bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gravity Drainage Performance of Depletion-Type Reservoirs in the Stripper Stage
Authors: Matthews C.S. , Lefkovits H.C. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 207, 1956, pages 265–274.

Abstract
The performance of depletion-type reservoirs at the stage in which the gas is at such low pressure that gravity is essentially the sole driving force has been investigated both theoretically and by use of scaled models. A simple theory is developed which completely explains the scaled model experiments. It also agrees with some field data.

Introduction
This investigation was undertaken to determine a method for prediction of performance of reservoirs where gravity is the sole driving agent. Depletion-type reservoirs fall into this category after the pressure has fallen to some low value. Some examples of this type are found at Healdton (Oklahoma), Oklahoma City (Oklahoma), Midway-Sunset (California), and East Coalinga (California). Generally the production rate per unit thickness is quite low in such reservoirs, with the consequence that this stage is sometimes called the stripper stage. However, per well production rates may be of the order of 50 B/D because of the considerable sand thickness open in some of the reservoirs.
In the past, predictions of behavior of such reservoirs have been based on empirical extrapolation of the rate of production to the economic limit. Difficulties arise when new wells are drilled in the field or when production is artificially curtailed, since in such cases the decline rate of individual wells or leases changes and no clear trend can be detected. It was hoped that the present study would lead to improved methods for evaluation of such reservoirs.
The study was initiated by building a scaled model for a particular field and by running a number of experiments on this model. Later a simple theory was developed which explained the laboratory results completely. The theory led, as shown below, to a hyperbolic-type decline equation which had been used previously in a completely empirical manner.
Practical Solution of Gas-Flow Equations for Wells and Pipelines with Large Temperature Gradients
Authors: Cullender M.H. , Smith R.V. 
Published: February 2020

Published in Petroleum Transactions, AIME, Vol. 207, 1956, pages 281–287.

Abstract
Rigorous equations for calculating subsurface pressures in flowing and static gas wells, and pressures along horizontal pipelines are presented in this paper. These general equations, based on the mechanical energy balance, contain no assumptions regarding temperature and can be used with either straight-line or curved temperature gradients. The friction factors recommended in this report are based on an absolute roughness of 0.0006 in. Flow is always considered to be turbulent.
Although these general flow equations are solved by numerical means, the methods are as convenient as many of those used today to calculate pressures in gas wells and pipelines. These numerical methods are illustrated for flowing and static columns of gas in wells and for flow in pipelines. The authors believe that the use of these methods will result in more accurately calculated pressures in gas wells and pipelines and that the methods are more flexible than any in use at the present time. Also, the methods are easily adaptable to automatic computers.

Introduction
The problem of calculating subsurface pressures in gas wells and along flowing pipelines has been studied by many investigators with the results that two widely used methods have been presented in technical literature. One approximates conditions in a gas well or pipeline by assuming that temperature and compressibility are constants for the entire gas column.
The Reservoir Mechanism of Sulfur Recovery
Authors: Rayne John R. , Craft B.C. , Hawkins Murray F. 
Published: February 2020

Published in Petroleum Transactions, AIME, Volume 207, 1956, pages 246–251.

Abstract
A reservoir mechanism of sulfur recovery by the Frasch process is presented. Improving the economics of recovery appears to be largely a well, rather than a reservoir problem. A most important factor is the limitation of the lateral extraction of sulfur about the wells due to the almost vertical flow of the injected hot water. Model studies are described which confirm the mechanism of sulfur recovery by presently used methods. Studies on a five-spot system indicate improved economics regarding recovery, recovery rate, thermal efficiency, and well spacing.

Introduction
Sulfur mining by the Frasch process is one of the most important methods of sulfur production. Developed by Herman Frasch in 1894, it enjoyed a rapid growth and presently supplies 40 per cent of the world's sulfur and about 80 per cent of the U. S. sulfur. The Frasch process of mining the underground native sulfur deposits involves melting the sulfur in place by introducing super-heated water into the sulfur bearing formations, and producing the sulfur as a liquid. Many problems are encountered in mining these native sulfur deposits, and sulfur production depends chiefly upon the nature of the sulfur deposit and the underground thermal efficiency of the heat transfer system.

