bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrically-active defects in reduced and hydrogenated rutile

TiO2
Authors: Bonkerud Julie , Zimmermann Christian , Herklotz Frank , Weiser Philip Michael , Seiffert Christoph , Verhoeven Espen Førdestrøm , Vines Lasse , Monakhov Eduard V
Published: November 2020

We report on electrically-active defects located between 0.054 and 0.69 eV below the conduction band edge in rutile

T
i

O

2

single crystals subjected to reducing and hydrogenating heat treatments. Deep-level transient spectroscopy measurements recorded on

T
i

O

2

samples subjected to different heat treatments are compared. In samples annealed in

H
2

gas, three defect levels are commonly observed. One of these levels,

E

192

, located 0.43 eV below the conduction band edge is tentatively assigned to a hydrogen-impurity complex. Two levels at 0.054 and 0.087 eV below the conduction band edge, which were present after all different heat treatments, are tentatively assigned as being related to O vacancies or Ti self-interstitials. Deep-level transient spectroscopy spectra of samples heat-treated in

N
2

display a larger number of defect levels and larger concentrations compared to samples heat-treated in

H
2

gas.

N
2

treatments are performed at considerably higher temperatures. Four energy levels located between 0.28 and 0.69 eV, induced by annealing in

N
2

, are tentatively attributed to O vacancy- or Ti interstitial-related complexes with impurities.
Silicon-based FMCW signal generators: A review
Authors: Deng Wei , Jia Haikun , Chi Baoyong
Published: November 2020

FMCW radars with high resolution necessities the generation of highly linear, low phase noise, and low spur chirp signals with large bandwidth and a short modulation period. This paper reviews recent research progress on silicon-based FMCW signal generators, identifies advances in architecture, fundamental design, performance analysis, and applications of the FMCW synthesizer.
A survey of active quasi-circulators
Authors: Tang Bingjun , Geng Li
Published: November 2020

With the development of multi-band wireless communication and the increasing data transmission rate, the circulator as an antenna interface must be able to work in multiple frequency bands and provides large bandwidth. It presents a high challenge to the design of circulators, especially the active quasi-circulators. In this survey, we review the representative active quasi-circulators and summarize three different techniques and the corresponding structures to show an incremental improvement of the isolation and bandwidth of the active quasi-circulators. In addition, we also compare the performance of several state-of-art active circulators, and analyze their advantages and disadvantages. Finally, we conclude the future trend of the active quasi-circulators.
A 12-bit 30-MS/s VCO-based SAR ADC with NOC-assisted multiple adaptive bypass windows
Authors: Pan Xiangxin , Zhou Xiong , Chang Sheng , Ding Zhaoming , Li Qiang
Published: November 2020

This paper proposes a technique that uses the number of oscillation cycles (NOC) of a VCO-based comparator to set multiple adaptive bypass windows in a 12-bit successive approximation register (SAR) analog-to-digital converter (ADC). The analysis of the number of bit cycles, power and static performance shows that three adaptive bypass windows reduce power consumption, and decrease DNL and have similar INL, compared with the SAR ADC without bypass windows. In addition, a 1-bit split-and-recombination redundancy technique and a general bypass logic digital error correction method are proposed to address the settling issues and optimize the size of the bypass window. This design is implemented in 40 nm CMOS technology. The conversion frequency of the ADC reaches up to 30 MS/s. The ADC achieves an SFDR of 85.35 dB and 11.12-bit ENOB with Nyquist input, consuming 380 μW, down from 427 μW without multiple adaptive bypass windows, at a 1.1 V supply, resulting in a figure of merit (FoM) of 5.69 fJ/conversion-step.
Fast-transient techniques for high-frequency DC–DC converters
Authors: Cheng Lin , Tang Kui , Ki Wang-Hung , Su Feng
Published: November 2020

A 30 MHz voltage-mode controlled buck converter with fast transient responses is presented. An improved differential difference amplifier (DDA)-based Type-III compensator is proposed to reduce the settling times of the converter during load transients, and to achieve near-optimal transient responses with simple PWM control only. Moreover, a hybrid scheme using a digital linear regulator with automatic transient detection and seamless loop transition is proposed to further improve the transient responses. By monitoring the output voltage of the compensator instead of the output voltage of the converter, the proposed hybrid scheme can reduce undershoot and overshoot effectively with good noise immunity and without interrupting the PWM loop. The converter was fabricated in a 0.13 μm standard CMOS process using 3.3 V devices. With an input voltage of 3.3 V, the measured peak efficiencies at the output voltages of 2.4, 1.8, and 1.2 V are 90.7%, 88%, and 83.6%, respectively. With a load step of 1.25 A and rise and fall times of 2 ns, the measured 1% settling times were 220 and 230 ns, with undershoot and overshoot with PWM control of 72 and 76 mV, respectively. They were further reduced to 36 and 38 mV by using the proposed hybrid scheme, and 1% settling times were also reduced to 125 ns.
III Workshop on Modeling and Simulation for Science and Engineering
Authors: Sandoval-Amador A , Dueñas-Ramírez L M , V-Niño E D
Published: November 2020

The III Workshop on Modeling and Simulation for Science and Engineering (III WMSSE) is an academic event that aims to highlight the close links between basic sciences, especially mathematics, and their implementation in engineering. During the event, which will be held in the city of Armenia, Colombia, talks in areas such Mathematical Physics, Computational Science, Dynamic Systems Model, Mechatronic Systems, Chemical Physics, and Physical Chemistry, Education and Communication is presented; moreover, courses in metaheuristics, financial market analysis, and software management is offered.

