bluuebunny/crossref_metadata_2025 huggingface dataset:
Time‐resolved circularly polarized luminescence of Eu3+‐based systems
Authors: Hananel Uri , Schwartz Gal , Paiss Guy , Arrico Lorenzo , Zinna Francesco , Di Bari Lorenzo , Cheshnovsky Ori , Markovich Gil
Published: December 2020

Chiral Eu3+‐based systems are frequently studied via circularly polarized luminescence spectroscopy. The emission lifetimes of each circular polarization, however, are virtually always ignored, because in a homogeneous sample of emitters, there should be no difference between the two. However, we show that in less robust Eu3+ complex structures, as in the chiral complex Eu (facam)3, a difference in the lifetimes of the two circularly polarized emission components arises due to heterogeneity of the complexes. In this case, each species within the sample could have different degrees of circularly polarized luminescence and decay rates at certain emission lines. The superposition of the emission components of the various chiral species leads to an overall difference in decay rate between the two circular polarizations. Such a difference is also shown for Eu3+‐doped chiral TbPO4·D2O nanocrystals. We believe that this kind of measurement could be a unique tool for determining the homogeneity of a lanthanide‐based chiral system, where other methods might fail in this task.
Electrodeposited Trimetallic NiFeW Hydroxide Electrocatalysts for Efficient Water Oxidation
Authors: Rajendiran Rajmohan , Chinnadurai Deviprasath , Chen Kai , Selvaraj Aravindha Raja , Prabakar Kandasamy , Li Oi Lun
Published: December 2020

Tungsten‐doped Ni−Fe hydroxides fabricated on a three‐dimensional nickel foam through cathodic electrodeposition are proposed as effective oxygen evolution reaction (OER) catalysts for alkaline water oxidation. Incorporating an adequate amount of W into Ni−Fe hydroxides modulates the electronic structure by changing the local environment of Ni and Fe and create oxygen vacancies, resulting in abundant active sites for the OER. The optimized electrocatalyst, with a substantial number of catalytic sites, is found to outperform the well‐established 20 wt% Ir/C electrocatalyst. The catalyst only requires small overpotentials of 224 mV and 251 mV to generate current densities of 10 mA cm−2 and 50 mA cm−2, respectively, at an extremely low Tafel slope. Surface study after long‐term chronopotentiometry (ca. 30 h) reveals that the tungsten dopant undergoes reduction to stabilize the Ni and Fe active sites for predominant water oxidation. This research provides new insight to apply optimum amounts of tungsten doping to enable more significant electronic coupling within Ni−Fe for the chemisorption of hydroxy and oxygen intermediates and greatly improved OER activity.
PEM Electrolysis‐Assisted Catalysis Combined with Photocatalytic Oxidation towards Complete Abatement of Nitrogen‐Containing Contaminants in Water
Authors: Ampurdanés Jordi , Bunea Sorin , Urakawa Atsushi
Published: December 2020

Electrolysis‐assisted nitrate (NO3−) reduction is a promising approach for its conversion to harmless N2 from waste, ground, and drinking water due to the possible process simplicity by in‐situ generation of H2/H/H+ by water electrolysis and to the flexibility given by tunable redox potential of electrodes. This work explores the use of a polymer electrolyte membrane (PEM) electrochemical cell for electrolysis‐assisted nitrate reduction using SnO2‐supported metals as the active cathode catalysts. Effects of operation modes and catalyst materials on nitrate conversion and product selectivity were studied. The major challenge of product selectivity, namely complete suppression of nitrite (NO2−) and ammonium (NH4+) ion formation, was tackled by combining with simultaneous photocatalytic oxidation to drive the overall reaction towards N2 formation.
Studying phenological phenomena in subarctic biomes with international school pupils as citizen scientists
Authors: Klütsch Cornelya F. C. , Aspholm Paul Eric , Polikarpova Natalia , Veisblium Olga , Bjørn Tor‐Arne , Wikan Anne , Gonzalez Victoria , Hagen Snorre B.
Published: December 2020

Citizen science can facilitate in‐depth learning for pupils and students, contribute to scientific research, and permit civic participation. Here, we describe the development of the transnational school‐based citizen science project Phenology of the North Calotte. Its primary goal is to introduce pupils (age 12–15; grades 7–10) in northern Norway, Russia, and Finland to the local and global challenges of climate change resulting in life cycle changes at different trophic and ecosystem levels in their backyards. Partnerships between regional scientists and staff from NIBIO Svanhovd, State nature reserves, national parks, and teachers and pupils from regional schools aim to engage pupils in project‐based learning. The project uses standardized protocols, translated into the different languages of participating schools. The phenological observations are centered around documenting clearly defined life cycle phases (e.g., first appearance of species, flowering, ripening, leaf yellowing, snow fall, and melt). The observations are collected either on paper and are subsequently submitted manually to an open‐source online database or submitted directly via a newly developed mobile app. In the long term, the database is anticipated to contribute to research studying changes in phenology at different trophic levels. In principle, guided school‐based citizen science projects have the potential to contribute to increased environmental awareness and education and thereby to transformative learning at the societal level while contributing to scientific progress of understudied biomes, like the northern taiga and (sub)arctic tundra. However, differences in school systems and funding insecurity for some schools have been major prohibiting factors for long‐term retention of pupils/schools in the program. Project‐based and multidisciplinary learning, although pedagogically desired, has been partially difficult to implement in participating schools, pointing to the need of structural changes in national school curricula and funding schemes as well as continuous offers for training and networking for teachers.
Recent Progress and Prospects of Layered Cathode Materials for Potassium‐ion Batteries
Authors: Liao Jiaying , Han Yu , Zhang Zhuangzhuang , Xu Jingyi , Li Jianbo , Zhou Xiaosi
Published: December 2020

