bluuebunny/crossref_metadata_2025 huggingface dataset:
The Transport Mechanisms and Dynamics of Shale via Multiscale Multiphysics Pore Network Modeling
Authors: Alafnan Saad , Yucel Akkutlu I.
Published: February 2020

Source rocks such as shale are highly heterogeneous, consisting of organic matter and various inorganic minerals. Microscopic images suggest that microcracks serve as conduits for the gas released from organic nanopores. The permeability of the shale matrix is primarily attributed to stress-sensitive microcracks that are highly influenced by changes in fluid pressure. As the microcracks are depleted, more gas molecules desorb from the organic nanopores; this, in turn, affects the fluid pressure in the microcracks. Linking the local properties of the organic nanopores to the microcracks allows for a better understanding of the coupling between them, which is necessary for improved modeling. In this research, a multiscale pore network modeling approach is presented to describe the organic material and microcrack system and investigate the large-scale features of gas transport in shale. A multiscale pore network model consisting of clusters of organic pore networks and microcracks was built to examine shale gas transport on a microscopic scale. The organic part of the network model consisted of nano-capillaries interconnected at nanopores. The network accounted for the adsorptive–convective–diffusive transport mechanisms recently derived for a single capillary. This organic nanopore network was hydraulically connected to a single microcrack. Then, the mass balance at each node in the new domain was solved, along with the assumed boundary conditions. Using the information at the nodes, the total flowrate and pressure distribution in the system were obtained as a function of time. The results show that the fluid pressure in the microcrack was primarily sensitive to the content of the organic material and its permeability. Then, the microcracks–organic materials interactions are studied and empirically quantified at larger macroscopic scale of gridblocks. This relationship can be investigated in the laboratory and used in theoretical models to predict shale gas production.
Design and Analysis of Energy-Efficient Low-Flow Centrifugal Compressors
Authors: Xu Cheng , Chen Lei , Amano Ryoichi S.
Published: February 2020

With the increasing demands of energy-saving from industries, the low-flow coefficient and low specific speed centrifugal compressors have gained more attention. The design of this type of compressor faced many challenges, for example, high secondary flow losses, high tip leakage losses, and low exit width based on a Reynolds number. The design also lacks a reliable database for preliminary studies. The impeller design studies were limited. Most designs for low-flow coefficient and low specific speed compressor follow the traditional methods. This paper presents design studies and discusses some unique design features to improve performance of this type of compressor. The detail computational fluids dynamics (CFD) results are presented to demonstrate the success of the design strategies. A prototype compressor for fuel cell applications was built, and performance tests were performed. The test results are compared with those of the computational analysis, and the agreement is reasonably satisfactory. The compressor meets the customer's performance goals. The design features can be used for future low-flow coefficient and low specific speed centrifugal compressor design.
Study of the Constraint Selection Through ASVDADD Method for Rate-Controlled Constrained-Equilibrium Modeling on Ethanol Oxidation Without PLOG Reactions
Authors: Roy Shrabanti , Askari Omid
Published: February 2020

Reduction of the detail chemical kinetic mechanism is important in solving complex combustion simulation. In this work, a model reduction scheme rate-controlled constrained-equilibrium (RCCE) is considered in predicting the oxidation of ethanol. A detail kinetic mechanism by Merinov from Lawrence Livermore National Laboratory (LLNL) is used in modeling this reduction technique. The RCCE method considers constrained equilibrium states which subjected to a lower number of constraints compared to the number of species. It then has to solve a smaller number of differential equations compared to the number of equations required in solving the detailed kinetic model (DKM). The accuracy of this solution depends on the selection of the constraint. A systematic procedure which will help in identifying the constraint at an optimal level of accuracy is an essential for RCCE modeling. A fully automated Approximate Singular Value Decomposition of the Actual Degrees of Disequilibrium (ASVDADD) method is used in this study to derive the constraint for RCCE simulation. ASVDADD uses an algorithm which follows the simple algebraic analysis on results of underlying DKM to find the degree of disequilibrium (DoD) of the individual chemical reactions. The number of constraints which will be used in RCCE simulation can be selected to reduce the number of equations required to solve. In the current work, this ASVDADD method is applied on ethanol oxidation to select the constraint for RCCE simulation. Both DKM and RCCE calculations on ethanol fuel are demonstrated to compare the result of temperature distribution and an ignition delay time for validating the method.
Polymerization in the actin ATPase clan regulates hexokinase activity in yeast
Authors: Stoddard Patrick R. , Lynch Eric M. , Farrell Daniel P. , Dosey Annie M. , DiMaio Frank , Williams Tom A. , Kollman Justin M. , Murray Andrew W. , Garner Ethan C.
Published: February 2020

Polymerization regulates hexokinase activity

The yeast hexokinase Glk1 is an actin-fold protein that forms polymers in response to binding its substrates and products. Stoddard
et al.
now show that Glk1 polymers are structurally distinct from actin filaments and suggest that polymerization of Glk1 evolved independently of the polymerization of other actin-like polymers. Glk1 polymerization inhibits its hexokinase activity, and the monomerpolymer equilibrium appears to set a maximum rate for the entire enzyme pool rather than a maximum rate per enzyme. This inhibition was found to be important for cell viability in the context of nutrient shifts, allowing yeast cells to modulate their metabolism rapidly in response to stochastic changes in the environment.

