bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Normalized Cumulative Production Curves to Estimate Ultimate Recovery of Unconventional Plays in North America
Authors: Olea Ivan , Tabatabaie Hamed , Mattar Louis , Khaksarfard Reza
Published: March 2020

Operators and investors are interested in finding better metrics to evaluate the production performance of unconventional multi-fractured horizontal wells (MFHWs). This paper discusses the use of cumulative productionratio curves,normalized to a given reference volume in time (e.g. 12-month cumulative production) for different unconventional plays in North America to investigate the median trend for each play, and investigate the median ultimate recovery per play. The selection of using 12-month cumulative production as a reference volume as a normalization parameter is discussed.

Historical production data from thousands of MFHWs in unconventional plays in the US (Bakken, Barnett, Eagleford, Fayeteville, Haynesville, Marcellus and Permian) and Canada (Duvernay, Montney and Horn River) was used to calculate normalized cumulative production curves for theprimary fluid, using different cumulative reference volumes at different points in time (e.g. 6, 12, 24, 36, 48 and 60 months). The observed trends for each of the selected plays werestudied using data analytics tools. A two-segment hyperbolic decline was used to match the median production trend to estimate the long-term performance of each play.

Depending on the data variance, some plays exhibit more clear trends than others. By using normalized cumulative production curves, general profiles for each play were generated and compared. These Cumulative Production Ratio Profiles (CPRP) were extended using a two-segment hyperbolic equation to determine the Expected Ultimate Recovery Ratios (EURR) per play.

Once a well in a region has been on production for a minimum duration equal to the reference time (e.g. 12 months), two results are readily determined: a) the EUR, and b) the production profile. The EUR is obtained simply by multiplying the appropriate EURR by the well's 12-month cumulative production; and the production profile is obtained by using the CPRP (cumulative production ratio profile) of the play and multiplying it by the 12-month cumulative production of the welland converting the results to daily rates.

This cumulative plot serves as a normalized typewell for the region and can be used to guide the production forecasts of wells with a short production life.
CGR Normalization-Convert Rates to a Common Surface Process
Authors: Carlsen Mathias Lia , Dahouk Mohamad Majzoub , Hoffmann Arnaud , Whitson Curtis Hays
Published: March 2020

Black oil tables used in reservoir simulation and/or RTA/PTA history matching exercises are generated based on a fixed surface process (number of separator stages, psep, Tsep). However, even though the number of separator stages remain fixed, the separator pressure and temperature vary over time. This variation of separator conditions over time leads to an inconsistency between the rates used in history matching (assumes constant separator conditions) and the actual measured rates (changing separator conditions in the field).

This paper provides a method to adjust all measured rates to a fixed surface process to ensure consistency between the black oil tables and rates used in history matching, and it also investigates for what fluid systems this normalization procedure is important. First, daily wellstream compositions are predicted based on a common equation of state (EOS) model, welltest and production data (separator oil and gas compositions, GOR, stock tank liquid API). Thereafter, these wellstreams are run through a fixed surface process, with the same separator pressure and temperature used to generate the black oil tables utilized in the reservoir modeling.

Several practical observations are made. CGR normalization is in general not important for black- and volatile oil systems. However, it may be very important for near-critical fluids and gas condensate systems.The obvious application of the proposed normalization scheme is to calculate a set of consistent oil and gas rates for every well that can be used for history-matching purposes. Additionally, as black oil PVT properties are a function of the separator process, it is recommended to define a common surface process for an entire field or basin to ensure consistent apple-to-apple comparison between wells.

Technical contributions include a qualitative framework of when CGR normalization is important and when it is not. The paper also proposes a simple solution to a widely known, but under-addressed and overlooked problem, not earlier presented in the open literature.
Unlocking Completion Design Optimization Using an Augmented AI Approach
Authors: Ma Zheren , Davani Ehsan , Ma Xiaodan , Lee Hanna , Arslan Izzet , Zhai Xiang , Darabi Hamed , Castineira David
Published: March 2020

An Augmented AI approach has been developed to optimize completion design parameters and access the full potential of unconventional assets by leveraging big data sculpting, domain-induced feature engineering, and robust and explainable machine learning models with quantified uncertainty. This method unlocks the full potential of a well using completion design parameters optimization that considers all the factors that impact well performance, geological characteristics, well trajectory, spacing, etc.

By leveraging basin-level knowledge captured by big data sculpting with the use of uncertainty quantification, Augmented AI can provide quick and science-based answers for completion optimization, and also assess the full potential of an asset in unconventional reservoirs.

By leveraging computer vision and natural language processing techniques, unstructured data from various sources were deciphered, combined and organized into a structured database. Imputation techniques were used to fill the gaps of missing data. With the Augmented AI approach, the median accuracies of IP and EUR predictions for new drills is around 90%, which often outperforms industry-standard type curving methods. With the explainable machine learning (ML) model, the direct impact of completion design parameters on well performance is deconvoluted among other parameters, such as engineering and geological attributes. The prediction also comes with an 80% confidence interval to quantify the prediction uncertainties, which allows for better risk management and confident business decision making. With the ML model and given economic inputs and metrics, many sensitivity analyses are performed to evaluate optimized completion design parameters. The proposed Augmented AI approach has been deployed to Eagle Ford wells.
Impact of Heterogeneity on Producing GOR for Tight Unconventional Wells
Authors: Alqahtani Fahd Mohamad , Khan Abdul Saboor , Chuparova Ellie , Whitson Curtis Hays
Published: March 2020

The purpose of this paper is to quantify the importance of lateral heterogeneity of permeability and porosity when modeling horizontal, multi-fractured tight unconventional wells exhibiting layer-wise fluid heterogeneity. Fluid and petrophysical properties are taken from the Eagle Ford basin.

