bluuebunny/crossref_metadata_2025_split huggingface dataset:
How Arthroscope Orientation Affects Performance
Authors: Wahl Elizabeth P. , Coughlin Ryan P. , Mickelson Dayne T. , Green Cynthia L. , Garrigues Grant E. 
Published: February 2019

Background:
Elements of competency-based training are being incorporated into surgical training. The primary objective of this study was to determine how the orientation of the arthroscope and the instruments relative to the standing position of the surgeon affects basic arthroscopic performance. The secondary objective was to determine how arthroscopic level of training affects performance.

Methods:
Participants from a single academic institution were recruited and divided by level of training into 2 groups: novice and advanced. The Fundamentals of Arthroscopic Surgery Training (FAST) Workstation (Sawbones) was used in this study. Performance on the ring transfer module was evaluated based on the total number of ring transfers that were completed and the errors that were made in timed sessions. All participants performed the task with the arthroscope facing away from (position A) and facing toward (position B) their standing position. Two trials were completed for each position, followed by a survey.

Results:
Fifty-seven subjects participated in this study. Overall, position A showed 2.7 times the amount of transfers compared with position B (p < 0.001). The advanced group had 1.6 times more transfers in position A than the novice group (p = 0.007), and there was no significant difference in transfers between training level in position B. The advanced group had 3.6 times more transfers in position A compared with position B (p < 0.001), while the novice group had 2.0 times more transfers in position A than in position B (p < 0.001).

Conclusions:
Performing an arthroscopic simulator task with the arthroscope directed toward the operator was found to be more difficult. An understanding of how the orientation of the operator, the arthroscope, and the instruments can strongly influence performance may be important for the primary surgeon, trainees, or assistants who may be standing opposite the arthroscope, and to optimize training to overcome this discrepancy.
Development of Squat-and-Smile Test as Proxy for Femoral Shaft Fracture-Healing in Patients in Dar es Salaam, Tanzania
Authors: Wu Hao-Hua , Liu Max , Challa Sravya T. , Morshed Saam , Eliezer E.N. , Haonga Billy T. , Zirkle Lewis , Shearer David W. 
Published: February 2019

Background:
There are few validated instruments that serve as a proxy for fracture-healing after lower-extremity trauma in low-resource settings. The squat-and-smile test (S&S) has been under development by SIGN (Surgical Implant Generation Network) Fracture Care International to monitor outcomes of lower-extremity long-bone fractures after intramedullary nailing in resource-limited settings. The goals of this study were to develop and identify domains of the S&S test.

Methods:
The S&S domains were developed through an iterative process, and consensus was achieved regarding 3: squat depth, support needed to squat, and facial expression. Adult patients with an OTA/AO type-32 femoral shaft fracture were included in this retrospective study and had the S&S administered at 6 weeks and 3, 6, and 12 months postoperatively. Two authors independently assessed photographs of the patients performing the S&S. S&S domains were correlated with the EuroQol 5-Dimensions (EQ-5D) index score, and comparisons were made between S&S domains and reoperation status. Interrater and test-retest reliability was assessed using the kappa statistic. Sensitivity and specificity analyses were performed.

Results:
Six hundred and nine S&S images were evaluated for 231 patients. Each domain improved over time and correlated positively with EQ-5D scores (p < 0.05). Squat depth and support needed to squat correlated with the need for a reoperation (p ≤ 0.01), and both had high specificity (0.95 and 0.97, respectively) for ruling out the need for a reoperation at 1 year. All 3 domains had high test-retest reliability (κ = 0.95, 0.92, and 0.96). Squat depth and need for support also had strong interrater reliability (κ = 0.75 and 0.78).

Conclusions:
The S&S is a potential tool for monitoring clinical and functional outcome of femoral shaft fractures in low-resource settings. Our data support the binary assessment of squat depth and need for support, but not facial expression, as a proxy for fracture-healing. Future prospective studies in external populations are warranted to evaluate the validity, reliability, and responsiveness of the S&S.