Science
, this issue p.
1039
Pectin homogalacturonan nanofilament expansion drives morphogenesis in plant epidermal cells
Authors: Haas Kalina T. , Wightman Raymond , Meyerowitz Elliot M. , Peaucelle Alexis
Published: February 2020

Wavy walls built by nanofilaments

In the model plant
Arabidopsis
, pavement cells fit together with the lobes and curves of jigsaw puzzle pieces. Such complex cell shapes, in plants, were generally thought to be driven by turgor pressure. Haas
et al.
now show that the extracellular cell wall can actively shape the cell it contains without relying on turgor pressure. Nanofilaments of pectin homogalacturonan in the cell wall shift between crystalline and anisotropic phases according to whether they are methylated. The shift in form drives changes in cell wall shape that stand independent of turgor pressure.

Science
, this issue p.
1003
Accuracy of cerebrospinal fluid ferritin for purulent meningitis
Authors: Garcia Pedro Celiny Ramos , Barcelos Andrea Lucia Machado , Tonial Cristian Tedesco , Fiori Humberto Holmer , Einloft Paulo Roberto , Costa Caroline Abud Drumond , Portela Janete L , Bruno Francisco , Branco Ricardo Garcia
Published: February 2020

Objective

To evaluate the use of cerebrospinal fluid (CSF) ferritin levels in the diagnosis of purulent meningitis (PM).

Method

We studied 81 children between 28 days and 12 years of age who presented with clinical suspicion of meningitis to the emergency department. CSF ferritin levels were measured and compared between diagnostic groups (PM, aseptic meningitis (AM) and no meningitis).

Results

The median age was 24 (IQR 8–69) months. There were 32 patients with AM (39%), 23 with PM (28%) and 26 with no meningitis (32%). Median CSF ferritin was 4.2 ng/mL (IQR 3.0–6.5), 52.9 ng/mL (IQR 30.7–103 ng/mL) and 2.4 ng/mL (IQR 2–4), respectively. CSF ferritin was higher in children with PM compared with AM (p<0.001) or no meningitis (p<0.001). There was no difference between AM and no meningitis.

Conclusion

CSF ferritin may be a useful biomarker to discriminate PM in children with clinical symptoms of this disease.
Disparity of microaneurysm count between ultrawide field colour imaging and ultrawide field fluorescein angiography in eyes with diabetic retinopathy
Authors: Ashraf Mohamed , Sampani Konstantina , AbdelAl Omar , Fleming Alan , Cavallerano Jerry , Souka Ahmed , El Baha Samir Mohamed , Silva Paolo S , Sun Jennifer , Aiello Lloyd Paul
Published: February 2020

Aims

To compare microaneurysm (MA) counts using ultrawide field colour images (UWF-CI) and ultrawide field fluorescein angiography (UWF-FA).

Methods

Retrospective study including patients with type 1 or 2 diabetes mellitus receiving UWF-FA and UWF-CI within 2 weeks. MAs were manually counted in individual Early Treatment Diabetic Retinopathy Study (ETDRS) and extended UWF zones. Fields with MAs ≥20 determined diabetic retinopathy (DR) severity (0 fields=mild, 1–3=moderate, ≥4=severe). UWF-FA and UWF-CI agreement was determined and UWF-CI DR severity sensitivity analysis adjusting for UWF-FA MA counts performed.

Results

In 193 patients (288 eyes), 2.4% had no DR, 29.9% mild non-proliferative DR (NPDR), 32.6% moderate (NPDR), 22.9% severe NPDR and 12.2% proliferative DR. UWF-FA MA counts were 3.5-fold higher (p<0.001) than UWF-CI counts overall, 3.2x-fold higher in ETDRS fields (p<0.001) and 5.3-fold higher in extended ETDRS fields (p<0.001) and higher in type 1 versus type 2 diabetes (p<0.001). In eyes with NPDR on UWF-CI (n=246), UWF-FA images had 1.6x–3.5x more fields with ≥20 MAs (p<0.001). Fair agreement existed between imaging modalities (k=0.221–0.416). In ETDRS fields, DR severity agreement increased from k=0.346 to 0.600 when dividing UWF-FA counts by a factor of 3, followed by rapid decline in agreement thereafter. Total UWF area agreement increased from k=0.317 to 0.565 with an adjustment factor of either 4 or 5.

Conclusions

UWF-FA detects threefold to fivefold more MAs than UWF-CI and identifies 1.6–3.5-fold more fields affecting DR severity. Differences exist at all DR severity levels, thus limiting direct comparison between the modalities. However, correcting UWF-FA MA counts substantially improves DR severity agreement between the modalities.
Impact of point-of-care panel tests in ambulatory care: a systematic review and meta-analysis
Authors: Goyder Clare , Tan Pui San , Verbakel Jan , Ananthakumar Thanusha , Lee Joseph J , Hayward Gail , Turner Philip J , Van Den Bruel Ann
Published: February 2020

Objectives

This article summarises all the available evidence on the impact of introducing blood-based point-of-care panel testing (POCT) in ambulatory care on patient outcomes and healthcare processes.

Design

Systematic review and meta-analysis of randomised-controlled trials and before-after studies.

Data sources

Ovid Medline, Embase, Cochrane Database of Systematic Reviews, Cochrane CENTRAL, Database of Abstracts of Reviews and Effects, Science Citation Index from inception to 22 October 2019.

