bluuebunny/crossref_metadata_2025 huggingface dataset:
Standardization of nitric oxide inhalation in extremely preterm infants in Japan
Authors: Shiraishi Jun , Kusuda Satoshi , Cho Kazutoshi , Nakao Atsushi , Hiroma Takehiko , Sugiura Hiroshi , Suzuki Satoshi , Oshiro Makoto , Yoshimoto Seiji , Watabe Shinichi
Published: December 2018

Background

In perinatal medicine, inhaled nitric oxide (iNO) has been an important tool for the treatment of full‐term and late‐preterm infants with persistent pulmonary hypertension of the newborn (PPHN) and hypoxemic respiratory failure (HRF). Its use in more premature infants, however, is controversial. To evaluate the current clinical practices regarding use of acute iNO in extremely preterm infants, a nationwide survey was conducted in Japan.

Methods

A questionnaire survey was conducted from May to September, 2015. Questionnaires about PPHN and iNO treatment were sent to the doctor in charge of the neonatal care unit in 213 perinatal medical centers (PMC) that possessed iNO equipment in Japan.

Results

A total of 143 of the 213 PMC provided responses (67.1%). A diagnosis of PPHN was made exclusively on echocardiography in all PMC. On definitive PPHN diagnosis, iNO was selected in the majority of the PMC (72%) and started from ≤10 p.p.m. in most PMC (49.7%) for extremely preterm infants. During iNO therapy, cardiac function was checked on echocardiography by a neonatologist every ≤8 h. iNO weaning was started when differential peripheral oxygen saturation (SpO2) disappeared, or when SpO2 reached 100% and so on. After iNO concentration reached 5 p.p.m., it was decreased gradually and carefully in five steps, taking 12–24 h to go from 5 to 0 p.p.m.

Conclusions

Inhaled nitric oxide was predominantly used in extremely preterm infants as early rescue therapy for PPHN based on echocardiography performed by a neonatologist.
Logical Realism and the Metaphysics of Logic
Authors: McSweeney Michaela Markham
Published: December 2018

‘Logical Realism’ is taken to mean many different things. I argue that if reality has a privileged structure, then a view I call metaphysical logical realism is true. The view says that, first, there is ‘One True Logic’; second, that the One True Logic is made true by the mind‐and‐language‐independent world; and third, that the mind‐and‐language‐independent world makes it the case that the One True Logic is better than any other logic at capturing the structure of reality. Along the way, I discuss a few alternatives, and clarify two distinct kinds of metaphysical logical realism.
Green Criminology and Environmental Crimes and Harms
Authors: Brisman Avi , South Nigel
Published: December 2018

The focus of criminology on crimes and harms committed by and against humans has broadened over time. Only since the 1990s, however, has the discipline recognized the significance of crimes and harms concerning the environment and nonhuman animals. A variety of approaches and bodies of work now contribute to what can be described as “green criminology.” This article summarizes research on types of environmental crime and harm, as well as different eco‐philosophical orientations and related justice‐based approaches. It concludes with an example illustrating the ways in which these approaches may overlap.
Learning opportunities: Understanding farmers’ soil testing practice through workshop activities to improve extension support for soil health management
Authors: Lobry de Bruyn Lisa A.
Published: December 2018

This paper examines the potential for extension providers to identify learning opportunities by intentionally surveying farmers attending soil testing workshops designed to improve soil health and its management. In south‐eastern Australia, regional government agencies have been running soil health workshops since 2014, yet they have rarely surveyed the participants to understand their previous experience or learning needs, and how that may inform their design. The workshop consisted of two sessions, separated by 6 weeks. Farmers at the first Session were told how to undertake soil measurements. At the second Session, they then discussed their soil test results. The workshop participants (n = 87) at four different localities in the Northern Tablelands of New South Wales were surveyed (68% response rate) at each session. Firstly, to examine their prior knowledge and experience of soil testing, and secondly on how they applied what they had learnt, examine if the soil test results matched their expectations, and their influence in land management decisions. The survey revealed to regional government agencies that the majority of survey respondents (62%) would soil test again. Despite more than half of the respondents infrequently or never having their soil tested, prior to the workshop, 50% indicated that the test results were unexpected. The motivation for those farmers who would soil test again was the specific desire to identify their soil's potential for improved production. The survey provided a way of profiling the workshop audience and obtaining important feedback on how to improve the impact of the workshops for participants.
The Warrumbungle Post‐Fire Recovery Project—raising the profile of soils
Authors: Tulau Mitchell John , McInnes‐Clarke Sally K. , Yang Xihua , McAlpine Robin A. , Karunaratne Senani B. , Zhu Qinggaozi , Morand David T.
Published: December 2018