Clinical Relevance:
The S&S provides a valuable proxy for femoral shaft fracture assessment for middle to low-income countries because it is locally relevant (based on squatting), it is easy to administer, and assessment can be performed remotely via mobile telephone or text messaging.
In Vivo Bioluminescence Imaging in a Rabbit Model of Orthopaedic Implant-Associated Infection to Monitor Efficacy of an Antibiotic-Releasing Coating
Authors: Miller Robert J. , Thompson John M. , Zheng Jesse , Marchitto Mark C. , Archer Nathan K. , Pinsker Bret L. , Ortines Roger V. , Jiang Xuesong , Martin Russell A. , Brown Isabelle D. , Wang Yu , Sterling Robert S. , Mao Hai-Quan , Miller Lloyd S. 
Published: February 2019

Background:
In vivo bioluminescence imaging (BLI) provides noninvasive monitoring of bacterial burden in animal models of orthopaedic implant-associated infection (OIAI). However, technical limitations have limited its use to mouse and rat models of OIAI. The goal of this study was to develop a larger, rabbit model of OIAI using in vivo BLI to evaluate the efficacy of an antibiotic-releasing implant coating.

Methods:
A nanofiber coating loaded with or without linezolid-rifampin was electrospun onto a surgical-grade locking peg. To model OIAI in rabbits, a medial parapatellar arthrotomy was performed to ream the femoral canal, and a bright bioluminescent methicillin-resistant Staphylococcus aureus (MRSA) strain was inoculated into the canal, followed by retrograde insertion of the coated implant flush with the articular surface. In vivo BLI signals were confirmed by ex vivo colony-forming units (CFUs) from tissue, bone, and implant specimens.

Results:
In this rabbit model of OIAI (n = 6 rabbits per group), implants coated without antibiotics were associated with significantly increased knee width and in vivo BLI signals compared with implants coated with linezolid-rifampin (p < 0.001 and p < 0.05, respectively). On day 7, the implants without antibiotics were associated with significantly increased CFUs from tissue (mean [and standard error of the mean], 1.4 × 108 ± 2.1 × 107 CFUs; p < 0.001), bone (6.9 × 106 ± 3.1 × 106 CFUs; p < 0.05), and implant (5.1 × 105 ± 2.2 × 105 CFUs; p < 0.05) specimens compared with implants with linezolid-rifampin, which demonstrated no detectable CFUs from any source.

Conclusions:
By combining a bright bioluminescent MRSA strain with modified techniques, in vivo BLI in a rabbit model of OIAI demonstrated the efficacy of an antibiotic-releasing coating.

Clinical Relevance:
The new capability of in vivo BLI for noninvasive monitoring of bacterial burden in larger-animal models of OIAI may have important preclinical relevance.
Hip Arthrography Complicated by Air Embolism in Infants
Authors: Bell Courtney , Greene Nattaly , Kato Meredith , Goldstein Rachel , Yang Scott 
Published: February 2019

Case:
We report 2 cases of infants with developmental dysplasia of the hip who underwent arthrography of the hip with use of air for structure identification, which resulted in a presumed air embolism and deep oxygen desaturation. This led to the hypothesis that there is an increased potential of air embolism in the pediatric population given the vascular anatomy of the hip.

Conclusion:
These 2 cases document the important and not well-known complication of air embolism during air arthrography, which resulted in a change of practice for the authors. We strongly recommend against the use of air as an adjunct to routine arthrography in children.
The Challenge of Public Perception
Authors: Rassenfoss Stephen 
Published: February 2019

