bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highest plasticity of carbon‐concentrating mechanisms in earliest evolved phytoplankton
Authors: Van de Waal Dedmer B. , Brandenburg Karen M. , Keuskamp Joost , Trimborn Scarlett , Rokitta Sebastian , Kranz Sven A. , Rost Björn 
Published: February 2019

AbstractPhytoplankton photosynthesis strongly relies on the operation of carbon‐concentrating mechanisms (CCMs) to accumulate CO2 around their carboxylating enzyme ribulose‐1,5‐bisphosphate carboxylase/oxygenase (RuBisCO). Earlier evolved phytoplankton groups were shown to exhibit higher CCM activities to compensate for their RuBisCO with low CO2 specificities. Here, we tested whether earlier evolved phytoplankton groups also exhibit a higher CCM plasticity. To this end, we collected data from literature and applied a Bayesian linear meta‐analytic model. Our results show that with elevated pCO2, photosynthetic CO2 affinities decreased strongest and most consistent for the earlier evolved groups, i.e., cyanobacteria and dinoflagellates, while CO2‐dependent changes in affinities for haptophytes and diatoms were smaller and less consistent. In addition, responses of maximum photosynthetic rates toward elevated pCO2 were generally small and inconsistent across species. Our results demonstrate that phytoplankton groups with an earlier origin possess a high CCM plasticity, whereas more recently evolved groups do not, which likely results from evolved differences in the CO2 specificity of RuBisCO.
Mathematical Modeling and Experimental Study of Water Diffusion and Swelling in Polymer Films
Authors: Gagliardi Mariacristina 
Published: February 2019

AbstractWater diffusion and swelling of polymer films can be modeled by nonlinear diffusion equations with fixed or moving boundaries, investigating the Fick and the Stefan problems. To form a better view of the dynamics of the problems, this paper reports the mathematical modeling of water diffusion with linear and nonlinear diffusion coefficients by using the finite element method, and the description of boundary movements calculated with a fully implicit upwind scheme. Experimental results are used to support theoretical data. It is found that porosity strongly affects diffusion properties and proposed models describe analyzed phenomena with high reliability. Models describing water diffusion and volume increase after swelling will be considered in future studies involving degradable and erodible matrices.
Experimental analysis and comparison between cross‐shaped metamaterial absorber and its complementary structure
Authors: Wang Yang , Wang Lili , Song Jian , Li Minhua 
Published: February 2019

AbstractIn this article, cross‐shaped metamaterial absorber (CSMA) and its complementary structure (CCSMA) with uniform parameters are experimentally analyzed in details. Perfect absorptions with intensities over 99.5% have been achieved at 4.99 GHz for CSMA and 5.39 GHz for CCSMA, respectively, both of which are equipped with polarization insensitive performance. For transverse electric (TE) mode, the parameter FSOIAs (frequency sensitivity of oblique incident angles) of these 2 absorbers is nearly the same with little values. However, the absorption peaks of the complementary one shift obviously to lower frequencies with wider transverse magnetic (TM) incident angles, and the FSOIA reaches up to 0.98% in simulation (0.66% in experiments), which is nearly 5 times stronger than that for TE situation. Besides, detailed comparison about the effective material parameters including relative permittivity, permeability, and relative impedance have been conducted by S‐parameter retrieval method. Microwave experiments are performed to successfully demonstrate the numerical results.
Explicit multistep time integration for discontinuous elastic stress wave propagation in heterogeneous solids
Authors: Cho S. S. , Kolman R. , González J. A. , Park K. C. 
Published: February 2019

SummaryA multistep explicit time integration algorithm is presented for tracking the propagation of discontinuous stress waves in heterogeneous solids whose subdomain‐to‐subdomain critical time step ratios range from tens to thousands. The present multistep algorithm offers efficient and accurate computations for tracking discontinuous waves propagating through such heterogeneous solids. The present algorithm, first, employs the partitioned formulation for representing each subdomain, whose interface compatibility is enforced via the method of the localized Lagrange multipliers. Second, for each subdomain, the governing equations of motion are decomposed into the extensional and shear components so that tracking of waves of different propagation speeds is treated with different critical step sizes to significantly reduce the computational dispersion errors. Stability and accuracy analysis of the present multistep time integration is performed with one‐dimensional heterogeneous bar. Analyses of the present algorithm are also demonstrated as applied to the stress wave propagation in one‐dimensional heterogeneous bar and in heterogeneous plain strain problems.
Anticholinergic and sedative medication use in older community‐dwelling people: A national population study in the Netherlands
Authors: van der Meer Helene G. , Taxis Katja , Teichert Martina , Griens Fabiënne , Pont Lisa G. , Wouters Hans 
Published: February 2019