Eligibility criteria for selecting studies

Included studies were based in ambulatory care and compared POCT with laboratory testing. The primary outcome was the time to decision regarding disposition that is, admission/referral termed disposition decision (DD) time. Secondary outcomes included length of stay (LOS) at the ambulatory care unit/practice and mortality.

Results

19 562 patients from nine studies were included in the review, eight of these were randomised-controlled trials, and one was a before-after study. All the studies were based in either emergency departments or the ambulance service; no studies were from primary care settings. General panel tests performed at the POCT resulted in DDs being made 40 min faster (95% CI −42.2 to −36.6, I2=0%) compared with the group receiving usual care, including central laboratory testing. This in turn resulted in a reduction in LOS for patients who were subsequently discharged by 34 min (95% CI −63.7 to −5.16). No significant difference in mortality was reported.

Discussion

Although statistical and clinical heterogeneity is evident and only a small number of studies were included in the meta-analysis, our results suggest that POCTs might lead to faster discharge decisions. Future research should be performed in primary care and identify how POCTs can contribute meaningful changes to patient care rather than focusing on healthcare processes.

PROSPERO registration number

CRD42016035426.
Shared decision-making in advanced kidney disease: a scoping review protocol
Authors: Engels Noel , de Graav Gretchen , van der Nat Paul , van den Dorpel Marinus , Bos Willem Jan , Stiggelbout Anne M
Published: February 2020

Introduction

Patients with advanced kidney disease (AKD) have to make difficult treatment modality decisions as their disease progresses towards end-stage kidney disease. International guidelines in nephrology suggest shared decision-making (SDM) to help patients make timely treatment modality decisions that align with their values and preferences. However, systematic reviews or scoping reviews on these SDM interventions and on their reported use or outcomes are lacking. This limits the adoption of SDM in clinical practice and hampers further research and development on the subject. Our aim is to provide a comprehensive and up-to-date overview of these SDM interventions by means of a scoping review of the literature. Scoping reviews can provide a broad overview of a topic, identify gaps in the research knowledge base and report on the types of evidence that address and inform practices. This paper presents our study protocol.

Methods and analysis

The proposed scoping review will be performed in accordance with the Joanna Briggs Institute’s (JBI) methodology for scoping reviews. It will cover both qualitative and quantitative scientific literature, as well as the grey literature on SDM interventions for treatment modality decisions in AKD. Only literature written in English will be considered for inclusion. Two independent reviewers will participate in an iterative process of screening the literature, paper selection and data extraction. Disagreements between the reviewers will be resolved by discussion until consensus is reached or after consultation with the research team when needed. Results will be reported with descriptive statistics and diagrammatic or tabular displayed information, accompanied by narrative summaries as explained in the JBI guidelines.

Ethics and dissemination

Ethical approval for the conduct of this study is not required. We will analyse previously collected data for the proposed scoping review. Our results will be published in a peer-reviewed journal and disseminated through conferences and/or seminars.
Reduction of paediatric head CT utilisation at a rural general hospital emergency department
Authors: Louie Jeffrey Paul , Alfano Joseph , Nguyen-Tran Thuy , Nguyen-Tran Hai , Shanley Ryan , Holm Tara , Furnival Ronald A
Published: February 2020

Background

Blunt head injury is a common pediatric injury and often evaluated in general emergency departments. It estimated that 50% of children will undergo a head computed tomography (CT), often unnecessarily exposing the child to ionizing radiation. Pediatric academic centers have shown quality improvement (QI) measures can reduce head CT rates within their emergency departments. We aimed to reduce head CT utilization at a rural community emergency department.

Methods

Children presenting with a complaint of blunt head injury and were evaluated with or without a head CT. Head CT rate was the primary outcome. We developed a series of interventions and presented these to the general emergency department over the duration of the study. The pre and intervention data was analysed with control charts.

Results

The preintervention and intervention groups consisted of 576 children: 237 patients with a median age of 8.0 years and 339 patients with a median age of 9.00 years (p=0.54), respectively. The preintervention HCT rate was 41.8% (95% CI 35.6% to 48.1%) and the postintervention rate was 27.7% (95% CI 23.3% to 32.7%), a decrease of 14.1% (95% CI 6.2% to 21.9%, p=0.0004). During the intervention period, there was a decrease in HCT rate of one per month (OR 0.96, 95% CI 0.92 to 1.00, p=0.07). The initial series of interventions demonstrated an incremental decrease in HCT rates corresponding with a special cause variation.

Conclusion

The series of interventions dispersed over the intervention period was an effective methodology and successfully reduced HCT utilisation among children with blunt head injury at a rural community emergency department.
Could a massive open online course be part of the solution to sport-related concussion? Participation and impact among 8368 registrants
Authors: Fremont Pierre , Schneider Kathryn , Laroche Anne , Emery Carolyn , Yeates Keith
Published: February 2020

Objectives

A massive open online course (MOOC) has the potential to help address the public health burden of concussion across all levels of sport and leisure activities. The main objectives of this study were to document the volume of participation and to estimate the impact of a MOOC on concussion protocol implementation.

Methods

Between April 2016 and October 2018, four editions of a French-language MOOC on concussion were presented. Each of the six modules contains a section presenting the main learning content and a section proposing a reflective process to support the implementation of a concussion protocol in the participant’s environment. The proportion of registrants who achieved successful completion of the course was the main outcome. Surveys were also used to document the types of participants and their intent to implement or update a protocol.