The Recovery Mechanism
Sulfur is typically found in salt dome cap rock as crystal aggregates occurring within the cavities, seams, and pores of limestone and gypsum formations. Sulfur-bearing limestone is typically cavernous, vugular, and fractured. Porosity averages about 20 per cent and sulfur saturation averages approximately 25 per cent by weight. The sulfur bearing formations are very heterogeneous in nature and physical characteristics vary widely within small distances. Total cap rock thickness may vary from 50 to more than 1,000 ft, and net productive thicknesses from a few feet to a few hundred feet. In most cases the upper portion of the limestone formation is barren of sulfur, varying from 5 to 2,000 ft in thickness. The immediately overlying sediments and the underlying dense anhydrite formation provide permeability barriers to the flow of water from the cap rock section.
Darcy's Law and the Field Equations of the Flow of Underground Fluids
Authors: Hubbert M. King 
Published: February 2020

Published in Petroleum Transactions, AIME, Vol. 207, 1956, pages 222–239. Paper prepared for presentation before Darcy Centennial Hydrology Symposium of the International Association of Hydrology held in Dijon, France. Sept. 20–26, 1956, and for dual publication as part of the Dijon Symposium and in the Darcy Centennial Issue of Journal of Petroleum Technology.

ABSTRACT
In 1856 Henry Darcy described in an appendix to his book, Les Fontaines Publiques de la Ville de Dijon, a series of experiments on the downward flow of water through filter sands, whereby it was established that the rate of flow is given by the equation:
q = − K (h2 − h1) /l.
in which q is the volume of water crossing unit area in unit time. l is the thickness of the sand, h1 and h2 the heights above a reference level of the water in manometers terminated above and below the sand, respectively, and K a factor of proportionality.
This relationship, appropriately, soon became known as Darcy's law. Subsequently many separate attempts have been made to give Darcy's empirical expression a more general physical formulation, with the result that so many mutually inconsistent expressions of what is purported to be Darcy's law have appeared in published literature that sight has often been lost of Darcy's own work and of its significance.
In the present paper, therefore. it shall be our purpose to reinform ourselves upon what Darcy himself did, and then to determine the meaning of his results when expressed explicitly in terms of the pertinent physical variables involved. This will be done first by the empirical method used by Darcy himself, and then by direct derivation from the Navier-Stokes equation of motion of viscous fluids.
The Validity and Reliability of the Patient Health Questionnaire-9 in Screening for Post-Stroke Depression
Authors: Dajpratham Piyapat , Pukrittayakamee Panate , Atsariyasing Wanlop , Wannarit Kamonporn , Boonhong Jariya , Pongpirul Krit 
Published: February 2020

