bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanisms for Huff-n-Puff Cyclic Gas Injection into Unconventional Reservoirs
Authors: Hoffman B. Todd , Rutledge Jeffrey M. 
Published: April 2019

Abstract
Unconventional oil reservoirs such as the Eagle Ford have had tremendous success over the last decade, but challenges remain as flow rates drop quickly and recovery factors are low; thus, enhanced oil recovery methods are needed to increase recovery. Interest in cyclic gas injection has risen as a number of successful pilots have been reported; however, little information is available on recovery mechanisms for the process. This paper evaluates oil swelling caused by diffusion and advection processes for gas injection in unconventional reservoirs.
To accurately evaluate gas penetration into the matrix, the surface area of the hydraulic fractures needs to be known, and in this work, three different methods are used to estimate the area: volumetrics, well flow rates and linear fluid flow equations. Fick's law is used to determine the gas penetration depth caused by diffusion, and the linear form of Darcy's law is used to find the amount from advection. Then, with the use of swelling test information from lab tests, we are able to approximate the amount of oil recovery expected from cyclic gas injection operations.
During the gas injection phase, gas from the fractures can enter the matrix by both advection (Darcy driven flow) and diffusion. We estimate that over 200 million scf of gas can enter the matrix during a 100 day injection/soak period. Using typical reservoir and fluid parameters, it appears that 40% is due to diffusion and 60% is due to advection. Sensitivity analysis shows that these numbers vary considerable based on the parameters used. Analytical models also show that during a 100 day production timeframe, over 14,000 stock tank barrels (STB) of oil can be produced due to huff-n-puff gas injection.
Both gas injection and oil recovery amounts are compared to recent Eagle Ford gas injection pilot data, and the model results are consistent with the field pilot data.
By determining the relative importance of the different recovery mechanisms, this paper provides a better understanding of what is happening in unconventional reservoirs during cyclic gas injection. This will allow more efficient injection schemes to be designed in the future.
Elastic Friction Reducer Facilitates Proppant Transport and FR Residual Analysis Provides Insight into Potential Formation Damage
Authors: Xu Liang , Ogle James , Collier Todd , French Jeremy , Nichols Rome , Simmons Brian 
Published: April 2019

Abstract
High viscosity friction reducers (HVFRs) are an important component of slickwater hydraulic fracturing applications. To continue to treat multiple clusters effectively within longer laterals, even for stages near the toe area, a high molecular weight HVFR polymer, such as polyacrylamide, is commonly used to overcome pipe friction at 1 gal/Mgal or lower. To carry proppant into fractures, it is commonly assumed that the higher viscosity the HVFR yields, the better the proppant transport, necessitating higher HVFR concentrations than 1 gal/Mgal. However, a field study within the Anadarko Basin demonstrates that viscosity is not necessarily the best indicator of how efficient HVFRs carry proppant. Instead, HVFR elasticity might play a more important role during proppant transport.
Secondly, HVFRs 1 gal/Mgal or higher could potentially plug the proppant pack or form a filter cake on the rock surface, causing formation damage. Although previous laboratory methods to determine potential formation damage exist, results are difficult to correlate with field applications; hence, the conclusions remain elusive. A relatively new analysis procedure yielding improved assessments of residual HVFR concentrations for both flowback and produced waters, which aid understanding potential formation damage after hydraulic fracturing, is discussed.
Self-Adjusting Anomaly Detection Model for Well Operation and Production in Real-Time
Authors: Snyder Jon , Scott Stuart , Kassim Rashid 
Published: April 2019

Abstract
Plunger lifted, and free-flowing gas wells experience a wide range of issues and operational inefficiencies such as liquid-loading, downhole and surface restrictions, stuck or leaking motor control valves, and metering issues. These issues can lead to extended downtime, equipment failures, and other production inefficiencies. Using data science and machine-learning algorithms, a self-adjusting anomaly detection model considers all sensor data, including the associated statistical behavior and correlations, to parse any underlying issues and anomalies and classifies the potential cause(s). This paper presents the result of a Proof of Concept (PoC) study conducted for a South Texas operator encompassing 50 wells over a three-month period. The results indicate an improvement compared to the operators’ visual inspection and surveillance anomaly detection system. The model allows operators to focus their time on solving problems instead of discovering them. This novel approach to anomaly detection improves workflow efficiencies, decreases lease operating expenses (LOE), and increases production by reducing downtime.
Validity of Mini-Fluid Challenge for Predicting Fluid Responsiveness Following Liver Transplantation
Authors: Mukhtar Ahmed , Awad Maha , Elayashy Mohamed , Hussein Amr , Obayah Gihan , Adawy Akram El , Ahmed Mai , Dahab Hisham Abul , Hasanin Ahmed , Elfouly Amr , Abdo Mostafa , Abdelaal Amr , Teboul Jean 
Published: April 2019