List of Organizing Committee, National Scientific Committee, Sponsor Partners are available in the pdf.
Analysis of a Galerkin scheme to avoid the locking phenomenon: solid-fluid interaction problem
Authors: Vásquez-Coronel A , Salazar-Jurado E , Cuesta-Herrera L , Altamirano-Fernández A
Published: November 2020

Determining the response to the forces applied to an elastic solid containing an ideal fluid with constant density is essential in the engineering and biomedical fields. Therefore this paper aims to present and analyze a mixed finite element method for an interaction problem solid-fluid that contributes to understanding these areas. It is assumed transmission conditions are maintained at the fluid boundary and are given by the balance of forces and the equality of normal displacements. The mixed variational formulation that avoids the locking phenomenon, for the coupled problem is in terms of displacement, stress tensor, and rotation in the solid and by pressure and scalar potential in the fluid, the main contribution of this work. The first transmission condition is imposed in the definition of the space and the rest of the conditions appear naturally, which means Lagrange multipliers are not needed at the coupling border. The unknowns for the fluid and the solid are approximated by finite element subspaces of Lagrange and Arnold-Falk-Winther of order 1, which lead to a Galerkin scheme for the continuous problem. Also, the resulting Galerkin scheme is convergent and derives optimal convergence rates. Finally, the model is illustrated using a numerical example.
Simulation of pollutants transport in rivers and its effect on the dynamics of a species by a high order method
Authors: Acosta-Minoli C A , Carmona P C , Mesa-Mazo M J
Published: November 2020

In the study of environmental transport phenomena, there is a standard analytic methodology to compute distribution, transport, and the fate of a pollutant in unbounded domains. However, to solve the problem in a nontrivial geometry accurately requires the use of a robust computational tool. This paper shows a derivation and an evaluation of a high order spectral element method to simulate the distribution and transport of a pollutant in surface waters and its effect on the population dynamics of a species. The algorithm implements a continuous Galerkin spectral element method in space and the trapezoid scheme to integrate in time. Finally, to validate the numerical method, this paper presents a time-space convergence study. Then, we simulated the transport of pollution runoff over a channel and its effect on a single species population dynamic.
Factors associated with capacities development in learning physic associate on numerical systems and Hamming code
Authors: Rojas-Suarez J P , Bustos-Urbano V J , Vergel-Ortega M
Published: November 2020

the research uses mixed, participatory action research tools within qualitative research, and factor analysis from the positivist approach; identifies and analyses factors associated with problem solving in capacity development within the framework of the metacognitive in learning of the physic, associate to approach with operations of numerical systems and detection error with Hamming code, is apply in the childhood of public educational institutions located in the border area of the Municipality of Villa del Rosario, Colombia. For this purpose, a diagnostic test was applied (α = 0.78), which allowed the identification of difficulties and variables related to learning and application in real contexts (r = 0.81); and a post-test (K = 0.7), that evaluates projects as a didactic strategy. There was evidence of the construction of knowledge and the application of these to practical life, also revealed that it was possible to awaken interest and motivation in students which significantly improved their level of analysis, interpretation and reasoning. Associated factors were coexistence (α = 0.788), emotional proposal didactics (α = 0.751), metacognitive skills (α = 0.767), self-control (α = 0.718), evaluation (α = 0.712), strategies and abilities in physic through the method and its application in logical circuits with indicators cognitive, attitudinal, motor processes.
Spaceborne detection of XCO2 enhancement induced by Australian mega-bushfires
Authors: Wang Jun , Liu Zhiqiang , Zeng Ning , Jiang Fei , Wang Hengmao , Ju Weimin
Published: November 2020

The 2019–20 Australian mega-bushfires, which raged particularly over New South Wales and Victoria, released large amounts of toxic haze and CO2. Here, we investigate whether the resulting CO2 enhancement can be directly detected by satellite observations, based on National Aeronautics and Space Administration’s Orbiting Carbon Observatory-2 (OCO-2) column-averaged CO2 (XCO2) product. We find that smoke from wildfires can greatly obscure satellite observations, making the available XCO2 mainly locate over outer fringes of plumes downwind of the major mega-bushfires in eastern Australia in three orbit observations during November–December 2019, with their enhancements of approximately 1.5 ppm. This fire-induced CO2 enhancement is further confirmed using an atmospheric transport model, Goddard Earth Observing System-Chem, forced by satellite observation-derived fire product Global Fire Emissions Database, version 4.1 and wind observations, with comparable simulated XCO2 enhancements. Model simulation also suggests that the sensitivity of the downwind maximum XCO2 enhancement is 0.41

±

0.04 ppm for 1 TgC d−1 fire emissions. In sum, though detectable to some extent, it remains a challenge to get the accurate maximum XCO2 enhancements due to the gaps in XCO2 detections obscured by smoke. Understanding the capability of OCO-2 XCO2 detection is prerequisite for monitoring and constraining wildfire CO2 emissions by inversions.
The Association of Orthostatic Hypotension With Ambulatory Blood Pressure Phenotypes in SPRINT
Authors: Ghazi Lama , Drawz Paul E , Pajewski Nicholas M , Juraschek Stephen P
Published: November 2020

Background

Clinic blood pressure (BP) when measured in the seated position, can miss meaningful BP phenotypes, including low ambulatory BP (white coat effects [WCE]) or high supine BP (nocturnal non-dipping). Orthostatic hypotension (OH) measured using both seated (or supine) and standing BP, could identify phenotypes poorly captured by seated clinic BP alone.