AbstractPurposeTo identify the proportion of older adults with a high anticholinergic/sedative load and to identify patient subgroups based on type of central nervous system (CNS)‐active medication used.MethodsA cross‐sectional study of a nationwide sample of patients with anticholinergic/sedative medications dispensed by 1779 community pharmacies in the Netherlands (90% of all community pharmacies) in November 2016 was conducted. Patients aged older than 65 years with a high anticholinergic/sedative load defined as having a drug burden index (DBI) greater than 1 were included. Proportion of patients with a high anticholinergic/sedative load was calculated by dividing the number of individuals in our study population by the 2.4 million older patients using medications dispensed from study pharmacies. Patient subgroups based on type of CNS‐active medications used were identified with latent class analysis.ResultsOverall, 8.7% (209 472 individuals) of older adults using medications had a DBI greater than 1. Latent class analysis identified four patient subgroups (classes) based on the following types of CNS‐active medications used: “combined psycholeptic/psychoanaleptic medication” (class 1, 57.9%), “analgesics” (class 2, 17.9%), “antiepileptic medication” (class 3, 17.8%), and “anti‐Parkinson medication” (class 4, 6.3%).ConclusionsA large proportion of older adults in the Netherlands had a high anticholinergic/sedative load. Four distinct subgroups using specific CNS‐active medication were identified. Interventions aiming at reducing the overall anticholinergic/sedative load should be tailored to these subgroups.
Conditional validation sampling for consistent risk estimation with binary outcome data subject to misclassification
Authors: Gravel Christopher A. , Farrell Patrick J. , Krewski Daniel 
Published: February 2019

AbstractPurposeMisclassification of a binary outcome can introduce bias in estimation of the odds‐ratio associated with an exposure of interest in pharmacoepidemiology research. It has been previously demonstrated that utilizing information from an internal randomly selected validation sample can help mitigate this bias.MethodsUsing a Monte Carlo simulation‐based approach, we study the properties of misclassification bias‐adjusted odds‐ratio estimators in a contingency table setting. We consider two methods of internal validation sampling; namely, simple random sampling and sampling conditional on the original (possibly incorrect) outcome status. Additional simulation studies are conducted to investigate these sampling approaches in a multi‐table setting.ResultsWe demonstrate that conditional validation sampling, across a range of subsampling fractions, can produce better estimates than those based on an unconditional simple random sample. This approach allows for greater flexibility in the chosen categorical composition of the validation data, as well as the potential for obtaining a more efficient estimator of the odds‐ratio. We further demonstrate that this relationship holds for the Mantel‐Haenszel misclassification bias‐adjusted odds‐ratio in stratified samples. Recommendations for the choice of validation subsampling fraction are also provided.ConclusionsCareful consideration when choosing the sampling scheme used to draw internal validation samples can improve the properties of the outcome misclassification bias‐adjusted odds‐ratio estimator in a (multiple) contingency table.
Continuous Infusion Ketamine for Adjunctive Analgosedation in Mechanically Ventilated, Critically Ill Patients
Authors: Garber Paige M. , Droege Christopher A. , Carter Kristen E. , Harger Nicole J. , Mueller Eric W. 
Published: February 2019