The impacts of a wildfire and subsequent rainfall event in 2013 in the Warrumbungle National Park in New South Wales, Australia were examined in a project designed to provide information on post‐fire recovery expectations and options to land managers. A coherent suite of sub‐projects was implemented, including soil mapping, and studies on soil organic carbon (SOC) and nitrogen (N), erosion rates, groundcover recovery and stream responses. It was found that the loss of SOC and N increased with fire severity, with the greatest losses from severely burnt sandstone ridges. Approximately 2.4 million t of SOC and ~74,000 t of N were lost from soil to a depth of 10 cm across the 56,290 ha affected. Soil loss from slopes during the subsequent rainfall event was modelled up to 25 t ha−1, compared to a long‐term mean annual soil loss of 1.06 t ha−1 year−1. Groundcover averages generally increased after the fire until spring 2015, by which time rates of soil loss returned to near pre‐fire levels. Streams were filled with sand to bank full levels after the fire and rainfall. Rainfall events in 2015–2016 shifted creek systems into a major erosive phase, with incision through the post‐fire sandy bedload deposits, an erosive phase likely related to loss of topsoils over much of the catchment. The effectiveness of the research was secured by a close engagement with park managers in issue identification and a communications programme. Management outcomes flowing from the research included installation of erosion control works, redesign of access and monitoring of key mass movement hazard areas.
Anthropogenically disturbed potentially toxic elements in roadside topsoils of a suburban region of Bishkek, Central Asia
Authors: Ma Long , Abuduwaili Jilili , Li Yaoming , Liu Wen
Published: December 2018

The ecological environment in Central Asia is vulnerable to pressure from human activity due to the physical geography and climatic fragility of this region. A set of indicators suitable for the future assessment of this pressure needs to be proposed. Thirty‐six topsoil samples (0–5 cm) were collected from roadsides in a suburban region of Bishkek, the capital of the Kyrgyz Republic in Central Asia, and a risk assessment of anthropogenically disturbed potentially toxic elements (PTEs) was systematically conducted with classic statistical methods. The results of detrended correspondence analysis and principal component analysis clearly showed that topsoil samples with high contents of PTEs (Pb, Zn and Cu) were strongly affected by traffic within a distance threshold of 200 m and that anthropogenic effects decreased significantly with increasing distance from the highway. The enrichment factor and anthropogenic contribution for Pb were the highest among the three PTEs, with average values of 2.0% and 47.4%, respectively, suggesting enrichment. However, the results of the human health risk assessment also indicated that noncarcinogenic risks did not occur for any of the anthropogenic PTEs. The reported method provides a new systematic pathway to reveal anthropogenic influences on the geochemical composition of soil. The conclusions of this work will be highly valuable as important guidelines for agriculture, and the results of the PTE contents will provide a scientific basis for soil collection in future studies.
An updated gene atlas for maize reveals organ‐specific and stress‐induced genes
Authors: Hoopes Genevieve M. , Hamilton John P. , Wood Joshua C. , Esteban Eddi , Pasha Asher , Vaillancourt Brieanne , Provart Nicholas J. , Buell C. Robin
Published: December 2018

Maize (Zea mays L.), a model species for genetic studies, is one of the two most important crop species worldwide. The genome sequence of the reference genotype, B73, representative of the stiff stalk heterotic group was recently updated (AGPv4) using long‐read sequencing and optical mapping technology. To facilitate the use of AGPv4 and to enable functional genomic studies and association of genotype with phenotype, we determined expression abundances for replicated mRNA‐sequencing datasets from 79 tissues and five abiotic/biotic stress treatments revealing 36 207 expressed genes. Characterization of the B73 transcriptome across six organs revealed 4154 organ‐specific and 7704 differentially expressed (DE) genes following stress treatment. Gene co‐expression network analyses revealed 12 modules associated with distinct biological processes containing 13 590 genes providing a resource for further association of gene function based on co‐expression patterns. Presence−absence variants (PAVs) previously identified using whole genome resequencing data from 61 additional inbred lines were enriched in organ‐specific and stress‐induced DE genes suggesting that PAVs may function in phenological variation and adaptation to environment. Relative to core genes conserved across the 62 profiled inbreds, PAVs have lower expression abundances which are correlated with their frequency of dispersion across inbreds and on average have significantly fewer co‐expression network connections suggesting that a subset of PAVs may be on an evolutionary path to pseudogenization. To facilitate use by the community, we developed the Maize Genomics Resource website (maize.plantbiology.msu.edu) for viewing and data‐mining these resources and deployed two new views on the maize electronic Fluorescent Pictograph Browser (bar.utoronto.ca/efp_maize).
The P‐class pentatricopeptide repeat protein PpPPR_21 is needed for accumulation of the psbI‐ycf12 dicistronic mRNA in Physcomitrella chloroplasts
Authors: Ebihara Tetsuo , Matsuda Takuya , Sugita Chieko , Ichinose Mizuho , Yamamoto Hiroshi , Shikanai Toshiharu , Sugita Mamoru
Published: December 2018