Methods

We examined the association of OH with WCE and night-to-daytime systolic BP (SBP) in a subpopulation of SPRINT, a randomized trial testing the effects of intensive or standard (<120 vs. <140 mm Hg) SBP treatment strategies in adults at increased risk of cardiovascular disease. OH was assessed during follow-up (6, 12, and 24 months) and defined as a decrease in mean seated SBP ≥20 or diastolic BP ≥10 mm Hg after 1 min of standing. WCE, based on 24-hour ambulatory BP monitoring performed at 27 months, was defined as the difference between 27-month seated clinic and daytime ambulatory BP ≥20/≥10 mm Hg. Reverse dipping was defined as a ratio of night-to-daytime SBP >1.

Results

Of 897 adults (mean age 71.5±9.5 years, 29% female, 28% black), 128 had OH at least once. Among those with OH, 15% had WCE (vs. 7% without OH). Moreover, 25% of those with OH demonstrated a non-dipping pattern (vs. 14% without OH). OH was positively associated with both WCE (OR=2.24; 95%CI: 1.28, 4.27) and reverse dipping (OR=2.29; 95% CI: 1.31, 3.99).

Conclusions

The identification of OH in clinic was associated with two BP phenotypes often missed with traditional seated BP assessments. Further studies on mechanisms of these relationships are needed.

Clinical trials registration

Trial Number NCT03569020.
Gondwanan or global? A commentary on: ‘Fossil evidence from South America for the diversification of Cunoniaceae by the earliest Palaeocene’
Authors: Carpenter Raymond J , Rozefelds Andrew C
Published: November 2020

This article comments on:

Nathan A. Jud and Maria A. Gandolfo, Fossil evidence from South America for the diversification of Cunoniaceae by the earliest Palaeocene, Annals of Botany, Volume 127, Issue 3, 16 February 2021, Pages 305–315, https://doi.org/10.1093/aob/mcaa154
Homology and functions of inner staminodes inAnaxagorea javanica(Annonaceae)
Authors: Li Bingxin , Xu Fengxia
Published: November 2020

Inner staminodes are widespread in Magnoliales and present in Anaxagorea and Xylopia, but were lost in the other genera of Annonaceae and have no counterparts in derived angiosperms. The coexistence of normal stamens, modified stamens and inner staminodes in Anaxagorea javanica is essential to understand the homology and pollination function of the inner staminodes. Anaxagorea javanica was subjected to an anatomical study by light and scanning electron microscopy, and the chemistry of secretions was evaluated by an amino acid analyser. Inner staminodes have a secretory apex, but do not have thecae. They bend towards either tepals or carpels at different floral stages, and function as a physical barrier preventing autogamy and promoting outcrossing. At the pistillate phase, the exudates from the inner staminodes have high concentration of amino acid, and provide attraction to pollinating insects; while abundant proline was only detected in stigmas exudates, and supply for pollen germination. Modified stamens have a secretory apex and one or two thecae, which are as long as or shorter than that of the normal stamens. As transitional structures, modified stamens imply a possible degeneration progress from normal stamens to inner staminodes: generating a secretory apex first, shortening of the thecae length next and then followed by the loss of thecae. The presence of modified stamens together with the floral vasculature and ontogeny imply that the inner staminodes are homologous with stamens.
The impact of epitranscriptomic marks on post-transcriptional regulation in plants
Authors: Yu Xiang , Sharma Bishwas , Gregory Brian D
Published: November 2020

Ribonucleotides within the various RNA molecules in eukaryotes are marked with more than 160 distinct covalent chemical modifications. These modifications include those that occur internally in messenger RNA (mRNA) molecules such as N6-methyladenosine (m6A) and 5-methylcytosine (m5C), as well as those that occur at the ends of the modified RNAs like the non-canonical 5′ end nicotinamide adenine dinucleotide (NAD+) cap modification of specific mRNAs. Recent findings have revealed that covalent RNA modifications can impact the secondary structure, translatability, functionality, stability and degradation of the RNA molecules in which they are included. Many of these covalent RNA additions have also been found to be dynamically added and removed through writer and eraser complexes, respectively, providing a new layer of epitranscriptome-mediated post-transcriptional regulation that regulates RNA quality and quantity in eukaryotic transcriptomes. Thus, it is not surprising that the regulation of RNA fate mediated by these epitranscriptomic marks has been demonstrated to have widespread effects on plant development and the responses of these organisms to abiotic and biotic stresses. In this review, we highlight recent progress focused on the study of the dynamic nature of these epitranscriptome marks and their roles in post-transcriptional regulation during plant development and response to environmental cues, with an emphasis on the mRNA modifications of non-canonical 5′ end NAD+ capping, m6A and several other internal RNA modifications.
Prognostic value of vasodilator stress perfusion CMR in patients with previous coronary artery bypass graft
Authors: Kinnel Marine , Sanguineti Francesca , Pezel Théo , Unterseeh Thierry , Hovasse Thomas , Toupin Solenn , Landon Valentin , Champagne Stéphane , Morice Marie Claude , Garot Philippe , Louvard Yves , Garot Jérôme
Published: November 2020

Aims 

The accuracy and prognostic value of stress perfusion cardiac magnetic resonance (CMR) are established in coronary artery disease (CAD) patients. Because myocardial contrast kinetics may be altered after coronary artery bypass graft (CABG), most studies excluded CABG patients. This study aimed to assess the prognostic value of vasodilator stress perfusion CMR in CABG patients.