ObjectiveKetamine is an N‐methyl‐D‐aspartate antagonist with emerging evidence assessing its use as a continuous infusion agent to provide concomitant analgesia and sedation. The role of ketamine as adjunctive therapy in mechanically ventilated patients is unclear. This study sought to investigate the impact of adjunctive continuous infusion ketamine on concomitant analgesic and sedative dosing while providing goal comfort in mechanically ventilated patients.MethodsThis retrospective two‐center intrapatient comparison study included mechanically ventilated adult ICU patients who received continuous infusion ketamine with at least one other analgesic or sedative infusion. The primary outcome assessed percent relative change in concomitant analgesic‐sedative doses 24 hours after ketamine initiation. Secondary outcomes included percent of Richmond Agitation and Sedation Score (RASS) assessments at goal, adverse effects, and delirium incidence. Exploratory evaluation of independent factors associated with ketamine responders (50% or more relative reduction in analgesic‐sedative dosing requirements at 24 hrs) and nonresponders (less than 50% relative reduction) was performed using multivariate logistic regression.ResultsOverall, 104 patients were included. A total of 160 concomitant analgesic‐sedative infusions were used in combination with ketamine, most commonly fentanyl (98 [61.3%]) and propofol (46 [28.8%]). A 20% (interquartile range [IQR] −63.6 to 0.0, p<0.001) relative reduction in total analgesic‐sedative infusion pharmacotherapy was achieved at 24 hours after ketamine initiation. Analgesic and sedative infusion doses decreased at 24 hours (fentanyl: pre, 175 μg/hr [IQR 100–200 μg/hr] vs post, 125 μg/hr [IQR 50–200 μg/hr], p<0.001; propofol: pre, 42.5 μg/kg/min [IQR 20.0–60.0 μg/kg/min] vs post, 20.0 μg/kg/min [IQR 3.8–31.3 μg/kg/min], p<0.001). Median percent time within goal RASS improved after ketamine initiation (pre, 7.1% [0–40%] vs post, 25% [0–66.7%], p=0.005). No differences were observed in secondary outcomes between responders and nonresponders, except a longer non‐ICU hospital length of stay in responders. Independent factors associated with ketamine response included a lower body mass index, higher starting dose of ketamine, lower severity of illness, and need for multiple concomitant analgesic‐sedative infusions before initiation of ketamine.ConclusionsAdjunctive continuous infusion ketamine promotes analgesic and sedative dose‐sparing effects in mechanically ventilated patients while improving time spent within goal sedation range. Further prospective research is warranted.
Solar photovoltaic capacity demand for a sustainable transport sector to fulfil the Paris Agreement by 2050
Authors: Breyer Christian , Khalili Siavash , Bogdanov Dmitrii 
Published: February 2019

AbstractThe Paris Agreement sets a clear target for net zero greenhouse gas (GHG) emissions by the mid‐21st century. This implies that the transport sector has to reach zero GHG emissions mainly through direct and indirect electrification in the form of synthetic fuels, such as hydrogen and Fischer‐Tropsch (FT) fuels. The results of this research document that this very ambitious target is possible. This research analyses the global solar photovoltaics (PV) demand for achieving the Paris targets in the transport sector by the year 2050. The methodology is composed of the derivation of the transportation demand converted into final energy demand for direct electrification, hydrogen, methane, and FT‐fuels production. The power‐to‐gas (H2, CH4) and power‐to‐liquids (FT fuels) value chains are applied for the total electricity demand, which will be mostly fulfilled by PV, taking into account previous results concerning the renewable electricity share of the energy transition in the power sector for the world structured in 145 regions and results aggregated to nine major regions. The results show a continuous demand increase for all transportation modes till 2050. The total global PV capacity demand by 2050 for the transport sector is estimated to be about 19.1 TWp, thereof 35%, 25%, 7%, and 33% for direct electrification, hydrogen, synthetic natural gas, and FT fuels, respectively. PV will be the key enabler of a full defossilisation of the transport sector with a demand comparable with the power sector but a slightly later growth dynamic, leading to a combined annual PV capacity demand of about 1.8 TWp around 2050.
COWAT Performance of Persons with Alzheimer Dementia, Vascular Dementia, and Parkinson Disease Dementia According to Stage of Cognitive Impairment
Authors: Lim Kil‐Byung , Kim Jiyong , Lee Hong‐Jae , Yoo Jeehyun , Kim Ha Seong , Kim Changgyu , Lee Hojin 
Published: February 2019