A numerical simulation model of a horizontal well drainage volume with multiple planar fractures is created for two layers having distinct fluids (e.g. solution GORs). The model is populated with laterally-heterogeneous, correlated porosities and permeabilities (k=aφb) ranging from 4 to 14 %, and 59 to 2600 nd, respectively. The layer petrophysical properties can map differently for each layer, but the arithmetic average properties are equal for each layer. For all cases studied we assume the initial solution GOR to be areally homogeneous in a given layer; the solution GORs considered range from 1000 to 8000 scf/STB. The petrophysical heterogeneous cases are compared with homogeneous cases (no lateral property variation), both models with the same average petrophysical properties.

Results show that for a heterogeneous-petrophysical case with varying lateral contrast between the petrophysical properties in the two layers, individual fractures produce with distinct GORs, even showing a variation of producing GOR (Rp) from different locations within a single hydraulic fracture. However, the total, well-producing GOR behavior is very similar for the heterogeneous- and homogeneous-petrophysical cases, regardless of the fluid contrast in the two layers, when the maximum-to-minimum permeability ratio kmax/kmin<10.

These observations apply when flowing bottomhole pressure (BHP) is above (single-phase) or below (two-phase) in-situ saturation pressure. These results indicate that lateral petrophysical heterogeneity can often be ignored when modeling tight unconventional wells. The explanation for this non-intuitive result is that the producing surface area from many hydraulic fractures is so extensive that the well-average GOR is very close to the GOR of a well producing from two petrophysically-homogeneous layers having arithmetic-average porosity and permeability. This finding reduces considerably the simulation run time (CPU) using a single "average" hydraulic fracture element, where the key fluid heterogeneity is solution GOR in each layer.

Another important finding is that significant time-variation of producing well GOR may result even when flowing BHP remains higher than in-situ saturation pressures (i.e. single-phase flow). This behavior is caused by differential depletion of the individual layers with fluid contrast in viscosity and compressibility, i.e. without any contrast in layer permeabilities.
The seasonal development dynamics of the yak hair cycle transcriptome
Authors: Bao Pengjia , Luo Jiayu , Liu Yanbin , Chu Min , Ren Qingmiao , Guo Xian , Tang Bolin , Ding Xuezhi , Qiu Qiang , Pan Heping , Wang Kun , Yan Ping
Published: March 2020

Background : Mammalian hair play an important role in mammals' ability to adapt to changing climatic environments. The seasonal circulation of yak hair helps them adapt to high altitude but the regulation mechanisms of the proliferation and differentiation of hair follicles (HFs) cells during development are still unknown. Here, using time series data for whole genome expression profiles and hormone contents, we systematically analyzed the mechanism regulating the periodic expression of hair development in the yak and reviewed how different combinations of genetic pathways regulate HFs development and cycling. Results : This study used high-throughput RNA sequencing to provide a detailed description of global gene expression in 15 samples from five developmental time points during the yak hair cycle. According to clustering analysis, we found that these 15 samples could be significantly grouped into three phases, which represent different developmental periods in the hair cycle. A total of 2,316 genes were identified in these three consecutive developmental periods and their expression patterns could be divided into 9 clusters. In the anagen, genes involved in activating hair follicle growth are highly expressed, such as the WNT pathway, FGF pathway, and some genes related to hair follicle differentiation. In the catagen, genes that inhibit differentiation and promote hair follicle cell apoptosis are highly expressed, such as FABP4 , BMP4 , and Wise . In the telogen, genes that inhibit hair follicle activity are highly expressed, such as DKK1 and BMP1 . Through co-expression analysis, we revealed a number of modular hub genes highly associated with hormones, such as SLF2 , BOP1 , DPP8 . They may play unique roles in hormonal regulation of events associated with the hair cycle. Conclusions : Our results revealed the expression pattern and molecular mechanisms of the seasonal hair cycle in the yak. The findings will be valuable in further understanding the alpine adaptation mechanism in the yak, which is important in order to make full use of yak hair resources and promote the economic development of pastoral plateau areas.
Can cluster analyses of linked healthcare data identify unique population segments in a General Practice-registered population?
Authors: nnoaham kelechi , Cann Kimberley
Published: March 2020

Background: Population segmentation is useful for understanding the health needs of populations. Expert-driven segmentation is a traditional approach which involves subjective decisions on how to segment data, with no agreed best practice. The limitations of this approach are theoretically overcome by more data-driven approaches such as utilisation-based cluster analysis. Previous explorations of using utilisation-based cluster analysis for segmentation have demonstrated feasibility but were limited in potential usefulness for local service planning. This study explores the potential for practical application of using utilisation-based cluster analyses to segment a local General Practice-registered population in the South Wales Valleys.