Methods and results 

Consecutive CABG patients referred for stress CMR were retrospectively included and followed for the occurrence of major adverse cardiovascular events (MACE) including cardiovascular (CV) death or non-fatal myocardial infarction (MI). Cox regression analyses were performed to determine the prognostic association of inducible ischaemia and late gadolinium enhancement (LGE) by CMR. Of 866 consecutive CABG patients, 852 underwent the stress CMR protocol and 771 (89%) completed the follow-up [median (interquartile range) 4.2 (3.3–6.2) years]. There were 85 MACE (63 CV deaths and 22 non-fatal MI). Using Kaplan–Meier analysis, the presence of inducible ischaemia identified the occurrence of MACE [hazard ratio (HR) 3.52, 95% confidence interval (CI): 2.27–5.48; P < 0.001] and CV death (HR 2.55, 95% CI: 1.52–4.25; P < 0.001). In a multivariable stepwise Cox regression including clinical characteristics and CMR indexes, the presence of inducible ischaemia was an independent predictor of a higher incidence of MACE (HR 3.22, 95% CI: 2.06–5.02; P < 0.001) and CV death (HR 2.15, 95% CI: 1.28–3.62; P = 0.003), and the same was observed for LGE (both P = 0.02).

Conclusion 

Stress CMR has a good discriminative prognostic value in patients after CABG, with a higher incidence of MACE and CV death in patients with inducible ischaemia and/or LGE.
Upside-down and kissing stent graft techniques for late extravasation of a prosthetic graft implanted in the abdominal aorta
Authors: Masuyama Shinji , Azuma Takashi , Inoue Takehiko , Ichihara Tetsuya
Published: November 2020

Extravasation of prosthetic grafts is rare. Various anatomical problems after graft replacement might make standard endovascular treatment difficult. Use of a commercially available main body requires an adequate distance of the flow divider. An 86-year-old man developed extravasation of a graft that had been implanted in the infrarenal abdominal aorta 24 years previously. Endovascular repair with upside-down and kissing stent graft techniques using the contralateral leg was successfully performed.
Sound Matters: How Sonic Formations Shape the Nuclear Deterrence and Non-Proliferation Regimes
Authors: Guillaume Xavier , Grayson Kyle
Published: November 2020

Sound matters for international political sociology. Drawing upon literature from cultural geography and sound studies, we argue that sound contributes to political dynamics that are constitutive of world politics. To capture these dynamics, we offer a set of conceptual frameworks to analyze sound. First, we differentiate the concept of sound from noise and show the importance of doing so. Second, we introduce “sonic formations” as a means of capturing how sound contributes to world politics. Third, we make the case for analyzing sound's historicity, adaptability, relationality, and performativity (SHARP) in any given context. Fourth, using sonic formations and the SHARP framework, we examine an illustrative case study: the nuclear deterrence and non-proliferation regimes. By focusing on the role of sound in these regimes, our preliminary findings demonstrate the utility for the field of undertaking additional work to capture the wider significance of sound. This includes its contributions to shaping relations of power.
Cognitive bias: how understanding its impact on antibiotic prescribing decisions can help advance antimicrobial stewardship
Authors: Langford Bradley J , Daneman Nick , Leung Valerie , Langford Dale J
Published: November 2020

The way clinicians think about decision-making is evolving. Human decision-making shifts between two modes of thinking, either fast/intuitive (Type 1) or slow/deliberate (Type 2). In the healthcare setting where thousands of decisions are made daily, Type 1 thinking can reduce cognitive load and help ensure decision making is efficient and timely, but it can come at the expense of accuracy, leading to systematic errors, also called cognitive biases. This review provides an introduction to cognitive bias and provides explanation through patient vignettes of how cognitive biases contribute to suboptimal antibiotic prescribing. We describe common cognitive biases in antibiotic prescribing both from the clinician and the patient perspective, including hyperbolic discounting (the tendency to favour small immediate benefits over larger more distant benefits) and commission bias (the tendency towards action over inaction). Management of cognitive bias includes encouraging more mindful decision making (e.g., time-outs, checklists), improving awareness of one’s own biases (i.e., meta-cognition), and designing an environment that facilitates safe and accurate decision making (e.g., decision support tools, nudges). A basic understanding of cognitive biases can help explain why certain stewardship interventions are more effective than others and may inspire more creative strategies to ensure antibiotics are used more safely and more effectively in our patients.
Magnetic Solid-Phase Extraction (MSPE) Using Magnetite-Based Core-Shell Nanoparticles with Silica Network (SiO2) Coupled with GC-MS/MS Analysis for Determination of Multiclass Pesticides in Water
Authors: Alam Samsul , Srivastava Neha , Iqbal Nusrat , Saini Mahesh Kumar , Kumar Jitendra
Published: November 2020

Background

For the analysis of pesticide residues in water samples, various extraction techniques are available. However, liquid–liquid extraction (LLE) and solid-phase extraction (SPE) are most commonly used. LLE and SPE extraction techniques each have their own disadvantages.