Chloroplast gene expression is controlled by numerous nuclear‐encoded RNA‐binding proteins. Among these, pentatricopeptide repeat (PPR) proteins are known to be key players in post‐transcriptional regulation in chloroplasts. However, the functions of many PPR proteins remain unknown. In this study, we characterized the function of a chloroplast‐localized P‐class PPR protein PpPPR_21 in Physcomitrella patens. Knockout (KO) mutants of PpPPR_21 exhibited reduced protonemata growth and lower photosynthetic activity. Immunoblot analysis and blue‐native gel analysis showed a remarkable reduction of the photosystem II (PSII) reaction center protein and poor formation of the PSII supercomplexes in the KO mutants. To assess whether PpPPR_21 is involved in chloroplast gene expression, chloroplast genome‐wide microarray analysis and Northern blot hybridization were performed. These analyses indicated that the psbI‐ycf12 transcript encoding the low molecular weight subunits of PSII did not accumulate in the KO mutants while other psb transcripts accumulated at similar levels in wild‐type and KO mutants. A complemented PpPPR_21KO moss transformed with the cognate full‐length PpPPR_21cDNA rescued the level of accumulation of psbI‐ycf12 transcript. RNA‐binding experiments showed that the recombinant PpPPR_21 bound efficiently to the 5′ untranslated and translated regions of psbImRNA. The present study suggests that PpPPR_21 may be essential for the accumulation of a stable psbI‐ycf12mRNA.
Measuring and improving the performance of customs valuation controls: An illustration with Gabon
Authors: Cariolle Joël , Chalendard Cyril , Geourjon Anne‐Marie , Laporte Bertrand
Published: December 2018

Modern customs administrations aim to both facilitate legal trade and combat fraud. To meet this dual objective, many customs administrations in developing countries must give risk management a highly prominent role. In this context of modernisation, this paper first provides stylised facts on the performance of the customs controls carried out at the Gabon border. Then, we compare Gabon′s granular import customs data with international trade statistics. Based on this comparison, we identify undetected fraud and present a methodology to target ex post audits. Finally, we define indicators to monitor the performance of customs valuation controls.
The Relationship between Elementary School Teachers’ Work Motivation and Well-Being: The Mediating Effects of Principal Leadership and Work Stress
Authors: Um ByeolBee , Joo HyunGyung , Her DaYeon
Published: December 2018

This research intends to examine the mediating effects of elementary school teachers’ perception of principal leadership and work stress on the relationship between work motivation and well-being. For this purpose, the present study sampled 400 elementary school teachers from the Seoul metropolitan area in South Korea. Subsequently, the participants answered four scales to measure work motivation, perception of principal leadership, work stress, and well-being. The 324 data finally collected consist of 276 females and 48 males. The research results are as follows. First, four variables had significant correlations with each other, positively or negatively. Second, there was no significant mediating effect of principal leadership on work motivation and well-being. Third, teachers’ work stress had a partial mediating effect on the relationship between work motivation and well-being. Fourth, principal leadership and work stress had a sequentially partial mediating effect on work motivation and well-being. This paper discusses these findings and then suggests the directions for future research.
Effect of microstructural changes in the biological behavior of magnetron sputtered ZnO thin films
Authors: Costa Diogo , Borges Joel , Mota Maria F. , Rodrigues Marco S. , Pereira-Silva Patrícia , Ferreira Armando , Pereira Cátia S. , Sampaio Paula , Vaz Filipe
Published: December 2018

This work is focused on the evaluation of the correlation between the microstructural changes of zinc oxide (ZnO) thin films and its biological behavior. For this study, ZnO thin films were prepared by reactive magnetron sputtering, using different deposition times and reactive gas (O2) flows, and tested against a fungal pathogenic species, Candida albicans. Results showed that the increase of thickness of the films did not affect significantly the surface roughness but changed the crystalline structure of the films (ZnO in the hcp structure), which was followed by a small increase of antifungal properties, leading to a decrease of viable cells. The decrease of O2 flow in the deposition chamber affected the roughness only slightly (roughly 1 nm difference between the different films) but resulted in a clear decrease in the crystallinity of thin films, which improved even further their antifungal activity. These results seem to indicate a correlation between structural features and the antifungal behavior of the ZnO thin films, which will be shown by different analyses. When tested against the fungal species, the films showed to be capable of reducing the growth rate and inhibit their growth, leading to a low number of microbial cells at the end of the experiment. A deeper analysis by flow cytometry on how the thin films affected the microbial cells showed a reduced global enzymatic activity in yeast cells after contact with the materials’ surface.
Temperature-dependent hypoxia explains biogeography and severity of end-Permian marine mass extinction
Authors: Penn Justin L. , Deutsch Curtis , Payne Jonathan L. , Sperling Erik A.
Published: December 2018

Drivers of the “Great Dying”

Though our current extinction crisis is substantial, it pales in comparison to the largest extinction in Earth's history, which occurred at the end of the Permian Period. Referred to as the “Great Dying,” this event saw the loss of up to 96% of all marine species and 70% of terrestrial species. Penn
et al.
explored the extinction dynamics of the time using Earth system models in conjunction with physiological data across animal taxa (see the Perspective by Kump). They conclude that increased marine temperatures and reduced oxygen availability were responsible for a majority of the recorded extinctions. Because similar environmental alterations are predicted outcomes of current climate change, we would be wise to take note.

Science
, this issue p.
eaat1327
; see also p.
1113
Spectrally resolved helium absorption from the extended atmosphere of a warm Neptune-mass exoplanet
Authors: Allart R. , Bourrier V. , Lovis C. , Ehrenreich D. , Spake J. J. , Wyttenbach A. , Pino L. , Pepe F. , Sing D. K. , Lecavelier des Etangs A.
Published: December 2018

Helium escaping from hot gas giants

Many gas giant exoplanets orbit so close to their host star that they are heated to high temperatures, causing atmospheric gases to escape. Gas giant atmospheres are mostly hydrogen and helium, which are difficult to observe. Two papers have now observed escaping helium in the near-infrared (see the Perspective by Brogi). Allart
et al.
observed helium in a Neptune-mass exoplanet and performed detailed simulations of its atmosphere, which put constraints on the escape rate. Nortmann
et al.
found that helium is escaping a Saturn-mass planet, trailing behind it in its orbit. They combined this with observations of several other exoplanets to show that atmospheres are being lost more quickly by exoplanets that are more strongly heated.