Layered materials with two‐dimensional ion diffusion channels and fast kinetics are attractive as cathode materials for secondary batteries. However, one main challenge in potassium‐ion batteries is the large ion size of K+, along with the strong K+−K+ electrostatic repulsion. This strong interaction results in initial K deficiency, greater voltage slope, and lower specific capacity between set voltage ranges for layered transition metal oxides. In this review, a comprehensive review of the latest advancements in layered cathode materials for potassium‐ion batteries is presented. Except for layered transition metal oxides, some polyanionic compounds, chalcogenides, and organic materials with the layered structure are introduced separately. Furthermore, summary and personal perspectives on future optimization and structural design of layered cathode materials are constructively discussed. We strongly appeal to the further exploration of layered polyanionic compounds and have demonstrated a series of novel layered structures including layered K3V2(PO4)3.
The challenges of documenting coevolution and niche construction: The example of domestic spaces
Authors: Stiner Mary C.
Published: December 2020

This essay delves into some of the challenges of studying the coevolution of humans and domestic spaces. These constructed arenas center on food preparation, and as part of the heritable niche they can shift the opportunities for, and constraints on, social interaction and cooperation in evolutionary time. Domestic spaces are widely evidenced in the archeological record, but investigators have made little progress in demonstrating causal links between proposed feedback spirals and constructed spaces of any sort. Bridging fine‐scale and large‐scale processes in coevolutionary systems is a complex problem that must engage higher levels of generative evolutionary theory. Archaeology nonetheless stands to offer a great deal to larger research programs by documenting and analyzing the pathways of change based on site formation processes along with evidence from subsistence refuse and technology. Choice models remain valuable tools for investigating aspects of the fine‐scale feedback processes involved.
Mesenchymal stem cells instruct a beneficial phenotype in reactive astrocytes
Authors: Vigo Tiziana , Voulgari‐Kokota Androniki , Errede Mariella , Girolamo Francesco , Ortolan Jasmin , Mariani Maria C. , Ferrara Giovanni , Virgintino Daniela , Buffo Annalisa , Kerlero de Rosbo Nicole , Uccelli Antonio
Published: December 2020

Transplanted mesenchymal stromal/stem cells (MSC) ameliorate the clinical course of experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS), reducing inflammation and demyelination. These effects are mediated by instructive cross‐talk between MSC and immune and neural cells. Astroglial reaction to injury is a prominent feature of both EAE and MS. Astrocytes constitute a relevant target to control disease onset and progression and, based on their potential to acquire stem cell properties in situ, to foster recovery in the post‐acute phase of pathology. We have assessed how MSC impact astrocytes in vitro and ex vivo in EAE. Expression of astroglial factors implicated in EAE pathogenesis was quantified by real‐time PCR in astrocytes co‐cultured with MSC or isolated from EAE cerebral cortex; astrocyte morphology and expression of activation markers were analyzed by confocal microscopy. The acquisition of neural stem cell properties by astrocytes was evaluated by neurosphere assay. Our study shows that MSC prevented astrogliosis, reduced mRNA expression of inflammatory cytokines that sustain immune cell infiltration in EAE, as well as protein expression of endothelin‐1, an astrocyte‐derived factor that inhibits remyelination and contributes to neurodegeneration and disease progression in MS. Moreover, our data reveal that MSC promoted the acquisition of progenitor traits by astrocytes. These data indicate that MSC attenuate detrimental features of reactive astroglia and, based on the reacquisition of stem cell properties, also suggest that astrocytes may be empowered in their protective and reparative actions by MSC.
A span of continuous trades and liquidity dynamics in foreign exchange markets
Authors: Chien Chih‐Chung , Chen Shikuan , Chang Ming‐Jen
Published: December 2020

This study incorporates the spans of sequences of continuous trades and reversal trades to investigate whether the currency liquidity is varying with the span of continuous trades or reversal trades. We highlight the dependency between the span of continuous trades and the realized bid‐ask spread to explain the currency liquidity dynamics using high‐frequency foreign exchange data. Our findings show that the spans of continuous trades play an important role in determining the market liquidity because a larger span of a continuous sequence puts a drain on the market liquidity and thereby consumes the funding liquidity, eventually increasing the bid‐ask spread.
The crypto‐trade volume, GDP, energy use, and environmental degradation sustainability: An analysis of the top 20 crypto‐trader countries
Authors: Mohsin Muhammad , Naseem Sobia , Zia‐ur‐Rehman Muhammad , Baig Sajjad Ahmad , Salamat Shazia
Published: December 2020