Methods: Primary and secondary care datasets were linked to create a database of 79,607 patients including socio-demographic variables, morbidities, care utilisation, cost and risk factor information. We undertook utilisation-based cluster analysis, using k-means methodology to group the population into segments with distinct healthcare utilisation patterns based on seven utilisation variables: elective inpatient admissions, non-elective inpatient admissions, outpatient first & follow-up attendances, Emergency Department visits, GP practice visits and prescriptions. We analysed segments post-hoc to understand their morbidity, risk and demographic profiles

Results: Ten population segments were identified which had distinct profiles of healthcare use, morbidity, demographic characteristics and risk attributes. Although half of the study population were in segments characterised as ‘low need’ populations, there was heterogeneity in this group with respect to variables relevant to service planning – e.g. settings in which care was mostly consumed. Significant and complex healthcare need was a feature across age groups and was driven more by deprivation and behavioural risk factors than by age and functional limitation.

Conclusions: This analysis shows that utilisation-based cluster analysis of linked primary and secondary healthcare use data for a local GP-registered population can segment the population into distinct groups with unique health and care needs, providing useful intelligence to inform local population health service planning and care delivery. This segmentation approach can offer a detailed understanding of the health and care priorities of population groups, potentially supporting the integration of health and care, reducing fragmentation of healthcare and reducing healthcare costs in the population.
Three-year Clinical Outcomes of Aspheric Micro-monovision LASIK for Correction of Presbyopia and Myopic Astigmatism
Authors: Liu Fang , Zhang Ting , Liu Quan
Published: March 2020

Background: To investigate the long-term safety and efficacy of aspheric micro-monovision LASIK for the correction of presbyopia and myopic astigmatism. Methods: In total, 114 eyes of 57 patients with a mean age of 48 ± 4.05 years (range: 43 to 62 years) who were undergoing aspheric micro-monovision LASIK treatment were enrolled. Visual acuity, manifest refraction, amplitude of accommodation, contrast sensitivity, entire eye aberrations and patients’ subjective ratings were evaluated from 1 day to 3 years postoperatively. Results: None of the eyes showed a spherical equivalent change of over 0.75 D between 3 months and 3 years, while 95% of the eyes were within ±0.50 D of the target correction of the spherical equivalent. The percentage of patients showing monocular uncorrected distance visual acuity ≥20/20 was 95%, and all eyes achieved a visual acuity of 20/25 or better. The percentage of patients showing binocular uncorrected near visual acuity ≥J2 was 93%, and all patients achieved a visual acuity of J4 or better. Ninety-one percent of the patients had an uncorrected visual acuity of 20/20 in both eyes and J2 or better binocular visual acuity. Six of 108 eyes (6%) lost 1 line, and no eyes lost 2 lines of corrected distance visual acuity. The overall satisfaction score for surgery was 93 ± 6. Conclusions: Aspheric micro-monovision LASIK using the Carl Zeiss Meditec MEL 80 Platform was an efficacious option for older myopic patients with presbyopia. Three-year postoperative outcomes in the Chinese population indicated improvements in uncorrected binocular vision at far and near distances with high satisfaction. Trial registration: The registration number is ChiCTR-IPC-15005842, and the date of registration is January 16, 2015.
Endoscopic intraventricular hematoma evacuation surgery versus external ventricular drainage for the treatment of patients with moderate to severe intraventricular hemorrhage: a multicenter, randomized, controlled trial
Authors: Zhu Junhao , Tang Chao , Cong Zixiang , Yang Jin , Cai Xiangming , Liu Yuxiu , Ma Chiyuan
Published: March 2020

Background

The application of neuroendoscopy in intraventricular hemorrhage (IVH) has attracted more and more attention in recent years. Studies have shown that the use of neuroendoscopy for IVH evacuation has advantages over external ventricular drainage (EVD) alone. However, the cases of most current research are small and all of them are retrospective studies. The aim of this study is to explore the prognosis of patients with moderate to severe IVH who undergo endoscopic IVH evacuation surgery versus those who undergo EVD alone.

Methods

The study is a prospective, randomized, controlled, multi-center clinical trial. Nine hundred and fifty-six subjects with moderate to severe IVH across four tertiary hospitals in China will be randomly assigned (1:1) to receive either endoscopic IVH evacuation surgery or EVD. The primary objective is to compare patients’ survival rate at 12 months postoperatively.

Discussion

The trial is designed to investigate the prognostic benefits of endoscopic IVH evacuation surgery for patients with moderate to severe IVH. Currently, it has never been investigated in a prospective randomized controlled clinical trial.
Clinical Characteristics of Coronavirus Disease 2019 (COVID-19) in Patients out of Wuhan from China
Authors: Zhang Hua , Du Feng , Cao Xiao-jun , Feng Xia-long , Zhang He-ping , Wu Zheng-xia , Wang Bao-Feng , Zhang Hong-juan , Liu Rui , Yang Jian-jun , Ning Bo , Chen Kai , HUANG ZHENPENG
Published: March 2020