Results

Thirty per cent of 8368 registrants successfully completed the course. Of the 3061 participants who completed a survey about their background, 58.8% were healthcare professionals, 16.3% were sport or school stakeholders, and 10.1% were parents or persons who sustained a concussion. Of the 1471 participants who completed a survey about their intent to implement or update a concussion protocol in their environment, 39.4% answered positively.

Conclusion

This study describes the first use of a MOOC to address the issue of concussion. The experience of a French-language MOOC shows promising results supporting the use of this innovative educational strategy as part of the solution to the public health issue of concussion.
Mitochondrial dysfunction during loss of prohibitin 1 triggers Paneth cell defects and ileitis
Authors: Jackson Dakota N , Panopoulos Marina , Neumann William L , Turner Kevin , Cantarel Brandi L , Thompson-Snipes LuAnn , Dassopoulos Themistocles , Feagins Linda A , Souza Rhonda F , Mills Jason C , Blumberg Richard S , Venuprasad K , Thompson Winston E , Theiss Arianne L
Published: February 2020

Objective

Although perturbations in mitochondrial function and structure have been described in the intestinal epithelium of Crohn’s disease and ulcerative colitis patients, the role of epithelial mitochondrial stress in the pathophysiology of inflammatory bowel diseases (IBD) is not well elucidated. Prohibitin 1 (PHB1), a major component protein of the inner mitochondrial membrane crucial for optimal respiratory chain assembly and function, is decreased during IBD.

Design

Male and female mice with inducible intestinal epithelial cell deletion of Phb1 (Phb1iΔIEC) or Paneth cell-specific deletion of Phb1 (Phb1ΔPC) and Phb1fl/fl control mice were housed up to 20 weeks to characterise the impact of PHB1 deletion on intestinal homeostasis. To suppress mitochondrial reactive oxygen species, a mitochondrial-targeted antioxidant, Mito-Tempo, was administered. To examine epithelial cell-intrinsic responses, intestinal enteroids were generated from crypts of Phb1iΔIEC or Phb1ΔPC mice.

Results

Phb1iΔIEC mice exhibited spontaneous ileal inflammation that was preceded by mitochondrial dysfunction in all IECs and early abnormalities in Paneth cells. Mito-Tempo ameliorated mitochondrial dysfunction, Paneth cell abnormalities and ileitis in Phb1iΔIEC ileum. Deletion of Phb1 specifically in Paneth cells (Phb1ΔPC) was sufficient to cause ileitis. Intestinal enteroids generated from crypts of Phb1iΔIEC or Phb1ΔPC mice exhibited decreased viability and Paneth cell defects that were improved by Mito-Tempo.

Conclusion

Our results identify Paneth cells as highly susceptible to mitochondrial dysfunction and central to the pathogenesis of ileitis, with translational implications for the subset of Crohn’s disease patients exhibiting Paneth cell defects.
Transcatheter treatment of postinfarct ventricular septal defects
Authors: Giblett Joel P. , Jenkins David P. , Calvert Patrick A.
Published: February 2020

Postinfarct ventricular septal defects (VSDs) are a mechanical complication of acute myocardial infarction (AMI) with a very poor prognosis. They are estimated to occur in 0.2% of patients presenting with AMI, with 1-month survival of 6% without intervention. Guidelines recommend surgical repair, but recent advances in transcatheter technology, and bespoke device development, mean it is increasingly viable as a closure option. Surgical mortality is between 30% and 50% for all-comers, while in series of transcatheter closure, mortality was 32%. Transcatheter closure appears durable, with no evidence of late leaks and low long-term mortality in series with up to 5-year follow-up. Guidelines recommend early closure, which is likely to provide most benefit for patients regardless of the closure method. Multimodality cardiac imaging including echocardiography, CT and cardiac MRI can define size, shape, location of defects and their relationship to other cardiac structures, assisting with treatment decisions. Brief delay to allow stabilisation of the patient is appropriate, but untreated patients risk rapid deterioration. Mechanical circulatory support may be helpful, although the preferred modality is unclear. Transcatheter closure involves large bore venous access and the formation of an arteriovenous loop (under fluoroscopic and trans-oesophageal echocardiographic guidance) in order to facilitate deployment of the device in the defect and close the postinfarct VSD. Guidelines suggest transcatheter closure as an alternative to surgical repair in centres where appropriate expertise exists, but decisions for all patients with postinfarct VSD should be led by the multidisciplinary heart team.
Two-year regional grey and white matter volume changes with natalizumab and fingolimod
Authors: Preziosa Paolo , Rocca Maria A , Pagani Elisabetta , Storelli Loredana , Rodegher Mariaemma , Moiola Lucia , Filippi Massimo
Published: February 2020

Objective

To compare the efficacy of fingolimod and natalizumab in preventing regional grey matter (GM) and white matter (WM) atrophy in relapsing-remitting multiple sclerosis (RRMS) over 2 years.

Methods

Patients with RRMS starting fingolimod (n=25) or natalizumab (n=30) underwent clinical examination and 3T MRI scans at baseline (month (M) 0), M6, M12 and M24. Seventeen healthy controls were also scanned at M0 and M24. Tensor-based morphometry and SPM12 were used to assess the longitudinal regional GM/WM volume changes.