Abstract
Background: Depression affects about 30% of stroke survivors within five years. Timely diagnosis and management of post-stroke depression facilitate motor recovery and improve independence. The original version of the Patient Health Questionnaire-9 (PHQ-9) is recognized as a good screening tool for post-stroke depression. However, no validation studies have been undertaken for the use of the Thai PHQ-9 in screening for depression among Thai stroke patients.
Methods: The objectives were to determine the criterion validity and reliability of the Thai PHQ-9 in screening for post-stroke depression by comparing its results with those of a psychiatric interview as the gold standard. First-ever stroke patients aged ≥ 45 years with a stroke duration 2 weeks–2 years were administered the Thai PHQ-9. The gold standard was a psychiatric interview leading to a DSM-5 diagnosis of depressive disorder. The summed-scored-based diagnosis of depressive disorder with the PHQ-9 was obtained. Validity and reliability analyses, and a receiver operating characteristic curve analysis, were performed.
Results: In all, 115 stroke patients with a mean age of 64 years (SD: 10 years) were enrolled. The mean PHQ-9 score was 5.2 (SD: 4.8). Using the DSM-5 criteria, 23 patients (20%) were diagnosed with depressive disorder. The Thai PHQ-9 had satisfactory internal consistency (Cronbach’s alpha: 0.78). The algorithm-based diagnosis of the Thai PHQ-9 had low sensitivity (0.52) but very high specificity (0.94) and positive likelihood ratio (9.6). Used as a summed-scored-based diagnosis, an optimal cut-off score of six revealed a sensitivity of 0.87, specificity of 0.75, positive predictive value of 0.46, negative predictive value of 0.95, and positive likelihood ratio of 3.5. The area under the curve was 0.87 (95% CI: 0.78–0.96).
Conclusions: The Thai PHQ-9 has acceptable psychometric properties for screening for post-stroke depression, with a recommended cut-off score of ≥ 6 for a Thai population.
Evaluation of Integrated Modular Teaching in Chinese Ophthalmology Trainee Courses
Authors: Xin Wei , Zou Yuxian , Ao Yong , Cai Yu , Huang Zheqian , Li Miaoling , Xu Chaochao , Jia Yu , Yang Ying , Yang Yangfan , Lin Haotian 
Published: February 2020

Abstract
Background: Before attending ophthalmology trainee courses in Zhongshan Ophthalmic Centre, the medical students from Sun Yat-sen University had finished two-year premedical education after the six-year medical courses including basic medical courses, clinical medical courses, clerkship, and research training in medical college. Integrated modular teaching using different problem-based teaching methods in ophthalmology was designed by the teaching steering committee of Zhongshan Ophthalmic Centre. This study aimed to evaluate the effectiveness and satisfaction scales of the integrated modular teaching among the trainee students. Methods: A total of 100 medical students attending ophthalmology trainee courses in Zhongshan Ophthalmic Centre were enrolled and randomly allocated into 4 groups according to the teaching arrangement. The trainee courses consisted of several sessions delivered in multiple methods, such as "flipped classroom" session and team-based learning session. The pre- and post-class tests were delivered to evaluate the effectiveness of the integrated modular teaching. The satisfaction survey questionnaire was collected from all participants to investigate the degree of satisfaction. Results: Compared with the first-day-test score, the total last-day-test score was significantly improved (t=3.288, P=0.001) by a paired t-test. Nineteen students obtain a significant improvement in ranking increased by more than 10 in the last-day-test, whereas failed to obtain a higher average score for daily performance than other students (t=0.469, P=0.654). According to the participant satisfaction questionnaires, these innovative teaching methods were considered as effective and satisfactory. Conclusions: Integrated modular teaching in ophthalmology trainee courses is effective and widely recognized by the medical college students.
Genomic heterogeneity of Dichelobacter nodosus within and between UK sheep flocks and between age groups within a flock
Authors: DAVIES PEERS , Blanchard Adam , Staley Ceri , Bollard Nikki , Coffey Tracey , Tötemeyer Sabine 
Published: February 2020

Abstract
Footrot and interdigital dermatitis are endemic infectious diseases in all sheep farming regions, impairing welfare and production. The development of efficacious vaccines against the primary causative pathogen has been hampered by the extensive antigenic diversity of Dichelobacter nodosus . Understanding the heterogeneity of the pathogen within and between farms is essential if the feasibility of bespoke vaccine production is to be assessed for use in the U.K. In this study 56 ewe and lamb isolates from 9 farms were compared by D. nodosus serogroup and Multi Locus Sequence Type which provides significantly enhanced discriminatory power for molecular epidemiology. Within farm genomic heterogeneity was significantly lower than between farms. Serogroup heterogeneity between flocks ranged from two to five unique serogroups per flock. Three flocks contained isolates of two serogroups, two flocks contained isolates of three serogroups and one flock included isolates of five serogroups. Analysis of 25 isolates from one flock with high prevalence of lameness, identified that serogroup and sequence type was significantly correlated with age. Significantly higher proportion of lambs were infected with serogroup B (principally ST85) as opposed to serogroup H (principally ST86), which predominated amongst adult sheep. This indicates that host-pathogen dynamics and susceptibility to particular D. nodosus strains may be age dependent.
Rno-microRNA-30c-5p promotes myocardial ischemia reperfusion injury in rats through activating NF-κB pathway and targeting SIRT1
Authors: Chen Jianfeng , Zhang Mingming , Zhang Shouyan , Wu Junlong , Xue Shufeng 
Published: February 2020