Background: A large-scale global outbreak of coronavirus disease-19 (COVID-19) out of Wuhan, from China, occurred in January 2020. Objective: To examine the clinical characteristics of COVID-19in infected patients out of Wuhan, from China. Patients and Methods: Thirteen patients were confirmed to be infected with novel coronavirus-2019 (2019-nCoV) between January 27andFebruary 8, 2020, in Baoji city, Shanxi, northwestern China. Epidemiological and clinical information, and computed to morphology imaging data from all COVID-19 patients were collected; cases were divided into two groups according to the severity of infection (mild or severe). Results: Nine (9/13) COVID-19patientsexhibitedmild disease severity, and defined as second-generation, human-to-human transmission cases. Most patients (11/13) had a history of travel to or from Wuhan. There were no differences in sex and age between the mild and severe cases (all P>0.05). A moderate degree of fever (11/13), cough (13/13), and fatigue (8/13) were common symptoms; however, there was no statistical difference between mild and severe cases in this regard (all P>0.05). Oxyhemoglobin saturation and oxygenation index decreased, and C-reactive protein (CRP) and serum amyloid A (SAA) levels were elevated in all patients with COVID-19infection, with statistically significant differences between those with severe disease and mild infection (all P<0.05).Twelve of 13COVID-19patients exhibited changes in chest CT imaging features, and time course changes were different between mild and severe cases (all P<0.05).Conclusion: Most cases of COVID-19infection were second-generation human-to-human transmissions from Wuhan and were mild in severity. The clinical characteristics of COVID-19varied.Oxyhemoglobin saturation, oxygenation index, CRP and SAA levels, and CT features were reliable parameters to evaluate the severity of COVID-19 infection. However, a few patients with mild COVID-19diseaselackedtypicalcharacteristics such as fever and changes in CT imaging features.
The carbonate concentration mechanism of Pyropia yezoensis (Rhodophyta): Evidence from transcriptomics and biochemical data
Authors: Zhang Baoyu , Xie Xiujun , Sun Yuanyuan , Wang Guangce
Published: March 2020

Background Pyropia yezoensis (Rhodophyta) is widely cultivated in East Asia and plays important economic, ecological and research roles. Although inorganic carbon utilization of P. yezoensis has been researched from a physiological aspect, the carbon concentration mechanism (CCM) of P. yezoensis remains unclear. To explore the CCM of P. yezoensis, especially during its different life stages, we tracked changes in the transcriptome, photosynthetic efficiency and in key enzyme activities under different inorganic carbon concentrations. Results Photosynthesis efficiency demonstrated that sporophytes were more sensitive to low carbon (LC) than gametophytes, with increased photosynthesis during both life stages under high carbon (HC) compared to normal carbon (NC) conditions. The structures of pyrenoids and starch and lipid droplets in cells corresponded with their growth reaction to different inorganic carbon (Ci) concentrations. We constructed 18 cDNA libraries from 18 samples (three biological replicates per Ci treatment at two life cycles stages) and sequenced these using the Illumina platform. De novo assembly generated 182,564 unigenes, including approximately 275 unigenes related to CCM. Most genes encoding internal carbonic anhydrase (CA) and bicarbonate transporters (anion exchange protein and ATP-binding cassette (ABC) transporter) involved in the biophysical CCM pathway were induced under LC in comparison with NC, with transcript abundance of these PyCA s in gametophytes typically higher than that in sporophytes. We identified all key genes participating in the C4 pathway and showed that their RNA abundances changed with varying Ci conditions. In particular, phosphoenolpyruvate carboxylase (PEPC) transcript abundance was significantly induced under LC conditions. Activities of key enzymes involved in the C4-like pathway were higher under HC than under the other two conditions, with enzyme activities slightly higher in sporophytes than in gametophytes, except for phosphoenolpyruvate carboxykinase (PEPCK). Conclusion We elucidated the CCM of P. yezoensis from transcriptome and enzyme activity levels. All results indicated at least two types of CCM in P. yezoensis , one involving CA and an anion exchanger (transporter), and a second, C4-like pathway belonging to the PEPCK subtype, possibly located in mitochondria. The latter pathway plays roles in both the sporophyte and gametophyte life cycles.
Molecular confirmation of hemothropic mycoplasmas (hemoplasmas) in domestic cats in Romania
Authors: Imre Mirela , Văduva Cristina , Dărăbuș Gheorghe , Morariu Sorin , Suici Tijana , Lait Philippa J.P. , Imre Kálmán
Published: March 2020

Background The hemotropic mycoplasmas (hemoplasmas) of the genus Mycoplasma are recognized as important bacteria that parasitize red blood cells, causing hemolytic anemia in many mammalian species, including cats. No information is available concerning the presence of feline hemoplasma infections in cats in Romania. Thus, the objective of the present study was to provide data on the occurrence and molecular characterization of hemothropic mycoplasmas in client owned cats in Romania. Methods Blood samples from 51 unhealthy cats, originating from Timişoara Municipality, Romania, were screened for the presence of hemoplasmas using conventional polymerase chain reaction (PCR) targeting the 16S rRNA gene and sequencing assays. Results Molecular analysis revealed 11 (21.6%) positive samples, consisting of 8 (72.7%) Candidatus Mycoplasma haemominutum and 3 (27.3%) Mycoplasma haemofelis confirmed positives. Candidatus Mycoplasma turicensis was not detected, and no co-infections were registered. No significant associations ( p > 0.05) were found between the hemoplasma infection status and age, gender, breed, presence of ectoparasites, FeLV/FIV positivity of cats or the sampling season. However, outdoor access was positively associated ( p =0.049) with infection and could be considered a risk factor (OR=4.1) in acquiring feline hemotropic mycoplasmas. Conclusions The findings support the emergence of feline hemoplasma infections in previously uninvestigated territories of Europe, providing useful information for small animal practitioners. To our knowledge, the present survey is the first reported molecular evidence of feline hemoplasma infections in Romania.
Development of a prognostic signature based on six immune related lncRNAs for hepatocellular carcinoma.
Authors: Song Ze-bing , Zhang Guo-pei , li shaoqiang
Published: March 2020

