bluuebunny/crossref_metadata_2025_split huggingface dataset:
Technology Focus: Tight Reservoirs (October 2020)
Authors: Kalfayan Leonard 
Published: November 2020

The low-oil-price environment continues to challenge and pressure our industry to reduce costs and optimize production. While cost reductions and efficiency improvements are always the primary focus during downturns such as we are now experiencing, history tells us that many technology and application breakthroughs have been developed in such periods. This is also a time for conducting or supporting technical studies that can provide insight on how operators can optimize production - especially from unconventional-resource developments. In the meantime, major operators are increasingly stepping out, supporting development of alternative, unconventional energy sources, such as natural gas production from gas hydrates, as the industry looks to the future.
With reduced new unconventional well activity, practices such as frac-hit mitigation - pressurization of parent wells during child-well fracture stimulation - have become increasingly important to reduce parent-well proppant cleanouts as well as to maximize production from both parent and child wells. With reduced new well activity, it is also increasingly important to dampen the sharp early-time production rate declines as much as possible, having longer-term recovery as the objective rather than just high initial production. Unlike with conventional oil wells, for example, unconventional wells have not seen the same degree of attention placed on the effects of high drawdowns on productivity decline.
Two paper synopses featured this month are along those lines. The first, paper IPTC 20260, presents the results of a geomechanics study on rock sensitivity to increasing compressive stress, such as would be experienced with high drawdowns and accelerated depletion. The paper describes and quantifies the stress-dependence of compaction and permeability for anisotropic rock matrix, natural fractures, and hydraulic fractures.
The second, paper SPE 197097, discusses the enhancement of frac-hit mitigation treatments with surfactant chemistry, showing that surfactant additive to the child-well treatments can migrate to parent wells, activating oil-recovery mechanisms.
Finally, for something different but within the world of unconventional resources, the third paper featured this month, paper SPE 29516, is a report on several offshore gas hydrate production tests in offshore sand reservoirs, which have become more-viable natural gas resource targets given the advancement in hydrate production technologies. The report focuses on key production tests conducted in northern Canada, Alaska, Japan, and the South China Sea.
Machine-Learning Approach Determines Spatial Variation in Shale Decline Curves
Authors: Feder Judy 
Published: November 2020

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper SPE 196110, “Machine Learning of Spatially Varying Decline Curves for the Duvernay Formation,” by Aleksandr Bakay, Jef Caers, and Tapan Mukerji, SPE, Stanford University, et al., prepared for the 2019 SPE Annual Technical Conference and Exhibition, Calgary, 30 September-2 October. The paper has not been peer reviewed.
The two most common techniques for forecasting production performance for a new shale well are decline- (type) curve analysis and machine learning. The complete paper describes an automated machine-learning approach to determine the spatial variation in decline type curves for shale gas production, based on existing data of production, completion, and geological parameters. The methodology allows the user to decide whether the focus should be purely on forecast quality or on a combination of forecast and clustering quality. The resulting model will enable the prediction and uncertainty quantification of production profiles for new target wells or areas in the basin.
Methods of Forecasting Production Performance
Decline-curve analysis is the most-popular technique for forecasting production performance in shale formations because of the need for fast decisions. The technique involves borrowing decline curves from the closest wells or from wells with similar geological, completion, or fluid properties.
The idea of decline-curve analysis is based on the fact that a similar production profile is expected from the closest wells or from wells with similar properties. However, the process is often manual and very subjective. As a result of the approach, each existing well is assigned to a particular cluster of decline curves, each cluster having a certain typical decline curve. Clusters can be spatial or represented in completion variable space. To obtain a production forecast for a new well, the authors use the decline curve from a cluster to which it is believed that the new well will belong, usually sampling from a cluster map.
The second approach to forecasting shale production performance is machine learning that focuses on statistical correlations. A statistical model is created that connects decline curves with the same well parameters used in decline curve analysis. Typically, the result is a trained machine-learning model. For a new well, it provides production performance, with or without an uncertainty range. Additionally, maps can be created of forecasted production profiles or total recovered fluid.
The objective of the project described in the complete paper was to provide a methodology that creates clusters of decline curves and estimates decline curves for a particular location or set of variables. The intent was to limit the manual aspect of clustering and create a robust work flow.
An outbreak of Coxsackievirus A6 infection in adults of a collective unit, China, 2019
Authors: Gao Yumeng , Ma Guangyuan , Xiao Yong , Cai Qun , Chen Yujun , Shi Ping , Shi Chao , Shen Yuan 
Published: November 2020