Science
, this issue p.
1384
, p.
1388
; see also p.
1360
Room-temperature cycling of metal fluoride electrodes: Liquid electrolytes for high-energy fluoride ion cells
Authors: Davis Victoria K. , Bates Christopher M. , Omichi Kaoru , Savoie Brett M. , Momčilović Nebojša , Xu Qingmin , Wolf William J. , Webb Michael A. , Billings Keith J. , Chou Nam Hawn , Alayoglu Selim , McKenney Ryan K. , Darolles Isabelle M. , Nair Nanditha G. , Hightower Adrian , Rosenberg Daniel , Ahmed Musahid , Brooks Christopher J. , Miller Thomas F. , Grubbs Robert H. , Jones Simon C.
Published: December 2018

Working toward fluoride batteries

Owing to the low atomic weight of fluorine, rechargeable fluoride-based batteries could offer very high energy density. However, current batteries need to operate at high temperatures that are required for the molten salt electrolytes. Davis
et al.
push toward batteries that can operate at room temperature, through two advances. One is the development of a room-temperature liquid electrolyte based on a stable tetraalkylammonium salt–fluorinated ether combination. The second is a copper–lanthanum trifluoride core-shell cathode material that demonstrates reversible partial fluorination and defluorination reactions.

Science
, this issue p.
1144
Salmonella
persisters undermine host immune defenses during antibiotic treatment
Authors: Stapels Daphne A. C. , Hill Peter W. S. , Westermann Alexander J. , Fisher Robert A. , Thurston Teresa L. , Saliba Antoine-Emmanuel , Blommestein Isabelle , Vogel Jörg , Helaine Sophie
Published: December 2018

Actively persistent
Salmonella

A proportion of
Salmonella
cells can enter a reversible state of growth arrest, which allows them to tolerate environmental stress such as antibiotics. Stapels
et al.
found that these cells are not dormant but are actively modulating their environment.
Salmonella
within their host macrophage niche deployed a specialized type 3 secretory system called SPI-2 to deliver virulence factors, including SteE, into host cells. SteE changed the cytokine profile of the infected macrophages to reprogram them into a noninflammatory and infection-permissive state. Thus, when antibiotics were removed, the
Salmonella
could reemerge and cause disease.

Science
, this issue p.
1156
Photonic crystals for nano-light in moiré graphene superlattices
Authors: Sunku S. S. , Ni G. X. , Jiang B. Y. , Yoo H. , Sternbach A. , McLeod A. S. , Stauber T. , Xiong L. , Taniguchi T. , Watanabe K. , Kim P. , Fogler M. M. , Basov D. N.
Published: December 2018

Twisting a route for surface plasmons

Graphene is an atomically thin material that supports highly confined plasmon polaritons, or nano-light, with very low loss. The properties of graphene can be made richer by introducing and then rotating a second layer so that there is a slight angle between the atomic registry. Sunku
et al.
show that the moiré patterns that result from such twisted bilayer graphene also provide confined conducting channels that can be used for the directed propagation of surface plasmons. Controlling the structure thereby provides a pathway to control and route surface plasmons for a nanophotonic platform.

Science
, this issue p.
1153
Practical Guidance for Clinical Microbiology Laboratories: Viruses Causing Acute Respiratory Tract Infections
Authors: Charlton Carmen L. , Babady Esther , Ginocchio Christine C. , Hatchette Todd F. , Jerris Robert C. , Li Yan , Loeffelholz Mike , McCarter Yvette S. , Miller Melissa B. , Novak-Weekley Susan , Schuetz Audrey N. , Tang Yi-Wei , Widen Ray , Drews Steven J.
Published: December 2018

Respiratory viral infections are associated with a wide range of acute syndromes and infectious disease processes in children and adults worldwide. Many viruses are implicated in these infections, and these viruses are spread largely via respiratory means between humans but also occasionally from animals to humans.
Assessing health-related quality of life of patients with colorectal cancer using EQ-5D-5L: a cross-sectional study in Heilongjiang of China
Authors: Huang Weidong , Yang Jinjin , Liu Yang , Liu Chaojie , Zhang Xin , Fu Wenqi , Shi Limei , Liu Guoxiang
Published: December 2018

Aim

This study aimed to assess the health-related quality of life (HRQoL) of patients with colorectal cancer (CRC) and its determinants.

Methods

A cross-sectional questionnaire survey was conducted on 300 newly diagnosed patients with CRC in China’s Heilongjiang province, measuring HRQoL using the EuroQol five-dimension five-level (EQ-5D-5L). Kruskal-Wallis analyses were performed to identify the independent variables associated with the EQ-5D-5L utility scores. Predictors of the utility scores were confirmed using a Tobit regression model.