Abstract
Background

Mini-fluid challenge is a well tested and effective tool to predict fluid responsiveness under various clinical conditions. However, mini-fluid challenge has never been tested in patients with end-stage liver disease. This study investigated whether infusion of 150 ml albumin 5% can predict fluid responsiveness in cirrhotic patients following liver transplant.

Methods

Fifty patients receiving living donor liver transplant were included in the analysis. Mini-fluid challenge composed of 150 ml of albumin 5% administered over 1 min in three consecutive 50-ml fluid boluses. An additional 350 ml was then infused at a constant rate over 15 min (for a total of 500 ml). Stroke volume (SV) was measured as the product of the subaortic velocity time integral (VTI) and left ventricular outflow tract (LVOT) area. Fluid responsiveness was defined as an increase in SV by ≥15% after the infusion.

Results

Fifty patients were enrolled in the study. Fourteen patients were classified with Child A, 15 patients with Child B, and 21 patients with Child C cirrhosis. Thirty four patients were fluid responders and 16 patients were fluid non-responders. After 150 ml of albumin 5%, the SV increased significantly in our cohort. The area under receiver operating curve (AUROC) was 0.7 (95% confidence interval [CI] 0.5–0.8, P = 0.005). In subgroup analysis, the SV increased significantly after mini fluid challenge in the Child A group (P = 0.017) but not Child B or C groups (P = 0.3 and 0.29, respectively). The AUROC for mini-fluid challenge in the Child A group was 0.86 (95% confidence interval [CI] 0.6–0.9, P = 0.0004), while mini-fluid challenge failed to discriminate between responders and non-responders in Child B and C groups.

Conclusion

A mini-fluid challenge of 150 ml albumin 5% can predict fluid responsiveness in liver transplant patients with fair sensitivity and specifiicty. Subgroup analyis revealed that minifluid challenge can predict fluid responsiveness in patients with Child A cirrhosis but not patients with Child B or C cirrhosis

Trial Registration Number

NCT03396159. (Prospective registered). Initial registration date was 10/01/2018
Amyloid-Negative Dementia in the Elderly is Associated with High Accumulation of Tau in the Temporal Lobes
Authors: Takeuchi Jun , Kikukawa Takayuki , Saito Haruna , Hasegawa Itsuki , Takeda Akitoshi , Hatsuta Hiroyuki , Kawabe Joji , Wada Yasuhiro , Mawatari Aya , Igesaka Ami , Doi Hisashi , Watanabe Yasuyoshi , Shimada Hitoshi , Kitamura Soichiro , Higuchi Makoto , Suhara Tetsuya , Itoh Yoshiaki 
Published: April 2019

Background:
We previously reported that among cases clinically diagnosed with Alzheimer’s disease, the proportion of amyloid beta (Aβ) -negative case increases in the elderly population. Tauopathy including Argyrophilic Grain Disease (AGD) and Neurofibrillary Tangle-Predominant Dementia (NFTPD), may be the leading causes of such dementia.

Objective:
To evaluate the involvement of tau, we studied tau accumulation in Amyloid-Negative Dementia Cases in the Elderly (ANDE) with Positron Emission Tomography (PET).

Methods:
Seven cases with slowly progressive dementia who were older than 80 years and were negative for Aβ were studied. In one case, autopsy obtained 2 years after the PET examination revealed neurofibrillary tangles limited around the parahippocampal gyrus. Four cases showed strong laterality in magnetic resonance imaging atrophy (clinical AGD), while the other three cases had no significant laterality in atrophy (clinical NFTPD). Age-corrected PET data of healthy controls (HC; n = 12) were used as control. Tau accumulation was evaluated with [11C]PBB3-PET.

Results:
High accumulation was found in the lateral temporal cortex in ANDE. In autopsy case, scattered neurofibrillary tangles were found in the parahippocampal gyrus. In addition, there was a very high accumulation of PBB3 in the large area of bilateral parietal lobes, although no corresponding tau component was found in the autopsied case.