BackgroundThe Controlled Oral Word Association Test (COWAT) evaluates frontal lobe and executive function. Therefore, it can be helpful in differentiating cognitive deficits. However, there are no studies comparing the COWAT performance according to the type and stage of cognitive impairment.ObjectiveTo compare performance among persons with Alzheimer dementia (AD), vascular dementia (VaD), and Parkinson disease dementia (PDD) on the COWAT according to stage of cognitive impairment.DesignRetrospective chart review.SettingsUniversity hospital rehabilitation psychology center.PatientsWe reviewed the medical records of 246 persons diagnosed with mild cognitive impairment (MCI) or dementia using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM‐5) and the Korean‐Instrumental Activities of Daily Living (K‐IADL). Patients were divided into a control group, Alzheimer groups (amnestic mild cognitive impairment [aMCI] + AD), Vascular groups (vascular mild cognitive impairment [VaMCI] + VaD), and Parkinson groups (Parkinson disease‐mild cognitive impairment [PD‐MCI] + PDD).MethodsTotal scores (ie, total number of words produced in 60 seconds on the semantic and phonemic fluency tests of the COWAT) were analyzed. Secondary analysis included calculating percentage scores of words produced during each of the four, 15‐second segments from the total number of words produced in each trial.ResultsAll MCI groups scored significantly lower than the control group on both semantic and phonemic fluency tests. Among the dementia groups, the VaD (mean ± SD, 5.6 ± 5.1) and PDD (5.5 ± 5.5) groups' scores were significantly lower and worse than that of the AD (11.0 ± 8.8) group on the phonemic test (P < .001). The difference in percentage scores was most marked between the PD‐MCI (17.0 ± 2.2) and PDD (1.2 ± 3.1) groups, followed by the VaMCI (13.3 ± 1.9) and VaD (5.6 ± 1.8) groups on the latter phonemic test (P = .007).ConclusionsThe COWAT is a sensitive test of frontal‐lobe and executive function impairment in persons with MCI. Decreased verbal output in the last 15 seconds of phonemic fluency test is significantly decreased and impaired in persons with VaMCI and PD‐MCI compared to persons with aMCI as they progress to dementia.Level of EvidenceIII.
Ribosome protection by ABC‐F proteins—Molecular mechanism and potential drug design
Authors: Ero Rya , Kumar Veerendra , Su Weixin , Gao Yong‐Gui 
Published: February 2019

AbstractMembers of the ATP‐binding cassette F (ABC‐F) proteins confer resistance to several classes of clinically important antibiotics through ribosome protection. Recent structures of two ABC‐F proteins, Pseudomonas aeruginosa MsrE and Bacillus subtilis VmlR bound to ribosome have shed light onto the ribosome protection mechanism whereby drug resistance is mediated by the antibiotic resistance domain (ARD) connecting the two ATP binding domains. ARD of the E site bound MsrE and VmlR extends toward the drug binding region within the peptidyl transferase center (PTC) and leads to conformational changes in the P site tRNA acceptor stem, the PTC, and the drug binding site causing the release of corresponding drugs. The structural similarities and differences of the MsrE and VmlR structures likely highlight an universal ribosome protection mechanism employed by antibiotic resistance (ARE) ABC‐F proteins. The variable ARD domains enable this family of proteins to adapt the protection mechanism for several classes of ribosome‐targeting drugs. ARE ABC‐F genes have been found in numerous pathogen genomes and multi‐drug resistance conferring plasmids. Collectively they mediate resistance to a broader range of antimicrobial agents than any other group of resistance proteins and play a major role in clinically significant drug resistance in pathogenic bacteria. Here, we review the recent structural and biochemical findings on these emerging resistance proteins, offering an update of the molecular basis and implications for overcoming ABC‐F conferred drug resistance.
Robotics‐assisted versus conventional manual approaches for total hip arthroplasty: A systematic review and meta‐analysis of comparative studies
Authors: Han Peng‐fei , Chen Cheng‐long , Zhang Zhi‐liang , Han Yi‐chen , Wei Lei , Li Peng‐cui , Wei Xiao‐chun 
Published: February 2019