Results

At M0, no clinical or GM/WM volume differences were found between treatment groups. At M24, both drugs reduced relapse rate (p<0.001 for both) and stabilised disability. At M6 vs M0, both groups experienced significant atrophy of several areas in the cortex, deep GM nuclei and supratentorial WM. Significant bilateral cerebellar GM and WM atrophy occurred in fingolimod patients only. At M12 vs M6 and M24 vs M12, further supratentorial GM and WM atrophy occurred in both groups. Bilateral GM/WM cerebellar atrophy continued to progress in fingolimod patients only. Compared with natalizumab, fingolimod-treated patients showed a significant cerebellar GM/WM atrophy, mainly at M6 vs M0, but still occurring up to M24. Compared with fingolimod, natalizumab-treated patients had a small number of areas of GM atrophy in temporo-occipital regions at the different time-points.

Conclusions

Natalizumab and fingolimod are associated with heterogeneous temporal and regional patterns of GM and WM atrophy progression. Compared with natalizumab, fingolimod-treated patients experience accelerated GM and WM atrophy in the cerebellum, while both drugs show minimal regional volumetric differences in supratentorial regions.
Autonomic and cortical response of soldiers in different combat scenarios
Authors: Tornero Aguilera José Francisco , Fernandez Elias V , Clemente-Suárez V J
Published: February 2020

Introduction

The study of chronic and acute responses when exposed to extreme, aggressive and stressful environments, such as in combat environments, is becoming increasingly popular as such information leads to better optimisation of soldiers’ physical and psychological performance, as well as mission effectiveness and efficiency. Due to internal complexity, uncertainty and variability of real combat scenarios, a specific approach to all possible types of military combat scenarios is necessary.

Methods

Modifications in the autonomic modulation and cortical arousal before and after asymmetrical, symmetrical and close quarter combat simulations were analysed in 31 male professional veteran soldiers (age: 34.5±4.2 years) with between seven and 18 years of experience in their respective units, as well as experience in international missions in current conflict areas such as Lebanon, Afghanistan, Bosnia, Kosovo and Iraq.

Results

The three combat situations produced a non-significant decrease in cortical arousal after combat simulations, presenting a trivial effect size in symmetrical and close quarter combat situations and a small effect size in asymmetrical situations. HR increased significantly in the three combat situations, and close quarter combat produced the highest sympathetic modulation of the three situations analysed.

Conclusion

Symmetrical, asymmetrical and close quarter combat situations produced an increase in sympathetic modulation, being highest in the close quarter combat situation, where actions are performed at a close distance and in closed spaces.
Veterans Universal Passport: a pilot of a health and social care record for UK ex-service personnel
Authors: Godier-McBard Lauren Rose , Fossey M
Published: February 2020

Background

The transfer of care between different health and social care systems are often associated with poor outcomes and disengagement. Indeed, following the transition from military to civilian life, ex-service personnel report difficulties in navigating civilian health and social care services. Personal healthcare records are associated with a number of benefits, including improved continuity of care and patient empowerment. As such, this pilot project aimed to assess the benefits of the Veterans Universal Passport (VUP) in supporting UK ex-service personnel accessing NHS services.

Methods

In-depth semi-structured interviews were carried out with eight participants (three ex-service personnel, two carers, three health and social care professionals) who had used the VUP. Interviews explored the benefits, challenges and unmet needs associated with the VUP. A thematic analysis was used to identify themes within this framework.

Results

Participants felt that the VUP improved continuity of care and promoted a feeling of control over care. The military-specific nature of the VUP promoted a sense of identity and provided a ‘support scaffold’ for navigating the complexities of the civilian healthcare system. Challenges included awareness among health and social care professionals, and engagement of users. All participants suggested development into a digital application.

Conclusions

Findings suggest that the VUP had a positive impact on veterans’ access to civilian health and social care services, highlighting that it provided a much-needed structure to their journey through treatment. Considering the parallels with other health and social care transitions, translation for other populations may be beneficial.
Digital subtraction angiographic characteristics of progression of moyamoya disease 6 months prior to surgical revascularisation
Authors: Ge Peicong , Zhang Qian , Ye Xun , Liu Xingju , Deng Xiaofeng , Wang Jia , Wang Rong , Zhang Yan , Zhang Dong , Zhao Ji Zong
Published: February 2020

Background

Evidence on the natural angiographic course of moyamoya disease (MMD) is lacking. It takes about 6 months for waiting for revascularisation surgery. The issue of when to perform subtraction angiography (DSA) for follow-up remains unclear. We investigated the natural course of MMD by DSA and attempted to determine the best interval to perform the follow-up DSA.

Methods

This is a single-centre cohort study of Chinese MMD inpatients treated from 1 January 2015 to 31 August 2019. Their angiographic findings were evaluated on Suzuki stage and collateral circulation between two follow-ups of the same hemisphere.

Results

A total of 110 patients who met the criteria were enrolled in this study. After a median 6 months follow-up, five patients (4.5%) had progression, four females and one male. Time interval of progression ranged from 4 to 137 months with a mean of 61.4 months. Of five patients with progression, four had unilateral lesion (two ipsilateral and two contralateral) and one had bilateral lesions. Collateral circulation was changed in three of five patients.