Objective

The aim of the study was to develop an environment-friendly multi-residue method for determination of multiclass pesticides in environmental water samples (ground water, agricultural field/irrigation run-off water, etc.).

Methods

The magnetic solid-phase extraction (MSPE) technique using surface-fabricated magnetic nano-particles was used for extraction of water samples, followed by quantification by gas chromatography tandem mass spectrometry. The developed multi-residue method was validated in terms of linearity, LOD, LOQ, recovery, and repeatability.

Results

Recovery data were obtained at the spiking concentration level of 1, 5, and 10 µg/L, yielding recoveries in the range of 70–120%. Overall, non-polar pesticides from all the groups, i.e., synthetic pyrethroid, organophosphorus, organochlorine, herbicides, and fungicides, show acceptable recovery percentages. Good linearity (r2 value ≥ 0.99) was observed at the concentration range of 0.5–100 µg/L. RSD values were found ≤ 18.8.

Conclusions

The study shows that the method is specific, rapid, and low cost, as well as having a good linearity and recovery; thus, this method is applied in routine purposes for the analysis of pesticide residue in real water samples.

Highlights

Due to better adsorption ability, permeability, and magnetic separability, the functionalized nano-particles were found effective in the enrichment of 22 multiclass pesticides including organo-phosphorus, organo-chlorine, synthetic pyrethroid, herbicides, and fungicides.
A National Treasure? The Role of Civil Society in Promoting and Enforcing Human Rights in the United Kingdom
Authors: Samuels Harriet
Published: November 2020

The article investigates the negative attitude towards civil society over the last decade in the United Kingdom and the repercussions for human rights. It considers this in the context of the United Kingdom government’s implementation of the policy of austerity. It reflects on the various policy and legal changes, and the impact on the campaigning and advocacy work of civil society organizations, particularly those that work on social and economic rights.
Collective Bargaining Rights and Police Misconduct: Evidence from Florida
Authors: Dharmapala Dhammika , McAdams Richard H , Rappaport John
Published: November 2020

We provide quasi-experimental evidence on the effects of law enforcement collective bargaining rights on violent incidents of misconduct. Our empirical strategy exploits a 2003 Florida Supreme Court decision (Williams) conferring collective bargaining rights on sheriffs’ deputies. Using a state administrative database of “moral character” violations over 1996–2015, we implement a difference-in-difference approach in which police departments (PDs; which were unaffected by Williams) serve as a control group for sheriffs’ offices (SOs). Our estimates imply that collective bargaining rights led to a substantial increase in violent incidents of misconduct among SOs relative to PDs. This result is robust to including only violent incidents involving officers hired before Williams, suggesting that it is due to a deterrence mechanism rather than compositional effects. In a separate event-study analysis, unionization is associated with higher levels of violent misconduct, and so appears to be a channel for the effect. (JEL K42, J50, J45).
BCCIP is required for nucleolar recruitment of eIF6 and 12S pre-rRNA production during 60S ribosome biogenesis
Authors: Ye Caiyong , Liu Bochao , Lu Huimei , Liu Jingmei , Rabson Arnold B , Jacinto Estela , Pestov Dimitri G , Shen Zhiyuan
Published: November 2020

Ribosome biogenesis is a fundamental process required for cell proliferation. Although evolutionally conserved, the mammalian ribosome assembly system is more complex than in yeasts. BCCIP was originally identified as a BRCA2 and p21 interacting protein. A partial loss of BCCIP function was sufficient to trigger genomic instability and tumorigenesis. However, a complete deletion of BCCIP arrested cell growth and was lethal in mice. Here, we report that a fraction of mammalian BCCIP localizes in the nucleolus and regulates 60S ribosome biogenesis. Both abrogation of BCCIP nucleolar localization and impaired BCCIP–eIF6 interaction can compromise eIF6 recruitment to the nucleolus and 60S ribosome biogenesis. BCCIP is vital for a pre-rRNA processing step that produces 12S pre-rRNA, a precursor to the 5.8S rRNA. However, a heterozygous Bccip loss was insufficient to impair 60S biogenesis in mouse embryo fibroblasts, but a profound reduction of BCCIP was required to abrogate its function in 60S biogenesis. These results suggest that BCCIP is a critical factor for mammalian pre-rRNA processing and 60S generation and offer an explanation as to why a subtle dysfunction of BCCIP can be tumorigenic but a complete depletion of BCCIP is lethal.
Functional vitamin K status and risk of incident chronic kidney disease and microalbuminuria: a prospective general population-based cohort study
Authors: Groothof Dion , Post Adrian , Sotomayor Camilo G , Keyzer Charlotte A , Flores-Guerero Jose L , Hak Eelko , Bos Jens H J , Schurgers Leon J , Navis Gerjan J , Gans Reinold O B , Eelderink Coby , de Borst Martin H , Bakker Stephan J L , Riphagen Ineke J
Published: November 2020

Background

Circulating desphospho-uncarboxylated matrix γ-carboxyglutamate (Gla) protein (dp-ucMGP), a marker of vitamin K status, is associated with renal function and may serve as a potentially modifiable risk factor for incident chronic kidney disease (CKD). We aimed to assess the association between circulating dp-ucMGP and incident CKD.

Methods

We included 3969 participants with a mean age of 52.3 ± 11.6 years, of whom 48.0% were male, enrolled in the general population–based Prevention of REnal and Vascular ENd-stage Disease study. Study outcomes were incident CKD, defined as either development of an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 or microalbuminuria. Associations of dp-ucMGP with these outcomes were quantified using Cox proportional hazards models and were adjusted for potential confounders.