The global ecosystem and human life are both endangered due to the amount of CO2 emission discharged into the natural environment. The exponential crypto‐trade growth, high density of modern technology, and rapidly changing technological needs of human beings have experienced an unresolved problem in environmental sustainability and poisonous emissions in the top 20 crypto‐trader countries. This research paper investigates the empirical impact of crypto‐volume, gross domestic product (GDP), and energy use on environmental sustainability. The CO2 emission is considered as a proxy of environmental degradation in the top 20 crypto‐trader countries. The cross‐sectional dependence and data homogeneity are checked by employing panel unit root and cointegration techniques for 2012–2019. The study's empirical findings indicated a long‐run relationship between CO2 emission, crypto‐volume, GDP, and energy use. The long‐run relationship confirmation was also received from the fully modified ordinary least square, dynamic ordinary least square, and vector error correction model (VECM). The VECM verifies bidirectional causality between environmental degradation and crypto‐volume for long‐ and short‐term and unidirectional causality for GDP and energy use. In this modern age, not only crypto‐trading but also energy use and GDP are interlinked with e‐wastage, which significantly disturbed environmental sustainability, leading to emissions and climate change. The adverse effects of crypto‐trade, GDP, and energy use increase inequalities. This research recommends to governments and fiscal policymakers to de‐socialize high energy‐consuming blockchain technology. It replaces it with green and less energy‐consuming technology to reduce the negative environmental impact of externalities. Furthermore, appropriate green fiscal reforms should follow to minimize the impacts of CO2 emission.
Student pacing in a master's level course: Procrastination, preference, and performance
Authors: Bird Zachary , Chase Philip N.
Published: December 2020

Previous research has shown that many students procrastinate, but wish that they did not do so. The current study replicated research that compared distribution of studying under contingent access to study materials and noncontingent access to study materials in a graduate‐level course (Perrin et al., 2011). It extended Perrin et al. (2011) in three ways. First, it evaluated preference for the treatment using a choice procedure; second, the choice procedure allowed for the elimination of an order confound; and third, different measures were used to evaluate performance results. Although contingent access to study materials was successful at reducing procrastination, students typically chose the noncontingent access condition. Preference on the end‐of‐semester survey aligned with choices made throughout the semester. The data are discussed in terms of implications and recommendations for future research regarding the design of graduate coursework to address student pacing along with student and professor preference.
A comprehensive association analysis between homocysteine metabolic pathway gene methylation and ischemic stroke in a Chinese hypertensive population
Authors: Li Bo , Li Yuying , Xu Shan , Chen Hongen , Dai Shudong , Peng Xiaoling , Wang Li , Liang Yaping , Li Cheng , Tang Biwei , Zhu Liqing , Zhang Tao , Lv Chunfang , Wang Changyi , Han Liyuan
Published: December 2020

Background

Ischemic stroke (IS) is a serious global health burden. In order to improve our understanding of the risk factors associated with IS, we investigated the combined effect of the methylation of five genes related to the metabolism of homocysteine on developing IS.

Methods

Quantitative methylation‐specific PCR was used to measure the levels of promoter methylation in hypertensive and stroke patients. The cutoff value calculated by the maximum Youden index was used to classify the levels of gene methylation as hypomethylation and hypermethylation. Logistic regression was used to explore the relationship between gene methylation and IS.

Results

The methylation levels of the genes encoding methylenetetrahydrofolate dehydrogenase 1 [MTHFD1], cystathionine β‐synthase [CBS], and dihydrofolate reductase [DHFR] in hypertensive patients were higher than those in stroke patients (all p < 0.01). MTHFD1 hypermethylation, CBS hypermethylation, and DHFR hypermethylation were protective factors for stroke after adjustment for confounding factors. Compared with individuals carrying none of the biomarkers, the ORs [95% CIs] for stroke of those with 1 and 2 elevated biomarkers were 4.068 [1.670–9.913] and 15.345 [6.198–37.994] after adjustment for confounding factors. The participants with a larger number of biomarkers had an increased risk of stroke (p for trend <0.001). For the combination biomarkers, the area under the curve of the receiver operating characteristic was 0.716.

Conclusion

A significant linear relationship between the number of elevated biomarkers and the risk of stroke has been observed, suggesting that elevations of these biomarkers could be used for potentially predicting the disease.
Pollen morphological assessment of specific selected species of district Sheikhupura, Punjab, Pakistan under LM and SEM
Authors: Alam Ayesha , Shaheen Shabnum , Sarwar Samina , Jaffer Mehwish , Saba Malka , Hanif Muhammad , Sajjad Sumera , Khan Farah
Published: December 2020

Around 30 pollen samples, 16 families and 25 genera that were gathered, identified and preserved from 6 different localities of District Sheikhupura. Light and scanning electron microscopy was done for all collected flora. Out of the total samples, 43% specie was identified as herbs, 23% as shrubs, and 33% were identified as trees. The flora was both wild and cultivated. Wild plants were 33%, cultivated 40% and 26% of them were both wild and cultivated. Qualitative and Quantitative survey of pollens revealed polar shape of pollens were 37% spheroidal, 20% prolate spheroidal, 17% oblate spheroidal, remaining were rectangular and pecolpate. Sexine and nexine were available in 100% of samples. Thirty‐three percentage of pollen grains were having spines on them. The presence of spines on pollen grains represents the evolutionary relationship amongst the plants. Current study was conducted to record and analyze palynomorphic diversity in district Sheikhupura, Punjab, Pakistan.
Developmental evolution of the distal ankle in the dinosaur–bird transition
Authors: Ossa‐Fuentes Luis , Soto‐Acuña Sergio , Bona Paula , Sallaberry Michel , Vargas Alexander O.
Published: December 2020