Abstract
Background: This study aimed to investigate the regulatory effect of rno-microRNA-30c-5p (rno-miR-30c-5p) on myocardial ischemia reperfusion (IR) injury in rats and the underlying molecular mechanisms.
Methods: A rat model of myocardial IR injury was established. The infarct size was detected by 2,3,5-triphenyltetrazolium chloride staining. The pathologic changes of myocardial tissues were detected by hematoxylin-eosin staining. The apoptosis of myocardial cells was measured by TUNEL staining and flow cytometry. The mRNA expression of rno-miR-30c-5p and Sirtuin 1 (SIRT1) was detected by quantitative real-time PCR. The levels of IL-1β, IL-6 and TNF-α were detected by enzyme linked immunosorbent assay. The protein expression of Bax, Bcl-2, caspase-3, p-IκBα, IκBα, p-NF-κB p65, NF-κB p65 and SIRT1 was detected by Western blot. The interaction between rno-miR-30c-5p and SIRT1 was predicted by TargetScan, and further identified by dual luciferase reporter gene and RNA immunoprecipitation assay.
Results: The myocardial IR injury model was successfully established in rats. IR induced the myocardial injury in rats and increased the expression of rno-miR-30c-5p. Overexpression of rno-miR-30c-5p enhanced the inflammation, promoted the apoptosis, and activated NF-κB pathway in IR myocardial cells. SIRT1 was the target gene of rno-miR-30c-5p. Silencing of SIRT1 reversed the effects of rno-miR-30c-5p inhibitor on the apoptosis and NF-κB pathway in IR myocardial cells.
Conclusions: Rno-miR-30c-5p promoted the myocardial IR injury in rats through activating NF-κB pathway and down-regulating SIRT1.
Promoting rational antibiotic prescribing for non-complicated infections: Understanding social influence in primary care networks in Germany
Authors: Poss-Doering Regina , Kamradt Martina , Glassen Katharina , Andres Edith , Kaufmann-Kolle Petra , Wensing Michel 
Published: February 2020

Abstract
Background Primary care networks in Germany are formalized regional collaborations of physicians and other healthcare providers. Common goals are optimized healthcare processes and services for patients, enhanced communication, agency for professional concerns and strengthened economic power. In the ARena study (Sustainable reduction of antibiotic-induced antimicrobial resistance), 14 primary care networks in two federal German states aimed to promote appropriate antibiotics use for acute non-complicated infections by fostering awareness and understanding. Factors related to the role of primary care networks were to be identified.
Methods
For this study, audio-recorded telephone interviews were conducted with physicians, non-physician health professionals and stakeholder representatives. Pseudonymized verbatim transcripts were coded using thematic analysis. In-depth analysis was based on the inductive categories ‘social support’, ‘social learning’, ‘social normative pressures’ and ‘social contagion’ to reflect social influence processes. Data generated through a survey with physicians and non-physician health professionals were analyzed descriptively to foster understanding of the networks’ potential impact on antibiotic prescribing.
Results

Social influence processes proved to be relevant regarding knowledge transfer, manifestation of best-practice care and self-reflection. Peer communication was seen as great asset, main reason for membership and affirmative for own perspectives. All interviewed physicians (n=27) considered their network to be a strong support factor for daily routines, introduction of new routines, and continuity of care. They utilized network-offered training programs focusing on best practice guideline-oriented use of antibiotics and considered their networks supportive in dealing with patient expectations. A shared attitude combined with ARena intervention components facilitated reflected management of antibiotic prescribing. Non-physician health professionals (n=11) also valued network peer exchange. They assumed their employers joined networks to offer improved and continuous care. Stakeholders (n=7) expected networks and their members to be drivers for care optimization.
Conclusion