AbstractBackgroundSeveral studies have compared robotics‐assisted (RA) and conventional manual (CM) approaches for total hip arthroplasty (THA), but their results are controversial.MethodsA literature search was conducted for controlled clinical trials (CCTs) comparing the clinical efficacy of the RA and CM approaches for THA and published between August 1998 and August 2018. The obtained data were analyzed using the statistical software Review Manager 5.3.ResultsFourteen articles were included in the meta‐analysis, which revealed that the RA group had less intraoperative complications, better cup angle, and more cases of cup placement in the safe zone than the CM group. However, the operation time required for the CM group was less than that required for the RA group. Moreover, postoperative complications (eg, dislocation and revision surgery) were less frequent in the CM group than in the RA group. However, the two groups had similar functional scores, total number of complications, and rate of occurrence of limb length discrepancy.ConclusionCompared with the CM approach, the RA approach yields better radiological outcomes and fewer intraoperative complications in THA, but similar functional scores.
A unified symplectic pseudospectral method for motion planning and tracking control of 3D underactuated overhead cranes
Authors: Wang Xinwei , Liu Jie , Zhang Yong , Shi Boyang , Jiang Dianheng , Peng Haijun 
Published: February 2019

SummaryIn this paper, a unified symplectic pseudospectral method for motion planning and tracking control of 3D underactuated overhead cranes is proposed. A feasible reference trajectory taking constraints into consideration is first generated offline by the symplectic pseudospectral optimal control method. Then, a trajectory tracking model predictive controller also based on the symplectic pseudospectral method is developed to track the reference trajectory. At each sampling instant, the trajectory tracking controller works by solving an open‐loop optimal control problem where linearized system dynamics is used instead to improve the computational efficiency. Since the symplectic pseudospectral optimal control method is the core algorithm for both offline trajectory planning and online trajectory tracking, constraints on state variables and control inputs can be easily imposed and hence theoretically guaranteed in solutions. By selecting proper weighted matrices on tracking error and control, the developed controller could achieve control objectives in both accurate trolley positioning and fast suppressing of residual swing angles. Simulations for 3D overhead crane systems in the presence of perturbations in initial conditions, an abrupt variation of system parameter, and various external disturbances demonstrate that the developed controller is robust and of excellent control performance.
Robust stability analysis for fractional‐order systems with time delay based on finite spectrum assignment
Authors: Liu Lu , Zhang Shuo , Xue Dingyu , Chen YangQuan 
Published: February 2019

SummaryIn this paper, the robust stability of a fractional‐order time‐delay system is analyzed in the frequency domain based on finite spectrum assignment (FSA). The FSA algorithm is essentially an extension of the traditional pole assignment method, which can change the undesirable system characteristic equation into a desirable one. Therefore, the presented analysis scheme can also be used as an alternative time‐delay compensation method. However, it is superior to other time‐delay compensation schemes because it can be applied to open‐loop poorly damped or unstable systems. The FSA algorithm is extended to a fractional‐order version for time‐delay systems at first. Then, the robustness of the proposed algorithm for a fractional‐order delay system is analyzed, and the stability conditions are given. Finally, a simulation example is presented to show the superior robustness and delay compensation performance of the proposed algorithm. Moreover, the robust stability conditions and the time‐delay compensation scheme presented can be applied on both integer‐order and fractional‐order systems.
A stability criterion for asynchronously switched linear systems via sampled‐data control
Authors: Park JunMin , Park PooGyeon 
Published: February 2019

SummaryThis paper considers an asynchronous problem for sampled‐data control of switched linear systems, which are described as switched linear systems with an input delay. To handle the problem, this paper proposes a stability criterion for the systems by constructing a novel Lyapunov‐Krasovskii functional dependent not on system modes but on controller modes. The functional continuously remains when the system modes are switched but discontinuously changes whenever the controller mode moves to the current system mode at the sampling instants. Furthermore, the functional is allowed to increase or decrease up to a certain level when the functional discontinuously changes and to increase up to a certain level when the system modes and the controller modes are asynchronous. Based on the functional, this paper derives an average dwell time associated with the interval of samplings and the incremental level of the functional for guaranteeing the stability of the systems. A numerical example illustrates the validation of the proposed method.