Results

The respondents had a mean EQ-5D-5L utility score of 0.617 (SD=0.371) and a median of 0.740 (range: −0.348 to 1.000). Pain/discomfort and anxiety/depression were major concerns of the respondents, with a prevalence of over 60% (all levels inclusive). The Kruskal-Wallis analyses found lower utility scores in those who were not married, worked as a farmer, enrolled with the new rural cooperative medical scheme and had lower household income (p<0.05). Those who were at a later stage of CRC, underwent surgical only therapy and had a stoma also had lower EQ-5D-5L scores than others (p<0.05). The Tobit regression model confirmed these predictors, except for occupation and marital status.

Conclusion

Patients with CRC have poor HRQoL, with pain/discomfort and depression/anxiety as the most frequently reported problems. The poor HRQoL is associated with the seriousness of the disease condition, as well as the low socioeconomic status of the patients.
Development and validation of a novel computer-aided score to predict the risk of in-hospital mortality for acutely ill medical admissions in two acute hospitals using their first electronically recorded blood test results and vital signs: a cross-sectional study
Authors: Faisal Muhammad , Scally Andrew J , Jackson Natalie , Richardson Donald , Beatson Kevin , Howes Robin , Speed Kevin , Menon Madhav , Daws Jeremey , Dyson Judith , Marsh Claire , Mohammed Mohammed A
Published: December 2018

Objectives

There are no established mortality risk equations specifically for emergency medical patients who are admitted to a general hospital ward. Such risk equations may be useful in supporting the clinical decision-making process. We aim to develop and externally validate a computer-aided risk of mortality (CARM) score by combining the first electronically recorded vital signs and blood test results for emergency medical admissions.

Design

Logistic regression model development and external validation study.

Setting

Two acute hospitals (Northern Lincolnshire and Goole NHS Foundation Trust Hospital (NH)—model development data; York Hospital (YH)—external validation data).

Participants

Adult (aged ≥16 years) medical admissions discharged over a 24-month period with electronic National Early Warning Score(s) and blood test results recorded on admission.

Results

The risk of in-hospital mortality following emergency medical admission was 5.7% (NH: 1766/30 996) and 6.5% (YH: 1703/26 247). The C-statistic for the CARM score in NH was 0.87 (95% CI 0.86 to 0.88) and was similar in an external hospital setting YH (0.86, 95% CI 0.85 to 0.87) and the calibration slope included 1 (0.97, 95% CI 0.94 to 1.00).

Conclusions

We have developed a novel, externally validated CARM score with good performance characteristics for estimating the risk of in-hospital mortality following an emergency medical admission using the patient’s first, electronically recorded, vital signs and blood test results. Since the CARM score places no additional data collection burden on clinicians and is readily automated, it may now be carefully introduced and evaluated in hospitals with sufficient informatics infrastructure.
High-sensitivity C reactive protein and risk of cardiovascular disease in China-CVD study
Authors: Dong Ying , Wang Xin , Zhang Linfeng , Chen Zuo , Zheng Congyi , Wang Jiali , Kang Yuting , Shao Lan , Tian Ye , Wang Zengwu
Published: December 2018

Background

This study aimed to assess the association of high sensitivity C-reactive protein (hs-CRP) with cardiovascular disease (CVD) in middle-aged Chinese population.

Methods

The baseline was collected 2009–2010, and follow-up was conducted in 2016–2017. Data of hs-CRP were from baseline examination and re-examination in 2016–2017 using transmission turbidimetry with a measurement range of 0–42 000. The primary outcome was CVD including coronary heart disease events and stroke events.

Results

Among 8688 participants free from CVD (at baseline, mean age, 50.1 years, 3897 were males), there were 189 CVD events, occurred during a median follow-up of 6.34 years (54 685 person-years at risk). From the Kaplan-Meier curve, we found that there was a progressive increase in CVD event rates by hs-CRP tertiles (log-rank test, p<0.001). Baseline hs-CRP was linearly associated with CVD (p for trend=0.015) even after adjusting for known CVD risk factors. Furthermore, the net reclassification improvement when hs-CRP was added to a model based on traditional factors was 7.85% for CVD (p=0.003). In addition, the correlation between change of hs-CRP and CVD was conducted in a subgroup (n=4778). However, we did not find the correlation between hs-CRP change and CVD (correlation coefficient: −0.003, p=0.846).

Conclusions

In the middle-aged Chinese population, hs-CRP was associated with increased risk of developing CVD. Although there was no correlation between hs-CRP change and CVD, the level of hs-CRP was higher at follow-up than baseline even among those with CVD. More attention should be given to those with higher level of hs-CRP for CVD prevention.
Preventing vessel perforations in endovascular thrombectomy: feasibility and safety of passing the clot with a microcatheter without microwire: the wireless microcatheter technique
Authors: Keulers Annika , Nikoubashman Omid , Mpotsaris Anastasios , Wilson Scott D , Wiesmann Martin
Published: December 2018

Background

To place a stent retriever for thrombectomy in acute ischemic stroke, the clot has to be passed first. A microwire is usually used for this maneuver. As an alternative, a wireless microcatheter can be used to pass the clot.

Objective

To analyze the feasibility and complication rates of passing the clot using either a microwire or a wireless microcatheter.