Special Section: The Value and Future of Petroleum Engineering
For petroleum engineers, it is aggravating to hear negative comments about the oil and gas industry, often by people who don’t understand the industry or get the facts wrong.
“I was asked about this whenever I spoke,” said Janeen Judah SPE, 2017 SPE President, recalling how members were unsure how to respond to negative or inaccurate claims. She agreed that it is disappointing to hear the work you are proud of misrepresented, and misconceptions can lead to bad policies. For example, those who assume that a transition from oil and gas to wind and solar will take just a few years rather than decades are also likely to oppose government policies that will allow for the exploration and production required to meet global energy demand.
Adding to the challenge, managing public perception is not something that petroleum engineers learn in college. Engineers are likely to struggle to understand a thought process that seems illogical and subjective.
Understanding how opinions are formed, and changed, requires dealing with the fact that the workings of our brains—including those of engineers—are influenced by logic, but the thought process also brings many other things into the equation to arrive at what may seem like a logical conclusion.
“A few years ago I thought it was 80% facts and reasoning and 20% gut reaction. Now I think we are the other way around,” said Lyn Arscott, SPE president in 1988. He realized that things are not always what they seem after reading about the growing body of psychological research concluding that the way people evaluate facts, or even decide what are the facts, is based on many considerations—strongly held beliefs, a sense of justice and safety, rules of thumb, and group norms. A phrase often used in this discussion: things are complicated.
It is not that the general public is made up of people who are not logical thinkers. But there are also automatic thinking processes in our brain that evolved to help people make quick decisions in a dangerous world.
“Psychology might not be a traditional subject for JPT but it is essential that engineers understand what makes people tick,” Arscott said. That understanding can help explain why “it is not enough to make a case going ‘point one and two and three and four and this is what you do,’” he said.
This realization helped him answer a question that bothered him during his long career in oil and gas: “Why don’t they love us?”
Shifting Expectations
Arscott is proud of how the industry reduced its environmental impact in the decades after he shifted from working in production to working in a health, safety, and environment (HSE) position. He helped drive Chevron’s first push to comply with then-new oil and water pollution regulations.
“Slowly we realized we did not have to sacrifice the environment. We had to literally change the culture. I am so proud we are there. There are pockets of resistance, but we are there,” Arscott said.
Ten Technologies From the 1980s and 1990s That Made Today’s Oil and Gas Industry
Authors: Edmundson Henry 
Published: February 2019

Special Section: The Value and Future of Petroleum Engineering
Contrary to popular imagination, which favors John Wayne stereotypes heroically rescuing the oil industry with wrench and hammer, the oilfield is a place of exquisite engineering, the match of anything on Earth, a marvel of innovation at the biggest and smallest scales.
The office-block sized blowout preventers on the ocean floor or the minute geopositioning electronics inside a logging while drilling (LWD) tool both are designed to operate perfectly within exacting environmental specifications. Almost every aspect of upstream exploitation is the result of exhaustively leveraging the glorious value chain of math, science, and engineering.
Along this trajectory, failure is met more often than success, as ideas and developments are tried out and eventually fine-tuned until something begins to work reliably. The journey is not for the faint-hearted. Whether it be one obsessive individual or a team with an equal desire to win, both energy and imagination must be sustained at every hurdle, to force progress and eventual success. This is as valid for the glamorous game-changing innovation as it is for a leap-of-faith improvement to existing technological practice.
Since the 1980s, our industry has experienced a technology renaissance all along this innovation spectrum—the oil price volatility in this modern era of our industry certainly focused minds on doing things more efficiently at less cost. As a celebration of these years of technical innovation, we now make so bold as to list perhaps 10 of the most significant contributions.
No doubt it is foolhardy to propose such a list because we all have an opinion on what should be on it. Nevertheless, there is surely enough common ground to guarantee some degree of objectivity. What may be objectionable is limiting the number to 10. Within that constraint, however, just the intellectual and practical bravado displayed surely merits all 10 to be included.
1981: Horizontal Wells Increase Production
The Soviet Union pioneered horizontal wells in the late 1960s only to turn its back on furthering the development of the practice in favor of vertical wells that were easier and faster to drill. But the mantle was picked up by Jacques Bosio, a drilling engineer with French oil company Elf Aquitaine, which needed horizontal drilling to intersect fractures and increase production from a karst reservoir found off the Italian coast, the Rospo Mare field.
In 1981, for twice the cost of a vertical well, horizontal drilling was sanctioned. The first well would bring in 3,000 B/D—more than 20 times its off-set vertical well. By the mid-1980s, horizontal drilling was seeing wider adoption as a way to target thin oil and gas reservoirs in Texas, the Middle East, and the North Sea. Operators had known about these skinny hydrocarbon- bearing layers for years—now they had a way to contact them with enough surface area to make money. Bosio would go on to become the first SPE President from outside the US, in 1993.
Surface-to-Borehole Electromagnetics Hold Promise for 3D Waterflood Monitoring
Authors: Carpenter Chris 
Published: February 2019