Results

Median plasma dp-ucMGP was 363 [interquartile range (IQR) 219–532] pmol/L and mean serum creatinine- and serum cystatin C-based eGFR (eGFRSCr-SCys) was 95.4 ± 21.8 mL/min/1.73 m2. During 7.1 years of follow-up, 205 (5.4%) participants developed incident CKD and 303 (8.4%) developed microalbuminuria. For every doubling of plasma dp-ucMGP, hazard ratios for the development of incident CKD and microalbuminuria were 1.85 [95% confidence interval (CI) 1.59–2.16; P < 0.001] and 1.19 (95% CI 1.07–1.32; P = 0.001), respectively. These associations lost significance after adjustment for baseline eGFRSCr-SCys [0.99 (95% CI 0.88–1.12; P = 0.86)] and baseline age [1.03 (95% CI 0.94–1.14; P = 0.50)], respectively.

Conclusions

The associations of plasma dp-ucMGP with incident CKD and microalbuminuria were driven by the respective baseline effects of renal function and age.
What is the burden of proof for tumor mutational burden in gliomas?
Authors: Khasraw Mustafa , Walsh Kyle M , Heimberger Amy B , Ashley David M
Published: November 2020

The treatment of patients with a variety of solid tumors has benefitted from immune checkpoint inhibition targeting the anti-programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) axis. The US Food and Drug Administration (FDA) granted accelerated approval of PD-1 inhibitor, pembrolizumab, for the treatment of adult and pediatric patients with high tumor mutational burden (TMB-H), solid tumors that have progressed following prior treatment, and who have no other treatment options, including the extension to tumors of the central nervous system (CNS). In general, pan-cancer approvals are viewed positively to empower patients and clinicians. There are subsets (eg, BRAF, NTRK) for which this pathway for approval is appropriate. However, the pan-cancer FDA approval of pembrolizumab raises several concerns regarding the generalizability of the evidence to other tumor types, including managing patients with gliomas and other CNS tumors. The cutoff for TMB-H is not well defined. There are intrinsic immunological differences between gliomas and other cancers types, including the immunosuppressive glioma microenvironment, the tumor’s effects on systemic immune function, and the transformation of the T-cell populations to an exhausted phenotype in glioma. Here, we address the caveats with pan-cancer approvals concerning gliomas and complexities of the unique CNS immune environment, discuss potential predictive biomarkers, including TMB, and explain why the recent approval should be applied with caution in CNS tumors.
PATIENT SIZE INDICES AND DOSE IN FLUOROSCOPICALLY GUIDED LUMBAR DISCECTOMY AND FUSION: A PRELIMINARY STUDY
Authors: Metaxas Vasileios I , Gatzounis George D , Tzortzidis Fotios N , Panayiotakis George S
Published: November 2020

Patient dose values varied significantly during interventional procedures, mainly due to the patient size, operators’ choices and clinical complexity. In this study, the effect of applying a previously described and validated size-correction method to normalise kerma-area product (KAP) and average KAP rate values of the whole procedure (KAP rate) and isolate variations in dose due to the patient size and complexity, during lumbar discectomy and fusion (LDF) procedures, was investigated. Fluoroscopy time (FT), KAP, KAP rate and patient size data (weight, height and equivalent diameter) were recorded, for 96 patients who underwent single or multilevel LDF procedures by three senior neurosurgeons, defining three different patient groups (surgeon 1, surgeon 2, surgeon 3). Simple linear regression and coefficients of determination were used to investigate the relationship between uncorrected and corrected KAP and KAP rate values and patient size indices in these groups. The results showed that the size correction decreased the influence of patient size and could contribute to the isolation of the variations in patient dose due to the patient size. From this point of view, dose surveys during lumbar spine interventions may include dosimetric data from all patients independently of their body size and not only for standard-sized patients, providing the advantage of accessible data collection for the establishment of local dose reference levels and optimisation purposes, within the framework of the radiation protection program in the Neurosurgery Department.
Importance of the Primary Motor Cortex in Development of Human Hand/Finger Dexterity
Authors: Naito Eiichi , Morita Tomoyo , Asada Minoru
Published: November 2020

Hand/finger dexterity is well-developed in humans, and the primary motor cortex (M1) is believed to play a particularly important role in it. Here, we show that efficient recruitment of the contralateral M1 and neuronal inhibition of the ipsilateral M1 identified by simple hand motor and proprioceptive tasks are related to hand/finger dexterity and its ontogenetic development. We recruited healthy, right-handed children (n = 21, aged 8–11 years) and adults (n = 23, aged 20–26 years) and measured their brain activity using functional magnetic resonance imaging during active and passive right-hand extension–flexion tasks. We calculated individual active control-related activity (active–passive) to evaluate efficient brain activity recruitment and individual task-related deactivation (neuronal inhibition) during both tasks. Outside the scanner, participants performed 2 right-hand dexterous motor tasks, and we calculated the hand/finger dexterity index (HDI) based on their individual performance. Participants with a higher HDI exhibited less active control-related activity in the contralateral M1 defined by the active and passive tasks, independent of age. Only children with a higher HDI exhibited greater ipsilateral M1 deactivation identified by these tasks. The results imply that hand/finger dexterity can be predicted by recruitment and inhibition styles of the M1 during simple hand sensory–motor tasks.
Seasonal variations and public search interests in Toxoplasma: a 16-year retrospective analysis of big data on Google Trends
Authors: Liu Lei , Wang Peng , Jiang Su-Qin , Zhong Zi-Rong , Zhan Ting-Zheng , Yang Zi-Yin , Zhang Ya-Nan , Li Chen , Xu Jing , Xia Chao-Ming
Published: November 2020

Background

This study aims to understand whether there is a seasonal change in the internet search interest for Toxoplasma by using the data derived from Google Trends (GT).