The adult ankle of early reptiles had five distal tarsal (dt) bones, but in Dinosauria, these were reduced to only two: dt3 and dt4, articulated to metatarsals (mt) mt3 and mt4. Birds have a single distal tarsal ossification center that fuses to the proximal metatarsals to form a new adult skeletal structure: the composite tarsometatarsus. This ossification center develops within a single large embryonic cartilage, but it is unclear if this cartilage results from fusion of earlier cartilages. We studied embryos in species from four different bird orders, an alligatorid, and an iguanid. In all embryos, cartilages dt2, dt3, and dt4 are formed. In the alligatorid and the iguanid, dt2 failed to ossify: only dt3 and dt4 develop into adult bones. In birds, dt2, dt3, and dt4 fuse to form the large distal tarsal cartilage; the ossification center then develops above mt3, in cartilage presumably derived from dt3. During the entire dinosaur–bird transition, a dt2 embryonic cartilage was always formed, as inferred from the embryology of extant birds and crocodilians. We propose that in the evolution of the avian ankle, fusion of cartilages dt3 and dt2 allowed ossification from dt3 to progress into dt2, which began to contribute bone medially, while fusion of dt3 to dt4 enabled the evolutionary loss of the dt4 ossification center. As a result, a single ossification center expands into a plate‐like unit covering the proximal ends of the metatarsals, that is key to the development of an integrated tarsometatarsus.
Aza‐Michael addition of 1,2‐diazoles to structurally diverse enones: Efficient methods toward β‐amino ketones
Authors: Polina Saibabu , Putta V. P. Rama Kishore , Gujjarappa Raghuram , Pujar Prasad Pralhad , Malakar Chandi C.
Published: December 2020

An efficient and mild protocol was realized using 1,2‐diazoles and related heterocycles with cyclic and acyclic enones in presence of T3P (2,4,6‐tripropyl‐1,3,5,2,4,6‐trioxatriphosphorinane‐2,4,6‐trioxide) toward the regioselective formation of N‐cycloalkyl heterocycles at room temperature. The developed reaction conditions showcased good selectivity over a wide range of 1,2‐diazoles and enones by delivering N‐cycloalkyl heterocycles in excellent yields.
Multicomponent one‐pot synthesis of novel imidazole‐2‐thione derivatives containing allomaltol fragment
Authors: Komogortsev Andrey N. , Melekhina Valeriya G. , Lichitsky Boris V. , Minyaev Mikhail E.
Published: December 2020

A convenient method for the synthesis of novel imidazole‐2‐thione derivatives containing allomaltol fragment was elaborated. This approach includes one‐pot multicomponent reaction of allomaltol, arylglyoxals, primary amines followed by addition of alkyl or aryl isothiocyanates. It was shown that the key intermediates of the studied process are substituted α‐aminoketones and the corresponding imidazolidine‐2‐thione. The advantages of this synthesis are mild reaction conditions, atom economy, and easy workup procedure, which can avoid chromatographic purifications. The structures of an intermediate imidazolidine‐2‐thione and one of the final imidazole‐2‐thiones were determined by X‐ray diffraction.
Estimation of fractional myocardial blood volume and water exchange using ferumoxytol‐enhanced magnetic resonance imaging
Authors: Colbert Caroline M. , Thomas Michael A. , Yan Ran , Radjenovic Aleksandra , Finn J. Paul , Hu Peng , Nguyen Kim‐Lien
Published: December 2020

Fractional myocardial blood volume (fMBV) estimated using ferumoxytol‐enhanced magnetic resonance imaging (MRI) (FE‐MRI) has the potential to capture a hemodynamic response to myocardial hypoperfusion during contrast steady state without reliance on gadolinium chelates. Ferumoxytol has a long intravascular half‐life and its use for steady‐state MRI is off‐label. The aim of this prospective study was to optimize and evaluate a two‐compartment model for estimation of fMBV based on FE‐MRI. Nine healthy swine and one swine with artificially induced single‐vessel coronary stenosis underwent MRI on a 3.0 T clinical magnet. Myocardial longitudinal spin–lattice relaxation rate (R1) was measured using the 5(3)3(3)3 modified Look‐Locker inversion recovery (MOLLI) sequence before and at contrast steady state following seven ferumoxytol infusions (0.125–4.0 mg/kg). fMBV and water exchange were estimated using a two‐compartment model. Model‐fitted fMBV was compared to simple fast‐exchange fMBV approximation and percent change in pre‐ and postferumoxytol R1. Dose undersampling schemes were investigated to reduce acquisition duration. Variation in fMBV was assessed using one‐way analysis of variance. Fast‐exchange fMBV and ferumoxytol dose undersampling were evaluated using Bland–Altman analysis. Healthy normal swine showed a mean mid‐ventricular fMBV of 7.2 ± 1.4% and water exchange rate of 11.3 ± 5.1 s−1. There was intersubject variation in fMBV (p < 0.05) without segmental variation (p = 0.387). fMBV derived from eight‐dose and four‐dose sampling schemes had no significant bias (mean difference = 0.07, p = 0.541, limits of agreement −1.04% [−1.45, −0.62%] to 1.18% [0.77, 1.59%]). Pixel‐wise fMBV in one swine model with coronary artery stenosis showed elevated fMBV in ischemic segments (apical anterior: 11.90 ± 4.00%, apical septum: 16.10 ± 5.71%) relative to remote segments (apical inferior: 9.59 ± 3.35%, apical lateral: 9.38 ± 2.35%). A two‐compartment model based on FE‐MRI using the MOLLI sequence may enable estimation of fMBV in studies of ischemic heart disease.