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 191544, “Surface-to-Borehole Electromagnetics for 3D Waterflood Monitoring: Results From First Field Deployment,” by Daniele Colombo and Gary McNeice, Saudi Aramco, and Nestor Cuevas and Mauro Pezzoli, Schlumberger, prepared for the 2018 SPE Annual Technical Conference and Exhibition, Dallas, 24–26 September. The paper has not been peer reviewed.
Monitoring the waterflooding oil-recovery process is a difficult task for seismic-based methods in hard carbonate reservoirs. The changes in velocity and density caused by water/oil substitution are too small when compared with the errors involved in repeating the measurements. The authors detail the development of a technique based on surface-to-borehole controlled-source electromagnetics (CSEM), which exploits the large contrast in resistivity between injected water and oil to derive 3D resistivity distributions, proportional to saturations, in the reservoir.
Introduction
CSEM techniques for reservoir-fluid characterization and monitoring are applied on a commercial basis for cross-well configurations. The method is based on electromagnetic (EM) induction and, as such, uses magnetic sources and magnetic receivers. While it has been implemented successfully in many field trials, the method is limited to 2D geometries and its sensitivity is biased toward detecting conductors. Modeling has shown that the setup of magnetic sources and magnetic receivers in a 3D surface-to-borehole configuration does not provide a useful signal above the estimated noise floor. For such configurations, an electric source needs to be adopted. Realistic modeling of 3D surface-to-borehole CSEM suggested that the vertical electric field (Ez) is the only component of EM radiation showing a signal above the estimated noise floor for waterfront variation over a period of 2 years. The results of the study led to modifications of the cross-well EM acquisition system where electric field sensors were added to the existing magnetic field sensors. A powerful custom electric-current source was also developed.
Survey Design
Three-dimensional surface-to-borehole CSEM data were acquired in a deep (reservoir-level) research well drilled near the known waterfront position. Surface current dipoles (transmitting antennae) were prepared by drilling shallow boreholes and completing them with a steel pipe coupled to the rock formations using a slurry of carbon backfill (coke breeze) to achieve sufficient electrical contact. The electrode setup was completed by cementing the top. Electrodes forming the dipole antennas were installed at a 200-m separation forming a setup of 48 inline (radial-direction) and 48 cross-line (tangential-direction) dipoles generating Ez and a vertical magnetic field (Hz) at the observation well.
Understanding the Mechanism of Interwell Fracturing Interference With Reservoir/Geomechanics/Fracturing Modeling in Eagle Ford Shale
Authors: Guo X.. , Wu K.. , Killough J.. , Tang J.. 
Published: February 2019

Summary
Tightly spaced horizontal wells are widely used in the development of unconventional resources. The effectiveness of this strategy is largely affected by interwell fracturing interference, indicated by interwell fracture geometry and fracture hits, because interwell interference affects both the parent- and infill-well production. This work proposes a reservoir/geomechanics/fracturing modeling work flow for understanding the interference mechanism and quantifying effects of parent-well fracture geometry, differential stress, and the design of infill-well completion on interwell fracturing interference.
Reservoir models are constructed for the analysis of Eagle Ford scenarios. The numerical work flow involves a finite-element model that fully couples reservoir flow and geomechanics, and a complex multifracture propagation model coupling rock mechanics and fluid flow in wellbore and fractures. The work flow characterizes the temporal-spatial evolution of pressure and stress caused by legacy-parent-well production. The fracture model is used to simulate the complex fracture geometry created by infill-well completion, on the basis of an updated heterogeneous reservoir stress state. The resulting fracture geometry quality is quantified by the occurrence of fracture hits and the relative growth of fractures in longitudinal and transverse directions. Nonuniform fracture geometries lead to more-complex stress changes, induced by depletion, rather than by uniform fracture geometries along parent wells. A smaller in-situ differential stress results in stronger stress reorientation that is caused by parent-well depletion, which induces longitudinal fractures along infill wells, and greatly reduces stimulated reservoir volume (SRV) and initial well performance of infill wells. A larger in-situ differential stress induces less stress reorientation and is more likely to lead the fractures to propagate toward pre-existing fractures, generate fracture hits, and affect the production of parent wells. The quantification study in the sensitivity analysis indicates that differential stress and the infill-well completion design have the most significant influences on interwell interference. This study suggests optimal infill-well completion designs for Eagle Ford scenarios. The study also provides insights for an infill-well completion design in unconventional reservoirs developed by tightly spaced horizontal wells, in terms of how to adjust field operational schedules to avoid fracture hits, and change the complexity of the interwell fracture networks.
Infant critical head injury could be a remote cause of middle-aged cerebral amyloid angiopathy
Authors: Tachiyama Keisuke , Nakamori Masahiro , Hayashi Yuki , Matsushima Hayato , Imamura Eiji , Wakabayashi Shinichi , Urakami Katsuya 
Published: February 2019