Methods

The present study searched for the relative search volume (RSV) for the search term ‘Toxoplasma’ in GT within six major English-speaking countries (Australia, New Zealand [Southern Hemisphere] and Canada, Ireland, the UK and the USA [Northern Hemisphere] from 1 January 2004 to 31 December 2019, utilizing the category of ‘health’. Data regarding the RSV of Toxoplasma was obtained and further statistical analysis was performed in R software using the ‘season’ package.

Results

There were significantly seasonal patterns for the RSV of the search term ‘Toxoplasma’ in five countries (all p<0.05), except for the UK. A peak in December–March and a trough in July–September (Canada, Ireland, the UK and the USA) were observed, while a peak in June/August and a trough in December/February (Australia, New Zealand) were also found. Moreover, the presence of seasonal patterns regarding RSV for ‘Toxoplasma’ between the Southern and Northern Hemispheres was also found (both p<0.05), with a reversed meteorological month.

Conclusions

Overall, our study revealed the seasonal variation for Toxoplasma in using internet search data from GT, providing additional evidence on seasonal patterns in Toxoplasma.
The Role of Biological Fusion and Anterior Column Support in a Long Lumbopelvic Spinal Fixation and Its Effect on the S1 Screw—An In Silico Biomechanics Analysis
Authors: Cho Woojin , Wang Wenhai , Bucklen Brandon , Ramos Rafael De la Garza , Yassari Reza
Published: November 2020

Study Design.

Finite element analysis.

Objective.

The aim of this study was to determine the role of biological fusion and anterior column support in a long lumbopelvic spinal fixation.

Summary of Background Data.

Retrospective studies have shown that adding anterior column support is not sensitive to construct failure, highlighting that posterior fusion quality may be a more important factor.

Methods.

Finite element models were created to match the average spinal-pelvic parameters of two patient cohorts reported in the literature: major failure and nonfailure. A moment load was applied at the T10 superior endplate to simulate gravimetric loading in a standing position. Effects of three factors on the biomechanical behavior of a fused spine were evaluated: sagittal alignment; posterior fusion versus no fusion; and anterior support at L4–S1 versus no anterior support.

Results.

Sagittal balance of the major failure group was positively correlated with 15% higher translation, 14% higher rotation, and 16% higher stress than in the nonfailure group. Simulated posterior fusion-only decreased motion by 32% and 29%, and alleviated rod stress by 15% and 5% and S1 screw stress by 26% and 35%, respectively, in major failure and non-failure groups. The addition of anterior fusion without posterior fusion did not help with rod stress alleviation but dramatically decreased S1 screw stress (by 57% and 41%), respectively. With both posterior fusion and anterior support, screw stress at the S1 was decreased by additional 30% and 6%, respectively.

Conclusion.

The spinopelvic parameters of the major failure group produced increased gravity load, resulting in increased stresses in comparison to the nonfailure group. Simulated posterior “solid” fusion in the lumbar region helped reduce stresses in both major failure and nonfailure patients. Anterior column support was an important factor in reducing S1 screw stress, with or without posterior fusion, and should be considered for patients with poor alignment.

Level of Evidence: N/A
Bone Morphogenetic Protein-2 Promotes Osteoclasts-mediated Osteolysis via Smad1 and p65 Signaling Pathways
Authors: Miao Xiong , Yuan Jiabin , Wu Jinhui , Zheng Jiaoyang , Zheng Weina , Wang Fei , Wang Chao , Li Xiaoming , Liu Shu , Shi Zhicai , Li Jingfeng
Published: November 2020

Study Design.

An in vitro biological study.

Objective.

The aim of this study was to explore the role of bone morphogenetic protein-2 (BMP-2) in the regulation of osteoclast-mediated osteolysis, and the possible mechanism involving BMP-2 and nuclear factor-kappa B (NF-κB) signaling pathways.

Summary of Background Data.

Recombinant human BMP-2 (rhBMP-2) has been approved as a therapeutic agent in spinal fusion and bone defect repair. However, its efficacy and clinical application are limited by associated complications including osteoclast-mediated bone resorption. The mechanism of BMP-2-induced osteolysis remains unknown.

Methods.

Bone marrow-derived macrophages (BMMs) were isolated from C57BL/6J mice and cultured with macrophage colony-stimulating factor (M-CSF) and receptor activator for nuclear factor-κB Ligand (RANKL) to induce osteoclast differentiation. An in vitro bone resorption assay was performed by co-culturing BMMs and bone slides. The expression of BMP canonical and NF-κB signaling factors and their interaction during signal transduction were quantitated by reverse transcription polymerase chain reaction, Western blot analysis, confocal microscopy, and co-immunoprecipitation.

Results.