Abstract
Background: Outbreaks/epidemic caused by Coxsackievirus A6 have been reported continuously since 2008. However, outbreaks caused by Coxsackievirus A6 infection in adults of a collective unit have not been reported.Methods: The nasopharyngeal swab specimens were collected to extract the total nucleic acid (DNA/RNA). The pathogen was determined using nucleic acid detection kits for 22 respiratory pathogens. The VP1 gene of this pathogen was amplified and sequenced. Sequence alignment and analysis were performed using Bioedit. The gene phylogenetic tree was constructed with MEGA software.Results: The factory emerged patients in succession from the February 14 and reached the peak on the 18th. The main symptoms were rash, ocular conjunctival hemorrhage, fever and sore throat. A total of 19 workers had symptoms in this factory up to March 31, 2019, giving an attack rate of 8.26%. The laboratory results showed that Coxsackievirus A6 was the main pathogen causing this outbreak. The risk of taking a bath in the bathroom was 7.37 times higher than that of not taking a bath (95% CI: 1.67-32.79).Conclusions: This manuscript further enriched the infection-related information of CVA6, which was helpful to better identify and deal with the epidemic in the future.
Isolation of axenic cyanobacterium and the promoting effect of associated bacterium on axenic cyanobacterium
Authors: Gao Suqin , Kong Yun , Yu Jing , Miao Lihong , Ji Lipeng , Song Lirong , Zeng Chi 
Published: November 2020

Abstract
Background: Harmful cyanobacterial blooms have attracted wide attention all over the world as they cause water quality deterioration and ecosystem health issues. Microcystis aeruginosa associated with a large number of bacteria is one of the most common and widespread bloom-forming cyanobacteria that secret toxins. These associated bacteria are considered to benefit from organic substrates released by the cyanobacterium. In order to avoid the influence of associated heterotrophic bacteria on the target cyanobacteria for physiological and molecular studies, it is urgent to obtain an axenic M. aeruginosa culture and further investigate the speciﬁc interaction between the heterotroph and the cyanobacterium. Results: A traditional and reliable method based on solid-liquid alternate cultivation is carried out to purify the xenic cyanobacterium M. aeruginosa FACHB-905. On the basis of 16S rDNA gene sequences, two associated bacteria named strain B905-1 and strain B905-2, are identified as Pannonibacter sp. and Chryseobacterium sp. with a 99% and 97% similarity value, respectively. The axenic M. aeruginosa FACHB-905A (Microcystis 905A) is not able to form colonies on BG11 agar medium without the addition of strain B905-1, while it grows well in BG11 liquid medium. Although the presence of B905-1 is not indispensable for the growth of Microcystis 905A, B905-1 has a positive effect on promoting the growth of Microcystis 905A. Conclusions: The associated bacteria are eliminated by solid-liquid alternate cultivation method and the axenic Microcystis 905A is successfully purified. The associated bacterium B905-1 has the potential to promote the growth of Microcystis 905A. Moreover, the purification technique for cyanobacteria described in this study is potentially applicable to a wider range of unicellular cyanobacteria.
The invasion depth measurement of bladder cancer using T2-weighted magnetic resonance imaging
Authors: Liu Yang , Zheng Haojie , Xu Xiaopan , Zhang Xi , Du Peng , Liang Jimin , Lu Hongbing 
Published: November 2020