Methods

A retrospective non-randomized analysis of 110 consecutive patients with acute ischemic stroke in the anterior circulation was performed, in whom video recordings of mechanical thrombectomies were available. In total, 203 attempts at mechanical recanalization were performed.

Results

Successful recanalization (TICI 2b–3) was achieved in 97.3% of patients. In 71.8% of attempts the clot was successfully passed using a wireless microcatheter only. When a microwire was used initially, clot passage was successful in 95.3% of attempts. Complication rates for angiographically detectable subarachnoid hemorrhage were 6.1% when a microwire was used to pass the clot compared with 0% when a wireless microcatheter was used (p<0.001). Complication rates for angiographically occult circumscribed subarachnoid contrast extravasation observed on post-interventional CT scans were 18.2% when a microwire was used to pass the clot and 4.5% when a wireless microcatheter was used (p<0.001).

Conclusions

In most cases of mechanical recanalization the clot can be passed with a wireless microcatheter instead of a microwire. In our study this method significantly reduced the risk for vessel perforation and subarachnoid hemorrhage. We therefore recommend the use of this technique whenever possible.
First attempt recanalization with ADAPT: rate, predictors, and outcome
Authors: Anadani Mohammad , Alawieh Ali , Vargas Jan , Chatterjee Arindam Rano , Turk Aquilla , Spiotta Alejandro
Published: December 2018

Introduction

The rate of first-attempt recanalization (FAR) with the newer-generation thrombectomy devices, and more specifically with aspiration devices, is not well known. Moreover, the effect of FAR on outcomes after mechanical thrombectomy is not properly understood.

Objective

To report the rate of FAR using a direct aspiration first pass technique (ADAPT), investigate the association between FAR and outcomes, and identify the predictors of FAR.

Methods

The ADAPT database was used to identify a subgroup of patients in whom FAR was achieved. Baseline characteristics, procedural, and postprocedural variables were collected. Outcome measures included 90-day modified Rankin scale (mRS) score, mortality, and hemorrhagic complications. Multivariate logistic regression was used to identify FAR predictors.

Results

A total of 524 patients was included of whom 178 (34.0%) achieved FAR. More patients in the FAR group than in the non-FAR group received IV tPA (46.6% vs 37.6%; p<0.05). For the functional outcome, higher proportions of patients in the FAR group achieved functional independence (mRS score 0–2; 53% vs 37%; p<0.05). Additionally, we observed lower mortality and hemorrhagic transformation rates in the FAR group than the non-FAR group. Independent predictors of FAR in the anterior circulation were pretreatment IV tPA, non-tandem occlusion, and use of larger reperfusion catheters (Penumbra, ACE 64–68). Independent predictors of FAR in the posterior circulation were diabetes, onset-to-groin time, and cardioembolic etiology.

Conclusion

FAR was associated with better functional outcome and lower mortality rate. When ADAPT is used, a larger aspiration catheter and pretreatment IV tPA should be employed when indicated.
Prognostic importance of CT ASPECTS and CT perfusion measures of infarction in anterior emergent large vessel occlusions
Authors: Raza Syed Ali , Barreira Clara M , Rodrigues Gabriel M , Frankel Michael R , Haussen Diogo C , Nogueira Raul G , Rangaraju Srikant
Published: December 2018

Background

Age, neurologic deficits, core volume (CV), and clinical core or radiographic mismatch are considered in selection for endovascular therapy (ET) in anterior circulation emergent large vessel occlusion (aELVO). Semiquantitative CV estimation by Alberta Stroke Programme Early CT Score (CT ASPECTS) and quantitative CV estimation by CT perfusion (CTP) are both used in selection paradigms.

Objective

To compare the prognostic value of CTP CV with CT ASPECTS in aELVO.

Methods

Patients in an institutional endovascular registry who had aELVO, pre-ET National Institutes of Health Stroke Scale (NIHSS) score, non-contrast CT head and CTP imaging, and prospectively collected 3-month modified Rankin Scale (mRS) score were included. Age- and NIHSS-adjusted models, including either CT ASPECTS or CTP volumes (relative cerebral blood flow <30% of normal tissue, total hypoperfusion, and radiographic mismatch), were compared using receiver operator characteristic analyses.

Results

We included 508 patients with aELVO (60.8% M1 middle cerebral artery, 34% internal carotid artery, mean age 64.1±15.3 years, median baseline NIHSS score 16 (12–20), median baseline CT ASPECTS 8 (7–9), mean CV 16.7±24.8 mL). Age, pre-ET NIHSS, CT ASPECTS, CV, hypoperfusion, and perfusion imaging mismatch volumes were predictors of good outcome (mRS score 0–2). There were no differences in prognostic accuracies between reference (age, baseline NIHSS, CT ASPECTS; area under the curve (AUC)=0.76) and additional models incorporating combinations of age, NIHSS, and CTP metrics including CV, total hypoperfusion or mismatch volume (AUCs 0.72–0.75). Predicted outcomes from CT ASPECTS or CTP CV-based models had excellent agreement (R2=0.84, p<0.001).