Background: Hepatocellular carcinoma (HCC) is one of the most common malignant tumor in the world which prognosis is poor. Therefore, a precise biomarker is needed to guide treatment and improve prognosis. More and more studies have shown that lncRNAs and immune response are closely related to the prognosis of hepatocellular carcinoma. The aim of this study was to establish a prognostic signature based on immune related lncRNAs for HCC.Methods: Univariate cox regression analysis was performed to identify immune related lncRNAs, which had negative correlation with overall survival (OS) of 370 HCC patients from The Cancer Genome Atlas (TCGA). A prognostic signature based on OS related lncRNAs was identified by using multivariate cox regression analysis. Gene set enrichment analysis (GSEA) and a competing endogenous RNA (ceRNA) network were performed to clarify the potential mechanism of lncRNAs included in prognostic signature. Results: A prognostic signature based on OS related lncRNAs (AC145207.5, AL365203.2, AC009779.2, ZFPM2-AS1, PCAT6, LINC00942) showed moderately in prognosis prediction, and related with pathologic stage (Stage I&II VS Stage III&IV), distant metastasis status (M0 VS M1) and tumor stage (T1-2 VS T3-4). CeRNA network constructed 15 aixs among differentially expressed immune related genes, lncRNAs included in prognostic signature and differentially expressed miRNA. GSEA indicated that these lncRNAs were involved in cancer-related pathways. Conclusion: We constructed a prognostic signature based on immune related lncRNAs which can predict prognosis and guide therapies for HCC.
Bicondylar Tibial Plateau Fractures Involving the Posterior Fragment: Injury Mechanism and Fracture Characteristics
Authors: Pan Shuo , Peng Aqin , Hu Yaning , Wang Shuai , Zhang Xiao
Published: March 2020

Background: Bicondylar tibial plateau fracture (BTPF) involving the posterior fragment is the most complex intra-articular fracture to treat. Although the fracture characteristics of BTPFs have been reported by many researchers, due to the sophisticated kinematics of the knee, reports focused on the injury mechanism are still scarce. The current injury mechanism is insufficient to explain the various fracture characteristics and to guide surgery. This study used a three-dimensional (3D) simulation method to investigate the injury mechanism and fracture characteristics of BTPFs involving the posterior fragment. Methods: Ninety-six BTPFs involving the posterior fragment were included. A computer-assisted 3D technique, which enabled us to move the femoral condyles to match the displaced fracture fragments of the tibial plateau, was applied to analysis the injury mechanism for all cases. The 3D and two-dimensional (2D) morphology of each fracture were reviewed thoroughly, and the main fracture lines were mapped and superimposed on a template. Results: After simulation and quantitatively analysis, three main types (extension, flexion-internal rotation, flexion-external rotation) and six sub-types (valgus and varus in each main type) of injury mechanism had been classified according to the degree of knee motion in three planes. In the extension type, femoral condyles compress the anterolateral tibial plateau and central medial plateau, resulting in an anterior-to-posterior fracture line. In the flexion-internal rotation type, the compressed areas are located on the posterolateral and anteromedial plateau, forming an oblique anteromedial-to-posterolateral fracture line. In the flexion-external rotation type, the compressed areas are located on the anterolateral and posteromedial plateau, exhibiting an anterolateral-to-posteromedial fracture line. Conclusions: Different injury mechanisms result in different fracture characteristics. A thorough understanding of the injury mechanisms underlying complex BTPFs involving the posterior fragment is meaningful not only for fracture characteristics reorganization but also for surgical decision making. The 3D simulation method employed in this study may be a useful supplemental method for investigating the mechanisms underlying fracture injuries.
Prognostic value of Serum miR-217 Level in Osteosarcoma Patients
Authors: Ye Jia , Jin Zhi-Hui , Chen Ren , Chen Sen , Ren Yi-Jun , Guo Wei-Chun , He Hui
Published: March 2020