Abstract
Background: Invasion depth is an important index for staging and clinical treatment strategy of bladder cancer (BCa). The aim of this study was to investigate the feasibility of segmenting the BCa region from bladder wall region on MRI, and quantitatively measuring the invasion depth of the tumor mass in bladder lumen for further clinical decision-making. This retrospective study involved 20 eligible patients with postoperatively pathologically-confirmed BCa. It was conducted in the following steps: (1) a total of 1159 features were extracted from each voxel of both the certain cancerous and wall tissues with the T2-weighted (T2W) MRI data; (2) the support vector machine (SVM)-based recursive feature elimination (RFE) method was implemented to first select an optimal feature subset, and then develop the classification model for the precise separation of the cancerous regions; (3) after excluding the cancerous region from the bladder wall, the three-dimensional bladder wall thickness (BWT) was calculated using Laplacian method, and the invasion depth of BCa was eventually defined by the subtraction of the mean BWT excluding the cancerous region and the minimum BWT of the cancerous region.Results: The segmented results showed a promising accuracy, with the mean Dice similarity coefficient of 0.921. The “soft boundary” defined by the voxels with the probabilities between 0.1 and 0.9 could demonstrate the overlapped region of cancerous and wall tissues. The invasion depth calculated from proposed segmentation method was compared with that from manual segmentation, with a mean difference of 0.277 mm.Conclusion: The proposed strategy could accurately segment the BCa region, and, as the first attempt, realize the quantitative measurement of BCa invasion depth.
Delayed COVID-19 sequel - A challenging case of recurrent spontaneous pneumothorax
Authors: Kasturi Srikanth , Muthirevula Arvind , Chinthareddy Rohan R , Lingaraju Vijay C 
Published: November 2020

Abstract
Pneumothorax, as a consequence of COVID-19 infection, has become an established entity but the delayed occurrence of pneumothorax after recovery from the illness is less commonly reported. We present a case of delayed recurrent spontaneous pneumothorax, presenting four weeks after recovery from COVID-19 in a previously healthy middle-aged gentleman, for which uniportal-VATS pleurectomy was performed but the cause of pneumothorax could not be ascertained. This report brings to light, the importance of continued surveillance of COVID-19 survivors, the unpredictability of the disease process, and the challenges of thoracic surgery in this unique subset of patients.
Endoscopic Retrieval of Ingested Dental Bur in a geriatric patient: A Case Report
Authors: K Keerthana , Shetty Karthik , Jathanna Vinod , Nath Kartik , M Roma 
Published: November 2020

Abstract
Background: Accidental ingestion of a dental bur during the dental procedure is not a routine incident, but can result in serious complication and consequences. Case scenario: In this case report, a 76 - year old male patient, accidentally ingested a dental bur during the procedure. The presence and location of the dental bur was confirmed using chest and abdominal x-rays and it was subsequently retrieved by endoscopy procedure under general anaesthesia. The analysis of this case reaffirms the importance of the use of physical barriers such as rubber dams and gauze screens as precautionary measures to prevent such incidents from occurring.Conclusion: Taking the patient into confidence and informing him regarding the possible complications of the accident and keeping him/her under observation until the object has been removed, would fulfil the professional responsibilities of a dentist, and will result in avoiding possible legal and ethical issues. Presented case represented the usage of physical barriers in dentistry and their usefulness in the treatment protocol.
Spatio-temporal Dynamics, Drivers, Effects and Environmental Implications of Land use/land Cover Changes in Ambo Town and Its Watershed, West Shoa Zone, Oromia Regional State, Ethiopia
Authors: Ogato Gemechu Shale , Bantider Amare , Geneletti Davide 
Published: November 2020

Abstract
Background: Land use/land cover change in urban watersheds of developing countries like Ethiopia is claimed to be a consequence of complex interaction of different actors, driving forces, and land itself. It is asserted to result in the degradation of natural vegetation and significant increases in impervious surfaces. The purpose of the study was to analyze spatio-teporal changes in land use/ land cover in Huluka watershed where Ambo town is situated and examine their drivers and effects with environmental implications.Results: The overall increase of urban built-up area, cultivated land, and bare land use/land cover type with 351%, 105%, and 41.9% respectively between the year 1979 and 2017 implies the increase in flooding disaster risk in the watershed as such land use/land cover types exacerbate the run-off conditions in the watershed. Infrastructural expansion, agricultural expansion, increased demand for fuel wood and wood for construction, local environmental factors, local biophysical drivers, and local Social events were identified as proximate drivers of land use/land cover changes in the study area. Demographic factors, economic factors, technological factors, policy and institutional factors and cultural factors were confirmed as the underlying drivers of land use/land cover change in the watershed. Increased flooding risk, increased soil erosion; increased sedimentation into the lake (Dendi lake) and rivers (Huluka, Awaro, Debis, Boji, Bolo, Aleltu, Karkaro, and Korke), decrease in soil fertility resulting from flooding risk, and change in climatic parameters (decrease in annual rainfall and increase in heat during dry season) were claimed as the negative effects of land use/land cover change in the study area.Conclusions: Practice of appropriate land use planning and management in the watershed, appropriate environmental impact assessment (EIA), and proper planning and management of socio-cultural, economic, and environmental development are of paramount importance to promote sustainable development in the watershed.
A Biomechanical Study of Double-row Suture-bridge and Double-screw Fixation Strength in Split-type Greater Tuberosity Fractures of the Humerus
Authors: Ma Man , Zhang Xiaomeng , Wang Yanhua , Zhang Dianying 
Published: November 2020