BMP-2 enhanced osteoclast-mediated bone resorption via inducing osteoclast differentiation in a concentration-dependent manner. In addition, a high concentration of BMP-2 significant upregulated phosphorylation of BMP signaling factors p-Smad1/5/8 and NF-κB downstream factor p65, and promoted the degeneration of IκBα. In addition, BMP-2 induced osteoclast differentiation through coupling between BMP receptor II and RANK.

Conclusion.

High concentrations of BMP-2 enhanced osteoclast-mediated bone resorption by promoting RANKL-induced pre-osteoclast differentiation, probably by mediating the cross-talk between BMP canonical and NF-κB signaling pathways.

Level of Evidence: N/A
Risk Factors for Cement Leakage in Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures
Authors: Tang Benqiang , Cui Libin , Chen Xueming , Liu Yadong
Published: November 2020

Study Design.

Retrospective study.

Objective.

To identify risk factors for cement leakage in percutaneous vertebroplasty (PVP) using low-viscosity bone cement for osteoporotic vertebral compression fractures (OVCFs).

Summary of Background Data.

Cement leakage is the most common complication for PVP and its risk factors have been discussed. However, data in previous series were heterogeneous. Additionally, relative smaller patient sample or more types of cement leakage classified in those studies made the results conflicting.

Methods.

A total of 1090 patients who underwent PVP with low-viscosity bone cement for OVCFs in 1456 levels between January 2016 and June 2019 were retrospectively reviewed. Parameters potentially affecting the occurrence of cement leakage were assessed using univariate and multivariate analyses. Cement leakage was assessed using postoperative computed tomography scanning, and classified into two types (cortical leakage and venous leakage) considering the mechanism.

Results.

The incidence of cortical and venous leakage were 20.3% (295/1456) and 56.2% (819/1456), respectively. Cortical disruption, basivertebral foramen were the strongest risk factors for cortical leakage (P = 0.000), venous leakage (P = 0.000), respectively. Greater cement volume is one risk factor for both cortical leakage and venous leakage. The intravertebral cleft, solid type of cement distribution were significant risk factors for cortical leakage, and they both were protective factors for venous leakage. For cortical leakage, older age and trauma were another two risk factors. For venous leakage, female was another one risk factor, and higher grade of fracture severity is the strongest protective factor.

Conclusion.

Both cortical leakage and venous leakage are prevalent. Adequate known of risk factors could help balance the incidence of two type leakage in unique vertebra and reduce the incidence of leakage in general in PVP for OVCFs.

Level of Evidence: 3
Efficacy of Intraoperative Intervention Following Transcranial Motor-evoked Potentials Alert During Posterior Decompression and Fusion Surgery for Thoracic Ossification of the Posterior Longitudinal Ligament
Authors: Kobayashi Kazuyoshi , Imagama Shiro , Yoshida Go , Ando Muneharu , Kawabata Shigenori , Yamada Kei , Kanchiku Tsukasa , Fujiwara Yasushi , Taniguchi Shinichirou , Iwasaki Hiroshi , Tadokoro Nobuaki , Takahashi Masahito , Wada Kanichiro , Yamamoto Naoya , Shigematsu Hideki , Funaba Masahiro , Yasuda Akimasa , Ushirozako Hiroki , Tani Toshikazu , Matsuyama Yukihiro
Published: November 2020

Study Design.

Prospective, multicenter, observational study.

Objective.

The aim of this study was to investigate the efficacy of intervention after an alert in intraoperative neurophysiological monitoring (IONM) using transcranial motor-evoked potentials (Tc-MEPs) during surgery for thoracic ossification of the posterior longitudinal ligament (T-OPLL).

Summary of Background Data.

T-OPLL is commonly treated with posterior decompression and fusion with instrumentation. IONM using Tc-MEPs during surgery reduces the risk of neurological complications.

Methods.

The subjects were 79 patients with a Tc-MEP alert during posterior decompression and fusion surgery for T-OPLL. Preoperative muscle strength (manual muscle testing [MMT]), waveform derivation rate at the start of surgery (baseline), intraoperative waveform changes; and postoperative motor paralysis were examined. A reduction in MMT score of ≥1 on the day after surgery was classified as worsened postoperative motor deficit. An alert was defined as a decrease in Tc-MEP waveform amplitude of ≥70% from baseline. Alerts were recorded at key times during surgery.

Results.

The patients (35 males, 44 females; age 54.6 years) had OPLL at T1-4 (n = 27, 34%), T5-8 (n = 50, 63%), and T9-12 (n = 16, 20%). The preoperative status included sensory deficit (n = 67, 85%), motor deficit (MMT ≤4) (n = 59, 75%), and nonambulatory (n = 26, 33%). At baseline, 76 cases (96%) had a detectable Tc-MEP waveform for at least one muscle, and the abductor hallucis had the highest rate of baseline waveform detection (n = 66, 84%). Tc-MEP alerts occurred during decompression (n = 47, 60%), exposure (n = 13, 16%), rodding (n = 5, 6%), pedicle screw insertion (n = 4, 5%), posture change (n = 4, 5%), dekyphosis (n = 2, 3%), and other procedures (n = 4, 5%). After intraoperative intervention, the rescue rate (no postoperative neurological deficit) was 57% (45/79), and rescue cases had a significantly better preoperative ambulatory status and a significantly higher baseline waveform derivation rate.

Conclusion.

These results show the efficacy of intraoperative intervention following a Tc-MEP alert for prevention of neurological deficit postoperatively.

Level of Evidence: 2