Abstract
Background

Cerebral amyloid angiopathy (CAA) is a sporadic condition in the elderly and is associated with Alzheimer’s disease. The younger cases, however, may have a history of traumatic brain injury (TBI) during infancy.

Case Presentation

We present a case of a 37-year-old man who had cerebral lobar hemorrhage. Magnetic resonance imaging revealed several lobar microbleeds, which along with the asymptomatic, lobar hemorrhages increased every year. At the age of 40 years, he developed mild cognitive impairment. Cerebrospinal fluid (CSF) analysis revealed a markedly decreased level of amyloid β42. Moreover, he had a subdural hematoma during infancy. Thus, we diagnosed him with CAA, which was related to the TBI at infancy.

Conclusion

TBI at infancy can be a remote cause of middle-aged CAA and dementia. This was supported by the low Aβ42 level in the CSF analysis.
Accuracy of Saturated Soil Hydraulic Conductivity Estimated from Numerically Simulated Single‐Ring Infiltrations
Authors: Bagarello Vincenzo , Iovino Massimo , Lai Jianbin 
Published: February 2019

Core Ideas
The accuracy of the PI method in estimating soil Ks was tested by numerical simulations.
Estimated Ks using two‐ponding‐depth and multiple‐ponding‐depth infiltration were compared.
Transient and steady‐state infiltration data for six soils were used to estimate Ks.
The PI should yield more accurate Ks estimates in coarse‐ than fine‐textured soils.
The transient method does not solve the Ks inaccuracy problems in fine‐textured soils.
The single‐ring pressure infiltrometer (PI) method is widely used to determine saturated soil hydraulic conductivity, Ks, directly in the field. The original and still most common way to analyze the data makes use of the steady‐state model developed by the Canadian School in the 90s and two (two‐ponding‐depth, TPD, approach) or more (multiple‐ponding‐depth, MPD, approach) depths of ponding. The so‐called Wu method based on a generalized infiltration equation allows analysis of the transient infiltration data collected by establishing a single ponding depth of water on the infiltration surface. This investigation, making use of simulated infiltration runs for initially unsaturated sand to silty clay loam soils, showed that, with a run duration of practical interest (e.g., 2 h), the PI can be expected to yield more accurate estimates of Ks in coarse‐textured soils than in fine‐textured soils even if the transient method is used instead of the steady‐state method. Performing a three‐level experiment and analyzing the estimated steady‐state infiltration rates with both the TPD and MPD approaches is a way to predict the reliability of the estimated Ks value. The Ks accuracy should be acceptable if the two approaches yield similar results. Otherwise, the MPD approach should be expected to yield more accurate Ks estimates than the TPD approach. The transient method does not solve the Ks inaccuracy problems in fine‐textured soils because obtaining accurate Ks data requires that the portion of total infiltration varying linearly with time represent a high percentage of total infiltration, but this percentage is small in fine‐textured soils when the run does not exceed a few hours. This investigation opens some new perspective on the use of infiltration data to make predictions on the expected reliability of the Ks calculations with reference to both steady‐state and transient data analysis procedures.