Conclusions

Incorporating CTP measures of core or penumbral volume, instead of CT ASPECTS, did not improve prognostication of 3-month outcomes, suggesting prognostic equivalence of CT ASPECTS and CTP CV.
Modeling traffic flow on a comprehensive network with competition and cooperation between urban logistic alliances
Authors: Ren Hualing , Dong Zhiheng
Published: December 2018

The traffic during rush hour in metropolises is always in heavy congestion, so the wagon trucks of logistic transportation are mostly forbidden during rush hour. In fact, quite a few logistic transportations are fulfilled by converted passenger vehicles. This paper aims to model the logistic companies’ behaviors and see through the effect of their cooperation modes on the companies and on the whole traffic conditions. The logistic companies decide their transportation pricing, warehouse using and route choosing separately or as a group (cooperation) to compete with others. It is also assumed that the heavy freight vehicles, light freight vehicles and the auto vehicles share the same network. Three models based on variational inequalities are proposed to describe the companies’ behaviors when there is no cooperation, simple cooperation and deep cooperation, respectively, and the modified diagonalization method is used to solve these models. The total transportation demand is elastic, which depends on the users’ choice of logistics company and further depends on all the companies’ prices, warehouse and route choices. The goodness of different coalitions to the companies and the whole traffic system is well investigated in the numerical examples.
Conceptual uncertainties in modelling the interaction between engineered and natural barriers of nuclear waste repositories in crystalline rocks
Authors: Finsterle S. , Lanyon B. , Åkesson M. , Baxter S. , Bergström M. , Bockgård N. , Dershowitz W. , Dessirier B. , Frampton A. , Fransson Å. , Gens A. , Gylling B. , Hančilová I. , Holton D. , Jarsjö J. , Kim J.-S. , Kröhn K.-P. , Malmberg D. , Pulkkanen V. M. , Sawada A. , Sjöland A. , Svensson U. , Vidstrand P. , Viswanathan H.
Published: December 2018

Nuclear waste disposal in geological formations relies on a multi-barrier concept that includes engineered components – which, in many cases, include a bentonite buffer surrounding waste packages – and the host rock. Contrasts in materials, together with gradients across the interface between the engineered and natural barriers, lead to complex interactions between these two subsystems. Numerical modelling, combined with monitoring and testing data, can be used to improve our overall understanding of rock–bentonite interactions and to predict the performance of this coupled system. Although established methods exist to examine the prediction uncertainties due to uncertainties in the input parameters, the impact of conceptual model decisions on the quantitative and qualitative modelling results is more difficult to assess. A Swedish Nuclear Fuel and Waste Management Company Task Force project facilitated such an assessment. In this project, 11 teams used different conceptualizations and modelling tools to analyse the Bentonite Rock Interaction Experiment (BRIE) conducted at the Äspö Hard Rock Laboratory in Sweden. The exercise showed that prior system understanding along with the features implemented in the available simulators affect the processes included in the conceptual model. For some of these features, sufficient characterization data are available to obtain defensible results and interpretations, whereas others are less supported. The exercise also helped to identify the conceptual uncertainties that led to different assessments of the relative importance of the engineered and natural barrier subsystems. The range of predicted bentonite wetting times encompassed by the ensemble results were considerably larger than the ranges derived from individual models. This is a consequence of conceptual uncertainties, demonstrating the relevance of using a multi-model approach involving alternative conceptualizations.
Modelling the Prototype Repository
Authors: Tsitsopoulos V. , Baxter S. , Holton D. , Dodd J. , Williams S. , Thompson S.
Published: December 2018

The Prototype Repository (PR) tunnel is located at the Äspö Hard Rock Laboratory near Oskarshamn in the southeast of Sweden. In the PR tunnel, six full-sized deposition holes (8.37 m deep and 1.75 m in diameter) have been constructed. Each deposition hole is designed to mimic the Swedish reference system for the disposal of nuclear fuel, KBS-3V. The PR experiment is designed to provide a full-scale simulation of the emplacement of heat-generating waste. There are three phases to the experiment: (1) the open tunnel phase following construction, where both the tunnel and deposition holes are open to atmospheric conditions; (2) the emplacement of canisters (containing heaters), backfill and seal in the first section of the tunnel; and (3) the emplacement of canisters, backfill and seal in the second section of the tunnel. This work describes the numerical modelling, performed as part of the engineered barrier systems (EBS) Task Force, to understand the thermo-hydraulic (TH) evolution of the PR experiment and to provide a better understanding of the interaction between the fractured rock and bentonite surrounding the canister at the scale of a single deposition tunnel. A coupled integrated TH model for predicting the wetting and the temperature of bentonite emplaced in fractured rock was developed, accounting for the heterogeneity of the fractured rock. In this model, geometrical uncertainties of fracture locations are modelled by using several stochastic realizations of the fracture network. The modelling methodology utilized information available at early stages of site characterization and included site statistics for fracture occurrence and properties, as well as proposed installation properties of the bentonite. The adopted approach provides an evaluation of the predictive capability of models, it gives an insight of the uncertainties to data and demonstrates that a simplified equivalent homogeneous description of the fractured host rock is insufficient to represent the bentonite resaturation.
Firefighting on Trees Beyond Integrality Gaps
Authors: Adjiashvili David , Baggio Andrea , Zenklusen Rico
Published: December 2018

The Firefighter problem and a variant of it, known as Resource Minimization for Fire Containment (RMFC), are natural models for optimal inhibition of harmful spreading processes. Despite considerable progress on several fronts, the approximability of these problems is still badly understood. This is the case even when the underlying graph is a tree, which is one of the most-studied graph structures in this context and the focus of this article. In their simplest version, a fire spreads from one fixed vertex step by step from burning to adjacent non-burning vertices, and at each time step
B
many non-burning vertices can be protected from catching fire. The Firefighter problem asks, for a given
B
, to maximize the number of vertices that will not catch fire, whereas RMFC (on a tree) asks to find the smallest
B
that allows for saving all leaves of the tree. Prior to this work, the best known approximation ratios were an
O
(1)-approximation for the Firefighter problem and an
O
(log
*
n
)-approximation for RMFC, both being LP-based and essentially matching the integrality gaps of two natural LP relaxations.