Level of Evidence

2.

Technical Efficacy Stage

2.
Quality assessment and traceability study of Angelicae Sinensis Radix via binary chromatography, triple quadrupole tandem mass spectrometry, and multivariate statistical analysis
Authors: Zhao Shuang‐Li , Fu Fei , Jia Yu‐Ran , Yu Xie‐An , Yu Bo‐Yang , Li Ren‐Shi
Published: December 2020

Angelicae Sinensis Radix is a world‐renowned herbal medicine originating in China. Owing to many environmental and geographical factors, Angelicae Sinensis Radix from various origins may have a difference in the content of ingredients, which made the confusion in the clinical practice and market. Herein, a binary chromatographic fingerprinting analysis method is developed via hydrophilic interaction chromatography and reversed‐phase liquid chromatography to obtain more chemical information. Following that, an ultra‐performance liquid chromatography with a triple quadrupole mass spectrometry method is furnished to simultaneously detect 17 ingredients of Angelicae Sinensis Radix gathered from six geographic zones in China. Eventually, the principal component analysis is successfully carried out to classify and differentiate the Angelicae Sinensis Radix from different origins, meanwhile the quantitative volcano plots was used to observe the changes of ingredient trends vividly. Accordingly, the proposed binary chromatography and triple quadrupole tandem mass spectrometry coupled with multivariate statistical analysis can be utilized as a facile and reliable method for origin tracing and quality control of Angelicae Sinensis Radix.
Transoral Robotic Retropharyngeal Lymph Node Dissection in Nasopharyngeal Carcinoma With Retropharyngeal Lymph Node Recurrence
Authors: Ding Xi , Lin Qing‐Guang , Zou Xiong , Liu You‐Ping , Hua Yi‐Jun , Xie Yu‐Long , Wang Zhi‐Qiang , Zhang Yi‐Nuan , Gu Yang‐Kui , You Rui , Yang Qi , Zhang Meng‐Xia , Chen Si‐Yuan , Ouyang Yan‐Feng , Yu Zi‐Kun , Sun Rui , Chen Ming‐Yuan
Published: December 2020

Objectives

Nasopharyngeal carcinoma (NPC) patients with retropharyngeal lymph node (RPLN) recurrence typically undergo reirradiation and experience severe radiotoxicity. Salvage open surgery is challenging because gaining access to the retropharyngeal space is complex and risky. Thus, only several centers can perform this procedure, and complications are common. We applied transoral robotic surgery RPLN dissection (TORS‐RPLND) to NPC patients with RPLN recurrence to address the problem with open surgery.

Materials and Methods

From March 2017 to October 2020, 10 NPC patients with RPLN recurrence underwent TORS‐RPLND using the da Vinci Si/Xi Surgical System. We applied the balloon occlusion test to protect the internal carotid artery, induction chemotherapy to shrink large tumors preoperatively, and ultrasound positioning to effectively locate unrecognizable RPLNs during surgery. Clinical characteristics, complications, and survival outcome data were retrospectively collected.

Results

Of 10 patients, 8 underwent en bloc resection via TORS‐RPLND, and the remaining 2 patients were converted to open surgery because we failed to identify the RPLN during TORS. After introducing intraoperative ultrasound positioning, no such failure occurred. The mean operative time and intraoperative blood loss were 297 ± 120 min and 40 ± 43 ml, respectively. All surgical margins were negative. TORS‐related complications were mild, and the most severe one was grade 3 dysphagia in one patient who underwent conversion to open surgery (10%). With a median follow‐up of 19 months, only 1 (10%) patient developed cervical recurrence.

Conclusions

TORS‐RPLND is feasible, safe, and effective in the treatment of NPC patients with RPLN recurrence, especially with the help of intraoperative ultrasound positioning.

Level of Evidence

4 Laryngoscope, 131:E1895–E1902, 2021
Nitrification and nitrous oxide dynamics in the Southern California Bight
Authors: Laperriere Sarah M. , Morando Michael , Capone Douglas G. , Gunderson Troy , Smith Jason M. , Santoro Alyson E.
Published: December 2020

The amount of primary production fueled by upwelled “new” nitrate can be used to estimate the amount of organic carbon available for export to the deep ocean. Nitrate production in the euphotic zone from the microbial process of nitrification affects these estimates, yet the controls on nitrification in the upper ocean are debated. This study examines how seasonal cycles in primary production influence rates of nitrification fueled by both ammonia and urea‐derived nitrogen (N), and how these processes relate to the distribution of the greenhouse gas nitrous oxide (N2O) using monthly rate measurements from the San Pedro Ocean Time‐series (SPOT) station. Nitrification rates were highest at the onset of upwelling and were correlated with depth‐integrated primary production in the lower euphotic zone. Similar ammonia and urea‐derived N oxidation rates suggest urea is a significant N source fueling nitrification, particularly below the euphotic zone. Nitrification supplied a large proportion of phytoplankton N demand in the lower euphotic zone, implying significant regenerated production. The Southern California Bight was always a source of N2O to the atmosphere, which likely was advected into the system from the eastern tropical North Pacific, rather than produced locally from nitrification, and ventilated to the atmosphere during upwelling. Together, the results suggest the coupling of N remineralization and primary production in the upper ocean have important implications for the amount of organic carbon available for export out of the surface ocean, but that transport may dominate over local production in explaining local N2O dynamics.
Stiffness of Nanoparticulate Mineralized Collagen Scaffolds Triggers Osteogenesis via Mechanotransduction and Canonical Wnt Signaling
Authors: Zhou Qi , Lyu Shengyu , Bertrand Anthony A. , Hu Allison C. , Chan Candace H. , Ren Xiaoyan , Dewey Marley J. , Tiffany Aleczandria S. , Harley Brendan A. C. , Lee Justine C.
Published: December 2020

