFITs and thousands of wellsite proppant conductivity tests to determine dimensionless conductivity estimates that best approach what is obtained in the field.
Proppant selection is typically based on crush resistance to stress loading and fracture conductivity under various flow conditions while having the lowest possible cost. However, dimensionless fracture conductivity is the main driver of well performance as it relates to proppant selection since it includes the relationship of fracture conductivity provided by the proppant relative to the actual flow capacity of the rock (the product of permeability and effective fracture length), which is supported by the production analyses in the paper. The paper shows how much fracture conductivity is adequate for a given effective fracture length and reservoir permeability and then looks at the economics of achieving this "just-good -enough" target conductivity, either through less proppant mass with higher-cost proppants or more proppant mass with-lower cost proppants, as well as mesh size considerations.
This paper does not rely on a single technique for proppant selection but uses a combination of various data sources, analysis techniques and economic criteria to provide a more holistic approach to proppant selection.
Protective and Therapeutic Effects of Nanoliposomal Quercetin on Acute Liver Injury in Rats
Authors: Liu Xiangyan , Zhang Yang , Liu Ling , Pan Yifeng , Hu Yu , Yang Pu , Liao Mingmei 
Published: January 2020

Abstract
Background Quercetin, a pigment (flavonoid) found in many plants and foods, has good effects on protecting liver function but poor solubility and bioavailability in vivo. A drug delivery system can improve the accumulation and bioavailability of quercetin in liver. Objective In this study, we used liposomal nanoparticles to entrap quercetin and evaluated its protective and therapeutic effects on drug-induced liver injury in rats. Design The nanoliposomal quercetin was prepared by a thin film evaporation-high pressure homogenization method and characterized by morphology, particle size and drug content. Acute liver injury was induced in rats by composite factors, including carbon tetrachloride injection, high-fat corn powder intake and ethanol drinking. After pure quercetin or nanoliposomal quercetin treatment, liver function was evaluated by detecting serum levels of glutamic-pyruvic transaminase (GPT), glutamic-oxal acetic transaminase (GOT) and direct bilirubin (DBIL). Histology of injured liver tissues was evaluated by hematoxylin and eosin staining. Results and discussion On histology, liposomal nanoparticles loading quercetin were evenly distributed spherical particles. The nanoliposomal quercetin showed high bioactivity and bioavailability in rat liver and markedly attenuated the liver index and pathologic changes in injured liver tissue. With nanoliposomal quercetin treatment, the serum levels of GPT, GOT and DBIL were significantly better than treated with pure quercetin. Using liposomal nanoparticles to entrap quercetin might be an effective strategy to reduce hepatic injury and protect hepatocytes against damage. Conclusions Liposomal nanoparticles may improve the solubility and bioavailability of quercetin in liver. Furthermore, nanoliposomal quercetin could effectively protect rats against acute liver injury and may be a new hepatoprotective and therapeutic agent for patients with liver diseases.
Multilocus phylogeny and cryptic diversity of white-toothed shrews (Mammalia, Eulipotyphla, Crocidura) in China
Authors: Chen Shunde , Qing Jiao , Liu Zhu , Liu Yang , Tang Mingkun , Murphy Robert W , Pu Yingting , Wang Xuming , Tang Keyi , Guo Keji , Jiang Xuelong , Liu Shaoying 
Published: January 2020

Abstract

Background: Crocidura , the most speciose mammalian genus, occurs across much of Asia, Europe and Africa. The taxonomy of Chinese representatives has been studied primarily based on cursory morphological comparisons and their molecular phylogenetic analyses remain unexplored. In order to understand the phylogeny of this group in China, we estimated the first multilocus phylogeny and conducted species delimitation, including taxon sampling throughout their distribution range. Results: We obtained one mitochondrial gene ( cytb ) (~ 1, 134 bp) and three nuclear genes ( ApoB , BRCA1 , RAG1 ) (~ 2, 170 bp) for 132 samples from 57 localities. Molecular analyses identified at least 14 putative species that occur within two major well-supported groups in China. Polyphyletic C. wuchihensis appears to be composed of two putative species. Two subspecies, C. rapax rapax and C. rapax kurodai should be elevated to full species status. A phylogenetic tree based on mitochondrial gene from Asian Crocidura species showed that the C. rapax rapax is embedded within C. attenuata , making the latter a paraphyletic group. Three strongly supported undescribed species ( C. sp.1, C. sp.2 and C. sp.3) are revealed from Zada County of Tibet (Western China), Hongjiang County of Hunan Province (Central China) and Dongyang County of Zhejiang Province (Eastern China), Motuo County of Tibet, respectively. The divergence time estimation suggested that China’s Crocidura species began to diversify during the late Pliocene (3.66 Ma) and the Early Pleistocene (2.29 Ma), followed by a series of diversifications through the Pleistocene. Conclusions: The cryptic diversity found in this study indicated that the number of species is strongly underestimated under the current taxonomy. We propose that the three undescribed species should be evaluated using extensive taxon sampling and comprehensive morphological and morphometric approaches. Climate change since the late Pliocene and the uplift of the Qinghai-Tibet Plateau may result in the diversification and speciation of China’s Crocidura species. In short, the underestimated diversity underlines the need for a taxonomic revision of Chinese Crocidura species.
Identification of a robust functional subpathway signature for pancreatic ductal adenocarcinoma by comprehensive and integrated analyses
Authors: Wang Ping , zhang chunlong , Li Weidong , Zhai Bo , Jiang Xian , Reddy Shiva , Jiang Hongchi , Sun Xueying 
Published: January 2020