Conclusion:
Relatively high burden of tau deposition was commonly observed in the lateral temporal cortex and parietal cortex of ANDE, part of which may explain dementia in these subjects. [11C]PBB3 may be useful in detecting tauopathy in ANDE.
Comparison of G-guide and Image-free Navigation System in Accuracy of Stem Anteversion Assessment During Total Hip Arthroplasty
Authors: Fujihara Yuki , Fukunishi Shigeo , Fukui Tomokazu , Nishio Shoji , Takeda Yu , Okahisa Shohei , Yoshiya Shinichi 
Published: April 2019

Introduction:
We have developed and utilized the Gravity-guide (G-guide) as a simple manual instrument for intraoperative assessment and adjustment of stem anteversion (AV). Since 2013, we simultaneously measured stem AV using the G-guide and image-free navigation during THA procedure. The purpose of this study was to compare the measurement accuracy of the G-guide and navigation system using the postoperative CT results as a reference.

Methods:
In total, 59 hips in 56 patients who underwent primary THA using both the G-guide and image-free navigation system were included in the study. All patients underwent postoperative CT examination, and the femoral stem AV was assessed using a 3D image analysis system (Zed hip, LEXI, Japan). The AV angle derived from the postoperative CT image analysis was used as the reference value to assess the accuracy of the two intraoperative measurement systems.

Results:
The discrepancy between the G-guide and the postoperative CT-measured values averaged 5.0° ± 3.9°, while the corresponding value for the navigation system was 5.2° ± 4.1°. Acceptable accuracy with a measurement error of less than 10° was achieved in 86% and 90% of the cases for the G-guide and navigation measurements respectively.

Conclusion:
Consequently, it was shown that both navigation and G-guide measurements can achieve comparative accuracy and are clinically useful.
Knowledge and Awareness about HIV and AIDS among Iraqi College Students
Authors: Naif Hassan Mohammad , Hwaid Asmaa H. , Hasan Abdul-Razak S.H. , Khalifa Rafal M. , Humadi Ashwak T. 
Published: April 2019

Background:Human Immunodeficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS) are the major global public health problems since their discovery in 1983. Knowledge and awareness about the transmission of the virus play an important role toward prevention and the control of the disease. This study aimed to assess the knowledge and awareness about HIV and AIDS among university students of two Iraqi Universities (Diyala and Al-Nahrain) by using a constructed self-administered questionnaire.Methods:This cross-sectional study was conducted on 506 students from two Iraqi Universities using a constructed self-administered questionnaire in 2010 and 2017 for Diyala University and in 2017 for Al-Nahrain University. Data obtained from the students’ responses were collected and statistically analysed. The level of knowledge and awareness was measured according to Bloom’s cut-off point.Results:The study comprised 506 students from the two universities, 341 were females with a mean age of 22.38±4.99 years and 165 were males with a mean age of 22.38±4.99 years. Data revealed that participants, regardless of their gender, on specific questions had different levels (high, moderate and low) of knowledge and awareness about HIV and AIDS. A high level was seen with the causative agent of AIDS and its transmission through blood transfusion, unprotected sexual contact, and sharing needle injection. However, a moderate level was observed regarding antenatal vertical transmission of HIV, shared use of a toothbrush or a razor. While there was inadequate or low knowledge and awareness about HIV spread through breast feeding, during birth, needle sharing and the availability of vaccines. The levels of knowledge and awareness among female students were significantly higher than males in most studied parameters (P=0.03-0.006). The general knowledge and awareness among Diyala’s students declined during the second survey scheduled in 2017 compared with that done in 2010 (P=0.004) for undefined reasons.Conclusion:The general knowledge and awareness about HIV and AIDS was fair among Iraqi students. With the increasing number of HIV cases in Iraq, the inadequacy in knowledge and awareness about spread and prevention of HIV must be considered in the public health strategy and education programs that should comply with Islamic rules and values.
Peningkatan Kapasitas Desa Tangguh Bencana
Authors: Oktari Rina Suryani 
Published: April 2019