The ability of the extracellular matrix (ECM) to instruct progenitor cell differentiation has generated excitement for the development of materials‐based regenerative solutions. Described a nanoparticulate mineralized collagen glycosaminoglycan (MC‐GAG) material capable of inducing in vivo skull regeneration without exogenous growth factors or ex vivo progenitor cell‐priming is described previously. Here, the contribution of titrating stiffness to osteogenicity is evaluated by comparing noncrosslinked (NX‐MC) and crosslinked (MC) forms of MC‐GAG. While both materials are osteogenic, MC demonstrates an increased expression of osteogenic markers and mineralization compared to NX‐MC. Both materials are capable of autogenously activating the canonical BMPR signaling pathway with phosphorylation of Smad1/5. However, unlike NX‐MC, human mesenchymal stem cells cultured on MC demonstrate significant elevations in the major mechanotransduction mediators YAP and TAZ expression, coincident with β‐catenin activation in the canonical Wnt signaling pathway. Inhibition of YAP/TAZ activation reduces osteogenic expression, mineralization, and β‐catenin activation in MC, with less of an effect on NX‐MC. YAP/TAZ inhibition also results in a reciprocal increase in Smad1/5 phosphorylation and BMP2 expression. The results indicate that increasing MC‐GAG stiffness induces osteogenic differentiation via the mechanotransduction mediators YAP/TAZ and the canonical Wnt signaling pathway, whereas the canonical BMPR signaling pathway is activated independent of stiffness.
Cholinergic Basal Forebrain Volumes Predict Gait Decline in Parkinson's Disease
Authors: Wilson Joanna , Yarnall Alison J. , Craig Chesney E. , Galna Brook , Lord Sue , Morris Rosie , Lawson Rachael A. , Alcock Lisa , Duncan Gordon W. , Khoo Tien K. , O'Brien John T. , Burn David J. , Taylor John‐Paul , Ray Nicola J. , Rochester Lynn
Published: December 2020

Background

Gait disturbance is an early, disabling feature of Parkinson's disease (PD) that is typically refractory to dopaminergic medication. The cortical cholinergic system, originating in the nucleus basalis of Meynert of the basal forebrain, has been implicated. However, it is not known if degeneration in this region relates to a worsening of disease‐specific gait impairment.

Objective

To evaluate associations between sub‐regional cholinergic basal forebrain volumes and longitudinal progression of gait impairment in PD.

Methods

99 PD participants and 47 control participants completed gait assessments via an instrumented walkway during 2 minutes of continuous walking, at baseline and for up to 3 years, from which 16 spatiotemporal characteristics were derived. Sub‐regional cholinergic basal forebrain volumes were measured at baseline via MRI and a regional map derived from post‐mortem histology. Univariate analyses evaluated cross‐sectional associations between sub‐regional volumes and gait. Linear mixed‐effects models assessed whether volumes predicted longitudinal gait changes.

Results

There were no cross‐sectional, age‐independent relationships between sub‐regional volumes and gait. However, nucleus basalis of Meynert volumes predicted longitudinal gait changes unique to PD. Specifically, smaller nucleus basalis of Meynert volume predicted increasing step time variability (P = 0.019) and shortening swing time (P = 0.015); smaller posterior nucleus portions predicted shortening step length (P = 0.007) and increasing step time variability (P = 0.041).

Conclusions

This is the first study to demonstrate that degeneration of the cortical cholinergic system predicts longitudinal progression of gait impairments in PD. Measures of this degeneration may therefore provide a novel biomarker for identifying future mobility loss and falls. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

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Tolerance of dinutuximab therapy for treatment of high‐risk neuroblastoma in two patients with end‐stage renal disease on dialysis
Authors: Emberesh Myesa , Rubinstein Jeremy D. , Young Jennifer , Benoit Stefanie W. , Dandoy Christopher E. , Weiss Brian D.
Published: December 2020

Autologous hematopoietic cell transplant (aHCT) has a significant survival advantage in patients with high‐risk (HR) neuroblastoma. Transplant‐associated thrombotic microangiopathy (TA‐TMA) is a serious complication and may result in chronic renal disease leading to delay in subsequent posttransplant therapy and limitations of treatment options. Dinutuximab represents an important therapeutic advance in the treatment of pediatric HR neuroblastoma, but historically has not been administered in patients with GFR < 60 mL/m2/min. Here, we present the safe outcome of dinutuximab administration while on renal replacement therapy in two cases of HR neuroblastoma with end‐stage renal disease secondary to TA‐TMA.
A novel carbon nanotube nanopaper polyurethane coating for fiber reinforced composite substrates
Authors: Zhang Dan , Cai Kaiyu , Pan Junjie , Lee L. James , Castro Jose M.
Published: December 2020