Abstract
Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy and its mortality continues to rise globally. Because of its high heterogeneity and complex molecular landscapes, published gene signatures have demonstrated low specificity and robustness. Functional signatures containing a group of genes involved in similar biological functions may display a more robust performance. Methods: The present study was designed to excavate potential functional signatures for PDAC by analyzing maximal number of datasets extracted from available databases with a recently developed method of FAIME (Functional Analysis of Individual Microarray Expression) in a comprehensive and integrated way. Results: Eleven PDAC datasets were extracted from GEO, ICGC and TCGA databases. By systemically analyzing these datasets, we identified a robust functional signature of subpathway (path:00982_1), which belongs to the drug metabolism-cytochrome P450 pathway. The signature has displayed a more powerful and robust capacity in predicting prognosis, drug response and chemotherapeutic efficacy for PDAC, particularly for the classical subtype, in comparison with published gene signatures and clinically used TNM staging system. This signature was verified by meta-analyses and validated in available cell line and clinical datasets with chemotherapeutic efficacy. Conclusion: The present study has identified a novel functional signature for PDAC and it is like to improve the current systems for predicting the prognosis and monitoring drug response, and to serve a potential linkage to therapeutic options for combating PDAC. However, the involvement of path:00982_1 subpathway in the metabolism of anti-PDAC chemotherapeutic drugs, particularly its biological interpretation, requires a further investigation.
Evaluation of radioactive 125I seed implantation for the treatment of refractory malignant tumors based on CT-guided 3D template assisted technique: efficacy and safety
Authors: Zhao Guang Sheng , Liu Song , Yang Liang , Li Chuang , Wang Ruo Yu , Zhou Jun , Zhang Yue Wei 
Published: January 2020

Abstract
Background: To observe the medium-and long-term clinical efficacy and safety of radioactive 125I seed implantation for refractory malignant tumors based on a CT-guided 3D template-assisted technique. Methods: Twenty-five patients with refractory malignant tumors who received radioactive 125I seed implantation based on a CT-guided 3D template-assisted technique were selected. The post-operative adverse reactions were recorded; the number of puncture needles and particles used in the operation, dosimetric parameters, post-operative physical strength scores, and tumor response were statistically analyzed. The overall survival time and survival rate were counted, and the effect and prognosis were assessed. Results: 125I seed implantation was successful in all patients and no serious complications occurred. The average number of implanted puncture needles was 17 (19.12±13.00) and the median number of particles was 52 (55.12±32.97). The D90 in the post-operative clinical target volume (CTV) (93.24±15.70 Gy) was slightly lower than pre-operative CTV (93.92±17.60 Gy; P>0.05). The D90 in the postoperative planning target volume (PTV) (142.16±22.25 Gy) was lower than the pre-operative PTV (145.32±23.48 Gy; P>0.05). The tumor responses at 6 months post-operatively: complete remission (CR), 20%(5/25); partial remission (PR), 48%(12/25); stable disease (SD), 24%(6/25); progressive disease (PD), 8%(2/25); CR+PR, 68%(17/25); and local control rate, 92%(23/25). The 6-, 12-, and 24-month survival rates were 100%, 88%, and 52%, respectively. The post-operative physical strength score (Karnofsky performance score, KPS) exhibited a gradual trend towards recovery, which rose to the highest value 12 months after seed implantation, then decreased slightly, but the average score was still > 90 points. There was one intra-operative pneumothorax and two patients with superficial malignant tumors developed skin ulcerations. Multivariate analysis of prognosis showed that tumor sites and types were independent risk factors affecting survival. The number of needles and particles, and template type were not factors that affected prognosis. Conclusions: 3D template combined with CT-guided radioactive 125I seed implantation was shown to improve the rational distribution of radiation dose in the tumor target area because accurate radioactive 125I particle implantation was achieved. It has fewer complications and can further extend the overall survival and quality of life in patients with refractory malignant tumors.
Multivariate joint modeling to identify markers of growth and lung function decline that predict cystic fibrosis pulmonary exacerbation onset
Authors: Andrinopoulou Eleni-Rosalina , Clancy John Paul , Szczesniak Rhonda 
Published: January 2020