ABSTRACT Lam Teungoh village is one of the most affected areas during the tsunami 2004. Twelve years after the tsunami, most of the tsunami preparedness facilities in Lam Teungoh Village, such as evacuation signs and information on tsunami hazards are found in poor conditions. This activity aims to improve the capacity and resilience of apparatus and community of Lam Teungoh Village in the facing disaster. This activity is carried out through participatory survey methods, lectures, discussions, simulation, observation, mentoring, and evaluation. This activity involves several partners including Aceh Besar District Disaster Management Agency, village and community governments, schools, and non-governmental organizations (NGOs). The outcomes of this activity include: i) Increased community understanding on disaster management, ii) Hazards, vulnerabilities, and capacities of Lam Teungoh Village on facing disaster are identified, iii) Disaster Management Plan Document, Disaster Risk Map, and Disaster Evacuation Map are formulated, iv) Disaster Risk Reduction Forum in Lam Teungoh Village is established, and v) Training needs of women and youth group in improving community economic status are identified. Keywords: Aceh Besar; Lam Teungoh; disaster resilient village; resilience community
Lesson Study & Project Based Learning sebagai Upaya Membentuk Forum Diskusi dan Perbaikan Kualitas Pembelajaran Guru IPA
Authors: Hidayat Saleh , Agusta Erie , Siroj Rusdy Abdullah , Hastiana Yetty 
Published: April 2019

ABSTRACT The implementation basic of this dedication begun by the problem of having not a forum for science teacher at SMPN 3 Banyuasin 1 to discuss in solving the problems faced at class. This dedication activity was aimed 1) to increase science teachers’ knowledge at SMPN 3 Banyuasin 1 about lesson study with project based learning model (PjBL) and 2) to know the level of participant's satisfaction toward the implementation of dedication activity. Implementation Methods of dedication activity included: 1) socialization of the PjBL model; 2) socialization of lesson study; 3) socialization of learning devices types; and 4) assistance of implementation simulation of lesson study based PjBL consisting of plan, do, and see. Data collection of knowledge was done by using the questions given before and after the PkM activity, while the satisfaction level of dedication implementation of devotion was taken by using the questionnaire. Data analysis of knowledge and questionnaire using descriptive analysis. The results of the dedication showed that 1) there was the increase of Science Teachers’ knowledge of SMPN 3 Banyuasin 1 about lesson study with PjBL model from 66 to 74,6; and 2) there was the indication of the participants being very satisfied of the implementation of dedication activities. Keywords: lesson study, project based learning, science teacher
Fatores prognósticos e tratamento de pacientes com metástases cerebrais
Authors: Chen Michael Jenwei , Weltman Eduardo , Brandt Reynaldo André , Hanriot Rodrigo De Morais , Nadalin Wladimir 
Published: April 2019

O desenvolvimento de metástases cerebrais é um evento muito freqüente no paciente com câncer, sendo a neoplasia maligna mais prevalente do sistema nervoso central (SNC). O tratamento médico destes pacientes inclui: 1) Medidas inespecíficas, tais como cuidados clínicos gerais (por exemplo, o uso de corticosteróide e drogas anticonvulsivantes, entre outros); 2) Medidas específicas gerais (que tratam todos os possíveis focos de doença no SNC, como radioterapia cerebral total e quimioterapia); e 3) Medidas específicas focais (que tratam somente os focos macroscópicos da doença cerebral, como radiocirurgia estereotáxica e neurocirurgia). Embora o aparecimento de metástases cerebrais represente uma situação clínicadramaticamente negativa, a crença que associa o diagnóstico desta entidade com uma sentença de morte iminente deve ser revista, pois dependendo dos fatores prognósticos associados, certamente a sobrevida dos pacientes pode variar desde semanas até anos. Esta revisão tem foco de discussão na influência que a correta valorização de possíveis fatores prognósticos pode exercer na escolha adequada da terapia para pacientes com metástases cerebrais, no sentido de maximizar benefícios, em termos de qualidade e tempo de sobrevida. A observação dos fatores prognósticos na avaliação do tratamento de metástases cerebrais, certamente uma forma de estadiamento desta entidade, pode ser um importante aliado do paciente na busca de algo além da mera paliação de sua doença.
Análise crítica e comentários acerca da craniectomia descompressiva no tratamento da hipertensão intracraniana refratária decorrente de isquemia no território da artéria cerebral média
Authors: Aguiar Paulo Henrique , De V. Fontes Ricardo Bragança , Simm Renata , Montenegro Myriam Carolina , Petitto Carlo , Faria Suzete , Hirsch Roberto 
Published: April 2019