Background MicroRNA (miR)-217 is a tumor suppressor significantly associated with osteosarcoma. We try to evaluate serum levels miR-217 in osteosarcoma patients and evaluate its prognostic significance. Methods A total of 163 consecutive osteosarcoma patients and 96 healthy participates were enrolled. Serum miR-217 levels were evaluated by using real-time quantitative reverse transcription polymerase chain reactions(RT-PCR). The association between serum miR-217 level and survival outcomes was evaluated by univariate and multivariate analysis. Results Serum miR-217 levels in osteosarcoma patients was significantly lower than healthy volunteers (P<0.05). Low serum miR-217 was significantly related to advanced cancer and metastasis (both P<0.05). Moreover, patients with a low serum miR-217 had a poorer overall survival than those with a high serum miR-217 levels (P<0.05). Serum miR-217 level also been showed as independent risk factor for osteosarcoma in multivariate analysis (HR, 0.42; 95%CI: 0.12–0.98; p<0.01). Conclusions Serum miR-217 levels was significantly downregulated in osteosarcoma patients and remarkably associated with poor prognosis, indicating that serum miR-217 might serve as a useful diagnostic and prognostic indictor for osteosarcoma.
Practice and the Influencing Factors of Nurses Working in the Intensive Care Unit regarding Physical Restraint use: Multi-centered cross-sectional study
Authors: Gebeyehu Tilahun Kassew , Tilahun Ambaye Dejen , Wudu Bikis Liyew
Published: March 2020

Background: Nurses working in the intensive care unit commonly use physical restraint on critically ill patients. The main reason for the restraining of patients is to prevent the dislodgement of invasive procedures/ medical equipment, reduce agitation. Patients are exposed to different complications from physical restraint like worsening of agitation and delirium, fall injury, limb edema, restricted circulation, and skin laceration at restraint site, and death as a result of nurses’ improper practice regarding restraining. Despite this impact, there was no documented study in Ethiopia in this regard. Objective: To assess practice and its influencing factors of nurses working in the Intensive Care Unit regarding physical restraint Methods: An institution-based cross-sectional study was conducted from July to August 2019 at Amhara regional state referral hospitals, Northwest Ethiopia. All (260) nurses working in the intensive care unit were invited to participate through a convenience sampling technique. Structured questionnaires which consist of socio-demographic, professional characteristics and Level of Knowledge, Attitudes and Practices of Staff Regarding Physical Restraints Questionnaire were used. Simple and multiple linear regression and beta (β) coefficient at 95% confidence interval was employed with p-value<0.05 as statistical significance. Result: The mean score of nurses’ practice regarding physical restraint use among critically ill patients was 30.94±5.44. Nurses with short (≤2 years) experience of the intensive care unit, received educational training during graduate class regarding restraining, knowledge and attitude scores were the factors significantly associated with nurses’ practice score regarding physical restraining use. Conclusion: The practice regarding physical restraint use among critically ill patients among participant nurses’ was a satisfactory. The administrators’ should develop and provide educational and in-service training programs for nurses working in intensive care unit settings regarding physical restraint use and its alternatives, which is crucial for the nurses’ to improve their behavior of restraining. Keywords: Intensive care unit, Nurses’, Practice, Physical restraint
Compound heterozygous mutations of two eIF2B genes in early childhood onset form of vanishing white matter disease
Authors: Wang Chunmei , Yuan Fang , Wu Shengnan , Liu Zhao , Wang Simei , Lan Xiaoping , Xu Quanmei , Luo Xiaona , Wang Yilin , Xu Wuhen , Xi Jiaming , Lu Yanfen , Zhang Yuanfeng , Lu Qin , Huang Jianjun , Avula Sreenivas K. , Tolaymat Abdullah , Wang Anqi , Jia Jia , Chen Yucai
Published: March 2020

Background Diagnoses of vanishing white matter disease (VWMD) were difficult due to variable clinical features, severity, age of onset and wide range of mutations in eIF2G genes which cause VWMD. This study reported two novel mutations in eIF2B genes associated with VWMD to and expand our understanding of VWMD. Case presentation Relevant data from clinical diagnoses and genetic mutational analyses in two Chinese female patients with sporad­ic VWMD were collected and analyzed. Protein structure/function was predicted. The identity of biological parents was confirmed based on variants called from the next-generation sequencing (NGS) data. Compound heterozygous mutations, c.254 T>A (p.Val85Glu), and c.597+2delT in the EIF2B2 gene, c.545C>T(p.Thr182Met) and c.1340C>T(p.Ser447Leu) in the EIF2B5 gene were detected in the two patients. Further phenotype investigation of both patients enables the diagnosis of the vanishing white matter disease .Three missense mutation c.254 T>A (p.Val85Glu) in the EIF2B2 gene, c.545C>T(p.Thr182Met) and c.1340C>T(p.Ser447Leu) in the EIF2B5 gene have been found and predicted to be deleterious. All the three mutation causes hydrophobicity and stability changes of proteins, and all the mutations were localized in conserved sequences. One novel mutation of c.1340C>T(p.Ser447Leu) in the EIF2B5 gene ,and two other known mutations. The iterative threading assembly refinement (I-TASSER) server generated three-dimensional (3D) atomic models based on protein sequences from the novel missense mutation of c.1340C>T(p.Ser447Leu) in the EIF2B5 gene, which showed that the protein structure changed . The novel mutation c.597+2delT in the EIF2B2 gene may cause the splice site to disappear. We also analyzed mutations in missense mutations that cause VWMD and found that most of the t Pathogenic sites are localized in conserved NT and I-patch homology regions and the catalytic domain of EIF2Bε. Conclusions This study expands the spectrum of genotypes and phenotypes of VWMD and provides new insights into the molecular mechanism of VWMD and aide the acute diagnosis and treatment of VWMD.
Non-invasive ventilation as the initial ventilatory strategy in very old critically ill patients with community-acquired pneumonia: a multicenter cohort study
Authors: Besen Bruno Adler Maccagnan Pinheiro , Park Marcelo , Ranzani Otavio Tavares
Published: March 2020