We improve on both approximations by presenting a PTAS for the Firefighter problem and an
O
(1)-approximation for RMFC, both qualitatively matching the known hardness results. Our results are obtained through a combination of the known LPs with several new techniques, which allow for efficiently enumerating over super-constant size sets of constraints to strengthen the natural LPs.
Constitutive interpretation of arterial stiffness in clinical studies: a methodological review
Authors: Reesink Koen D. , Spronck Bart
Published: December 2018

Clinical assessment of arterial stiffness relies on noninvasive measurements of regional pulse wave velocity or local distensibility. However, arterial stiffness measures do not discriminate underlying changes in arterial wall constituent properties (e.g., in collagen, elastin, or smooth muscle), which is highly relevant for development and monitoring of treatment. In arterial stiffness in recent clinical-epidemiological studies, we systematically review clinical-epidemiological studies (2012–) that interpreted arterial stiffness changes in terms of changes in arterial wall constituent properties (63 studies included of 514 studies found). Most studies that did so were association studies (52 of 63 studies) providing limited causal evidence. Intervention studies (11 of 63 studies) addressed changes in arterial stiffness through the modulation of extracellular matrix integrity (5 of 11 studies) or smooth muscle tone (6 of 11 studies). A handful of studies (3 of 63 studies) used mathematical modeling to discriminate between extracellular matrix components. Overall, there exists a notable gap in the mechanistic interpretation of stiffness findings. In constitutive model-based interpretation, we first introduce constitutive-based modeling and use it to illustrate the relationship between constituent properties and stiffness measurements (“forward” approach). We then review all literature on modeling approaches for the constitutive interpretation of clinical arterial stiffness data (“inverse” approach), which are aimed at estimation of constitutive properties from arterial stiffness measurements to benefit treatment development and monitoring. Importantly, any modeling approach requires a tradeoff between model complexity and measurable data. Therefore, the feasibility of changing in vivo the biaxial mechanics and/or vascular smooth muscle tone should be explored. The effectiveness of modeling approaches should be confirmed using uncertainty quantification and sensitivity analysis. Taken together, constitutive modeling can significantly improve clinical interpretation of arterial stiffness findings.
Dynamic cerebral autoregulation measurement using rapid changes in head positioning: experiences in acute ischemic stroke and healthy control populations
Authors: Lam Man Y. , Haunton Victoria J. , Robinson Thompson G. , Panerai Ronney B.
Published: December 2018

The ideal technique for dynamic cerebral autoregulation (dCA) assessment in critically ill patients should provide considerable variability in blood pressure (BP) but without the need for patient cooperation. We proposed using rapid head positioning (RHP) over spontaneous BP fluctuations for dCA assessment in patients with acute ischemic stroke (AIS). Cerebral blood velocity (transcranial Doppler), beat-to-beat BP (Finometer), and end-tidal CO2 (capnography) were recorded during 5-min baseline and RHP in 16 controls (8 women and 8 men, mean age: 57 ± 16 yr) and 15 patients with AIS (7 women and 8 men, mean age: 69 ± 8 yr) at two (12 ± 8 days) and three visits (13.3 ± 6.9 h, 4.8 ± 3.2 days, and 93.9 ± 11.5 days from the symptom onset), respectively. All participants were able to complete the RHP protocol without difficulty. Compared with controls, patients with AIS were hypocapnic (all visits, P < 0.0024) and hypertensive ( visit 1, P = 0.011), although BP gradually reduced after the acute phase. RHP demonstrated greater beat-to-beat BP variability (BPV) in controls ( visits 1 and 2, P < 0.001) but not in patients with AIS at any visit. Compared with controls, a reduced autoregulation index (ARI) was demonstrated in patients with AIS, at visit 2 for the baseline recording but not at other visits or during RHP. The area under the receiver-operating curve was 0.53 and 0.54 for baseline and RHP, respectively. The RHP paradigm required minimal patient cooperation and could be considered a feasible alternative for assessing dCA, mainly in conditions leading to increased BPV. The lack of BPV increase in AIS with RHP deserves further investigation.

NEW & NOTEWORTHY This study used rapid head positioning (RHP) to enhance blood pressure (BP) variability (BPV) to improve BP signal-to-noise ratio and reliability of dynamic cerebral autoregulation (dCA). RHP was well accepted by controls and acute ischemic stroke (AIS); the increased BPV induced in controls was not observed in AIS, suggesting BPV at rest was already elevated. RHP did not improve detection of impaired CA in AIS; further work is needed to understand the different responses observed.