Introdução: A hipertensão intracraniana refratária secundária ao infarto do território da artéria cerebral média ainda hoje representa uma complexa questão neurocirúrgica. Neste contexto, a craniectomia descompressiva, incluindo suasvariantes, representa uma alternativa envolta em controvérsia. Materiais e métodos: A literatura recente (após 1990) sobre o assunto é revisada, focalizando as principais indicações, diferentes técnicas, timing da cirurgia, complicações e resultados. O total de 19 artigos foram considerados mais relevantes, porémnenhum deles consiste em estudo prospectivo e/ou randomizado. Resultados: A maioria dos artigos, embora longe de um consenso, inclina-se em favor da indicação mais precoce da descompressão baseada em sinais de diminuição do fluxo e aumento da hipertensão intracraniana ou de grande área isquêmica nosexames de imagem com detecção precoce do infarto, enfatizando ainda a importância da avaliação do fluxo sangüíneo regional através do Doppler transcraniano ao longo de toda a evolução do paciente. A maior parte dos estudos também exclui da craniectomia descompressiva aqueles pacientes mais idosos ou com comorbidades graves ou neoplásicas. Conclusão: Apesar de não haver protocolos clínicos de nível I ou II sobre o assunto, cristaliza-se a indicação da craniectomia descompressiva como medida destinada a preservar a vida do paciente.
Tratamento cirúrgico dos meningeomas da goteira olfatória
Authors: Da Silva Carlos Eduardo 
Published: April 2019

Objetivos: O artigo revisa as manifestações clínicas e radiológicas dos meningeomas da goteira olfatória e discute a abordagem cirúrgica destas lesões. Métodos: Foi realizada revisão da literatura com especial atenção nos acessos frontorbitários unilateral e bilateral, além de utilizados casos clínicos ilustrativos do manejo cirúrgico destas lesões. Conclusões: Os meningeomas da goteira olfatória são lesões que envolvem uma região de importantes estruturas neurovasculares e,portanto, representam um formidável desafio neurocirúrgico. A ressecção microcirúrgica radical deve ser sempre o objetivo inicial do tratamento, independentemente do volume da lesão. A ressecção óssea e dural da implantação tumoral diminui o risco de recidiva. A reconstituição da dura-máter da base do crânio deve ser rigorosamente efetuada para prevenção da fístula de liquor.
Cognitive function in neurosurgical clipping of patients with unruptured intracranial aneurysms
Authors: Pereira Filho Arthur A. , Kang Matthew M. , Becske Tibor , Nelson Peter K. , Jafar Jafar J. 
Published: April 2019

There is a consensus that most unruptured intracranial aneurysms can be treated with acceptably low morbidity and mortality. However, some studies recently reported postoperative cognitive impairment, suggesting that it could be attributableto neurosurgical clipping. The goal of this report is to review and discuss aspects referring to cognitive function and neurosurgical repair in patients with unruptured intracranial aneurysms.
Biópsia vertebral percutânea pelo método de preensão direta do tumor vertebral
Authors: Scardino Fabrizio Borges , Barcelos Alécio Cristino Evangelista Santos , Rotta José Marcus , Botelho Ricardo Vieira 
Published: April 2019

O tratamento das metástases vertebrais depende do grau de malignidade e do estadiamento do tumor primário. A biópsia vertebral é uma arma fundamental no diagnóstico e planejamento terapêutico dos tumores vertebrais. Objetivos: Avaliar segurança e eficácia da biópsia vertebral percutânea (BVP) pelo método de preensão direta em diagnosticar malignidades e excluir outras lesões; avaliar a possibilidade de obtenção direta dos espécimes de tumor paraexame de congelação. Método: Foram estudados 10 casos submetidos à biópsia vertebral percutânea de lesões sugestivas de neoplasia no períodode janeiro de 2002 a janeiro de 2006, sendo analisados: indicação da biópsia, estado neurológico do paciente pré e pós-procedimento, complicações e diagnóstico. Em três pacientes, foi realizado exame de congelação da lesão vertebral biopsiada. Resultados: A via predominantemente utilizada para a realização da BVP foi a via transpedicular (9 casos). O diagnóstico histológico foi obtido em 8 casos. O exame de congelação, realizado em três amostras, detectou malignidade em dois casos. Nenhuma amostra foi considerada insuficiente para o diagnóstico. Conclusões: A BVP é um método prático e seguro de aquisição de material para diagnóstico de neoplasias vertebrais. Ométodo de preensão direta dos espécimes possibilita a realização do exame de congelação em tumores “moles”.