Background The very old patients (≥ 80 years-old, VOP) comprise a subpopulation increasingly admitted to intensive care units (ICUs). Community-acquired pneumonia (CAP) is a common reason for admission and the best strategy of mechanical ventilation for respiratory failure in this scenario is not fully known. Methods Multicenter cohort study of VOPs admitted with CAP in need of invasive (IMV) or noninvasive (NIV) mechanical ventilation to 11 Brazilian ICUs from 2009 through 2012. We used logistic regression models to evaluate the association between ventilator strategy (NIV vs. IMV) and hospital mortality adjusting for confounding factors. We evaluated effect modification with interaction terms in pre-specified sub-groups. Results Of 369 VOPs admitted for CAP with respiratory failure, 232 (63%) received NIV and 137 (37%) received IMV as initial ventilatory strategy. IMV patients were sicker at ICU admission (median SOFA 8 vs. 4, p < 0.001). Hospital mortality was 114/232 (49%) for NIV and 90/137 (66%) for IMV. For the comparison NIV vs. IMV (reference), the crude odds ratio (OR) was 0.50 (95% CI, 0.33–0.78, p=0.002). This association was largely confounded by antecedent characteristics and non-respiratory SOFA (adjOR = 0.70, 95% CI, 0.41–1.20, p=0.196). The fully adjusted model, including Pao2/Fio2 ratio, pH and Paco2, yielded an adjOR of 0.81 (95% CI, 0.46–1.41, p=0.452). There was no strong evidence of effect modification among relevant subgroups, such as Pao2/Fio2 ratio ≤ 150 (p = 0.30), acute respiratory acidosis (p = 0.42) and non-respiratory SOFA ≥ 4 (p = 0.53). Conclusions NIV was not associated with lower hospital mortality when compared to IMV in critically ill VOP admitted with CAP, but there was no strong signal of harm from its use. The main confounders of this association were both the severity of respiratory dysfunction and of extra-respiratory organ failures.
Identification of stable reference gene for qPCR studies in common wheat (Triticum aestivum L.) seedlings under short-term osmotic stress
Authors: Dudziak Karolina , Sozoniuk Magdalena , Börner Andreas , Szczerba Hubert , Kuzdraliński Adam , Kowalczyk Krzysztof , Nowak Michał
Published: March 2020

BackgroundQuantitative PCR (qPCR) is one of the most common and accurate methods of gene expression analysis. However, the biggest challenge for this kind of examinations is normalization of the results, which requires the application of dependable internal controls. The selection of appropriate reference genes (RGs) is one of the most crucial points in qPCR data analysis and for correct assessment of gene expression. Because of the fact that many reports indicate that the expression profiles of typically used RGs can be unstable in certain experimental conditions, species or tissues, reference genes with stable expression levels should be selected individually for each experiment. In this study, we analysed a set of ten candidate RGs for wheat seedlings under short-term drought stress. Our tests included five ‘traditional’ RGs (GAPDH, ACT, UBI, TUB, and TEF1) and five novel genes developed by the RefGenes tool from the Genevestigator database.ResultsExpression stability was assessed using five different algorithms: geNorm, NormFinder, BestKeeper, RefFinder and the delta Ct method. In the final ranking, we identified three genes: CJ705892, ACT, and UBI, as the best candidates for housekeeping genes. However, our data indicated a slight variation between the different algorithms that were used. We revealed that the novel gene CJ705892, obtained by means of in silico analysis, showed the most stable expression in the experimental tissue and condition.ConclusionsOur results support the statement, that novel genes selected for certain experimental conditions have a more stable level of expression in comparison to routinely applied RGs, like genes encoding actin, tubulin or GAPDH. Selected CJ705892 gene can be used as a housekeeping gene in the expression analysis in wheat seedlings under short-term drought. The results of our study will be useful for subsequent analyses of gene expression in wheat tissues subjected to drought.
Prevalence of depressive symptoms and its predicted factors among medical students in University of Bisha, Saudi Arabia
Authors: Al-Shahrani Mohammad S. , Alharthi Muffarah H. , Alamri Mohannad S. , Ibrahim Mutasim E
Published: March 2020