Abstract
Background: Attenuated decreases in lung function can signal the onset of acute respiratory events known as pulmonary exacerbations (PEs) in children and adolescents with cystic fibrosis (CF). Univariate joint modeling facilitates dynamic risk prediction of PE onset and accounts for measurement error of the lung function marker. However, CF is a multi-system disease and the extent to which simultaneously modeling growth and nutrition markers improves PE predictive accuracy is unknown. Furthermore, it is unclear which routinely collected clinical indicators of growth and nutrition in early life predict PE onset in CF. Methods: Using a longitudinal cohort of 17,100 patients aged 6-20 years (US Cystic Fibrosis Foundation Patient Registry; 2003-2015), we fit a univariate joint model of lung-function decline and PE onset and contrasted its predictive performance with a class of multivariate joint models that included combinations of growth markers as additional submodels. Outcomes were longitudinal lung function (forced expiratory volume in 1 s of % predicted), percentiles of body mass index, weight-for-age and height-for-age and PE onset. Relevant demographic/clinical covariates were included in submodels. We implemented a univariate joint model of lung function and time-to-PE and four multivariate joint models including growth outcomes. Results: All five joint models showed that declining lung function corresponded to slightly increased risk of PE onset (hazard ratio from univariate joint model: 0.97, P < 0.0001), and all had reasonable predictive accuracy (cross-validated area under the receiver-operator characteristic curve > 0.70). None of the growth markers alongside lung function as outcomes in multivariate joint modeling appeared to have an association with hazard of PE. Jointly modeling only lung function and PE onset yielded the most accurate (area under the receiver-operator characteristic curve = 0.75) and precise (narrowest interquartile range) predictions. Dynamic predictions were accurate across forecast horizons (0.5, 1 and 2 years) and precision improved with age. Conclusions: Including growth markers via multivariate joint models did not yield gains in prediction performance, compared to a univariate joint model with lung function. Individualized dynamic predictions from joint modeling could enhance physician monitoring of CF disease progression by providing PE risk assessment over a patient’s clinical course.
Does urethral length affect continence outcomes following robot assisted laparoscopic radical prostatectomy (RALP)?
Authors: Lin Diwei , O'Callaghan Michael E , David Rowan , Fuller Andrew , Wells Richard , Sutherland Peter , Foreman Darren 
Published: January 2020

Abstract
Background : Post-operative urinary incontinence is a significant concern for patients choosing to undergo a radical prostatectomy (RP) for treatment of prostate cancer. The aim of our study was to determine the effect of pre-operative MUL on 12 month continence outcomes in men having robot-assisted laparoscopic prostatectomy (RALP). Methods : We use the South Australian Prostate Cancer Clinical Outcomes Collaborative (SA-PCCOC) database, to identify 602 patients who had undergone RALP by a high volume surgeon. Only patients who received an assessment and education by a specialist pelvic floor physiotherapist, had completed EPIC questionnaires before treatment and did not have radiotherapy treatment within 12 months of surgery were included. MUL measurements were taken from pre-operative magnetic resonance imaging (MRI) scans. The short-form version of the Expanded Prostate Cancer Index Composite (EPIC-26) was used to measure continence outcomes. Continence was defined as 100/100 in the EPIC-26 Urinary Continence domain score. Results : The observed median MUL in this study was 14.6mm. There was no association between MUL and baseline continence. MUL was associated with continence at 12 months post RALP (OR 1.13, 95% CI 1.03-1.21, p=0.0098). In men who were continent before surgery, MUL was associated with return to continence at 12 months after RALP (OR 1.15, 1.05-1.28, p=0.006). MUL was also associated with change in continence after surgery (β=1.22, p=0.002). Conclusions : MUL had no effect on baseline continence but had a positive and significant association with continence outcomes over 12 months post RALP.