Conclusions

The angiographic evidence of progression in MMD was rare in the short-term follow-up, and most patients with progression had initial unilateral involvement. DSA re-examination may be not needed in patients with bilateral MMD, but needed in unilateral MMD.
Mutually unbiased unitary bases of operators on d-dimensional hilbert space
Authors: Nasir Rinie N. M. , Shaari Jesni Shamsul , Mancini Stefano
Published: February 2020

Analogous to the notion of mutually unbiased bases for Hilbert spaces, we consider mutually unbiased unitary bases (MUUBs) for the space of operators, [Formula: see text], acting on such Hilbert spaces. The notion of MUUB reflects the equiprobable guesses of unitary operators in one basis of [Formula: see text] when estimating a unitary operator in another. Though, for prime dimension [Formula: see text], the maximal number of MUUBs is known to be [Formula: see text], there is no known recipe for constructing them, assuming they exist. However, one can always construct a minimum of three MUUBs, and the maximal number is approached for very large values of [Formula: see text]. MUUBs can also exist for some [Formula: see text]-dimensional subspace of [Formula: see text] with the maximal number being [Formula: see text].
Injective coloring of complementary prism and generalized complementary prism graphs
Authors: Raksha M. R. , Hithavarshini P. , Dominic Charles , Sudev N. K.
Published: February 2020

The complementary prism [Formula: see text] of a graph [Formula: see text] is the graph obtained by drawing edges between the corresponding vertices of a graph [Formula: see text] and its complement [Formula: see text]. In this paper, we generalize the concept of complementary prisms of graphs and determine the injective chromatic number of generalized complementary prisms of graphs. We prove that for any simple graph [Formula: see text] of order [Formula: see text], [Formula: see text] and if [Formula: see text] is a graph with a universal vertex, then [Formula: see text].
Photometric Light Curves Classification with Machine Learning
Authors: Gabruseva Tatiana , Zlobin Sergey , Wang Peter
Published: February 2020

The Large Synoptic Survey Telescope will begin its survey in 2022 and produce terabytes of imaging data each night. To work with this massive onset of data, automated algorithms to classify astronomical light curves are crucial. Here, we present a method for automated classification of photometric light curves for a range of astronomical objects. Our approach is based on the gradient boosting of decision trees, feature extraction and selection, and augmentation. The solution was developed in the context of The Photometric LSST Astronomical Time Series Classification Challenge (PLAsTiCC) and achieved one of the top results in the challenge.
Characteristics of a wing-like sandstone intrusion, Volund Field
Authors: Satur Nicholas , Hurst Andrew , Bang Asgeir , Skjærpe Ivar , Muehlboeck Sarah Alexandra
Published: February 2020

Reservoirs in the Volund Field are all sandstone intrusions with wings on three sides forming the main reservoir volumes. The southern wing was the target of exploration and appraisal wells, which led to the field development. Identification of three smaller intrusions proves the southern wing to be a composite intrusion, similar to outcrop analogues. Identification from core and borehole logs shows that it comprises sandstone-, mudstone- and mudstone-rich intervals, including mudstone clast breccia. Mudstone clast breccia constitutes a significant missed pay candidate. Breccia is porous and has a sand-supported matrix, which gives it excellent reservoir quality. This may be missed pay using analysis of borehole logs. Well data, largely borehole logs, show consistently uniform sandstone porosity distribution within the intrusions, independent of depth. Significantly, at about 100 m from the depth at which the wing emanates from sills, porosity has a broader spread of values. The spread of values is attributable to mudstone clast breccia and thin-bedded sandstone and mudstone. Porosity derived from borehole logs does not differentiate breccia from siltstone, but inference is possible using calibration of logs with core.
From gravity cores to overpressure history: the importance of measured sediment physical properties in hydrogeological models
Authors: Mencaroni Davide , Llopart Jaume , Urgeles Roger , Lafuerza Sara , Gràcia Eulàlia , Le Friant Anne , Urlaub Morelia
Published: February 2020

The development of overpressure in continental margins is typically evaluated with hydrogeological models. Such approaches are used to both identify fluid flow patterns and to evaluate the development of high pore pressures within layers with particular physical properties that may promote slope instability. In some instances, these models are defined with sediment properties based on facies characterization and proxy values of porosity; permeability or compressibility are derived from the existing literature as direct measurements are rarely available. This study uses finite-element models to quantify the differences in computed overpressure generated by fine-grained hemipelagic sediments from the Gulf of Cadiz, offshore Martinique and the Gulf of Mexico, and their consequences in terms of submarine slope stability. By comparing our simulation results with
in situ
pore pressure data measured in the Gulf of Mexico, we demonstrate that physical properties measured on volcanic-influenced hemipelagic sediments underestimate the computed stability of a submarine slope. Physical properties measured on sediments from the study area are key to improving the reliability and accuracy of overpressure models, and when that information is unavailable, literature data from samples with similar lithologies, composition and depositional settings enable better assessment of the overpressure role as a pre-conditioning factor in submarine landslide initiation.
PBS
Authors: Zhang Yiming , Li Huiba , Liu Shengyun , Xu Jiawei , Xue Guangtao
Published: February 2020

Block storage provides virtual disks that can be mounted by virtual machines (VMs). Although erasure coding (EC) has been widely used in many cloud storage systems for its high efficiency and durability, current EC schemes cannot provide high-performance block storage for the cloud. This is because they introduce significant overhead to small write operations (which perform
partial write
to an entire EC group), whereas cloud-oblivious applications running on VMs are often small-write-intensive. We identify the root cause for the poor performance of partial writes in state-of-the-art EC schemes: for each partial write, they have to perform a time-consuming write-after-read operation that reads the current value of the data and then computes and writes the
parity
delta, which will be used to “patch” the parity in journal replay.