Background: Identification of the potential factors of depression among medical students is the first step towards academic excellence and future safe medical practice. Methods: A cross-sectional study was conducted during a period from November 2019 to February 2020 at the University of Bisha, College of Medicine (UBCOM), Bisha province, Saudi Arabia. Medical students from year one to year six were involved. A self-administered questionnaire was used to collect data about socio-demographic and academic characteristics of students. The Arabic version of the PHQ-9 scale with a score of ≥10 was used for diagnosis depressive. Logistic regression analysis was used to assess the prevalence and risk of depression.Results: Of the 190 students enrolled, 26.8% had depressive symptoms, of which 45.1% were having moderate to severe symptoms. The highest proportion of depression was found among second-year students (43.8%), followed by sixth-year students (41.2%), whereas lowest proportion of depression reported among first-year students (8.9%). Univariate regression revealed significant associations between depression and un-satisfaction of family income, loss of family members, having psychological illness, difficulties in personal relationships, regretted study medicine, failure in academic year, a lower grade than expected, conflict with tutors, lack of college facilities and heavy academic load. In multivariate analysis, loss of a family members (AOR=0.077; 95% CI 0.013-0.451), difficulties in personal relationships (AOR=2.371; 95% CI 1.009-5.575), regret study medicine (AOR=3.764; 95% CI 1.657-8.550), failed in academic year (AOR=2.559; 95% CI 1.112-5.887) were independently associated with depression.Conclusion: The study concluded that medical students at UBCOM also experience the existence of depressive symptoms associated with various risk indicators. Optimizing the educational and social environment coupled with infrastructure facilities at UBCOM might promote students' mental health and well-being.
Microbial community similarity and dissimilarity inside and across full-scale activated sludge processes for simultaneous nitrification and denitrification
Authors: Wen Jianfeng , LeChevallier Mark W. , Tao Wendong
Published: March 2020

Simultaneous nitrification and denitrification under low dissolved oxygen conditions is an energy-saving modification of the activated sludge process to achieve efficient nitrogen removal. Geographically distinct full-scale treatment plants are excellent platforms to address the links of microbial community with operating parameters. Mixed liquor samples were collected from a sequencing batch reactor plant, oxidation ditch plant, and step-feed activated sludge plant. Next-Generation Sequencing of the samples showed that the microbial communities were similar at the phylum level among the plants, being dominated by Proteobacteria. Microbial composition of functional groups was similar between the react fill and react phases of the sequencing batch reactors, among four sequencing batch reactors, and among four oxidation ditches. Nitrospira was the only identified genus of autotropic nitrifying bacteria with a relative abundance of 2.2–2.5% in the oxidation ditches and 0.4–0.7% at the other plants. Heterotrophic nitrifying–aerobic denitrifying bacteria were dominated by Dechloromonas with a relative abundance of 0.4–1.0%. Microbial community composition and nitrogen removal mechanisms were related to overall level and local zonation of dissolved oxygen, mixed liquor suspended solids concentration, nitrogen and organic loadings, and solids retention time. Low dissolved oxygen and low organic and nitrogen loadings favored growth of Nitrospira.
THE IMPORT OF INSTITUTIONS TO THE BRICS COUNTRIES
Authors: Zharikov M.
Published: March 2020

This article explores the potential approaches to optimising the way the institutions of mutual common use by the BRICS countries are constructed. The topic is time-relevant, for it reveals the need to work out a new institutional basis to understand the workings of the BRICS institutions as a result of recent transformations, such as Brexit, in the phenomenon of international and regional economic integration. The article is founded on the hypothesis that the import of institutions by the BRICS may be a more effective approach to the member countries’ convergence than the conventional approach. The originality of the theme lies in the fact that the modern economic literature has not studied to the full extent the impact of this exogenous factor on financial integration. There is also a need for the further development of the least-studied areas of regional monetary integration, namely the lack of the ability of current world institutions to manage the common monetary policies and debt of the member countries. The author proposes principles for creating and operating a virtual contractual republic of the BRICS contrary to the exploitation-state model of the EU. The article rediscovers the institutionalist idea about democratic decisions by a group of subjects such as the member countries of a particular integration agreement. The author maintains that the new institutions of the BRICS may cause dramatic changes in the world monetary system, international liquidity and international reserves. The general conclusions of the article encompass the significance of creating integration institutions on the basis of the experience of the BRICS as a way to more economic and financial stability in the world. The results contribute to the search for opportunities of optimal operation of the BRICS regional debt market. In his closing remarks, the author outlines the prospects of settling the debt problems in the BRICS based on the virtual debt market.
REGULATION OF MERGERS AND ACQUISITIONS IN TERMS OF THE SOUTH AFRICAN COMPANIES ACT 71 OF 2008: AN OVERVIEW
Authors: Phakeng M.
Published: March 2020

The Companies Act 71 of 2008 (the 2008 Act) replaced the Companies Act No. 61 of 1973, effective 1 May 2011. The 2008 Act was aimed at keeping pace with developments in company law internationally. It is not intended to entirely replace the well-established principles and has largely retained the pre-existing South African company law. The mergers and acquisitions provisions are aimed at creating transparent, efficient, and simple procedures. Different types of mergers and acquisitions are clearly defined as “affected transactions” or “offers” in section 117. Section 118 provides for companies to which the provisions apply. The reasons for regulating these transactions and powers of the regulator – The Takeover Regulation Panel, have been reviewed, clarified, and improved. The previous section on disposal of all or greater part of assets or undertaking of a company has been re-written. The 2008 Act further introduces a new type of affected transaction in section 113, in the form of a “merger” or an “amalgamation.” The 2008 Act has retained the scheme of arrangement in section 114, but has changed its format by removing compulsory court application and approval. The courts get involved under certain prescribed circumstances. The 2008 Act has enhanced shareholder protection for fundamental transactions in the form of section 164 – Appraisal Rights and section 115, dealing with shareholder approval of fundamental transactions. Some scholars and practitioners have criticised certain provisions. However, in general, the provisions have received favourable commentary. They regarded as progressive and comparable with others internationally.