High performance carbon nanotube (CNT) nanopaper (NP) reinforced polyurethane (PU) nanocomposite coating with high potential for aerospace and automotive applications was successfully fabricated and evaluated in this work. Different PU formulations were used to fabricate nanocomposites to study the effect of hard segment content on resin infiltration and nanocomposite mechanical properties. The process window of PU infiltration into the CNT NP was established by rheology measurements and thermal gravimetric analysis (TGA). The micro‐structure morphology of the nanocomposite was characterized by scanning electron microscope (SEM). Uniform CNT distribution in PU matrix was observed in the high‐resolution SEM images, which indicated good resin impregnation quality. Based on mechanical properties and process window, a PU formulation was selected as matrix to fabricate NP/PU nanocomposite coating for carbon fiber/epoxy composites (CFPC) substrate. The flexural strength and impact resistance of the CFPC were significantly improved by 9% and 14.7% after applying the NP/PU nanocomposite coating. Aimed at industrial applications, a continuous nanopaper fabrication process was successfully demonstrated in this work. Through the process window study, a continuous process to fabricate nanocomposite is proposed for future scale‐up.
End‐tidal CO2 and transcutaneous CO2: Are we ready to replace arterial CO2 in awake children?
Authors: Dicembrino Manuela , Alejandra Barbieri Irene , Pereyra Carla , Leske Vivian
Published: December 2020

Introduction

Arterial blood gas analysis (ABG) is the gold standard test for carbon dioxide measurement. End‐tidal PCO2 (PetCO2) and transcutaneous PCO2 (PtcCO2) are noninvasive alternative methods.

Objective

To examine the use of PetCO2 and PtcCO2 as PaCO2 surrogates in awake children.

Methods

A prospective observational study. Consecutive awake children in a stable condition referred to the Sleep Unit of Hospital de Pediatría Dr. J. P. Garrahan with suspected or confirmed sleep‐related respiratory disorders requiring ABG were included. PetCO2 and PtcCO2 were recorded simultaneously during arterial puncture. PetCO2 and PtCO2 values were compared with PaCO2. Correlation coefficient and Bland–Altman analysis were applied. The sample size was calculated considering a mean difference ≤3 mmHg as clinically acceptable.

Results

Sixty‐eight sample sets were obtained from 67 patients. The median age was 9.11 years (0.23–18.76). During 94.1% of the procedures patients breathed spontaneously, 30% needed multiple punctures and 92% resulted in pain. Median (IQR) PaCO2 (mmHg) was 36.3 (31.45; 40.90), PetCO2 33.0 (29; 39) and PtcCO2 38.8 (32.95; 43.32). Correlation and agreement for PaCO2/PetCO2 and PaCO2/PtcCO2 was r = .6 and .9, and media of bias = 2.83 (−9.97; 15.64) and −1.88 (−9.01; 5.24), respectively. Hypercapnia (PaCO2 > 45.0 mmHg) was present in 8/68 (11.8%) samples. Sensitivity, specificity, positive predictive value and negative predictive value to detect hypercapnia with PetCO2 was 38%, 98%, 75%, and 92%, respectively, and with PtcCO2, 100%, 90%, 57%, and 100%, respectively.

Conclusion

PtcCO2 showed better agreement with PaCO2 than PetCO2 but because of the wide dispersion of values, neither method can replace the gold standard. Transcutaneous CO2 might be a good screening tool to detect hypercapnia in awake children.
Genetic counseling prior to assisted reproductive technology
Authors: Katagiri Yukiko , Tamaki Yuko
Published: December 2020

Background

Reproductive medicine deals with fertility and is closely related to heredity. In reproductive medicine, it is necessary to provide genetic information for the patients prior to assisted reproductive technology (ART). Japan Society for Reproductive Medicine (JSRM) requires doctors involved in reproductive medicine to have standard knowledge of reproductive genetics and knowledge of reproductive medicine, which is covered in their publication, “required knowledge of reproductive medicine.”

Methods

With the aim of providing straightforward explanations to patients in the clinical situation at pre‐ART counseling, we provide the following five topics, such as (a) risk of birth defects in children born with ART, (b) chromosomal abnormalities, (c) Y chromosome microdeletions (YCMs), (d) possible chromosomal abnormal pregnancy in oligospermatozoa requiring ICSI (intracytoplasmic sperm injection), and (e) epigenetic alterations.

Main findings

The frequency of chromosome abnormalities in infertile patients is 0.595%‐0.64%. YCMs are observed in 2%‐10% of severe oligospermic men. High incidence of spermatozoa with chromosomal abnormalities has been reported in advanced oligospermia and asthenozoospermia that require ICSI. Some epigenetic alterations were reported in the children born with ART.