In this article, we present a speculative partial write scheme (called P
ARI
X) that supports fast small writes in erasure-coded storage systems. We transform the original formula of parity calculation to use the
data
deltas (between the current/original data values), instead of the
parity
deltas, to calculate the parities in journal replay. For each partial write, this allows P
ARI
X to
speculatively
log only the new value of the data without reading its original value. For a series of
n
partial writes to the same data, P
ARI
X performs pure write (instead of write-after-read) for the last
n
-1 ones while only introducing a small penalty of an extra network round-trip time to the first one. Based on P
ARI
X, we design and implement P
ARI
X Block Storage (PBS), an efficient block storage system that provides high-performance virtual disk service for VMs running cloud-oblivious applications. PBS not only supports fast partial writes but also realizes efficient full writes, background journal replay, and fast failure recovery with strong consistency guarantees. Both microbenchmarks and trace-driven evaluation show that PBS provides efficient block storage and outperforms state-of-the-art EC-based systems by orders of magnitude.
Proteomics of Select Neglected Tropical Diseases
Authors: Saviola Anthony J. , Negrão Fernanda , Yates John R.
Published: February 2020

Technological advances in mass spectrometry have enabled the extensive identification, characterization, and quantification of proteins in any biological system. In disease processes proteins are often altered in response to external stimuli; therefore, proteomics, the large-scale study of proteins and their functions, represents an invaluable tool for understanding the molecular basis of disease. This review highlights the use of mass spectrometry–based proteomics to study the pathogenesis, etiology, and pathology of several neglected tropical diseases (NTDs), a diverse group of disabling diseases primarily associated with poverty in tropical and subtropical regions of the world. While numerous NTDs have been the subject of proteomic studies, this review focuses on Buruli ulcer, dengue, leishmaniasis, and snakebite envenoming. The proteomic studies highlighted provide substantial information on the pathogenic mechanisms driving these diseases; they also identify molecular targets for drug discovery and development and uncover promising biomarkers that can assist in early diagnosis.
Spinal cord neural network interactions: implications for sympathetic control of the porcine heart
Authors: Dale Erica A. , Kipke Jasmine , Kubo Yukiko , Sunshine Michael D. , Castro Peter A. , Ardell Jeffrey L. , Mahajan Aman
Published: February 2020

Inherent and acquired factors determine the integrated autonomic response to cardiovascular stressors. Excessive sympathoexcitation to ischemic stress is a major contributor to the potential for sudden cardiac death. To define fundamental aspects of cardiac-related autonomic neural network interactions within the thoracic cord, specifically as related to modulating sympathetic preganglionic (SPN) neural activity. Adult, anesthetized Yorkshire pigs ( n = 10) were implanted with penetrating high-density microarrays (64 electrodes) at the T2 level of the thoracic spinal cord to record extracellular potentials concurrently from left-sided dorsal horn (DH) and SPN neurons. Electrical stimulation of the T2 paravertebral chain allowed for antidromic identification of SPNs located in the intermediolateral cell column (57 of total 1,760 recorded neurons). Cardiac stressors included epicardial touch, occlusion of great vessels to transiently alter preload/afterload, and transient occlusion of the left anterior descending coronary artery (LAD). Spatial/temporal assessment of network interactions was characterized by cross-correlation analysis. While some DH neurons responded solely to changes in preload/afterload (8.5 ± 1.9%) or ischemic stress (10.5 ± 3.9%), the majority of cardiovascular-related DH neurons were multimodal (30.2 ± 4.7%) with ischemia sensitivity being one of the modalities (26.1 ± 4.7%). The sympathoexcitation associated with transient LAD occlusion was associated with increased correlations from baseline within DH neurons (2.43 ± 0.61 to 7.30 ± 1.84%, P = 0.04) and between SPN to DH neurons (1.32 ± 0.78 to 7.24 ± 1.84%, P = 0.02). DH to SPN network correlations were reduced during great vessel occlusion. In conclusion, increased intrasegmental network coherence within the thoracic spinal cord contributes to myocardial ischemia-induced sympathoexcitation.

NEW & NOTEWORTHY In an in vivo pig model, we demonstrate using novel high-resolution neural electrode arrays that increased intrasegmental network coherence within the thoracic spinal cord contributes to myocardial ischemia-induced sympathoexcitation.
Characteristics and Treatment of Anaphylaxis in Children Visiting a Pediatric Emergency Department in Korea
Authors: Lee Won Seok , An Jaewoo , Jung Young-Ho , Jee Hye Mi , Chae Kyu-Young , Park Young A. , Han Man Yong , Lee Kyung Suk
Published: February 2020