Primary care networks play a crucial role in providing a platform for professional peer exchange, social support and reassurance. With regards to their impact on antibiotic prescribing for acute non-complicated infections, networks seem to facilitate and amplify quality improvement programs by providing a platform for refreshing awareness, knowledge and self-reflection among care providers. They are well suited to promote a rational use of antibiotics.
Long-term Outcomes of Conservative Treatment and Endovascular Treatment in Patients with Symptomatic Spontaneous Isolated Superior Mesenteric Artery Dissection: A Single-center Experience
Authors: Xu Leyin , Shao Jiang , Zhang Daming , Qiu Chenyang , Wang Jingjing , Li Kang , Fang Lijing , Zhang Xin , Lei Jinsong , Lai Zhichao , Ma Jiangyu , Yu Yanying , Yu Xiaoxi , Du Fenghe , Qi Wanting , Chen Junye , Liu Bao 
Published: February 2020

Abstract
Background: Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a rare vascular disorder, and the treatment strategies remain controversial. This study aimed to compare outcomes of conservative and endovascular treatments in symptomatic patients with SISMAD.
Methods: Forty-two consecutive SISMAD patients who were admitted to a single center between October 2009 and May 2018 were enrolled in this study. Based on their symptoms, 15 had conservative treatment, and 27 had endovascular treatment. The baseline characteristics, treatments, and follow-up results of the conservative group and endovascular group were analysed.
Results: The rates of symptom relief were 93.3% in the conservative group and 96.3% in the endovascular group. The procedure-related complications in the endovascular group included one case of pseudoaneurysm formation in the left brachial artery. During the follow-up period (median 28.5 months), a higher proportion of patients in the conservative group had symptom recurrence (42.9% in the conservative group versus 4.8% in the endovascular group, p < 0.001). Four patients in the conservative group and one patient in the endovascular group had additional endovascular intervention during follow-up. Compared with the conservative group, patients in the endovascular group had statistically significantly longer symptom-free survival ( p = 0.014) and a higher rate of superior mesenteric artery (SMA) remodeling ( p < 0.001).
Conclusions: For symptomatic SISMAD, endovascularly treated patients had a lower rate of symptom recurrence and a higher rate of SMA remodeling in the long term. Prospective, multi-center studies are needed to confirm the long-term outcomes of both treatments.
Reversed paired-gRNA plasmid cloning strategy for efficient genome editing in Escherichia coli.
Authors: Ding Tingting , Huang Chaoyong , Liang Zeyu , Ma Xiaoyan , Wang Ning , Huo Yi-Xin 
Published: February 2020

Abstract
Background: Co-expression of two distinct guide RNAs (gRNAs) has been used to facilitate the application of CRISPR/Cas9 system in fields such as large genomic deletion. The paired gRNAs are often placed adjacently in the same direction and expressed individually by two identical promoters, constituting direct repeats (DRs) which are susceptible to self-homologous recombination. As a result, the paired-gRNA plasmids cannot remain stable, which greatly prevents scalable application of the CRISPR/Cas9 system. Results: To address this limitation, different DRs-involved paired-gRNA plasmids were designed and the events of recombination were characterized. Deletion between DRs occurred with high frequencies during plasmid construction and subsequent plasmid propagation. This recombination event was RecA-independent, which agreed with the replication slippage model. To increase plasmid stability, a reversed paired-gRNA plasmids (RPGPs) cloning strategy was developed by converting DRs to the more stable invert repeats (IRs), which completely eliminated DRs-induced recombination. Using RPGPs, rapid deletion of chromosome fragments up to 100 kb with an efficiency of 83.33% was achieved in Escherichia coli. Conclusions: The RPGPs cloning strategy serves as a general solution to avoid plasmid RecA-independent recombination. It can be adapted to applications that rely on paired gRNAs or repeated genetic parts.