Conclusion

Certain genetic knowledge is important for professionals involved in reproductive medicine, even if they are not genetic experts.
The virome in early life and childhood and development of islet autoimmunity and type 1 diabetes: A systematic review and meta‐analysis of observational studies
Authors: Faulkner Clare L. , Luo Yi Xuan , Isaacs Sonia , Rawlinson William D. , Craig Maria E. , Kim Ki Wook
Published: December 2020

Viruses are postulated as primary candidate triggers of islet autoimmunity (IA) and type 1 diabetes (T1D), based on considerable epidemiological and experimental evidence. Recent studies have investigated the association between all viruses (the ‘virome’) and IA/T1D using metagenomic next‐generation sequencing (mNGS). Current associations between the early life virome and the development of IA/T1D were analysed in a systematic review and meta‐analysis of human observational studies from Medline and EMBASE (published 2000–June 2020), without language restriction. Inclusion criteria were as follows: cohort and case–control studies examining the virome using mNGS in clinical specimens of children ≤18 years who developed IA/T1D. The National Health and Medical Research Council level of evidence scale and Newcastle–Ottawa scale were used for study appraisal. Meta‐analysis for exposure to specific viruses was performed using random‐effects models, and the strength of association was measured using odds ratios (ORs) and 95% confidence intervals (CIs). Eligible studies (one case–control, nine nested case–control) included 1,425 participants (695 cases, 730 controls) and examined IA (n = 1,023) or T1D (n = 402). Meta‐analysis identified small but significant associations between IA and number of stool samples positive for all enteroviruses (OR 1.14, 95% CI 1.00–1.29, p = 0.05; heterogeneity χ2 = 1.51, p = 0.68, I2 = 0%), consecutive positivity for enteroviruses (1.55, 1.09–2.20, p = 0.01; χ2 = 0.19, p = 0.91, I2 = 0%) and number of stool samples positive specifically for enterovirus B (1.20, 1.01–1.42, p = 0.04; χ2 = 0.03, p = 0.86, I2 = 0%). Virome analyses to date have demonstrated associations between enteroviruses and IA that may be clinically significant. However, larger prospective mNGS studies with more frequent sampling and follow‐up from pregnancy are required to further elucidate associations between early virus exposure and IA/T1D.
Adolescent stress, help‐seeking intentions, subjective achievement and life satisfaction in New Zealand: Tests of mediation, moderated mediation and moderation
Authors: Sotardi Valerie A. , Watson Penelope , Swit Cara , Roy Deepika , Bajaj Maansa
Published: December 2020

We present the results of a study examining adolescent help‐seeking intentions (HSIs), stress, subjective school achievement and life satisfaction. Using a cross‐sectional design with a sample of New Zealand adolescents (n = 1601), we tested whether HSIs could mediate or moderate relations between stress and subjective achievement, and between stress and life satisfaction. We inspected these dynamics alongside different help sources (informal and formal) and domains where stress might be experienced (school and personal). Using mediation testing, findings suggest that informal HSIs have at least some influence on the relations between stress and well‐being indicators, whereas formal HSIs did not. Conditional indirect effects for the mediation models (moderated mediation) revealed that gender and age did not moderate the relations between stress and informal HSIs, or between stress and well‐being indicators with one exception: gender moderated the relation between personal stress and informal HSIs. In most models, tests of moderation lent support for a protective‐reactive model in which HSIs reduce the adverse effects of stress on well‐being indicators. Discussion focuses on modelling and promoting help‐seeking activities across diverse support sources, and doing so earlier in life so that adolescents can benefit from well‐honed coping strategies.
Effect of Deep Cryogenic Treatment on the Microstructure and Wear Resistance of a Novel Nanobainite Steel
Authors: Fan Shichao , Hao Hai , Zhang Xingguo
Published: December 2020

A novel nanobainitic (NB) steel is treated by three different heat treatment routes: quenching‐tempering (QT), quenching‐austempering‐tempering (AT), and quenching‐austempering‐deep cryogenic treatment‐tempering (ACT). To investigate the effects of retained austenite (RA) with different morphologies, stabilities, and volume fractions on the wear resistance of NB steel, the microstructure is observed by optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The volume fraction and stability of RA are determined by quantitative X‐ray diffraction (XRD) analysis. It is found that deep cryogenic treatment (DCT) after low‐temperature austempering can effectively eliminate the blocky RA, increase the stability of filmy RA and have no effect on the NB microstructure. The AT and ACT treatments have higher surface residual compressive stress and better wear resistance than conventional QT treatments. For the ACT treatment, a multiphase microstructure composed of NB, martensite, and filmy RA is obtained near the surface, and the wear resistance of the steel is optimized, with increases of 23%, 52%, and 93% for austempering times of 8, 12, and 24 h, respectively. The results show that DCT can be combined with low‐temperature austempering treatment, thereby effectively eliminating unstable blocky RA, avoiding the transformation of brittle martensite, and obtaining improved wear resistance.
Purple and Beige‐Fleshed Sweet Potato Starches Modified by Autoclaving
Authors: Paixão e Silva Giselle de Lima , Bento Juliana Aparecida Correia , Bataus Luiz Artur Mendes , Soares Júnior Manoel Soares , Caliari Márcio
Published: December 2020

In this study, the effects on the morphological, functional, pasting, and thermal properties of purple (PSP) and beige (BSP)‐fleshed sweet potato starches, resulting from the application of the physical autoclave method (at 121 °C and 1.1 Kgf cm−2) under different moisture conditions and exposure times, are evaluated. The micrograph shows cracks on the surfaces of the starch granules exposed for 15 and 60 min with 30% moisture. The maximum points on the response surface graphs show that the treatment increases the initial and peak gelatinization temperatures, as well as the pasting temperature and the water absorption and solubility values. In relation to the pasting properties, there is a reduction in both the final viscosity and setback values of the autoclaved starches. Thus, the method proves to be useful for the modification of these native starches and for future research with their applications in different processed foods.