Abstract
Background: This study aimed to compare the fixation strength of double-row suture-bridge (DR) and double-screw (DS) fixation methods in treating split-type greater tuberosity fracture of the humerus.Methods: We established 24 fracture models of frozen pig shoulders with reserved supraspinatus, infraspinatus, and teres minor muscles. The specimens were randomly divided into two groups according to the fixation methods of double-row suture-bridge (group A) and double screws (group B). The loads of 3-mm displacement, 5-mm displacement, and fixation failure of each group were measured using a biomechanical device in both traction directions of the supraspinatus muscle (horizontal direction) and infraspinatus-teres minor muscles (vertical backward direction). Results: In the direction of supraspinatus traction, there was no statistical difference in the mean load values of 3-mm displacement, 5-mm displacement, and fixation failure in both groups (p > 0.05). In the direction of infraspinatus-teres minor traction, the mean load values of 3-mm displacement, 5-mm displacement, and fixation failure of double-screw fixation were greater than those of double-row suture-bridge fixation (p = 0.000). Conclusion: The fixation strength of double-screw suture-bridge and double screws were equivalent in the direction of the supraspinatus. However, the fixation strength of double-screw suture-bridge was less than that of double screws, indicating poor anti-rotation property. Double-screw suture-bridge fixation alone is not recommended to treat split-type greater tuberosity fracture with a large fragment.
Quercetin Prevents Primordial Follicle Loss via Suppression of PI3K/Akt/Foxo3a Pathway Activation in Cyclophosphamide - Treated Mouse
Authors: Yu Sha , Li Jianghui , Long Hui , Cong Yanyan , Gao Hongyuan , Lyu Qifeng , Kuang Yanping 
Published: November 2020

Abstract
Background: Chemotherapy improves survival rates but often causes some adverse effects associated with ovarian damage, characterized by a decreased of primordial follicle stockpiles. Recent studies reveal that chemotherapy may stimulate the PI3K signaling pathway, who has roles in manipulating the dormancy and activation of mammalian primordial follicles, resulting in accelerated primordial follicles activation followed by the loss of ovarian reserve. As an inhibitor of PI3K pathway, whether quercetin has protective properties against chemotherapy - induced follicle loss in mice is worth to be explored.Methods：The effects of quercetin on the mouse model of cyclophosphamide-induced ovarian dysfunction were investigated. Paraffin sections of mouse ovary were stained with hematoxylin and eosin for differential follicles count and TUNEL assay for apoptosis detection. Immunohistochemistry stain with ki67 and Foxo3a were used to evaluate the activation of primordial follicles. The function of PI3K signaling pathway were assessed via the western blot of ovary.Results: Quercetin cotreatment rescued the reduction number of dormant primordial follicles induced by cyclophosphamide. Moreover, analysis of the PI3K/Akt/Foxo3a pathway demonstrated that quercetin co - administration decreased phosphorylation of proteins that stimulate follicle activation in ovary induced by cyclophosphamide. Meanwhile, Quercetin prevents cyclophosphamide - induced apoptosis in early growing follicles and early antral follicles, maintaining AMH level secreted by these follicles, preserving the quiescence of the primordial follicle pool, characterized by the intranuclear staining of Foxo3a in primordial follicle. Conclusions: Quercetin attenuates cyclophosphamide - induced follicle loss by preventing the phosphorylation of PI3K/Akt/Foxo3a pathway members and maintaining AMH level secreted by growing follicles.
Visuo-postural Dependency Index (VPDI) in Human Postural Control.
Authors: Danna-dos-Santos Alessander , Santos Maria M Ribeiro dos , Magalhaes Alessandra T , Cardoso Vinicius S , Driusso Patricia , Mochizuki Luis , Degani Adriana M 
Published: November 2020