Anaphylaxis is a serious life‐threatening allergic disease in children. This study is aimed at determining the characteristics of pediatric patients who experienced anaphylaxis along with treatments administered in order to determine the usefulness of tryptase level assessment as a marker of anaphylaxis in Korean children. A total of 107 patients who were diagnosed with anaphylaxis in a single pediatric emergency center over a 3‐year period were included in the study. Patient clinical characteristics, symptoms, signs, allergy history, trigger factors, treatments, and laboratory findings, including serum tryptase levels, were included in the analysis. Food allergies (39.3%) were the most commonly reported patient allergic history, and 58 patients (54.2%) were triggered by food. Among this group, nuts and milk exposure were the most common, affecting 15 patients (25.9%). History of anaphylaxis and asthma were more common in severe anaphylaxis compared to mild or moderate anaphylaxis cases. Epinephrine intramuscular injection was administrated to 76 patients (71.0%), and a self‐injectable epinephrine was prescribed to 18 patients (16.8%). The median tryptase level was 4.80 ng/mL (range: 2.70–10.40) which was lower than the 11.4 ng/mL value commonly documented for standard evaluation in adults with anaphylaxis. The most common cause of pediatric anaphylaxis was food including nuts and milk. The rate of epinephrine injection was relatively high in our pediatric emergency department. The median tryptase level associated with anaphylaxis reactions in children was lower than 11.4 ng/mL. Further studies are needed to help improve diagnostic times and treatment accuracy in pediatric patients who develop anaphylaxis.
Association of Epoxide Hydrolase 2 Gene Arg287Gln with the Risk for Primary Hypertension in Chinese
Authors: Ma Liang , Zhao Hailing , Yu Meijie , Wen Yumin , Zhao Tingting , Yan Meihua , Liu Qian , Jiang Yongwei , Cao Yongtong , Li Ping , Niu Wenquan
Published: February 2020

Background. Epoxide hydrolase 2 (EPHX2) gene coding for soluble epoxide hydrolase is a potential candidate in the pathogenesis of hypertension. Objectives. We aimed to assess the association of a missense mutation, R287Q, in EPHX2 gene with primary hypertension risk and examine its association with enzyme activity of soluble epoxide hydrolase. Methods. This study involved 782 patients with primary hypertension and 458 healthy controls. Genotyping was done using TaqMan technique. Activity of soluble epoxide hydrolase fusion proteins was evaluated by the conversion of 11,12-EET to corresponding 11,12-DHET using ELISA kit. Results. After taking carriers of R287Q variant GG genotype as a reference, those with GA genotype had a significantly reduced risk of hypertension (adjusted odds ratio: 0.72, 95% confidence interval: 0.56 to 0.93, P = 0.013). Five significant risk factors were identified, including age, body mass index, total cholesterol, homocysteine, and R287Q variant. These five risk factors for hypertension were represented in a nomogram, with a descent prediction accuracy (C-index: 0.833, P<0.001). Enzyme activity of soluble epoxide hydrolase was significantly lower in the R287Q group than in the wild type group. Conclusions. We provide evidence that R287Q mutation in EPHX2 gene was associated with reduced risk of primary hypertension and low activity of soluble epoxide hydrolase.
Neuroprotective Effects of Lindleyin on Hydrogen Peroxide‐Induced Cell Injury and MPTP‐Induced Parkinson’s Disease in C57BL/6 Mice
Authors: Zhang Jin-Jie , Shi Xiao-Rong , Lv Wen-Wen , Zhou Xiao-Long , Sun Ying-Dong , Li Bao-Yuan , Hu Xiao-Long
Published: February 2020

Oxidative stress (OS) is a crucial factor influencing the development of Parkinson’s disease (PD). Here we first reported that Lindleyin (Lin), one of the major components of rhubarb, possessed neuroprotective effects against H2O2‐induced SH‐SY5Y cell injury and MPTP‐induced PD of C57BL/6 mice. The results showed that Lin can decrease cell death and apoptotic rate induced by H2O2 through inhibiting mitochondrial apoptotic pathway and increasing the activities of SOD, GSH‐Px, and CAT as well as decreasing the level of MDA. In addition, in vivo studies showed that oral administration of Lin (5 or 20 mg/kg) showed significant change in motor function deficits, antioxidant enzyme activities, apoptotic pathway, and tyrosine hydroxylase expression. Our results reveal that Lin might be a promising anti‐PD agent by reducing OS and apoptosis.
Synthesis and Characterisation of a Monolithic Imprinted Column Using a Methacrylic Acid Monomer with Porogen Propanol for Atenolol Analysis
Authors: Hasanah Aliya Nur , Maelaningsih Firdha Senja , Apriliandi Fadli , Sabarudin Akhmad
Published: February 2020

A monolithic imprinted atenolol column was constructed by in situ polymerisation using a methacrylic acid monomer and a 1 : 1 (v/v) porogen of propanol: toluene with two template: monomer: crosslinker combinations, namely, MIP 1 (1 : 4 : 20) and MIP 2 (1 : 5 : 20). Physical characterisation of the monolithic columns consisted of permeability testing, Fourier transform infrared (FTIR) testing, surface area analysis (SAA), and scanning electron microscopy (SEM). The permeability value of four monolithic columns was in the good category: MIP 1 (24.01 mD), NIP 1 (56.43 mD), MIP 2 (23.03 mD), and NIP 2 (14.47 mD). The polymerisation process of these four monolithic imprinted columns was carried out perfectly, as shown by the absence of vinyl groups (1000 cm−1 and 900 cm−1) during FTIR testing. Based on SAA testing, the pores of the four polymers were classified as mesopores. The best monolithic column was MIP 1, as seen from the intercolumn and intracolumn reproducibility values and a % RSD <2.0%. The MIP 1 column was selective towards atenolol, as seen from the selectivity factor, imprinting factor (IF), and resolution (Rs) values. The IF values of MIP 1 were atenolol (204.62), metoprolol (3.36), and propranolol (1.27). The Rs value between atenolol and the analogue compounds was 7.23. The MIP 1 column can be used for the analysis of atenolol in blood serum samples with an average percentage recovery rate of 94.88 ± 4.43%.