Abstract
Background: Computerized stabilometry has been utilized to investigate the effect of vision on the neuromechanisms of human postural control. However, this approach lacks operational methods to quantify visual dependency during upright stance. Objectives: The study had three goals: (1) To introduce the concept of visuo-postural dependency indices (VPDI) representing balance sway characteristics in multiple analytical domains (spatial, temporal, frequency, and structural), (2) To investigate the age and gender effects on VPDIs, and (3) To investigate the degree of relationships between VPDI and both subjective visual vertical and horizontal perception (SVV and SVH, respectively). Methods: 102 participants (16 to 80 years old) performed bipedal stance on a force platform with eyes open and closed. Response variables included the VPDIs computed for each postural index. In addition, 29 participants also performed SVV and SVH assessments. Results: Fifteen VPDIs showed to be robust indicators of visual input modulation, and the variation across their magnitudes of modulation revealed a non-homogeneous response to changes in visual stimuli. Gender and age were not found to be a significant factor to VPDI modulation. Conclusions: VPDIs revealed to be potential measures capable to quantitatively assess visuo-postural dependency and aid the assessment of fall risks and balance impairments.
Combination of Lyophilized Adipose-Derived Stem Cells Concentrated Conditioned Medium and Polysaccharide Hydrogel in the Inhibition of Hypertrophic Scarring
Authors: Zhang Chaoyu , Wang Ting , Zhang Li , Chen Penghong , Tang Shijie , Chen Aizhen , Li Ming , Peng Guohao , Gao Hangqi , Weng Haiyan , Zhang Haoruo , Li Shirong , Chen Jinghua , Chen Liangwan , Chen Xiaosong 
Published: November 2020

Abstract
BackgroundMesenchymal stem cell-based acellular therapies have been widely exploited in managing hypertrophic scar. However, low maintenance dose and transitory therapeutic effects during topical medication remain a thorny issue. Herein, this study aimed to optimize the curative effect of adipose-derived stem cells conditioned medium (ADSC-CM) in the prevention of hypertrophic scarring. MethodsIn the present study, ADSC-CM was concentrated via the freeze-drying procedure. The efficacy of different dose groups (CM, CM5, CM10) was conducted on the proliferation, apoptosis, and α-smooth muscle actin (α-SMA) expression of human keloid fibroblasts (HKFs) in vitro. Incorporation of adipose-derived stem cells concentrated conditioned medium (ADSCC-CM) into polysaccharide hydrogel was investigated in rabbit ear, in vivo. Haematoxylin-eosin (H&E) and Masson's trichrome staining were performed for the evaluation of scar hyperplasia. ResultsWe noted that ADSCC-CM could downregulate the α-SMA expression of HKFs in a dose-dependent manner. In the rabbit ear model, the scar hyperplasia in the medium-dose group (CM5) and high-dose group (CM10) was inhibited with reduced scar elevation index (SEI) under 4 months of observation. It is noteworthy that the union of CM5 and polysaccharide hydrogel (CM5+H) yielded the best preventive effect on scar hyperplasia. Briefly, melanin, height, vascularity and pliability in the CM5+H group were better than those of the control group. Collagen was evenly distributed, and skin appendages could be regenerated.ConclusionsAltogether, ADSCC-CM can downregulate the expression of α-SMA due to its anti-fibrosis effect, and promote the rearrangement of collagen fibres, which is integral to scar precaution. The in situ cross bonding of ADSCC-CM and polysaccharide hydrogel could remarkably enhance the therapeutic outcomes in inhibiting scar proliferation. Hence, the alliance of ADSCC-CM and hydrogel may become a potential alternative in hypertrophic scar prophylaxis.